Document NGLRZQxZ54L3zQKJX33m5v16D

Work supported by the US Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Cincinnati, Ohio. Printed in the United States of America. Available from National Technical Information Service U.S. Department of Commerce 528S Port Royal Road Springfield, VA 22161 Price: Printed Copy J6.75 Microfiche $3,00 TfcU M|n rl wu prrpr'rl ar * >mii rf rt raataar4 hy hr I'aiirrf Mtrtrr ................. Nrithar ihr Uhkal fliaira r lh* llaiM Xelra Karw Brwarrfc aal |1 >! ml A4tlirinilM. nar rr. tl (hair raaUy*ra. Mr any a/thaUraatrarlarr. irferMinrlrr,, rr Ihrtr tiplmtt. Brhn un armair. nirtr rr aytial. rr uhim, ary tcai ItaMlav ar rtaiaaiiUUIr far (hr araarac*. rriptrwrrw. ar u.iftilaaaa W ary MamuilUa, apyaralw. yralaal. ar pracaar 4tarUral, rr 'Walla lhr! Hr mar arauU aal lafriacr pH.-Tarty imar I richti. >AL 0( -i ! i .--H r CONTENTS ABSTRACT ................................................................................................................................................. 1 CHAPTER ONE. INTRODUCTION ................................................................................................... Background................................................................................................................................................. The Guide.................................................................................................................................................... 2 2 3 CHAPTER TWO. HISTORY OF RESPIRATORY PROTECTION......................................... 5 CHAPTER THREE. THE RESPIRATORY SYSTEM AND RESPIRATION.................... Metabolism................................................................................................................................................. The Structure of the Respiratory System....................................................................................... The Mechanics of Respiration ........................................................................................................... 9 9 10 11 CHAPTER FOUR. RESPIRATORY HAZARDS ........................................................................... Respiratory Hazards..................................................................... The Normal Atmosphere....................................................................................................................... Oxygen Deficiency .................................................................................................................................. Entry of Toxic Materials into the Body.......................................................................................... Particulate Contaminants (Aerosols)................................................................................................ Gaseous Contaminants .......................................................................................................................... Expressing Air Contaminant Concentrations................................................................................. Hazard Evaluation................................................................................................................................... 16 16 16 16 19 20 21 23 23 CHAPTER FIVE. RESPIRATORS ...................................................................................................... General Respirator Classifications ...................................................................................................... Air-Purifying Respirators....................................................................................................................... Atmosphere-Supplying Respirators................................................................................................... 27 27 33 43 CHAPTER SIX. RESPIRATOR SELECTION .............................................................................. OSHA Standards..................................................................................................................................... ANSI Z88.2-1969 Standards.................................. Selection...................................................................................................................................................... Selection of Respirators for Routine Use ....................................................................................... Selection of Respirators for Nonroutine and Emergency Use................................................. Respirator Protection Factors.............................................................................................................. Examples of Respirator Selection ..................................................................................................... 56 56 57 57 57 57 58 58 CHAPTER SEVEN. RESPIRATOR USE.......................................................................................... Legal Requirements ............................................................................................................................... Practicalities of Respirator Issue........................................................................................................ Supervision of Respirator Use.............................................................................................................. Functional and Physical Characteristics and Use Limitations of Respirators............................................................................................................................................. 65 65 65 65 66 m bal O0f 0057216 Respirator Use under Special Conditions...................................................................................... 6g Special Problems in Respirator Use................................................................................................. gg CHAPTER EIGHT. TRAINING AND FITTING.......................................................................... Elements of an Adequate Training Program................................................................................ Respirator Fitting Methods ................................................................................................................ 71 7l 72 CHAPTER NINE. RESPIRATOR INSPECTION, CLEANING, MAINTENANCE, AND STORAGE.......................................................................................................................................... Elements of an Adequate Respirator Inspection, Cleaning, Maintenance, and Storage Program ............................................................................................... Inspection for Defects ............................................................................................................................ Field Inspection....................................................................................................................................... Cleaning and Disinfecting ................................................................................................................... Maintenance and Repair...................................................................................................................... Storage........................................................................................................................................................ 79 79 79 80 81 84 84 CHAPTER TEN. PHYSIOLOGICAL AND PSYCHOLOGICAL LIMITATIONS ON RESPIRATOR USE.................................................................................................................................... Physiological Limitations...................................................................................................................... Psychological Limitations .............. 87 87 88 CHAPTER ELEVEN. PROGRAM ADMINISTRATION............................................................ Written Standard Operating Procedures ...................................................................................... The Program Administrator................................................................................................................ The Duties of the Program Administrator ................................................................................... 89 89 90 91 CHAPTER TWELVE. SURVEILLANCE AND PROGRAM EVALUATION .................... Surveillance................................................................................................................................................ Evaluation of Respirator Program Effectiveness ........................................................................ 92 92 92 ACKNOWLEDGMENTS...............................................................................................................................93 APPENDIX A. 29 CFR PART 1910.134 ............................................................................................ 94 APPENDIX B. 30 CFR PART 11 ........................................................................................................ 98 APPENDIX C. RESPIRATOR DRYING CABINET..................................................................... 131 APPENDIX D. QUANTITATIVE RESPIRATOR FITTING TEST PROCEDURES ... 134 APPENDIX E. QUANTITATIVE RESPIRATOR FITTING TEST EQUIPMENT .... 138 APPENDIX F. JOINT NIOSH/OSHA RESPIRATOR DECISION LOGIC ....................... 141 APPENDIX G. STANDARD OPERATING PROCEDURES.................................................... 153 t A GUIDE TO INDUSTRIAL RESPIRATORY PROTECTION by John A. Pritchard ABSTRACT The Occupational Safety and Health Act of 1970 has increased the emphasis on proper selection and use of respirators in situations where engineering controls are not feasible or are being implemented. Although a great deal of information on respiratory protection has been published, most of it is more technical than necessary for the average user faced with dayto-day problems of respiratory protection in industrial environments. This Guide is to provide the industrial user a single reference source con taining enough information for establishing and maintaining a respirator program that meets the OSHA requirements outlined in 29 CFR Part 1910.134. It includes chapters on respirator selection, use, maintenance, and inspection, a complete description of all types of respirators and their ad vantages and limitations, and chapters on respirator fitting and wearer training, respiratory physiology, respiratory hazards, and physiological and psychological limitations. Also included are samples of the decision logic used in respirator selection, guidance on setting up an adequate respirator program through formulation of written standard operating procedures, and discussion of the meaning of the "approved1' respirator. ooo 8 1 CHAPTER ONE INTRODUCTION Until the enactment of the Williams and Steiger Occupational Safety and Health Act (OSHA) in 1970, most guidance on respiratory protective device (respirator) use in hazardous environments was ad visory rather than mandatory. Now, OSHA Part 1910.134 (presented as Appendix A of this guide) sets forth specific legal requirements for selection, use, and maintenance of respirators, and gives guidelines for establishing a respirator program to meet those requirements. This guide is written to describe methods for meeting the OSHA require ments, especially for those whose knowledge of respirators is limited. It is meant to complement, not replace, other publications such as the American Industrial Hygiene Association and American Conference of Governmental Industrial Hygienists (ACGIH) Respiratory Protective Devices Manual. BACKGROUND American National Standard Institute (ANSI) Standard Z88.2-1969, "Practices for Respiratory Protection," is the origin of the first six sections of OSHA Part 1910.134, "Respiratory Protection." The seventh section is a direct, complete inclusion of ANSI Standard K13.1-1969, "Identification of Gas Mask Canisters." Certain aspects of ANSI Z88.2 deserve comment. Each ANSI standard is the consensus of the Stan dards Committee that created it. The Z88.2 com mittee consisted of 30 members and 17 alternates representing government, industry, and respirator manufacturers. The document they produced, a spin-off from the older ANSI Z2.1-1959, "American National Standard Safety Code for Head, Eye, and Respiratory Protection," like all ANSI standards, is to be revised every five years. At present, Z88.2 can be used to further explain points in the OSHA stan dards, but it is an advisory document only, not a legal one. However, because insight into the OSHA standards may be gained by reading the corresponding parts of Z88.2, the reader is strongly urged to use a copy as a companion to this guide. It may be obtained from: American National Standards Institute, Inc. 1430 Broadway New York, NY 10018. The OSHA standards state that "approved or ac cepted respirators shall be used when they are available." That one sentence is the basis for much of this guide. Legally, the Occupational Safety and Health Administration may recognize a respirator evaluated by any competent authority as "ap proved." However, it has chosen to recognize only those approved by the National Institute for Oc cupational Safety and Health (NIOSH) and/or the Mine Enforcement and Safety Administration .(MESA), the former obtaining its authority from the OSHA provisions and the latter from those of the 1969 Coal Mine Health and Safety Act. The NIOSH and MESA respirator performance require ments are given in Title 30, Code of Federal Regula tions, Part 11, commonly known as "Part 11." A copy is presented as Appendix B. The Bureau of Mines (BOM) began approving self-contained breathing apparatus and gas masks for mine rescue work in 1919 and has added ap proval schedules for other types of respirators over the years until NIOSH and MESA (which assumed the BOM mine health and safety responsibilities) started the present approval program in 1971. NIOSH performs the respirator approval tests under Part 11, and the results are reviewed by NIOSH and MESA, who grant an approval. The reader should become familiar with Part 11. Understanding of the approval process may provide better understanding of the conditions in which approved devices should, and, more important, should not, be used. 2 Contributing further to the confusion about respirator standards is the fact that still other Federal Regulations, Military Standards, advisory standards, etc., are made part of the OSHA require ments by reference. Figure 1-1 shows the in terrelationship of all these standards. THE GUIDE To be effective, a respirator guide must be almost all-encompassing because: Respirator users' needs vary greatly. A small manufacturing concern may have to protect only one or two employees from a single hazardous at mosphere, perhaps only infrequently. A large chemical company may have hundreds of workers who must wear respirators more or less regularly in many different hazardous atmospheres. Unfor tunately, the OSHA requirements do not differen tiate between such large and small users. Users' knowledge of respiratory protection varies. A small firm may have only one, poorly trained, employee. Large concerns with extensive respirator programs to cope with many hazards usually hire industrial hygienists and safety engineers who have detailed knowledge of respiratory protection. This guide is designed to provide adequately detailed information for the least knowledgeable respirator user. There is a chapter on the basic con cepts of the pulmonary system and respiration, one that describes and classifies respiratory hazards, and one on basic types of approved respirators. These should provide adequate background for a satisfactory respirator program. Other chapters, useful to both experienced and inexperienced users, discuss detailed methods for providing OSHA's "minimal acceptable respirator program." The program requirements often can be met in more than one way, and an attempt is made to show how both large and small users can do so. Respirator wearers' physiological and psychological limitations are treated separately because of their importance. To conform to the OSHA usage, "shall" is used here only to indicate an OSHA requirement. "Should" indicates that an action is "strongly ad vised," but not legally required. "May" indicates that there is a choice of actions. A!... 0 0 0 05 72 2 Fig. l-l. Sources of the OSHA standards. CHAPTER TWO HISTORY OF RESPIRATORY PROTECTION Recognition of the need to protect the respiratory system is very old. Pliny (ca A.D. 23-79) mentioned use of a loose fitting animal bladder in the Roman mines to protect against inhalation of red oxide of lead. The Greek writer Dioscorides (A.D. 50) described the same hazard and other dangers of mining. A century later, Julius Pollox (A.D, 124192) described a respirator made from an animal bladder with an attached sackcloth filter for protec tion against the dust in mines. It is interesting that all the surviving early references involve the hazards of mining, an occupation that is still the subject of a significant share of the effort to improve respiratory protection. Not surprisingly, Leonardo da Vinci (1452-1519) considered the problems of respiratory protection. As usual, he anticipated history by a few centuries in recommending use of a wet cloth as protection against chemical warfare agents. He also devised two types of underwater breathing devices. One used a mysterious substance he called "Alito" which when fastened to the chest with iron rings allowed the wearer to breathe without an outside air source. The other, really quite practical, was a "snorkel," consisting of a breathing tube with an attached float. Later, Bernadino Ramazzin, (1633-1714) wrote a critical review of the inadequate respiratory protection prevalent in his time. He mentioned the hazards faced by such diverse people as arsenic miners; gypsum, lime, and tobacco workers; bakers and millers; sifters and measurers of grain; and stone cutters. Any good work on occupational dis eases will show that we now have named diseases in curred in each of these occupations. In the 1700's appeared the first description of the ancestors of today's atmosphere-supplying devices, such as open and closed-circuit self-contained breathing apparatus and hose masks. With the coming of the industrial revolution in the early 1800's, respirators rapidly became more sophisticated. One of the greatest advances was realization of the separate natures of particulates and gases or vapors. Until then, the only recognized hazard had been industrial dusts. John Roberts in 1825 developed a "smoke filter" for firemen, a leather hood and a hose strapped to the leg, the theory being (correctly) that the best air during a fire would be near the floor. At the lower end of the hose was an inverted funnel containing a coarse woolen cloth to trap particulates and a moist sponge to remove water-soluble gases and vapors. This device is shown in Fig. 2-1. In 1814 came development of a particulateremoving Filter encased in a rigid container, the / Fig. 2-1. John Roberts "smoke filter," ca 1825. 5 SAL 0000 7272 predecessor of modern filters for air-purifying respirators. In 1823, C. A. Deane developed a "smoke jacket" for firemen which had a breathing hose with a bellows that supplied clean air under pressure. This was the early equivalent of today's hose mask with blower. Discovery of the phenomenon of Brownian motion by Robert Brown in 1827 explained the zig-zag mo tion of very small airborne particles caused by their bombardment by rapidly moving gas molecules in the air. This quickly led to improvement in design of particulate-removing filters through understanding of the principle involved in filtration. Efficient filters had been produced earlier, but their resistance to breathing was usually intolerably high. Probably the most significant development dur ing the last century was discovery in 1854 of the properties of activated charcoal in removing organic vapors and gases from air. This discovery was almost immediately put to use in respirators. An ex ample, shown in Figs. 2-2 and 2-3 was a fire-fighting "smoke cap" developed by Sir E. M. Shaw and the ORY COTTON WOOL WOOL YATUAATCD WITH CLYCEniNC S FRAGMENTS OF CHARCOAL I dr v cancN WOOL f 1 LIMC | FRACMCNT* OF 1 ORY COTTON WOOL ] Fig. 2-2. Tyndall and Shaw "smoke cap. 6 Fig. 2-3. Tyndall and Shaw smoke cap filter. famous physicist John Tyndall. Its significant feature was clear recognition of the need to protect against particulates (with dry cotton wool), carbon dioxide gas (with lime), and other gases and vapors (with charcoal). The most rapid advances in respiratory protection grew out of the use of chemical warfare in World War I. German use of poison gas brought about almost immediate improvement in gas sorbents used in military masks. This was countered by the German attempt to disperse highly toxic particulate matter on the battlefield, which led to development of still more efficient filters. Although crude by to day's standards, the WW I military respirators are definitely recognizable as close relatives of devices manufactured now. Since WW I, there have been few major breakthroughs in respirator design, with the possi ble exception of N. L. Hansen's development of the resin-impregnated dust filter in 1930. This material '(ii.. 0 0 0 0 uses electrostatic force fields to remove dust parti cles from air. Almost all present respirator use is for protection against moderately toxic dusts, and most dust filters are resin-impregnated. This develop ment has made available efficient, inexpensive filters that have good dust-loading characteristics and low breathing resistance. Another, more recent, development is the ultrahigh-efficiency filter made from paper that contains very fine glass fibers. These extremely efficient filters for very small air borne particles also have low breathing resistance and are commonly used where high dust concentra tions are not a problem. Figures 2-4 through 2-7 show early respirators whose basic designs are still represented in those marketed today. Fig. 2-5. Magirus, Germany, ca 1820. Supplied air suit for firemen, similar to today's hose mask or air line respirator. Fig. 2-4. Magirus, Germany, ca (840. Early positive pressure self-contained breathing apparatus. X ... .,.-.n * SAL. 000AO/ protection. Sponge placed inside flap over nose. Fig. 2-7. Puimoscm dust mask, ca 1920. Very similar to today's single use dust respirator. 8 CHAPTER THREE THE RESPIRATORY SYSTEM AND RESPIRATION METABOLISM To understand the respiratory system's role, we must consider how the body uses the oxygen that the respiratory system supplies. Figure 3-1 is gTeatly simplified diagram of this use, called metabolism. At its simplest, the body is a "furnace," or ordered arrangement of countless tiny "furnaces" called cells. As a "furnace," the body takes food into the digestive tract where it is converted into a fuel suitable for use by the individual cells. This fuel, in the form of a sugar--glucose--is transported to the cells by the blood stream. The oxygen needed to burn the fuel originates in the air surrounding the body. The air is drawn into the respiratory system, and the needed oxygen is transferred to the blood stream, to travel with the glucose fuel to the cells. ENERGY Fig. 3-1. The metabolic process. 9 In the cells, the glucose and oxygen combine in a combustion process to produce energy. The energy is used in many ways, ranging from muscle action (mechanical) and control of body temperature (thermal) to maintenance of the body systems. The combustion products, as in all such processes, are primarily carbon dioxide and water, which are carried away in the blood stream for elimination from the body. Because the body contains a lot of water, that produced by metabolism cannot be called a waste product, but it does contain dissolved wastes that must be removed. This is done primarily by the kid neys which remove the dissolved wastes from the blood stream. These wastes are flushed out in the urine along with water that must be replaced through the digestive tract. There is, however, a quantity of water which circulates throughout the system in the blood stream or is contained in the body tissues. The system that carries fuel to the cells and removes waste products is unidirectional, as the material enters and leaves the body at separate locations. On the other hand, the system that sup plies oxygen and removes carbon dioxide is bidirec tional. Although the oxygen gets to the cells through the arteries and carbon dioxide is removed by the veins, transfer to and from the surrounding air takes place at a common location, the lungs. The effect and importance of the lungs' dual role will become apparent when gas transport and exchange are discussed. THE STRUCTURE OF THE RESPIRATORY SYSTEM The metabolic aspect of greatest concern here is the structure and workings of the respiratory system, shown much simplified in Fig. 3-2. The respiratory system is a single airway that branches into many smaller passages that end in the lungs. The upper, or conducting, part consists of the nasal passages and pharynx in the head and the larynx and trachea in the neck. Below the trachea, the con ducting part branches into two airways called bronchi that lead into the lobes of the lungs. The bronchi subdivide into smaller and smaller pathways, called bronchioles, ending in very small Fig. 3-2. The respiratory system. passages, the terminal bronchioles. No gas transfer takes place in the pathways up to this point. It is at the respiratory surfaces, shown in Fig. 3-3, that the major function of the lungs takes place. Branching from the terminal bronchioles are the respiratory bronchioles, to each of which are at tached three to six clusters of extremely small sacs called alveoli. Each of the approximately 300 million alveoli is separated from the blood stream only by an extremely thin membrane, about 0.2 micrometer (/zm) thick.* This membrane, which forms the alveolar wall, is permeable to gas molecules. It is here that most of the oxygen passes into the blood stream and that carbon dioxide is removed. This barrier is so large that it provides almost in stantaneous exchange between the gases in the alveolar spaces and the blood stream on the other side. This membrane is approximately 70-100 square meters in surface area and is two cells thick. Human hair is 5-500 in diameter. 10 This large lung surface area is necessary because the body cannot store oxygen and, therefore, must be able to absorb a lot of it quickly from the air when necessary. The body has far more storage capacity for water (throughout) and fuel (in the fatty tissues). Man can live for weeks without food and for days without water, but only for minutes without oxygen. The brain is particularly susceptible, as only four minutes without oxygen causes permanent damage, and six to eight minutes kills. Because of its critical relationship to the immediate function ing of the body, the respiratory system demands the utmost protection and care. THE MECHANICS OF RESPIRATION Respiration, or breathing, involves inhalation during which fresh air, rich in oxygen and low in car bon dioxide, is drawn into the lungs. This is followed by exhalation in which the air, containing less ox ygen and more carbon dioxide owing to gas ex change at the respiratory surfaces, is expelled. One combined inhalation and exhalation is called a breathing cycle. Lung action during a breathing cy cle is like the operation of a bellows. The thoracic (chest) cavity, formed by the rib cage around the lungs, expands during inhalation because of con traction of the intercostal muscles attached to the ribs. This contraction enlarges the chest, and the lungs expand to Fill the additional space. The chest cavity enlarges further as the diaphragm, a domed muscular partition between it and the abdominal cavity, moves downward. Expansion of the chest and lungs varies with the body's needs. Under sedentary (inactive) condi tions, there is very little expansion because the need for oxygen is slight. Heavy work, however, greatly increases the need for oxygen, causing increased respiration rate and volume. As the chest and lungs expand, a greater surface for transfer of oxygen and carbon dioxide is exposed as the alveoli are ven tilated more effectively. The individual alveoli also expand, further increasing the surface area available for gas exchange. This is a mechanism by which the body compensates for its inability to store oxygen; it has a reserve capacity for transferring ox ygen by increasing both the size and number of alveoli in use. During inhalation, the muscles involved are con tracted. During exhalation, most of them are relaxed. At the end of inhalation, the intercostal muscles are in a contracted state, and the diaphragm has been pulled down. During exhala tion, these muscles and the diaphragm return to their original relaxed state, reducing the volume en closed by the thoracic cavity (chest) and forcing the air out of the lungs. Almost no physical energy is ex pended during normal exhalation, analogous to releasing a stretched rubber band. There are some muscles located in the lower ab domen which can be contracted during forced ex halation, as during heavy work or blowing up a balloon. Because these relatively weak muscles are not used routinely, most people Find their sustained use tiring. This is one reason why exhalation resistance in respirators is kept as low as practicable. The Concept of Partial Pressures Air is a mixture of several gases, including nitrogen (N2), oxygen (02), carbon dioxide (C02), and water vapor (H20). At sea level, this mixture has a normal atmospheric pressure of 14.7 pounds/ square inch (psi), 29.92 inches of mercury (in. Hg), or 760 millimeters of mercury (mm Hg), all 11 equivalent values. Here, pressures are expressed in millimeters of mercury. The concept of partial pressures is that in any mixture of gases, the total gas pressure is the sum of the partial pressures of all the gases. An analogy is a stack of blocks weighing an amount that is the sum of the weights of the individual blocks. Because nor mal air at sea level contains about 20.9% 02 at a total pressure of 760 mm Hg, the partial pressure of 02 (P02) must be about 159 mm Hg (760 mm Hg x 20.9% = 159 mm Hg), Similarly, the partial pressure of C02 (PC02) makes up about 0.04% of the normal atmosphere, or about 0.3 mm Hg. Nitrogen, although it makes up about 80% of the atmosphere, plays only a minor role in respiration, and then only in special circumstances, such as deep sea diving. NOTE: It is not the percentage of 02 in the air, but its partial pressure, which is important. As one ascends, the percentage of 02 and the other gases stays about the same but the partial pressure of each drops owing to the lower total atmospheric pressure. The importance of this fact will become apparent when we discuss gas exchange in the lungs. Inhaled Air Syslemic Veins Systemic Arteries Fig. 3-4. Gas exchange in the lungs. Gas Exchange in the Lungs During the time the air travels to the alveolar space, mixing takes place, reducing the P02 to about 110 mm and then increasing the PC02 to about 40 mm. At the end of each exhalation, the lungs and upper part of the airway are filled with ex haled air that contains less 02 and more C02 than the atmospheric air, owing to gas transfer, Inhala tion draws approximately 500 milliliters (ml) of air into the lungs. However, only about 350 ml of the fresh air reaches the alveoli because the first air that reaches them is the old air left in the upper respiratory tract at the end of the previous exhala tion. This 150 ml of air, called the anatomic dead space volume, mixes with the incoming fresh air to give the P02 and PC02 shown in the alveoli in Fig. 34. Increasing the dead space volume, as by wearing a respirator, may have important consequences. For example, consider the following. Without a respirator Dead space = 150 ml. Volume inhaled per breath = 500 ml, Breaths per minute = 10. The volume reaching the alveoli per minute would be 10 x (500 - 150) = 3500 ml. Wearing a respirator whose volume (dead space) is 100 ml Dead space = 100 4- 150 = 250 ml, Volume inhaled per breath = 500 ml. Breaths per minute = 10, The volume reaching the alveoli per minute would be 10 x (500 - 250) = 2500 ml. If there is a pressure difference across a permeable membrane like that separating the alveoli from the pulmonary capillaries, gas molecules pass from the high- to the low-pressure region until the pressures are equalized. The 40-mm-Hg PC02 in the alveoli (Fig. 3-4) is lower than the 46-mm PC02 in the pulmonary arteries carrying the C02-rich blood from the cells, so C02 molecules pass from the bloodstream into the alveoli. Conversely, the 110mm-Hg P02 in the alveoli is greater than the 40-mm P02 in the pulmonary arteries, so Og passes from the alveoli into the bloodstream where the pulmonary veins, heart, and systemic arteries carry it to the cells to be metabolized. P02 and PC02 in the pulmonary veins are the same as those in the alveoli 12 SAL 00005722? because the 02 and C02 pressures are equalized constant, no matter what the level of work. This fact almost instantaneously in a healthy person at rest. implies that there must be a mechanism that can However, when one works hard or has impaired react quickly to changes in this balance to bring the breathing, the concentration of oxygen in the blood P02 and PC02 back into proper proportion, and this may be considerably less than that in the alveoli. is also true, but not completely understood. I Oxygen is carried in the blood physically dis The body is sensitive to changes in both P02 and solved in the blood water and chemically combined PC02. The P02 sensors are located in the carotid ar with the iron atoms in the hemoglobin molecules tery that supplies blood to the head, near the aorta that are part of the red blood cells. Because 02 is leading from the heart. These sensors send their relatively insoluble in water, 98% of it is carried by signals to the respiratory control center in the lower the red blood cells. Only about 3 ml of 02 can be part of the brain, the medulla, If the P02 is reduced dissolved in 100 ml of blood,-but about 197 ml can by about half, the control center increases lung ven be carried chemically attached to the hemoglobin- tilation. Although this seems an insensitive molecules in the red blood cells. mechanism, recent studies indicate that the body is Carbon dioxide is carried similarly to 02, about much more sensitive to lowered 02 levels than was 8% of it being physically dissolved in the blood thought. What happens is that response to the high plasma and red cells. Sixty seven per cent of it com PC02 is much stronger than response to the lowered bines with the water in the blood, is converted to P02. Therefore, the PC02 response overrides the carbonic acid (H2COa), and is carried in ionized P02 response until the P02 becomes very low. form (HCOa + H+). (The remaining 25% reacts with This fact implies that the PC02 level influences the hemoglobin molecules as does 02.) Ionized C02 respiration much more than does the P02 level. This 4 is extremely soluble, in contrast to gaseous C02. The is most emphatically true; however, the full answer concentration of hydrogen ions (H+) in the blood is lies not in the C02 molecule itself, but in its ionized crucial in control of respiration, as is discussed in form in the blood, HCO"3 and H+. The latest infor the next section. mation indicates that the H+ concentration in the Some airborne contaminants hurt the red blood cerebrospinal fluid surrounding the brain and spinal cells' ability to combine chemically with 02 column is the controlling factor. Extremely sensitive molecules. For example, carbon monoxide (CO) sensors detect slight changes in the H+ concentra combines preferentially with the hemoglobin tion and send signals to the respiratory control cen molecules, thereby preventing their combination ter, which brings the system back into balance with 02 molecules. P-nitroaniline, an organic vapor, almost immediately by reducing or increasing the changes the chemical state of the iron atoms, breathing rate. abolishing their capacity to combine with 02. Such roundabout regulation of respiration may seem strange until one remembers that the brain is most easily damaged by lack of oxygen. It makes Respiration Control perfectly good sense that the regulatory mechanism is in the most critical area. In summary, control of Respiration control is very complex, and can be respiration is related primarily to the PC02, not the treated only superficially here. Furthermore, P02, concentration in the blood. respiration control as a reaction t'o increased work rate is not fully understood. Briefly, however the Voluntary and Involuntary Control. The major task of the nervous system in regulating respiratory control system's response to changing respiration rate and depth is to ensure that 02 is gas concentrations in the blood is something over delivered to the cells and C02 is removed at exactly which we have no conscious control; it is an involun the rate needed to meet the body's demands. tary response. Obviously, we do have a great deal of (Remember, the body cannot store oxygen.) In voluntary control, for we can hold our breath, adjust tuitively, one could guess that this has something to our breathing rate, and cough almost at will. do with maintaining proper P02 and PC02 levels in However, this voluntary control has definite limits. the blood, and, indeed, this is true. Generally speak For example, we can hold our breath only so long ing the P02 and PC02 balance remains relatively 0 0 () 0!.v.i723 0 13 before the involuntary drive to breathe overrides our intention not to. Involuntary reactions of other parts of the nervous system sometimes affect the respiration rate. Emotional states, such as fear, joy, or sorrow can change it. Pain increases the respiration rate, and irritation of the respiratory passages causes ex plosive exhalation, or sneezing. Effect of Increased Work Rate. As physical ac tivity increases, the respiration rate and volume in crease almost immediately as the body compensates for increased metabolic demands through the mechanism just described. Therefore, a greater volume of air per unit of time is taken into and ex pelled from the lungs. This volumetric flow rate is usually measured as the volume of air inhaled or ex haled per minute, called the minute volume and ex pressed in liters per minute (1pm). Instantaneous volumetric flow rates at any time during the breathing cycle are measured in the same units. cubic meters in eight hours is about 20.81pm. or just slightly above the rate for light work. When one con siders the situation if these volumes were laden with harmful respirable particulates or gases and vapors, the need for proper respiratory protection becomes apparent. Instantaneous Air Flow Rates. With increased physical activity, breathing volume and rate both increase as shown in Fig. 3-5. During rest, breathing is shallow and each cycle takes several seconds. As activity increases, the instantaneous flow rates in crease and each cycle becomes shorter as indicated A Tim* Air Minute Volume Requirements. The typical worker breathes about 10 cubic meters (m3) of air in 8 hours. (A cubic meter is approximately a cubic yard.) On a minute volume basis, the flow rates may vary widely with the type of work, as Table 3-1 shows. The minute volumes may range from approx imately 9.3 1pm during rest periods to 132 1pm dur ing the heaviest work. An 8-hour work day might in volve total inhaled air volumes of 4.5 - 63.4 m3. Ten TABLE 3-1 MINUTE VOLUME AHt FLOW.BATES Activity Sleep Rest Light work Medium work Med heavy work Heavy work Maximum work Minute Volume ( (Ipm) 1 9.3 19.7 29.2 40 59.5 132.0 Fig. 3-5. Breathing rate and volume vs activity level. 14 3AL 00005723 by the curves for moderate and heavy work. The area under the inhalation cycles (totaled over 1 min) constitutes the minute volume. The high instantaneous flow rates required at high work rates become significant when one con siders the resistance to inhalation presented by most airpurifying respirators. As the flow rate through a filter or bed of granular sorbent in a respirator in creases, (see Chap. 5) the resistance to air flow also increases. Therefore 30 CFR Part 11 keeps the allowable inhalation resistance offered by respirators at specified flow rates as low as possible. If the resistance is too great, the wearer expends ex tra energy in overcoming it, and the situation wor sens as the work level increases. CHAPTER FOUR RESPIRATORY HAZARDS* RESPIRATORY HAZARDS In choosing the proper respirator for use against a specific hazard, one obviously must assess the type and extent of the hazard. Here, we will discuss the various classes of respiratory hazards, their effects on the body, and methods for evaluating them. Respiratory hazards are either: Oxygen deficiency or Air contamination by Particulates, Vapor and gases, or a Combination of particulates, vapors, and gases. Respiratory hazards in the work environment must be assessed to determine the effectiveness of engineering and administrative controls and to per mit selection of proper respirators. A hazardous or harmful atmosphere is one that is oxygen deficient or contains a toxic or diseaseproducing particulate, vapor, or gas in a concentra tion immediately or ultimately dangerous to life or health. An atmosphere immediately dangerous to life or health poses an immediate threat to life or health or an immediate threat of exposure that will probably cause delayed harm. Whether there is an immediate threat depends partly on the physical configuration of the workplace. Can the worker, if his respirator fails, escape unharmed? The joint OSHA and NIOSH Standards Completion Program defines an atmosphere immediately' dangerous to life and health as one from which a person cannot escape un protected within a half hour without irreversible health effects or one that has the potential for "ob- vious severe eye or respiratory irritation which would inhibit escape without injury." An atmosphere not immediately hazardous to life or health may cause immediate physical discomfort or irritation, produce harm after prolonged ex posure, or cause chronic poisoning after repeated short exposures, but it does not cause irreversible damage during a single exposure. THE NORMAL ATMOSPHERE Earth's atmosphere has an essentially fixed com position of the following gases in the dry state. Gas Nitrogen Oxygen Argon Carbon dioxide Vol% 78.09 20.95 0.93 0.04 Partial Pressure (mm Hg at sea level) 594 159 7 0.3 - Normal air always contains small amounts of other gases such as neon, helium, and krypton. Water vapor, an important constituent of the normal at mosphere, may be up to 5% of the total volume. Note that the per cent by volume of these gases does not vary with altitude, but that the partial pressures decrease with increasing altitude because the total pressure decreases. "With the kind permission of the American Optical Corporation, Southbridge, MA, this chapter is adapted in part from a "Refresher Course in Respiratory Protection," presented by VV. H. Revoir at the 1974 Conference of the American Industrial Hygiene Association in Miami Beach, Florida. OXYGEN DEFICIENCY An atmosphere that does not contain enough ox ygen to support metabolism for an unlimited period 16 SAL 00005723: is called "oxygen deficient." The precise description of an oxygen deficient atmosphere is important for strictly physiological reasons and also for proper respirator selection. j&MBrfttmoephere :is oxygen ' deficient, only atmosphere-supplying, not airpurifying respirators mgy-be used (see Chap. Five). Making this distinction would seem a simple matter of applying the description of an oxygen deficient atmosphere. Unfortunately, no one definition (value) is universally accepted. The range of defini tions listed in government regulations and other documents can leave the respirator user in a quan dary. Table 4-1 is a partial listing of definitions, based primarily on the volume per cent (vol%) of ox ygen in the atmosphere at sea level. With a range of 16.0-19.5 vol% to choose from, only practical course is to Use thexiefinitionlisted in the regulation by which his work is governed. It is instructive to consider oxygen deficiency (or, in medical terminology, anoxia and asphyxia) from a strictly physiological standpoint, Anoxia is defined as diminished availability of oxygen to the cells of the body, and asphyxia is the condition of the body due to anoxia. (If the reader has not yet read Chap. Three, he should do so.) Table 4-2 lists the outward indications of oxygen deficiency, or TABLE 4-1 DEFINITIONS OF OXYGEN DEFICIENT ATMOSPHERE Source Oxygen Content (vol%) Conditions for Determination Sea Level PO (mm Hg) ACGIH Threshold Limit Values For 1973 Federal Regulations 29 CFR Part 1915.81 (Maritime Standards) 29 CFR Part 1910.94 (Ventilation Standards) 29CFR Part 1910.134 (Respirator Standards) 30 CFR Part 11 (Respirator Approval Tests) ANSI Standards Z88.2-1969 (Respirator Practices) Z88.5-1973 (Firefighting) K13.1-1973 (Marketing of air-purifying canisters and cartridges) 18.0 "...under normal atmosphere pressure..." 16.5 19.5 16.0 19.5 (not specified) (not specified) (not specified) "...by volume at sea level..." 16.0 19.5 "...normal air..." "...where oxygen partial pressure is less than 148 mm Hg at sea level..." 19.5 "...atsea level..." 135 125.4 148 122 148 122 148 148 Notes ANSI Standard Z86.1-1972, "Commodity Specification for Air," as revised in October 1974, specified 19.5-23.5 vol% for all grades of breathing air. bal 0000" 1 17 TABLE 4-2 EFFECTS OF OXYGEN DEFICIENCY O.Volft At Sea Level Physiological Effect in. i-2 10-G Less than G Imrn-a^ccl brenthinn volume, AcccU ralc-d heuri heat, hiij'.iirt (I ,j1 Imil ion and thinking. Impairi'd coordination. Very faulty judgment. Very poor in oscular coord'mil ion Muscular exertion causes rapid fatigue that may cause permanent heart damage, Intermittent respiration. Nausea, Vomiting, Inability to perform vigorous movement, or ioss of all movement, Unconsciousness, followed by deach. Spasmatic breathing, Convulsive movements, Death in minutes. ' M- - Fig. 4-1. .ys ' Hemoglobin saturation curve. asphyxia, and shows that in atmospheres containing less than 19 vol% oxygen some adverse physiological effects occur but they are unnoticeable. In at mospheres containing less than 16 vol% oxygen, some impairment may be noticed. In those contain ing less than 6 vol% oxygen, death occurs quickly. Obviously, there are various opinions as to what constitutes an oxygen deficient atmosphere. Although we cannot change the legal definitions, we can place them in a physiological context. As described in Chap. Three, normal ambient air at sea level contains about 20.9 vol% oxygen, or 160-mmHg P02, which is reduced to 110-mm P02 in the alveolar space. As Fig. 4-1 shows, the hemoglobin is about 95% saturated with oxygen at this P02 level. As the oxygen content in the'Smbient air and, conse quently, the alveolar P02, are reduced, the satura tion of the hemoglobin drops, but at an alveolar P02 of 60 mm, the hemoglobin is still 90% saturated. It is at this point that most physiologists agree that ox ygen deficiency symptoms become evident. In the following discussion, 60-ram-Hg alveolar P02 is taken to be the physiological limit that establishes an oxygen deficient atmosphere. This 60-mm-Hg P02 limit can be approached in two ways, The first is through reduction of the 02 content of the ambient air at a given altitude. At sea level, this means that the 02 content could drop to about 14.5 voI% before the P02 in the alveolar space dropped to 60 mm Hg. The lowest defined value, 16%, in Table 4-1 therefore provides a margin of safety. The second way to approach a P02 of 60-mm Hg is through increasing:altitud* Because the total at mospheric pressure decreases with altitude, the P02 also decreases, until at about 10 000 ft the P02 in the alveolar space is about 60-mm Hg* (Remember that even at this high altitude the air still contains 20.9% oxygen, but it is 20.9% of a much lower total pressure.) The physiological significance is that altitudes over 10 000 ft are normally oxygen deficient and workers theoretically should be prohibited from wearing air-purifying respirators. There are isolated locations, primarily in Colorado, where air-purifying respirators are being used at about 10 000 ft, apparently without difficulty, so even this statement cannot be taken as absolute. /.I 1 <v. v-/7^35 18 As the altitude increases, the P02 in the alveolar space comes closer to the 60-mm-Hg level. Therefore, a higher minimum volume per cent of 02 must be maintained to keep the alveolar P02 from dropping below 60. Figure 4-2 shows the minimum volume per cent of Oa in the air which must be maintained. Note that this does not provide any safety factor, as do the listed sea level definitions of oxygen deficiency. To understand Fig. 4-2, let us consider Denver. Colorado, at an elevation of 5280 ft. The solid line indicates that an atmosphere in Denver must con tain approximately 17.9 vol% oxygen to avoid being oxygen deficient, assuming no safety factor. To calculate the same safety factor as the lowest sea level definition of oxygen deficiency --16 voI%--provides, we can draw a line parallel to the solid line, starting at 16% at sea level. This dashed line indicates that we would need about 19.4 vol% 02 in Denver to provide the same margin of safely that 16% provides at sea level. What should the respirator user do with informa tion that seems to disagree with the legal re quirements? The important thing is the respirator wearer's safety. If the legal definition of 02 deficiency is above the 02 level you can consider safe for humans, you are justified in following the legal definition. If the 02 deficiency level as legally defined is less than the 02 concentration you believe safe for human exposure, you must consider raising your minimum 02 level above the legal limit. Although not infallible, the P02 limit of 60 mm Hg in the alveolar space should be the absolute minimum to which the 02 level should be allowed to drop. This means that the aiy should not drop below *bout 120 mm Hg. This problem is under study, and eventually "oxygen deficient atmosphere" will be redefined to eliminate the present discrepancies and account for the effect of altitude. ENTRY OF TOXIC MATERIALS INTO THE BODY Toxic materials can enter the body through the skin, the digestive tracr, or the respiratory tract. Through the Skin When a toxic substance touches the skin, four, things can happen. The skin may act as a barrier that the substance cannot enter or penetrate. The substance may injure the skin surface. The substance may penetrate the skin surface and injure the skin tissues. The substance may penetrate the skin, enter the blood stream, and be disseminated throughout the body to injure various parts of it. Generally the skin is an effective barrier, and few substances enter the body through it. However, serious injury and even death may result from short exposures of skin to high concentrations of certain very toxic substances, pesticides for example Lacerations and open wounds obviously increase the possibility of their entering the body. Fig. 4-2. The effect of altitude on the definition of ox ygen deficient atmospheres. By the Digestive System The body may absorb toxic substances through the digestive system. A harmful amount of toxic material can be swallowed accidentally, but inges tion of toxic substances is uncommon in industry. Particles in inspired air which are insoluble in the mucous of the respiratory tract may be carried to the mouth where they are either spit out or swallowed so that they enter the digestive system. 19 3 a i... 0 0 0 05 7 7 3 6 The fact that a substance has been swallowed does not necessarily mean that it will be absorbed, as a certain selectivity in absorption through the walls of the digestive tract tends to prevent absorp tion of unnatural substances or to limit the amount absorbed. Materials not absorbed are eliminated in the feces. Food and liquid in the digestive tract dilute the toxic substance and may react with it to produce a harmless or insoluble substance. Also, the toxic substance, if absorbed by the blood stream, will pass to the liver which may alter and detoxify it, but possibly be damaged in the process. Mechanical Dispersoid. A mechanical disper soid consists of particles of solid or liquid matter, formed and dispersed into air by mechanical means such as grinding, crushing, drilling, blasting, and spraying. Condensation Dispersoid, A condensation dis persoid consists of particles of solid or liquid matter formed and dispersed into air by reactions such as combustion. By the Respiratory Tract The respiratory tract is the most important route by which toxic substances enter the body. (Most in dustrial poisonings result from inhalation of toxic substances.) One reason why the respiratory tract is the most important route of entry is that it has a much larger surface area than the skin or digestive tract. The surface area of the adult respiratory tract, about 70 - 100 m2 during inhalation, is large com pared to the total skin area, which is not over 2 m2, or the total surface area of the digestive tract, which is not more than 10 m2. The huge quantity of air in haled, the continuous flow of blood through the pulmonary capillaries surrounding the alveoli (see Chap. Three), and the fact that the air in the alveoli and the blood in the pulmonary capillaries are separated by membranes whose total thickness is only two cells also help make the respiratory tract the most important route. PARTICULATE (AEROSOLS) CONTAMINANTS Particles of solid or liquid mhtter suspended in air may be classified according to their physical state and properties or according to their effects on the body. The term aerosol is often applied to particles in air. An aerosol is a system in which air is the con tinuous phase or dispersing medium and the parti cles are the dispersed phase or dispersoid. Dust: A dust's dispersed phase is a solid mechanical dispersoid. Dust particles range from submicroscopic to visible. Spray, A spray's dispersed phase is a liquid mechanical dispersoid. The particles are generally visible. Fume, A fume's dispersed phase is a solid con densation dispersoid. The particles are extremely small, generally less than 1 in diameter. Mist. A mist's dispersed phase is a liquid conden sation dispersoid. The particles vary from submicroscopic to visible. A fog is a mist dense enough to obscure vision. ^Smfikft^Smoke generally is defined as the products of incomplete combustion of organic sub stances in the form of solid and liquid particles suspended in air and gaseous products mixed with air. It is usually visible or obscures vision. iSfyyog Smog may consist of any combination of dispersoids, solid and/or liquid, suspended in air and gas or vapor contaminants dispersed in air. Smog sometimes is referred to as a mixture of fog and smoke. It is generally visible or obscures vision. P*lLll Ilf rt m Nuisance and/or Inert. These aerosols produce no known injuries when inhaled but may cause dis comfort and minor irritation. However, large quan tities of nuisance and/or inert particulate may overwhelm the lungs' capacity to dispose of them and large deposits in the lungs may, in the long run, produce injury. Examples of nuisance and/or inert aerosols are dusts containing particulate clay, limestone, gypsum, or aluminum oxide. Inert Pulmonary Reaction Producing. These aerosols produce nonspecific reactions in the lungs. Examples are dusts containing particulate silicates or aluminum. are dusts containing particulate pollen, plastic resins, gums, spices, fur fibers, tobacco, or vegetable fibers such as cotton jute, and soft hemp. Febrile-Reaction Producing. These aerosols produce chills followed by intense fever. Examples are dusts containing particulate bagasse (sugar cane residue) and fumes containing particulate metals such as zinc and copper. GASEOUS CONTAMINANTS Vapors or gases mixed with air also may be classified according to their chemical properties and composition or their physiological effects. Minimal Pulmonary Fibrosis Producing. These aerosols produce nodulation (discrete deposits of particulate) and a slight diffuse fibrosis (growth of scattered nonelastic tissue) in the lungs. Examples are dusts containing particulate barium sulfate, iron, or iron oxide, and fumes containing particles of iron oxide or tin oxide. Extensive Pulmonary Fibrosis Producing. These aerosols produce extensive nodulation and fibrosis in the lungs, Examples are dusts containing particulate silica and asbestos. Silicosis and asbestosis are the occupational diseases that result from breathing air containing these contaminants. Chemical Irritant. These aerosols irritate, in flame, and ulcerate the respiratory tract. Examples are dusts, sprays, fumes, and mists containing par ticulate acids, alkalies, peroxides, or chromates. Systemic Poison. These aerosols when inhaled and absorbed produce toxic pathological reactions, including cancer in various body systems. Examples are dusts, sprays, fumes, and mists containing par ticulate lead, manganese, cadmium, pesticides, or radioactive materials. Allergy-Producing. These aerosols produce allergic, hypersensitivity reactions such as itching, swollen membranes, and increased liquid secretion in the nose; sneezing; labored breathing; and reduced ventilating capacity of the lungs. Examples Chemical Classification Gaseous air contaminants cannot be classified perfectly according to chemical composition and properties, because there are a multitude of chemical compositions and the chemical properties within each can vary widely. The following is a meaningful classification system for air contami nants. Some of the classes depend on chemical com position only; others involve chemical properties only. Some contaminants could belong to more than one chemical class. Acidic. Gaseous air contaminants that are acids or react with water to become acid are called acid vapors and gases. Acids contain hydrogen and produce positively charged hydrogen ions when dis solved in water. Acids taste sour, are corrosive, react with metals to produce hydrogen gas and salts, and react with alkaline substances to produce salts, Acids that readily release hydrogen ions in water solution and react rapidly with other substances are called strong; those that do not are called weak. Strong acid gaseous contaminants include hydrogen chloride, sulfur dioxide, chlorine, and fluorine; weak ones are carbon dioxide, hydrogen sulfide, and hydrogen cyanide. The toxicity does not depend upon the strength; some of the most toxic gaseous air contaminants are weak acids. Alkaline. Gaseous air contaminants that are alkalies or react with water to become alkaline are called alkaline (or basic) vapors and gases. Alkalies (or bases) produce negatively charged hydroxyl ions when dissolved in water. (A hydroxyl ion consists of an oxygen and a hydrogen atom, but acts like a single entity. It always has a negative charge.) Alkalies taste bitter, may be corrosive, cause organic materials to disintegrate, and react with acids to produce salts. Alkalies that readily produce hydroxy! ions in water solution and react readily with other substances are called strong; those that do not are called weak, No really strong alkaline substances exist in the gaseous state. The toxicity does not depend upon the strength; some of the most toxic gaseous air contaminants are very weak alkalies. Examples of gaseous air contaminants that can be considered moderate to weak alkalies are am monia and amines; very weak ones include phosphine, arsine, and stibine. Organic. Gaseous air contaminants that are organic compounds are classified as organic vapors and gases. Organic compounds are compounds of carbon, which can form many compounds because its atoms can share electrons with many other kinds of atoms and with many other carbon atoms. There are thousands of known organic compounds and more are discovered or synthesized constantly. Organic compounds are classified by molecular structure. Some of the more common and important organic gaseous air contaminants are vapors and gases of saturated hydrocarbons such as methane, ethane, and propane; unsaturated hydrocarbons such as ethylene and acetylene; methyl and ethyl alcohol; methyl and ethyl ether; formaldehyde and acetaldehyde; dimethyl and methyl-ether ketone; formic and acetic acid; halides such as chloroform, carbon tetrachloride, and trichlorethylene; formamide and acetamide; toluene diisocyanate; methylamine and ethylamine; epoxies such as epox yethane, epichlorohydrin, and propylene oxide; and aromatics such as benzene, toluene, and xylene. Hydride. Hydrides are compounds in which hydrogen is chemically bonded to metals and metalloids (elements intermediate between metals and nonmetals). Examples of gaseous hydride air contaminants are diborane, pentaborane, and decaborane. Inert. Substances that seldom react chemically with other substances are called inert. Inert gases include helium, neon, argon, krypton, and xenon. Physiological Classification Gaseous air contaminants can be classified by their effect on the body. Such classification is im perfect because the effects of many vapors and gases depend on their concentrations and some have more than one effect. Irritant. Gaseous irritants are corrosive. They injure the respiratory tract by producing painful in flammation and increased mucus secretion. Severe inflammation and a large accumulation of mucus may close the respiratory tract and cause suffoca tion. Inflammation of the lungs' terminal air sacs, the alveoli, may cause pulmonary edema, increased secretion of fluids into the alveoli and the spaces between them. This edema may interfere severely with gas exchange between the air in the alveoli and the blood in the pulmonary capillaries and obstruct blood flow through the pulmonary capillaries, thus straining the heart. Pulmonary edema can kill by suffocation or heart failure. Gaseous irritants that affect the upper respiratory tract include ammonia, hydrogen chloride, hydrogen fluoride, sulfur triox ide, formaldehyde, acetaldehyde, and vinegar. Those that affect both the upper and lower respiratory tract include sulfur dioxide, iodine, bromine, chlorine, fluorine, ozone, phosphorus trichloride, and phosphorus pentachloride. Those that affect chiefly the lower and terminal parts are nitrogen dioxide, phosgene, and arsenic trichloride. Organometallic. Organometallic compounds are those in which metals are chemically bonded to organic groups. Some are volatile and can become gaseous air contaminants. One example is tetraethyl lead, Asphyxiant. Gaseous asphyxiants interfere with the supply or use of oxygen in the body. They act without directly interfering with breathing. They may be subdivided into two groups, simple and chemical. Simple asphyxiants are inert gases that 22 0 0 0 0 5 7 7 ;o dilute the oxygen in the air below the concentration required for body function. They must be present in quantity to have appreciable effect. Chemical asphyxiants, even in very low concentrations, by diluting the ambient atmosphere, interfere with the supply of oxygen or its use in the body. They prevent the blood from transporting oxygen from the lungs to the body tissue cells or prevent the tissue cells from using oxygen to release the energy needed for life. Asphyxiation may kill or it may injure various organs, particularly the nervous system. Simple asphyiants include nitrogen, hydrogen, helium, methane, and ethane. Chemical asphyxiants in clude carbon monoxide which combines with hemoglobin, thus interfering with the blood's oxygen-carrying capacity, and hydrogen cyanide which inhibits utilization of oxygen in tissue cells by interfering with the catalytic action of enzymes that regulate the reactions of oxygen with substances in the cells. Anesthetic. Anesthesia is partial or complete loss of sensation. Local anethesia is loss of sensation in a particular area, whereas general anesthesia is total loss of sensation and unconsciousness. Gas or vapor anesthetics depress the central nervous system. The initial effect is mild intoxication with dizziness and loss of coordination. Continued exposure causes un consciousness, and severe or long exposure may cause respiratory paralysis and death. All organic vapors and gases are anesthetics. Some are also systemic poisons, as mentioned below. Anesthetics are sometimes called narcotics. Anesthetics that generally have no serious effects are nitrous oxide, hydrocarbons (such as propane, butane, ethylene, and acetylene), and ethyl and isopropyl ether. Systemic Poison. Gaseous systemic poisons in jure specific organs and body systems. They include mercury, a protoplasmic poisoh (a substance that destroys the vitality of any living matter it contacts) that damages mainly the nervous system, the kid neys, and various glands and undermines the general health; phosphorus that makes bones fragile; hydrogen sulfide that paralyzes the respiratory control center and stops breathing; hydrogen selenide that severely injures the liver and spleen; and arsine that destroys red blood cells; and severely injures the liver. Carbon tetrachloride injures the liver and kid neys; methyl chloride severely injures the kidneys, heart, and nervous system; ethylene dichloride severely injures the liver and kidneys; benzene damages bone marrow where the red blood cells are formed and thus interferes with production of red blood cells; and methyl alcohol seriously damages the nervous system, especially the optic nerve. EXPRESSING AIR CONTAMINANT CONCENTRATIONS The concentration of particles suspended in air may be expressed as the number of particles or as the mass of particles in a given volume of air. When concentration is expressed as the number of parti cles, it generally is given in terms of millions of par ticles in one cubic foot (abbreviated mppcf) or as the number of particles in one cubic centimeter (ppcc). When concentration is expressed as the mass of particles, it usually is given in terms of milligrams of particulate in one cubic meter (mg/m3), milligrams in one liter (mgH), or micrograms in one liter (y.g/Z). The concentration of vapor or gas in air may be expressed as the per cent by volume or as the num ber of volumes per million volumes of air (ppm). Sometimes, extremely small quantities are given as the number of volumes per billion volumes of air (ppb). When the concentration is expressed as the mass of vapor or gas in a given volume of air, it generally is given as the number of milligrams per cubic meter (mg/ms) or per liter (mg/i). HAZARD EVALUATION Normally, respiratory hazards are evaluated by a safety engineer who understands the concepts of in dustrial hygiene. The industrial hygienist or safety engineer often calls upon other specialists such as the industrial physician, toxicologist, and chemist. The evaluator must have the cooperation of others in obtaining information on the industrial process, the work area, and work activities and materials. Small firms that do not have their own industrial hygienist or safety engineer may have respiratory SAL 0000 240 23 hazards assessed by qualified personnel from outside Casualty insurance companies employ in dustrial hygienists to make occupational health sur veys of insured firms. There are also many private industrial hygiene consultants and consulting firms. Most states have an industrial hygiene division in their department of labor or health which will make studies without charge. The OSHA requires the U.S. Department of Health, Education, and Welfare (HEW) to evaluate hazards on written re quest by any employer or group of employees. Such evaluations are free. (If HEW finds a violation of OSHA standards, there will not automatically be an OSHA inspection.) The NIOSH Health Hazard Evaluation Program is given in the code of Federal Regulations (42 CFR 85, Federal Register, Nov. 7. 1972). Procedure Proper assessment of industrial respiratory hazards involves a systematic procedure such as: learning about the industrial process, including Construction of equipment, Operation of equipment, Physical conditions during equipment opera tion. Learning about the work area, including Size, Equipment layout, Ventilation, Temperature and humidity. Learning about personnel activity in the work area, including Job routines. Work locations. Time spent in work area, both continuously and intermittently, Work rates. Learning about the materials involved in the process, including Raw materials, End-products, Actual and potential by-products. Listing known and potential respiratory hazards, including their Chemical composition, Type (oxygen deficiency or air contamination) Acute and chronic toxicity at various con centrations. Established concentration limits for breathing Using the above information to select the proper instrument(s) and procedure(s) for determining the degree of workers' exposure to respiratory hazards. Using the instruments to measure Time-weighted average exposure concentra tions, Peak exposure concentrations. If possible, having a biochemist test body tissues and wastes to determine worker exposure to respiratory hazards. Having a physician determine how the hazards af fect exposed workers. Studying and evaluating the measured timeweighted average and peak exposure levels. Com paring them with the biochemical and physiological test results and with established concentration limits for breathing, to determine whether and how to improve engineering and administrative controls to eliminate or reduce the hazards and to determine what types of respirators, if any, are needed in the meantime. The above procedure is only one of many ap proaches, and some parts may not be applicable in a given situation, whereas other conditions may re quire additional considerations. Industrial hygiene experience and professional judgment should play an important part in any hazard evaluation procedure, Identification of Potential Hazards Detailed information about the physical and chemical characteristics of raw materials, endproducts, and by-products of the industrial process should be available from the manufacturing or engineering departments. If they provide insuf ficient information, it may be necessary to consult the purchasing department or the material sup pliers. If data on end-products are inadequate, it may be necessary to consult a chemist or engineer. Determination of what by-products are produced may require considering all chemical reactions that could occur. Consultation with a chemist or 24 OOv,.OsJ -xV '-.>..,.1..'.i <J i I 1 i ii i } t t engineer who will consider the raw materials and the conditions under which they are processed may be helpful. Identifying potential respiratory hazards in an in dustrial work area requires thorough knowledge of the raw materials, end-products, and by-products, the industrial process, the means by which sub stances could escape from the processing equipment into the work area, and chemical reactions that could take place between escaped substances and the atmosphere in the work area or other materials present there. Many relatively inert, nontoxic materials, when machined, heated, dissolved in li quids, or placed in contact with other materials, decompose or react to form highly toxic substances. The type and form of a hazard are determined by the materials and conditions. Dust may be generated by crushing, grinding, abrading, or polishing solids. Spray particles may be produced by atomizing a liquid. Heating and vaporizing a solid may form a solid fume particulate when the vapor condenses. Liquid mist particles can be produced when a vapor condenses. Often, fume and mist particles are formed through oxidation of finely divided condensation particles by the oxygen in the air. Two gases may react chemically to produce solid fume or liquid mist particles, and the hazard then may consist of both particulate and gas. Heating some solids and liquids decomposes them and releases gas, Some vapors and gases react with water vapor in the air to generate new vapors, gases, or liquid parti cles. Certain gases have a great affinity for water, and their molecules act as nuclei for condensation of water vapor that will cause development of a liquid mist particulate. Certain solid particles also act as nuclei for water vapor condensation to form liquid mist particles. High temperatures like those in welding and cutting flames cause nitrogen and oxygen in the air to form toxic gaseous nitrogen oxides. Radiant energy from sources such as gas-shielded welding arcs may decompose chlorinated hydrocarbon vapors to produce new substances including highly toxic phosgene gas. In an enclosed space, some substances slowly combine with the oxygen in the air to produce an oxygen-deficient atmosphere. Release of a large quantity of gas, although it is inert or nontoxic, can dilute the oxygen in a work space and cause oxygen deficiency. Toxicity Toxicity and hazard are not the same. Toxicity is a material's ability to hurt the body. A hazard is toxic material in a condition in which it can cause bodily harm. Almost any substance can be toxic if enough of it is absorbed. Toxicity depends on the quantity of material absorbed and the rate, method, and site of absorption. In assessing respirator hazards, toxicities should be considered. Information on toxicity is given in industrial hygiene and occupational medicine journals and books, product bulletins, and product labels. It also can be obtained from Industrial Safety Data Sheets, published by the National Safety Council (NSC); Hygiene Guides, published by the American In dustrial Hygiene Association; and Chemical Safety Data Sheets, published by the Manufacturing Chemists Association, Toxicity information also is available from casualty insurance firms, the in dustrial hygiene division of state labor or medical departments, and the manufacturers of chemical products, Also, consulting toxicologists are available for a fee. Any regional NIOSH or HEW of fice will provide free toxicity data. These offices have access to NIOSH computerized technical in formation. The OSHA requires HEW to publish, at least an nually, a list of all known toxic substances and the concentrations at which they become toxic. The OSHA also requires HEW to determine, upon writ ten request by an employer or authorized employee representative, whether any substance in the work area atmosphere is potentially toxic in the concen trations used or found. Concentration Limits Recently enacted federal occupational safety and health laws require that workers be provided a safe, healthful work environment. They specify at mospheric quality standards for work areas and list time-weighted average concentrations and, in some cases, ceiling concentrations of air contaminants. S AI... 000057242 25 These laws and standards necessitate use of engineering and administrative controls to reduce respiratory hazards in work areas to levels that will not cause bodily harm, and if these controls are in adequate or not feasible, workers must wear suitable respirators. Determining Degree of Exposure The degree of exposure to respiratory hazards is determined by measuring the concentration of air borne contaminant in the worker's breathing zone. This testing must be adequate to define the timeweighted average concentration and the peak con centration. The volume of air sampled must contain enough of the substance for accurate analysis. The volume to be sampled, or the duration of sampling, depends on: Estimated concentration of the substance, Sensitivity of instrument and test procedures, Established concentration limit for the substance. Concentrations of a substance in the worker's breathing zone should be measured during the time he spends in the work area to define the timeweighted average concentration and peak concen tration accurately. The concentrations are affected by changes in process operation, changes in rate and direction of air movement and temperature, changes from day to night operations, and seasonal changes. Instruments and Procedures There are many instruments and procedures for measuring concentrations of airborne substances. There is no single, universal instrument for all such measurements, and there probably never will be In fact, the trend is toward development of a greater number of specialized instruments. Instruments and procedures may be classified as follows: Those that give a direct reading, Those that remove the substance from a measured volume of air for later analysis, Those that collect and retain a measured volume of air for later analysis, Choice of instrument and procedure depends on many factors, including: Portability of instrument and ease of operation. Sensitivity and accuracy of procedure, Reliability of instrument, Availability of instrument, Type of information desired. Personal experience. instrument or Grab, or instantaneous direct reading, tests re quire only a few seconds to a few minutes. They in dicate fluctuations in concentration of airborne sub stances and are useful in determining maximum and minimum concentrations. Many grab tests or samples are needed to determine a time-weighted average concentration. A continuous test or collected sample requires from several minutes to an entire work shift. Such tests give information on the average concentration of the airborne substance. There is a definite need for both grab and continuous methods, as both give useful information. Instruments and procedures for measuring air contaminant concentrations are specified in some federal standards. Both NIOSH and OSHA have published such lists. SAL 0000!5724i 26 CHAPTER FIVE RESPIRATORS Several hundred different respirators have been approved under various BOM schedules and 30 CFR Part 11. To select the correct respirator for protec tion against a particular hazard as the OSHA re quires, one must have a thorough knowledge of those available. Choosing among the hundreds of devices as individual items would be a formidable task. Unfortunately, there has been a tendency to think of respirators as individual items rather than as part of a system. The 30 CFR Part 11 approval tests, as well as the old BOM tests, cultivated this attitude by approving respirators for protection against specific hazards or groups of hazards, for example, only dust, fumes, and mists, or a specific gas or vapor. Here, we take a different approach and present respirators by classes. There are two major classes each of which has many subclasses of the basic respirator modified for particular purposes. Study of this chapter, especially Figs. 5-1 and 5-2, will make selection and use of the proper device easier. GENERAL RESPIRATOR CLASSIFICATIONS The basic purpose of any respirator is, very sim ply, to protect the respiratory system from harmful airborne physical or chemical agents. It provides this protection by removing the contaminant from the air before it is inhaled or by supplying an in dependent source of respirable air. Basically, a respirator is an enclosure (in 30 CFR 11 terms, a respiratory inlet covering) that covers the nose and mouth or the entire face or head. They are of two general types, tight fitting and loose fitting. Tight-fitting ones are generally a molded, impervious rubber or plastic facepiece that covers the nose and mouth or the entire face. In the latter case, the facepiece has a lens or eyepieces. Sometimes these coverings are called "masks" or, more technically, "oronasal masks." A mouthpiece, held in the wearer's mouth and a clamp that closes his nostrils sometimes make up the respirator. Loose-fitting respirators include hoods, helmets, blouses, or full suits, all of which cover the head completely. Their configuration varies widely depending on the use for which they are designed. Attached to the coverings are the elements'for removing contaminants from the air (in tight-fitting facepieces only), or hoses to supply respirable air (in both tight- and loose-fitting coverings). It is these accessories that divide respirators into two major classes. If the device removes contaminants, it is an air-purifying respirator (see Fig. 5-1). These devices do not supply oxygen, so they cannot be used in oxygen-deficient atmospheres. This point must never be forgotten. A wide variety of air-purifying elements are available to tailor respirators for protection against specific contaminants. These also fall into two subclasses; particulate-removing ele ments that intercept particles before they enter the facepiece, and vapor- and gas-removing elements that entrap gas and vapor molecules. Here we call particulate-removing elements "filters" and vaporand gas-removing elements either "chemical car tridges" or "canisters," Combination elements for protection against both particulates and vapors and gases are also available. If, instead of cleaning the air, the accessory at tached to the respirator provides respirable air from a source other than the surrounding atmosphere, the respirator is called t/tntatpherersuppiyin^ (see Fig. 5-2). These respirators are generally complex and come in many configurations. Because they supply breathable air, they may be used in oxygendeficient atmospheres (subject to some limitations) as well as against particulates, vapors, and gases. SAL 00 0 0157244 27 \ PARTICULATE. REMOVING AIR PURIFYING RESPIRATORS* COMBINATION PARTICULATE.REMOVING. AND VAPOR. ANO GAS-REMOVING .VAPOR- AND GA& REMOVING Single Uft ` Replaceable or Rentable Filter Moutho*oe Quarter Mask Hall Mask Full faapiea Single useditpoable rtspirator. Fii luring surface permanently attached to facepiece body. Mouthpiece Quaker Maik Kail Mali* Pull Facep.ew Particulate filter lor protection aga>nst pnaaumocomcsis-and Lbrosit pbducing due1tt1. .130<b) Molded facepiece eouipped wi piaceable or reusabla liltgrli). Particulate filter tor protection , 93inn the loliotting: mMouthpiece Quarter Mask <11 Half Mask1*1 Full Facepiece* Hood or Halmet Molded lacepieta, hood, or helmet usually equipped with breathing tube end electrically powered blower to which replaceable or reutable filter is attached. , {11 Mo devicet with thit configuration presently approved lOctober 1975), although the potential exists for the design, manufacture, and Ducts 11.130(1) Metal fumet 11.1301b) Mien Radon daughters Combination! of 11.13010 11.l30it) any of the above wToaic dusts Asbetlot dust 11.130(gl I1.130|dl and min (> o. 11.130111 TL\' Fig. 5-1(a). Particulate-removing respirators. AlR PURIFVIMG RESPIRATORS PARTICULATE REMOVING COMBINATION PARTICUIATE HEMOVING AND VAPOR AND GAS-REMOVING VAPOR- AND GASREMOVING (4 *, :/ 0. . S - ~ y i. Single Use'-*. Mouthpiece Quarter Mask Half Mask FuW Facepiece Single use-discotable res pirator. Filtering surface and sorbent bed perma nently attached to lacepiece body. ' Replaceable Cartridge. Cenister, and Filter Powered Mouthpiece Quarter Mask Half Mask Full Facepiece Hood o< Helmet NonPowered Mouthpiece**1 Quarter Mask") Half Mask Full Fac*p -- (1) Classified es "escape gas ma*'* 11.90(il(4i 12) No devices with this mnfiguratton presently approved {October 19751, elthou^ the potentiaf exists for the design, manufacture, end approval in the future. Molded facepiece, hood & helmet equipped with breathing tube and elect' ri&Hly powered blower to which replaceable combirr ation filter end certrid^ d attached. Molded facepiece equipped with replaceable combina tion filter{5) and cert- ndgefsl. Molded full faeepiece equipped with breathing tuba and chesl, baA, or chin mounted canister, Pirtiojlate filter in com* bfoinr aytieonowr imthorseorvbaepnotrIs()il end pas(eel for protection against the following: Farticulate filter in com* bination with sorbent It) for protection against particulatei. vapors, end gates, and on tome (Type Nl carbon monoxide* 11.90 Palm Spreyi 11.162-4 1_ PartiajUtes. vapors, and gases 11.1627 Rtmcidas 11.170 Fig. 5-l(b). 28 0 () 0 0 ':ji 7 2 4 5 AIR PURIFYING RESPIRATORS PARTICULATECOMBINATION PARTICULATE REMOVING REMOVING ANO VAPOFI- AND GAS-REMOVING VAPOR. AND GASREMOVING I Single Ul2> Replaceable Cart'id9* 0 Canister Mouthpiece Quarter Madr Half Mash Full Facepiea Single use-disposable rw pirator Sorbent bed is per manenil v attached to facepiao body. Porrsied1*' Mouthpiece Quartet Mask Half Mask Full Facepiece Hood or Meimet Molded facepiece, hood, or helmet equipped with breathing tube and elect* xicaliy powered blower with attached canister. Non-Powtred Mouthpiece^11 QuHaarltferMMasaksk11' Full Facecta Molded facepiece equipped with replaceable cart* ndgeU). Ml Classified as "escape gas mask" 11,90(a)(4) (2) No devices with this configuration presently approved (October 197$), although the potential exists for the design, manufacture, and approval m the future. - A'y \'r Molded facepiece equipped with breathmq tube and chest, beck, or chin mount* ad canister. . Sorbent(il for protection against vaporIsi and pastes). U ISO Sorbent(t) for protection against vepor(s) and gas(s). 11.90 Fig. 5-lfc). I-- Vapor- and gas-removing respirators. BREATHING APPARATUS ATMOSPHERE SUPPLYING RESPIRATORS COMBINATION BREATHING APPARATUS AND SUPPLIED AIR RESPIRATOHS Closed Circuit Compressed Oxygtn Cherniesl Oxygen Liquid Oxygen Demend Moutti piece Quete Malt HH Mssfc Full Fecep^ce ---------1 Open Circuit Compressed Air Compresad Ozy^n Liquid Air Liquid Oxygen ____________ | n Pressure Oemend IService Timel lr I 4 hour* IS minutes 3 hours 45 minutes 10 minutes 2 hours 30 minutee S minutes 1 tour 3 minute* I Approved for Approved for Recommended for I mar* rescue 11-S3UJH lo 4) auxiliary mine rescue esape use only 11.53(7 to 101 11.70(e) 11.53(a)(5,6J 11.70(d) 3AL- 000057 29 SELF-CONTAINED BREATHING APPARATUS ATMOSPHERE SUPPLYING RESPIRATORS COMBINATION SELF CONTAINED BREATHING APPARATUS AND SUPPLIED AIR Type C or CE Supplied Air Respirator with Auxiliary Air Supply Quarter Math Halt Mas* Full Facepiea Hood or Helmet SUPPLIED AIR RESPIRATORS Da mind Preuura Demand Continuous Flow ACuoxmilpiarrisyed Air Supply ___ I___ 3, 5. or 10 minulii service lima 11.70(bH1[ >15 minute fervid tin* 117010)121 A Fig. 5-2(b). ----- Combination SCBA and supplied air respirators. SELF-CONTAINED BREATHING APPARATUS ATMOSPHERE SUPPLYING RESPIRATORS COMBINATION SELF-CONTAINEO BREATHING APPARATUS AND SUPPLIED AIR SUPPLIED AIR RESPIRATORS How Mask Quarter Made Half Mask Full Facepiece Hood or Helmet A.rln Quarter Mask Had Made Full Fap*ece Hood or Helmet ) With ^ Without Blower Blower Witti Without Demand Blower Blower PraiMre Demand Continuous Flow 11.110(11(1) Type A 11.110UK21 Type AE 11.110(lH9t Typo B 11.110(a> 14) Typo BE 11.110ta) 15) TypoC (1) No devices with this configuration presently approved (October 197S), although the potential exists for the design, manufacture, and approval in the future. Fig. 5-2(c). Supplied ai* respit&$oQ. iL 00005 ..... Air-Purifying and Atmosphere-Supplying Respirators Here, we will discuss air-purifying respirators by the types available for use against specific hazards. Atmosphere-supplying devices are more nearly of a single type, so they are subclassified by mode of operation. Classification of air-purifving respirators is dic tated primarily by the NIOSH approval tests in 30 CFR Part 11 (see App. B), This approval is reflected in Figs. 5-1 and 5-2 where the pertinent Part 11 paragraphs are indicated below each type of devfce. To fully understand this relationship, one might use Figs, 5-1 and 5-2 and the appropriate paragraphs in Part 11 together. Particulate-removing respirators are generally called "dust," "fume," or "mist" respirators, or com binations thereof. Although the implication is that there are specialized respirators for specialized func tions, all dust, fume, and mist respirators protect in exactly the same way, hy removing and retaining the particulate before it can be inhaled.The types of particulate-removing respirators that may be ap proved are listed in 30 CFR Part 11 K, "Dust, Fume, and Mist Respirators." Vapor- and gas-removing respirators for protec tion against specific hazards are available. Chemical cartridges and canisters are approved un der Part 11 for protection against acid gases, such as sulfur dioxide (S02) and nitrogen dioxide (N02), alkaline gases, such as ammonia (NH3), and organic vapors such as carbon tetrachloride or carbon monoxide (CO). The approvals may be for a single vapor or gas or a combination of several. Further descriptions are given in Part 11, Subparts I, L, and M, "Gas Masks," "Chemical Cartridge Respirators," and "Pesticide Respirators," respectively. These Subparts also describe the combination particulate and gas- and vapor-removing respirators such as paint spray respirators and those for protection against pesticides. Atmosphere-supplying respirators (Fig. 5-2) are divided into self-contained and supplied-air types. When wearing self-contained apparatus, the user carries a supply of respirable air or oxygen and can move around as he pleases. Supplied-air respirators depend on air supplied through a hose. They use compressed air, never compressed oxygen. See Parts 11 H, "Self-Contained Breathing Apparatus," and J, "Supplied-Air Respirators." The pertinent paragraphs are indicated under each device in Fig. 5-2. Combination self-contained and supplied-air respirators are covered by Part 11 H. These are generally supplied-air respirators to which a small auxiliary compressed air supply is attached for emergency escape use. Respiratory Inlet Coverings The respiratory inlet covering serves as an imper vious barrier against the contaminated atmosphere and as a framework to which air-purifying or atmosphere-supplying elements may be attached. Tight-Fitting Coverings. Tight-Fitting coverings are usually called "facepieces" and made of flexible molded rubber or plastic. Rubber or woven elastic headstraps are attached at two to six points. They buckle together at the back of the head, or sometimes are a continuous loop of material. Facepieces are available in three basic configura tions. The first, called a "quarter-mask," covers the mouth and nose, and the lower sealing surface rests between chin and mouth (Fig. 5-3). Good protection may be obtained with a quarter-mask, but it is more easily dislodged than other types. Some "dust" respirators have quarter-masks. A second type, the "half-mask," fits over the nose and under the chin (Fig. 5-4). Half-masks generally Fig. 5-3. Typical quarter-mask respirator. 31 FacepH Fig. 5-4. Typical half-mask respirator. seal more reliably than quarter-masks, so they are preferred for use against more toxic materials. A third type (Fig. 5-5) is the "full facepiece," which covers from roughly the hair line to below the chin. They provide the greatest protection and usually seal most reliably. Also, the lenses or eyepieces must meet the impact and penetration re quirements of Federal Specification GGG-M-125d, October 11, 1965, and thereby provide eye protec tion as well. Full-facepiece respirators, both airpurifying and atmosphere-supplying, are designed for use in higher concentrations of toxic materials than are quarter- or half-mask respirators. They may be used in less toxic atmospheres, but, as they are expensive and difficult to maintain, little is gained by using them in such conditions. A special tight-fitting respirator that is coming into increasingly extensive use is the "single-use" disposable type. It is shaped much like the half- or quarter-mask, but the air purifier is permanently attached to the facepiec^ or the entire facepiece is made of filter material. At present, these respirators are approved only for pneumoconiosis- and fibrosisproducing dusts. Another special type of respirator is the "mouthpiece and nose clamp" shown in Fig. 5-6. It consists of a mouthpiece held in the teeth (the lips seal around it) and a clamp that closes the nostrils. The air-purifying elements are either permanent or replaceable. These small devices are easily carried in a pocket and are designed primarily for Exhalation Valve Fig. 5-5. Typical full-facepiece respirator. emergency escape or intermittent use. They do not provide eye protection, Loose-Fitting Coverings. Loose-fitting respirators include hoods, helmets, suits, and blouses. The wide variety of designs precludes any simple description, but Fig. 5-7 shows a blouse that illustrates the principles of construction and opera tion of all such devices. Generally, loose-fitting respirators enclose at least the head, neck, and shoulders. This enclosure Fig. 5-6. Typical "mouthpiece" respirator. 32 OOOC'5 / B AL ? Fcep>ec t,t*t ScfMfi Mood r'3 Gjcm McfdJ Hoiiwal Coiir Fix>bJ Tube Flexibl Tub* Air F lov I Control Valve Quick Gonnect-Oiuonnect Coupling Fig. 5-7. Typical supplied-air blouse. AJr Flow Control Viv Quick &nnrt O'KQnnoet Coupiir^ Fig. 5-8. Typical abrasive blasting hood. usually contains perforated rigid or flexible tubing through which dean compressed air is distributed around the breathing zone. A light flexible device covering only the head, neck, and shoulders is called a hood. If rigid protective headgear is incorporated into the design, it is called a helmet, Blouses extend down to the waist, and some have wrist-length sleeves. Full suits, as the name implies, enclose the whole body, and, in them, additional air is supplied to the extremities for cooling. Generally, full suits are used where skin protection as well as respiratory protection is required. The permeability of the respirator material by toxic gases and vapors must be^considered. Tritium, a radioactive gas, is a good example. The 14 OSHA carcinogen standards specify use of full suits in cer tain conditions, so permeability by these substances must be considered. At present, there is no NIOSH approval test for supplied-air suits, so no approved suits are available. A special type of loose-fitting covering in common use is the abrasive-blasting hood {Fig. 5-8). The hood material is designed to withstand rebounding particles of abrasive sand, steel shot, etc. Also, there is usually an impact-resistant glass or plastic view ing lens with plastic, glass, or woven wire shielding that deflects the rebounding particles. AIR-PURIFYING RESPIRATORS Particulate-Removing. All particulate-removing respirators use fibrous material (a filter) to remove the contaminant. As a particle is drawn into the filter, it is trapped by the fibers. The probability that a single particle will be trapped depends on such factors as its size relative to the fiber size, its velocity, and, to some extent, the composition and shape of both particle and fiber. Here it is enough to say that the particles are retained on the filter fibers. No filter is 100% efficient in removing particles. An essentially 100% efficient filter could be made, but it would be unacceptably hard to breathe through. Therefore, manufacturers try to produce the most efficient filter with the lowest breathing S'AL 000057250 33 resistance. Generally, the higher the efficiency, the greater the breathing resistance. Another consideration is particle loading. As more and more particulate material collects on the fibers, the openings between them become smaller, so the breathing resistance increases. The filter also becomes more efficient. Filters in general, and dust filters in particular, are designed to remove as much material as possible without excessive breathing resistance. For the 30 CFR Part 11 approval tests, particulate filters are classified as designed for protection against dust, fumes, mists, and any combination thereof. High-efficiency filters are aiso dust, fume, and mist filters, but they are designed to protect against particulate contaminants with a threshold limit value (TLV}* less than 0.05 mg/m1. These filters are at least 99.97% efficient against 0.3-Aim particles. Figure 5-9 shows a typical high-efficiency dust, fume, and mist filter. The filter is a flat sheet of material that is pleated and placed in the filter "can." The pleating provides a large filtering area to improve the particle-loading capacity and lower the breathing resistance, When viewed from the top, this type of filter shows a series of concentric rings. This configuration is common, but other methods of construction also are used. High-efficiency filters generally have poorer particle-loading characteristics than those designed for protection against the less toxic dusts, Some filters for protection against fumes of various metals, used on the so-called "fume" respirators, look similar. The basic difference is that the fume filter is less efficient (90-99% against 0.6-Mm parti cles) and is approved only for contaminants whose TLV is 0.05 mg/m3 or more. Less efficient are the so-caUed-Mcwt* filters used on respirators designed**#ar' protection -against "pneumoconiosis- aniiwwfibi'uuiB-prodBcmgr dusts"- whose TLV is 0.05 mgifa* or m~rc of these respirators are also approved for mists whose TLV is 0.05 mg/m3 or more, as well as for dusts. This class of respirator accounts for as much as 90% of total Fig. 5-9. Typical high-efficiency dust, fume, and mist filter. sales. Their lower efficiency (80-90% against 0.6-pm particles) results from being designed to withstand heavy dust loadings without unacceptably increas ing breathing resistance. Two types of dust filter predominate. The first and probably most common (Fig. 5-10) is a flat disk of compressed natural wool or synthetic fiber felt, or a blend, to which an electrostatic charge is imparted during manufacture by impregnating the material with a resin and mechanically beating or "needling" it. This charge increases the filter efficiency by elec trostatically1 attracting the particles to the fibers. These filters are less expensive than the pleated type and protect adequately against most industrial dusts, but one precaution must be observed in their use. Certain agents such as oil mists, extremely small solid particles, and storage in very humid air 'Threshold limit values are time-weighted concentrations of air borne substances to which nearly all workers may be con tinuously exposed (during 8-hour workdays and 40-hour workweeks! without adverse effects. NOTE: ANSI Standard Z86.1-1972, "Commodity Specification for Air." as revised in October 1974, specified 19.5-23.5 vol% Oj for all grades of breathing air. Fig. 5-10. Typical resin-impregnated felt dust filter. 34 ,1... 00005 h remove the electrostatic charge. Therefore this type of filter should be used as soon as possible after purchase and should be kept out of oil mists, such as occur around lathes, and high (>80%) humidity. The resin-impregnated felt filter is readily iden tified by rubbing it between the fingers and then rubbing the fingers together. They will feel slightly sticky. Another type of dust filter is shown in Fig. 5-11. The filtering medium is only loosely packed in the filter "can." so it is much thicker than the com pressed type. Such filters are generally made of fiber glass, although nonfelted resin-impregnated natural wool fibers have been used. They are not so common as the felted type. A typical dust respirator is shown in Fig. 5-12. A major variant is the single-use, or disposable, dust respirator shown in typical use in Fig. 5-13. In these devices, the filter is either an integral part of the facepiece, or it may be the entire facepiece itself. When the filtering surface is permanently attached to the facepiece, the material often is resinimpregnated natural wool fiber or synthetic fiber felt. In some currently approved devices, the entire facepiece is a fabric filtering medium. At present, single-use disposable respirators are approved only for pneumoconiosis- and fibrosis-producing dusts although they could also be approved for such mists. This does not mean that it is impossible or imprac tical to make more efficient single-use respirators for protection against more toxic dusts and mists and even fumes. It means only that they cannot be Typical dust respirator with replaceable filters. approved as Part 11 is now written. Significant ad vances probably will be made in single-use respirators, and the user should watch for develop ments. Some particulate filters may vary from the designs described. The important thing to recognize is the type of medium rather than the shape. Fig. 5-11. Typical dust filter with loose-packed medium. Fig. 5-13. Typical single use dust respirators. &AI... 00005/252 35 Vapor- and Gas-Removing The other major class of airborne contaminants consists of gases and vapors. Air-purifying respirators are available for protection against both specific gases and vapors, such as ammonia, and classes, such as organic vapors or acid gases. In con trast to filters, which are effective to some degree no matter what the particulate, the cartridges and canisters used for vapor and gas removal are designed more for protection against specific con taminants. Vapor- and gas-removing respirators all remove the contaminant by interaction of its molecules with a granular, porous material, commonly called the sorbent. The general method by which the molecules are removed is called sorption. Adsorption, Absorption, and Catalysis. Three sorptive mechanisms are used in vapor- and gasremoving respirators. The first, adsorption, retains the contaminant molecule on the exposed surface of the sorbent granule by physical or chemical attrac tion whose intensity varies with the type of sorbent and contaminant. In physical attraction, the adsorbed molecules are held more or less weakly. These bonds may be broken by heating the sorbent so that the gas and vapor molecules are released into their original state. If chemical forces are involved, the adsorption process is called chemisorption. Then the bonds holding the molecules to the sorbent granules are much stronger and can be broken only with great difficulty. A characteristic common to all adsorbents is a large specific surface area, up to 1500 mVg of sor bent. Activated charcoal is probably the most com mon adsorbent. It is used primarily to remove organic vapors, although it does^have some capacity for adsorbing acid gases. Activated charcoal also can be impregnated with other substances to make it more selective against specific gases and vapors. Ex amples are activated charcoal impregnated with iodine to remove mercury vapor, with metallic ox ides to remove acid gases, and with salts of metals to remove ammonia gas. Other adsorbents used in vapor- and gas-removing respirators include molecular sieves, activated alumina, and silica gel. Absorbents differ from adsorbents in that although they are porous, they do not have as large a specific surface area. Absorption is also different because the gas or vapor molecules penetrate deeply into the molecular spaces throughout the sorbent and are held there chemically. Probably, absorption cannot occur without prior adsorption on the surface of the particles. Furthermore, adsorption occurs in stantaneously, whereas absorption is slower. Most absorbents are used for protection against acid gases. They include mixtures of sodium or potassium hydroxide with lime and/or caustic silicates. A catalyst is a substance that influences the rate of chemical reaction between other substances. A catalyst used in respirator cartridges and canisters is hopcalite, a mixture of porous granules of manganese and copper oxides, which speeds the reaction between toxic carbon monoxide and oxygen to form relatively nontoxic carbon dioxide. As applied to respirators, the foregoing processes ' are essentially 100% efficient until the sorbent's capacity to adsorb gas and vapor or catalyze their reaction is exhausted. Then the contaminant will pass completely through the sorbent material and into the facepiece. This is in contrast to particulateremoving filters which become more efficient as matter collects on them and plugs the spaces bet ween the fibers. This difference is important to remember. Water vapor reduces the effectiveness of some sorbents and increases that of others. Vaporand gas-removing cartridges must generally be protected from the atmosphere while in storage. Cartridges and Canisters. The basic difference between cartridges and canisters is the volume of sorbent contained, not its function. Cartridges are vapor- and gas-removing elements that may be used singly or in pairs on quarter- and half-masks and oc casionally on full facepieces. The sorbent volume of a cartridge is small, about 50-200 cm3, so the useful lifetime is usually short, particularly in high gas or vapor concentrations. Therefore, use of respirators with cartridges generally is restricted to low concen trations of vapors and gases. Canisters have a larger sorbent volume and may be chin-, front-, or back-mounted. Respirators with canisters can be used in higher vapor and gas con centrations than those with cartridges. Chin-style 36 canisters have a volume of about 250-500 cm5 and are used on full-facepiece respirators. Front- or back-mounted canisters are held in place by a harness and connected to the facepiece by a corrugated, flexible breathing tube. They have a sorbent volume of 1000-2000 cm3 and are designed for use in higher concentrations or for prolonged use in lower concentrations of gases and vapors, Frontor back-mounted canisters are used with full facepieces as part of "gas masks." The "gas mask" is not a special, exotic type of respirator. It differs from the chemical cartridge respirator only in its larger sorbent volume and the higher concentrations of vapors and gases against which it provides protec tion. Also, gas masks, except for escape gas masks, are required to have full facepieces. Labeling. As vapor- and gas-removing cartridges and canisters are designed for protection against specific contaminants, or classes thereof, how does the user know he is selecting the proper device? An American National Standard, ANSI K.13.1, es tablished a color code for the various types of sor bent cartridges and canisters which identifies the contaminants they are designed to protect against, The printed approval label also clearly lists these contaminants. Whether the user memorizes the color code or not, he should always READ THE LABEL! This is the only foolproof way of ensuring use of the correct cartridge or canister. ANSI K.13.1 has been included verbatim in the OSHA regula tions, 29 CFR 1910.134(g). Construction. Construction of vapor- and gasremoving cartridges and canisters varies little.from manufacturer to manufacturer. The type, of sorbent for a particular substance may differ with manufac turer, but the basic construction problems are about the same, to provide enough sorbent bed depth and volume to ensure that the contaminant is totally removed in the test times specified in the 30 CFR Part 11 bench tests, and that the sorbent remains mechanically stable in the container. Figure 5-14 shows a typical chemical cartridge ap proved for use with a half- or quarter-mask. The bed of sorbent granules is retained in the cylindrical "can" by a screen and coarse filter pad at the top and by a coarse particulate filter pad and a screen at the bottom. The pads only keep the fines in the sorbent Fig. 5-14. Typical chemical cartridge. from escaping from the cartridge; they are not designed for protection against particulate contami nants. Various precautions for use of these car tridges are discussed in Chap. Seven, Respirator Use. One problem in design and manufacture of sor bent canisters is to prevent passage of large quan tities of air through small areas of the bed of packed sorbent granules. Such air channeling through the canister reduces its useful service life. Selection of the proper sorbent granule size and careful packing in the canister minimize air channeling. There is also a tendency toward channeling where the irregular sorbent granules touch the smooth canister wall. Sometimes this is prevented by forming ridges in the canister shell like those in Fig. 5-15. The retaining screens and pads hold the granular sorbent bed in place. The spring ensures that the sorbent remains tightly packed. Even with these precautions, sorbent canisters may be damaged by dropping. This can crush the granules, disturb the retaining screens or pads, or create channels between the sorbent granules and the canister wall. Cartridges and canisters should also be stored upright. In short, treat sorbent canisters very carefully. Chemical Cartridge Respirators. Figure 5-16 shows a typical chemical cartridge air-purifying respirator. In 30 CFR Part 11.150 is a listing of the vapors and gases and maximum concentrations for which chemical cartridge respirators are approved. H! () 0 V1 37 Breathing Tube Ito Facepiece) - Retaining Screen Coarse Filter Pad -Canister Shell Vapor- and GasRemoving Sorbent Material Inhalation Valve Coarse Filter Pad - Retaining Screen Fig. 5-15. Typical front- or back-mounted canister. Note the accompanying restrictions on use and remember that these concentrations pertain to the cartridge only, not to facepiece fit. Gas Masks. According to Subpart I of Part 11, the following gas masks may be approved, Front- or back-mounted Type N, front- or back-mounted, combination gas, vapor, and particulate Chin-style Escape Front- or Back-Mounted. Front- or backmounted gas masks are usually approved for use with a full facepiece. A "super size" or "industrial" size canister is fastened to the user's body, and a breathing tube connects the canister to the facepiece inlet. A typical front- or back-mounted canister is shown in Fig. 5-15. Note that the con struction does not differ markedly from that of the chemical cartridge shown in Fig. 5-14. Other than the volume of sorbent contained (1000-2000 cm8), the greatest difference is that the canister, rather than the facepiece usually contains the inhalation valve. Figure 5-17 shows typical front- (back)mounted canister gas masks. Fig. 5-16. Typical chemical cartridge respirator being used during weed spraying. Type N. Type N, front- or back-mounted, com bination gas, vapor, and particulate gas masks are approved under Subpart I of Part 11 for protection against acid gases, ammonia, carbon monoxide, organic vapors, and particulates. However, we do not discuss these devices here because the Type N canister contains a high-efficiency particulate filter as well as various sorbents, so it should be classified as part of a combination particulate- and vapor- and gas-removing respirator. Chin-Style. Chin-style gas masks typically have a medium-sized (250-500 cm3) canister (Fig. 5-18), rigidly attached to a full facepiece. The useful lifetime is less than that of a front- or back-mounted canister owing to the smaller sorbent volume, but greater than that of chemical cartridges. Figure 5-19 shows a typical chin-style gas mask. Other types of canisters are designed for protec tion against more than one vapor or gas. In them, the sorbents are either arranged in layers or inter mixed. Figure 5-20 shows these two arrangements as either might appear in a chin-style canister. In cer tain instances, one type of construction has an ad vantage over the other, but mostly it is a matter of manufacturing convenience, with sorbent layering being most common. 38 SAL ; vj / a "j a Hk1 Csrtm Body Strip Typical front- or back-mounted canister gas masks. bt \\~ ;>60000573" 39 Fig. 5-18. Typical chin-mounted canister. Fig. 5-20. Methods of packing more than one sorbent Maximum use concentrations established in 30 CFR Part 11 for all types of gas masks, are being withdrawn (1975). NIOSH is advising the user to contact the NIOSH Testing and Certification Laboratory, Morgantown, West Virginia, or the Mine Enforcement Safety Administration, Pittsburgh, Pennsylvania, for guidance in use of gas masks in high contaminant concentrations. Escape Masks. Gas masks for use during escape * from (not reentry into) atmospheres immediately hazardous to life and health are approved under Subpart I, 30 CFR Part 11. They can be approved only if they have a half-mask facepiece or a mouthpiece. Where eye irritation is a consideration, a full-facepiece gas mask is preferable. Fig. 5-19. Typical chin-style gas mask in use in a chemical plant. 40 Particulate-, Vapor-, and Gas-Removing^ Cartridges and canisters are available to protect against both particulates and vapors and gases. These devices look much like the sorbent cartridge or sorbent canister alone. Figure 5-21 shows the two methods of attaching a particulate filter to a typical cartridge used with half- or quarter-masks. In A, the particulate filter is inside the cartridge "can," in B it is outside the can and held in place by a snap-on cover. Other variations may be found, but the prin ciple is the same. Pesticide and paint spray respirators use combination respirator cartridges, although paint spray respirators are approved under Subpart L of 30 CFR 11 (Chemical Cartridge Respirators), and pesticide respirators under Sub part M. A typical combination particulate- and vapor- and gas removing respirator is shown in Fig. 5-22, being used in paint spraying. A. \ 0000* I Fig. 5-21. Typical combination particulate- and uapor- and gas-removing cartridges. High-efficiency particulate filters are included on some types of combination canisters like the chinmounted canister shown in Fig. 5-23. A very specialized type of combination particulate- and vapor- and gas-removing canister is the so-called, "Type N," or "Universal" canister, Fig. 5-24. It looks much like a front- or back- mounted canister, being about the same size and held on the body in the same way. Internally, however, there is a great deal of difference. The distinguishing feature is that it contains several different sorbents for various vapors and gases; a catalyst, hopcalite, to convert carbon monoxide to carbon dioxide; and fibrous filters for particulates. .The multiple protection the Type N canister provides has led to unfortunate, sometimes tragic, misuse. Usually the user assumed that he could get the same useful service life from a Type N canister as from an industrial canister of about the same size. Obviously, this is not so, for as Fig. 5-24 shows, Fig. 5-22. Typical combination particulate- and gas- and vapor-removing cartridge respirator being used in paint spraying. Cojr FiIt* p*6 Vapor. Maiar,u C*- Gtniftar S*li Co*w FitT RatAirnng Seravrt PKPeulata Pillar Fig. 5-23. Typical chin-mounted combination particulate-removing and gas- and vaporremoving canister. 41 user is well aware of its limitations. Figure 5-25 shows a typical Type N canister attached to a full facepiece. Fig. 5-24. Typical Type N canister. Powered Air-Purifying Respirators The powered air-purifying respirator uses a blower to pass contaminated air through an element that removes the contaminants and to supply the purified air to a respiratorv-inlet covering. The purifying element may be a filter to remove par ticulates, a cartridge to remove vapors and gases, or a combination filter and cartridge. The covering may be a facepiece, helmet, or hood. These respirators are approved under 30 CFR, Part 11. Subparts K, L, and M. One type of powered air-purifying respirator con sists of an air-purifying element attached to the housing of a small battery-powered blower that is sorbents for several different vapor and gas contami nants, two layers of drying agent to protect the catalyst from water vapor, and fibrous particulate filters are packed into the equivalent space. Therefore, the sorptive capacity of any single layer of sorbent in the Type N canister must be less than that of the large sorbent bed in the industrial size canister for use against a single contaminant. Con sequently, the useful service life of the Type N canister is short. All Type N canisters have an indicator, usually behind a small window, that supposedly shows when the canister is exhausted. Actually, it in dicates the condition of the drying agent upstream of the catalyst. The CO sorbent, hopcalite, is ren dered useless by moisture'? and this indicator tells only the condition of this critical layer, not that of the acid gas, ammonia gas, or organic vapor sorbent. Therefore, it cannot be used as an indication of the overall canister condition. Because of the difficulties in use of Type N canisters, they are being withdrawn from the market. These canisters were originally designed for emergency use, a purpose being met increasingly by atmosphere-supplying devices. However, even with its drawbacks, the Type N canister is useful if the 42 Fig. 5-25. Typical Type N canister attached to a full facepiece. (Courtesy Mine Safety Appliances Co.) SAL. OOOOSi7259 connected by flexible tubing to the respiratory inlet covering. The wearer carries this entire assembly. Another type consists of an air-purifying element at tached to a stationary blower, powered by a battery or externally supplied electricity and connected bv a long flexible tube to the respiratory inlet cover ing. The respirator aproval document requires that the blower deliver at least 4 cfm of air to a tightfitting facepiece and at least 6 cfm to a loose-fitting helmet or hood. A battery-powered air-purifving respirator should supply air for at least 4 hours without recharging of the battery. The great advantage of the powered air-purifying respirator is that it usually supplies air at positive pressure so that any leakage is outward from the facepiece. Thus, even if the fit is poor, contaminated air cannot enter. The type and degree of protection depend on the air-purifying element whose protec tion level and useful service time depend, in turn, on its material, size, and shape and on the nature and concentration of the contaminant. Also affecting the degree of protection is the wearer's work rate. At high work rates, it is possible, through rapid breathing to create a negative pressure in the facepiece, thereby potentially in creasing facepiece leakage. Furthermore, because there is a constant air flow through the air-purifying element, instead of flow only during inhalation, the useful lifetimes of sorbent canisters and cartridges attached to the blower assemblies are much shorter than when the same elements are attached to the common air purifying respirator. Disadvantages. General. Air-purifying respirators cannot be used in atmospheres immediately hazardous to life and health or when the contaminant has poor warning properties, except for escape. Quarter-Mash, Half-Mash, and Mouthpiece Respirators. Maximum use concentrations may be restricted because of unreliable sealing. These respirators do not protect the eyes or skin. Further restrictions should be placed on their use owing to small sorbent or filter capacity. Full Facepiece Respirators. Eye protection is provided, but use may be restricted by limited sor bent capacity. They are more expensive than other facepieces. ATMOSPHERE-SUPPLYING RESPIRATORS The class of respirators which provide air from a source independent of the surrounding atmosphere instead of purifying the atmosphere is shown in Fig. 5-2. The basic types of atmosphere-supplying respirators vary less than the air-purifying types, but there is greater variation among devices designed for a given purpose. It may be difficult to recognize a particular type of device by appearance alone. The different types may be recognized in two ways, by the method by which air is supplied and the way in which the air supply is regulated. Advantages and Limitations of Air-Purifying Respirators Self-Contained Breathing Apparatus It is important that the user be thoroughly familiar with the following information. Many in stances of misuse arise because the user is unaware of the performance limits of a particular device. Advantages. Air-purifying devices are small, relatively inexpensive, and easily maintained. They restrict the wearer's movement least. Many com binations of facepieces, mouthpieces. Filters, car tridges, and canisters allow the user to match the device to the particular situation. The distinguishing feature of all types of selfcontained breathing apparatus (SCBA) is that the wearer need not be connected to a stationary air source, such as a compressor, Instead, enough air or oxygen for up to 4 hours, depending on the design, is carried on the person. As Fig. 5-2 shows, SCBAs are classified as "closed-circuit" or "open-circuit." Circuit* Another name for closed-circuit SCBAs j i>`VrtWftlflTingu1dmi*^t indicative of the mode of operation. The air is rebreathed after the exhaled carbon dioxide has been removed and the oxygen content restored by a compressed or liquid oxygen source or an oxygen-generating solid. Had Harness Descriptions and approval tests for the closed- circuit apparatus are given in Subpart H of 30 CFR Part 11. These devices are designed primarily for 1- to 4- hour use in oxvgen-deficient atmospheres such as might be encountered during mine rescues. They have been used thus since the early 1900's when the Gibbs and McCaa devices were developed. The designs have not changed much since then, a signifi cant commentary on their acceptance and good per formance. NOTE: 30 CFR Part 11 approves for mine rescue only devices that give 1 hour or more perfor mance. Devices that give 30-min or longer perfor mance may be approved for auxiliary mine rescue service. Closed-circuit devices are not a cure-all; there are design features that restrict their use. Because negative pressure is created in the facepiece during inhalation, there is increased leakage potential. Therefore, the devices should be used in at mospheres immediately hazardous to life and health only when their long-term use capability is necessary, as in mine rescue, They should not be used in preference to pressure demand SCBAs for short times in immediately hazardous atmospheres. For use in oxygen-deficient atmospheres over a long period, these devices are ideal. For 1/2 hour or less, in highly toxic atmospheres immediately hazardous to life, a positive pressure open-circuit SCBA is recommended. Two basic types of closed-circuit SCBA are available, distinguished by whether they use a tank of compressed oxygen or a solid oxygen-generating substance. Figure 5-26 shows a typical closed-circuit 1 SCBA with a small cylinder^ compressed oxygen. Available from several manufacturers, these devices are all based on the old McCaa device. Breathable air is supplied from an inflatable bag. The exhaled air passes through a granular solid adsorbent that removes the carbon dioxide, thereby reducing the Fig. 5-26. Closed-circuit SCBA. Mb flow back into the breathing bag. The bag collapses so that a pressure plate bears against the admission valve which opens and admits more pure oxygen that reinflates the bag. Thus, the consumed oxygen is made up. The advantage of the rebreathing process is that only the oxygen supply need be carried, as all the other air constituents except the waste carbon dioxide are recirculated. The advan tage of this type of device is its long-term (1- to 4hour) protection. However, it i^gifc&and does not provide the ultimate in protection because negative 44 :-ii... 00005726 1 i i ' pressure is created in the facepiece during inhala Oxygen is continually released into the breathing tion. Figure 5-27 shows a closed-circuit SCBA in bag(s) which acts as a reservoir to accommodate use. breathing fluctuations. A pressure relief valve and The second type t>f closed-circuit SCBA (Fig. 5- saliva trap release the excess pressure created by 28) uses an oxygen-generating solid, usually nitrogen buildup in the facepiece. potassium superoxide (K02). The H20 and C02 in the exhaled breath react with the K02 to release 02. This closed-circuit apparatus is lighter, simpler? and cheaper than the tank type. However, it is useful for only about 1 hour and, once initiated, can 2K02 + C02 + H20- K2C03 + 1.50, + H20 . not be turned off. The precautions mentioned for 2KOa + 2C02 + H20^ KHC02 + 1.50,. the type containing a cylinder of compressed oxygen apply. Figure 5-29 shows a typical oxygen As the 02 is released when the wearer's exhaled generating closed-circuit SCBA being worn. breath reaches the canister, there is a short time lag I after the canister is initiated before 02 flow begins. This has been overcome in some devices by Open-Circuit. An open-circuit SCBA exhausts ! providing a "quick start" feature, a canister section the exhaled air to the atmosphere instead of recir ; filled with mixed sodium chlorate and iron. Oxygen culating it. 30 CFR Part 11 does not specify what flow is started by striking the device, somewhat like breathing gas may be approved for these devices, lighting a match. This provides enough oxygen until but it is almost always compressed air. Compressed the potassium superoxide in the canister begins to oxygen could be used in a device designed for com function. pressed air, but it must not be, because minute amounts of oil or other foreign matter in the device components can cause an explosion. In fact, 30 CFR Part 11 prohibits approval of any device designed to permit interchangeable use of oxygen and air, IN Fig. 5-27. Typical oxygen-supplying closed circuit SCBA as used for mine rescue. Release Oxygen and with Carbon Dioxide to Produce a Nonvolatile Salt Fig. 5-28. Oxygen-generating closed circuit SCBA. 45 r5 hk1 Hi Fig. 5-30. Open-circuit SCBA. Fig. 5-29. Typical oxygen-generating closed circuit SCBA. (Courtesy Mine Safety Appliances Co.) GENERAL, OXYGEN SHALL NEVER BE USES IN A DEVICE UNLESS IT IS SPECIFICALLY DESIGNED FOR THAT PURPOSE. Figure 5-30 shows a typical open-circuit SCBA. A tank of highpressure (~-2000-psi), compressed air, carried on the back, supplies air to a two-stage regulator that reduces the pressure for delivery to the facepiece. This regulator also serves as a flow regulator by passing air to the facepiece only on demand. A flexi ble corrugated hose connects the regulator to the respiratory-inlet covering, usually a full facepiece. Because it has to provide the total breathing re quirements, not just the oxygen requirements as in the closed-circuit SCBA, the service life of the opencircuit SCBA is usually shorter. Most open-circuit devices have a service life of 30 min. NIOSH ap proves units with less than 1-hour, but not less than 30-min, service time, for auxiliary mine rescue, Therefore open-circuit devices are very seldom used for this purpose, but they are widely used in fire Fighting and industrial emergencies. They art- less expensive than the closed-circuit SCBAs. SC BAs with less than 30-min service time are approved but only for escape use in combination with a suppliedair air line respirator. Two types of open-circuit SCBA are available. "demand'1 or "pressure-demand." The difference is very important and best explained by describing the operation of a typical open-circuit SCBA regulator, shown in Fig. 5-31. This is a regulator. Air at approximately 2000 psi is supplied to the regulator through the main valve. A bypass valve passes air to the facepiece in case of regulator failure. Downstream from the main valve, a twostage regulator reduces the pressure to approx imately 50-100 psi at the admission valve, which is actuated by movement of a diaphragm and its associated levers. The admission valve stays closed as long as positive pressure in the facepiece (during exhalation) presses the diaphragm away from the valve assembly. Inhalation creates negative pressure in the facepiece, and the diaphragm con tracts, opening the admission valve and allowing air into the facepiece. In other words, air flows into the facepiece only on "demand" by the wearer, hence the name. A fSMSiifleBSWaaHW^regulator is very similar ex cept that there is usually a spring between the diaphragm and the outside case of the regulator. 46 0 0 0 0572 63 Fig. 5-31. Open-circuit SCBA regulator. This spring tends to hold the admission valve slightly open, theoretically allowing continual air flow into the facepiece. This would be true except that all pressure-demand devices have a special ex halation, valve that maintains about 1.5-3 in. H20 positive back pressure in the facepiece, and opens only when the pressure exceeds that value. This combination of modified regulator and special ex halation valve maintains positive pressure in the facepiece at all times, and the regulator still sup plies additional air on "demand." Because of the positive pressure, any leakage is outward so a pressure-demand SCBA provides very good protec tion. Contrary to common belief, the pressuredemand SCBA has the same service time as a de mand version of the same device, if it seals well on the wearer's face. Any leakage increases air con sumption and decreases service time. A FACEPIECE WHOSE EXHALATION VALVE IS DESIGNED FOR DEMAND OPERATION CAN NOT BE USED WITH-A-PRESSURE-DEMAND REGULATOR AS"imr-\faLL FLOW CON TINUALLYAND QUICKLY EXHA UST THE AIR SUPPLY. In a demand-type SCB^negative pressure in the facepiece during inhalation opens the demand valve. This negative pressure is approximately the same as that created in an air-purifying respirator. Therefore, leakag^^-rimr infwl and of the same magnitude as that in an air-purifying respirator. Re cent studies showed that a demand-type SCBA is no more efficient than an air-purifying respirator with the same facepiece. Therefore, a'ifinlartittpp&ffpeflE* circuitSCBA should not be used in atmospheres imv mediately hazardous to life or healthi like closedcircuit SCBAs, they are, however, adequateagainst oxygen-deficient atmospheres. Some open-circuit SCBAs can be switched from demand to pressure-demand operation; others are available only in one configuration or the other. There is certainly an advantage in being able to change from demand to pressure-demand at will, but there is also a good argument against it. Because these devices are primarily for emergency use, the user should not have the choice, as a demand device is no more efficient than an air-purifying respirator with the same facepiece. In short, if the ultimate in protection is required for emergency use, a pressuredemand SCBA should be purchased. Because of the high instantaneous flow rate- that may be required during inhalation (see Chap. Three), both demand and pressure-demands regulators can deliver flows of 350-400 1pm. This en sures that the wearer will obtain adequate air and generally not be able to "overbreathe" a device. Overbreathing creates extreme negative pressure in the facepiece of a demand SCBA, potentially in creasing facepiece leakage. This also can happen in a pressure-demand SCBA, but is less likely because the wearer must overcome the 1.5- to 3-in. H?0 positive pressure. Several required safety features on all approved closed- and open-circuit SCBAs provide additional protection. Among these are: Pressure gauges or liquid level gauges visible to the wearer which indicate the quantity of gas or li quid (air or oxygen) remaining in the cylinder. Remaining service life indicators or warning devices that show when only 20-25% remains. Fittings on devices that use compressed or li quid oxygen which are incompatible with com pressed or liquid air fittings. The choice of demand or pressure-demand device is best left to the user, and should be based on thorough evaluation of the respiratory hazards. If there is any potential atmosphere immediately hazardous to life, a pressure-demand SCBA should most certainly be used. Typical demand or pressuredemand SCBAs are shown in Fig. 5-32. ... o A .> i\Q 1 ' " 47 Fig. 5-32. Typical open-circuit SCBAs. Supplied-Air Respirators Air line respirators are categorized in 30 CFR Part 11 J as one of the types of supplied-air respirators, along with hose masks which will be described later. The distinction of air line devices is that they all use a stationary source of compressed ai& delivered through a high-pressure hose. 30 CFR Part 11 specifies that the pressure shall not exceed 125 psi at,, the point where the hose attaches to the air supply. When the manufacturer submits an air line respirator for approval, he must specify the operating pressure and the hose length, from 25 to 300 ft. At the lowest pressure and greatest hose length, the device must deliver at least 6 cfm to a helmet or hood. The flow rate must not exceed 15 cfm. Air line respirators are available in demand, pressure-demand, and continuous flow configura tions (see Fig. 5-2). They are called Type "C" supplied-air-respirators. The respiratory-inlet covering may be a facepiece, helmet, hood, or com plete suit, although there are presently no approval tests for suits. When a full facepiece, helmet, or hood provides special protection against impact and abrasion from rebounding abrasive material, it is called a Type "CE" supplied-air respirator. 48 A demand or pressure-demand air line respirator is very similar to a demand or pressure-demand open-circuit SCBA. except that the air is supplied through a small-diameter hose from a stationary source of compressed air rather than from a portable high-pressure air source. Because the air pressure is limited to 125 psi, regulators for air line respirators have only single-stage reduction. Figure 5-33 shows a typical demand-type regulator. Its operation is self-explanatory and identical to that of a demandtype open-circuit SCBA regulator. Like the pressure-demand open circuit SCBA regulator, the pressure-demand air line regulator has a spring bet ween the diaphragm and the outer case. In combina tion with a special exhalation valve on the facepiece, it provides positive pressure in the facepiece at all times. Fig. 5-34 shows typical demand or pressuredemand air line respirators with tight fitting facepieces. Note that the regulator sometimes is mounted on the facepiece. Continuous-flow air line respirators maintain air flow at all times, rather than only on demand. In place of a demand or pressure-demand regulator, an air flow control valve or orifice partially controls the air flow. According to 30 CFR Part 11, a flow of at SAL. 0000 i .! C: Exhalation. High pressure of exhaled air stretches diaphragm, Resulting lever movement and spring action close admission valve, and air flow ceases. Inhalation, Low pressure created by inhalation pulls diaphragm inward. Resulting lever movement compresses spring and opens admission valve. Air flows through valve. Fig. 5-33. Typical demand-type air flow regulator. least 4 cfm to a tight-fitting respiratory-inlet cover ing and 6 cfm to a loose-fittir^ one must be main tained at the lowest air pressure and longest hose length specified. This means that, by design, the control valve cannot be closed completely or a con tinually open bypass is provided to allow air to flow around the valve and maintain the required minimum rates. Never replace an air flow control valve with another type of valve, even one from another manufacturer's air line respirator. Besides possibly creating a hazard owing to improper air flow rates, substitution of another component negates NIOSH and MESA approval of the device. Furthermore, only the air supply hose furnished by the respirator manufacturer may be used with a supplied-air respirator. Substitution of another type of hose, even though equivalent, negates approval of the device. Figure 5-35 depicts a typical continuous flow air line respirator with a tight fitting facepiece. Notice the air-purifying element on the air supply line. Figure 5-36 shows typical such devices, which also may be obtained with half-masks. Although addition of an air-purifying element in the supply line just upstream of the air supply hose attachment is a good idea, other precautions also must be taken to ensure breathing air quality. The air supply to air line respirators is required to meet the requirements for Type I gaseous air (Grade D or higher quality) set forth by the Compressed Gas Association Commodity Specification for Air, G-7.1. Furthermore, OSHA requires that a breathing air compressor have certain safety devices to protect the air quality (see Chap. Six). Air line respirators with special items to protect the wearer's head and neck from rebounding abrasive material may have facepieces, helmets, or, hoods. Plastic, glass, and metal wire screen are used to protect the lenses of facepieces and the windows of helmets and hoods against the rebounding material. These respirators are known as abrasive blasting air line respirators or Type "CE" suppliedair respirators. Figures 5-7 and 5-8 showed two types of con tinuous flow air line abrasive blasting hoods, although it might .be preferable to call them "blouses" as they extend to the waist. The figures in dicate the design variations within the Type ''CE" device category. Figure 5-37 shows a typical abrasive blasting hood, and Fig. 5-38 shows a varia tion designed specifically for lead grinding. Note the protective screen over the lens and the heavy apron on the abrasive blasting hood. Full-suit air line respirators are available..They provide purified air not only for breathing but also to isolate the whole body from the surrounding at mosphere. They are used against substances that irritate or corrode the skin or which may penetrate the skin and enter the blood stream to produce toxic effects. At present, 30 CFR Part 11 does not provide for approval of air line suits. Typical full suits are shown in Figs. 5-39 and 5-40. Air line respirators provide a high degree of protection, but their use is limited to atmospheres not immediately hazardous to life, The reasoning is 49 Fig. 5-34. Typical demand or pressure demand air line respirators. 50 000057267 Headtunds On-Off Cock Fig. 5-35. Continuous flow air line respirator. that the wearer is totally dependent upon the in tegrity of the air supply hose. Therefore, he must be able to escape from the contaminated area without endangering his life. Combination SCBA and Supplied Air Respirators To be usable in an - atmosphere immediately hazardous to life, an mr fae.resniratnE must have an auxiliary air supply-te* protecfr against potential failure of the primary supply. This is provided by adding a self-contained tank of high-pressure com pressed air to a Type "C" or "CE" air line respirator. The auxiliary air supply may be approved for 3-, 5-, or 10-min service time, or for 15 min or longer (see Fig. 5-2). The approval tests for these combination devices are found in 30 CFR Part 11, Subpart H, "Self-Contained Breathing Apparatus." The combination air line and SCBA respirator is essentially the same as the air line respirator itself, with an added small compressed air cylinder that may be carried on one's back or at one's side in a sling. The device shown in Fig. 5-41 is only representative of this general class; designs vary widely. Because of the short service time of the selfcontained breathing air supply, combination units generally are used for emergency entry into and es cape from atmospheres immediately hazardous to life. The self-contained part of the device is used only when the air line part fails and the wearer must escape, or when it may be necessary to disconnect the air line temporarily while changing locations. A combination air line and SCBA may be used for emergency entry into a hazardous atmosphere (to connect the air line), if the SCBA part is classified for 15-min or longer service and not more than 20% of the air supply's rated capacity is used during en try. It is seldom used as a routine means of protec tion, as the open-circuit SCBA might be. 51 Fig. 5-36. Typical air line continuous flow respirators with full facepieces. (Courtesy Mine Safety Ap pliances Co. and Scott Aviation.) Hose masks supply air from an uncontaminated source through a strong, iMFQiMWiflgfi1 Muhuiw to a respiratory-inlet covering. Two types are available. One has a hand- or motor-operated air blower that pushes low-pressure air through the hose to the respiratory-inlet covering. The blower is designed so that air flows freely through it when it is not in operation, Therefore, if the blower fails, the wearer can still inhale respirable ainby normal breathing. The other type of hose mask has no blower and re quires the wearer to inhale through the hose. categorized by 30 CFR Part 11 Subpart J,tfBlBhBMMfsupplied-air respirator and is approved for use in atmospheres immediately dangerous to life or health. The hose mask and is approved for use only in atmospheres not im mediately hazardous to life or health. The hose mask with a blower may have a facepiece, helmet, or hood, but the one without a blower must have a tight-fitting facepiece. Hose masks may have special equipment to protect the wearer's head and neck from rebounding material during abrasive blasting. Such a hose mask with a blower is classified as a Type "AE" supplied-air respirator, and the one without a blower is classified as Type "BE." An approved hose mask with a blower may have up to 300 ft of air supply hose in multiples of 25 ft, but one without a blower may have only up to 75 ft in multiples of 25 ft. The hand- or motor-operated blower must deliver air through the maximum length of hose at not less than 50 1pm. The motoroperated blower of a device with 50 ft of hose must deliver no more than 145 1pm. However, no max imum air flow rate is specified for the hand-operated blower. Figure 5-42 shows a typical hose mask with a hand-operated blower. Notice that* I 52 C; | 0000 Fig. 5-37. Typical abrasive blasting hood. (Courtesy Mine Safety Appliances Co. and Scott Avia tion.) Fig. 5-38. Supplied air hood for lead grinding. (Courtesy Mine Safety Appliances Co. and Scott Avia tion.) Fig. 5-39. Simple flexible plastic full suit. Fig. 5-40. Complex full suit for protection in demanding conditions. 53 ,s,....-r .i / v 0000... The wearer's mobility and area of movement are restricted by the large hose that requires him to I leave a contaminated area by the way he entered. He must be careful not to damage the hose and to prevent it from becoming caught on objects. NOTE: Although the hose mask with blower is approved at present for use in atmospheres im mediately dangerous to life or health, it is not per mitted for such use in the standards that NIOSH is developing for OSHA. A hose mask with blower should not be used in an atmosphere immediately hazardous to life or health because air flow as low as 50 1pm will result in negative air pressure during inhalation, permitting contaminated air to leak into the covering. Also, if the air supply hose is cut or flattened, the wearer will be unprotected. Figure 5-43 shows a typical hose mask with hand operated blower in use in a tank en try operation. Fig. 5-41. Typical combination air line and SCBA respirator. (Courtesy Mine Safety Appliances Co.) C'.O v' 54 Fig. 5-43. Typical hose mask with hand-operated blower being used for tank entry. (Courtesy Mine En forcement Safety Administration.) 0000572 55 r CHAPTER SIX RESPIRATOR SELECTION OSHA STANDARDS OSHA 1910.134 states that respirators shall be selected on the basis of the hazards to which workers are exposed and that ANSI Z88.2-1969 shall be used for guidance in their selection. OSHA also requires that approved or accepted respirators be used when available. For certain respiratory hazards, specific instructions about respirator use are given in other OSHA regulations. The trend seems to be toward regulations that specify the conditions of respirator use for each task. OSHA 1910.134 is then consulted for general instructions. Regardless of the regula tions, respirators must be selected with the environ ment in which they will be used in mind. To do so re quires certain basic information, so one should always ask the following questions before selecting a respirator. L. What is the estimated contaminant concentra tion where the respirator will be used? 2. What is the permissible limit of exposure to the contaminant? 3. Is the contaminant a gas, vapor, mist, dust, or fume? 4. Could the contaminant concentration be termed immediately hazardous to life or health? 5. If the contaminant is flammable, does the es timated concentration approach the lower explosive limit? 6. Does the contaminant have adequate warning properties? 7. Will the contaminant irritate the eyes at the estimated concentration? 8. If the contaminant is a gas or vapor, is there an available sorbent that traps it efficiently? 9. Can the contaminant be absorbed through the skin as a vapor or liquid? If so, will it cause serious injury? The answers to these questions can provide enough information for choosing a respirator for routine use. There is nothing strange or unique about these questions. They represent the factors that a good industrial hygiene program would incor porate for respirator selection or any other type of control and form the basis for the Respirator Deci sion Logic (incorporated verbatim as Appendix F) used in the Joint NIOSH and OSHA Standards Completion Program, You should review the Decision Logic when con sidering respirator selection because it incorporates the above questions in an orderly sequence. By fol lowing this logic, you will be able to choose a respirator that is satisfactory for the situation at hand and be assured that you have not overlooked any important factor. The Decision Logic is being used (in 1975) in development of detailed work practices for the material listed in 29CFR Part 1910.1000. Tables Z-l, 2, and 3. It will be useful to you in developing your own respirator program until standards are listed for the particular materials in which you are interested. Before proceeding to examples of how to use the Decision Logic, we would like to point out four criteria of particular interest. When respirators are used for protection against gases and vapor, it is commonly recommended that cartridges be changed when the wearer smells the vapor. This indicates that there must be some smell or irritation to alert the wearer. Section IV B of the Decision Logic states that a substance should be considered to have warning properties if the odor or irritation threshold is not more than three times the exposure limit, and there is no ceiling limit. Con sideration is given to whether undetected exposure in this concentration range could cause serious or ir reversible health effects. If not, the substance is con sidered to have adequate warning properties. Section IV C states that where there is sup porting evidence of vapor breakthrough in less than three minutes at concentrations immediately dangerous to life or health or below, a cartridge or canister sorbent air-purifying device should not be 56 |q a, () () 0 0 b / <' - allowed for any use. The principal sources of infor mation on sorbent efficiencies are Lawrence Liver more Laboratory and 30 CFR-11 on certain specific materials on which cartridge tests are run. Users should be alert to any future information on sorbent efficiency, as it will definitely affect choice of airpurifying respirators. Section IV D states that for routine operations any perceptible eye irritation is considered unaccep table. No definition of perceptible eye irritation is given. Section IV E concerns atmospheres immediate ly dangerous to life or health, (IDLH). Opinions on the correct definition of IDLH differ, but this section gives several guidelines to assist you in defining it. Although not everyone will agree with all the conser vative guidelines given, this is the best information available for assessing IDLH problems. ANSI Z88.2-1969 STANDARDS Before development of the NIOSH and OSHA Decision Logic, the ANSI 288.2-1969 Standards were the main source of information on respirator selec tion. Section 3.5.2, Requirements for a Minimal Ac ceptable Respirator Program, states that "respirators shall be selected on the basis of the hazards to which workers are exposed." Section 3.8 states that "approved or accepted respirators shall be used when available." Section 6 is devoted ex clusively to respirator selection; however, new technology has made much of that information ob solete. The Standard is being revised, and when it is reissued it should contain useful details on respirator selection. SELECTION s, OSHA 1910.134 requires that approved or ac cepted respirators be used when available. What does "available" mean? If at least one brand of ap proved or accepted respirator suitable for the specific application exists, it is available. Therefore, those who must provide respirators to workers must select and use approved or accepted respirators. An approved respirator is one that has been tested, found to meet established performance criteria, and listed as approved by an authority such as the Mining Enforcement and Safety Administra tion (MESA) of the US Department of the Interior, or the National Institute for Occupational Health, (NIOSH) of the US Department of Health, Educa tion, and Welfare. The Bureau of Mines (BOM) no longer tests and approves respirators; however, BOM-approved respirators now in the possesssion of industrial firms who must provide them to workers will be recognized as approved for various periods depending upon their type. Approval will continue until March 31, 1976, for particulate-filter and chemical cartridge respirators, until March 31,1979, for self-contained breathing apparatus, and until March 31, 1980, for supplied-air respirators. An ex piration date for gas masks had not been established at the time of printing. MESA and NIOSH now test and approve respirators jointly under the provisions of a respirator test and approval document, 30 CFR Part 11. There are some respirators, full suits, for example, for which there are no approval criteria. Such a special-respirator is said to be "accepted" if it has been tested and found satisfactory for its specific ap plication by some recognized organization. SELECTION OF RESPIRATORS FOR ROUTINE USE Routine use of a respirator is daily or frequent use on a regular basis. For such use, a respirator of low initial cost, simple maintenance to keep operating costs down, minimal wearing discomfort, low resistance to breathing, light weight, and compact construction should be considered. Nonpowered airpurifying respirators and air line and hose mask supplied-air respirators are suitable. SELECTION OF RESPIRATORS FOR NONROUTINE AND EMERGENCY USE A respirator used nonroutinely is used for hazar dous situations that occur only occasionally. For such applications, initial costs and maintenance costs are less important than for routine applica tions. The degree of protection and the useful service time provided are important. SAL 000057274 57 Any respirator that protects adequately against a hazardous atmosphere that occurs suddenly may be used for escape purposes. If the hazardous at mosphere causes eye irritation, the respirator should have a full facepiece. Compact air-purifying respirators with mouthpieces and nose clamps have been used successfully for escape from some hazar dous atmospheres. if an area containing an unknown air contaminant concentration must be entered, a pressure demand SCBA or a combination SCBA and air line suppliedair respirator, either of which is specifically designed to maintain positive air pressure inside the facepiece, should be used. A pressure demand SCBA should be used in fire fighting. All the questions that should be answered in selecting respirators for routine use should also be answered in selecting respirators for emergency use. In the NIOSH Decision Logic, emergency use is mentioned under respirator protection factors. RESPIRATOR PROTECTION FACTORS Definition The respirator protection factor indicates how much protection a respirator provides. It is the ratio of the contaminant concentrations outside and in side the respirator. Determination of the protection factor requires quantitative performance tests of the respirator worn in a test atmosphere during exercise simulating motions made by workers, or worn by workers carrying out tasks in contaminated work areas (see Chap. Eight). Assignment Much research has been done recently on assign ing protection factors to various types of respirators. Table 6-1, reproduced verbatim from the LASL protection factor document, lists assigned respirator protection factors resulting from this research. When using Table 6-1, pay strict attention to its footnotes as they are essential in interpreting the table and assist in application of protection factors. The protection factors listed in the Decision Logic are taken from Table 6-1. Application To apply an assigned protection factor for a par ticular type of respirator, one must know both the actual contaminant concentration in the work area and the established time-weighted average con eentration. Multiplying the time-weighted average concentration by the respirator protection factor gives the maximum concentration of the contami nant against which the particular type of respirator may be used. If the actual concentration is less than the calculated maximum use concentration, the respirator may be used. In describing use of protection factors in respirator selection, it is assumed that a complete respirator program is in force. A protection factor is not ap. plicable if the wearer cannot satisfactorily seal the respirator to his face or head. Anything such as facial hair or spectacles that prevents satisfactory sealing of a respirator nullifies application of a respirator protection factor. A protection factor can, be used only if the respirator is in good operating condition, so the respirator must be properly main tained. Other limitations of various types of respirators discussed in Chap. Eight must also be considered in applying protection factors. EXAMPLES OF RESPIRATOR SELECTION The following are hypothetical but typical exam ples of the respirator selection process. They should not be used as cookbook models, but as guides to the rationale for selecting particular respirators, and, equally important, to the industrial hygiene aspects of the hazards. In these examples, we assume that regular use of respirators is permissible. 1. A muller operator in a foundry complame^ef dustdtkie air, and the superintendent supplies him a single-use, disposable respirator. The steward tells the superintendent that this is a violation of the OSHA Regulations as the particular respirator does not have NIOSH and MESA approval. Who is right, and what should be done? Answer: Nothing bans the sale or use of unap proved devices in areas where respirators are not re quired. Before deciding about use of this respirator, we need information about the dust concentration in the air. Samples were taken in the muller'9 58 ohL 00005727^ TABLE 6*1 RESPIRATOR PROTECTION FACTORS' Type Respirator Facepiece2 Pressure Protection Factor I. Air-Purifying A. Particulate3 removing Single-use,4 dusts Quarter-mask, dust6 Half-mask, dust6 Half-or Quarter-mask, fume7 Half- or Quarter-mask, High-Efficiency8 Full Facepiece, High-Efficiencv Powered, High-Efficiency, all enclosures Powered, dust or fume, all enclosures B. Gas and Vapor-Removing10 Half-Mask Full Facepiece -5 -5 -- 10 - 10 - 10 -- 50 + 1000 + X9 -- 10 - 50 II. Atmosphere-Supplying A. Supplied-Air Demand, Half-mask Demand, Full Facepiece Hose Mask Without Blower, Full Facepiece Pressure-Demand, Half-Mask11 Pressure-Demand, Full Facepiece12 Hose Mask With Blower, Full Facepiece Continuous Flow, Half-Mask11 Continuous Flow, Full Facepiece12 Continuous Flow, Hood, Helmet, or Suit13 B. Self-Contained Breathing Apparatus (SCBA) Open-Circuit, Demand, Full Facepiece Open-Circuit, Pressure-demand Full Facepiece Closed-Circuit, Oxygen Tank-type, Full Facepiece + + + + + -- + -- 10 50 50 1000 2000 50 1000 2000 2000 50 10.00014 50 III. Combination Respirator A. Any combination of air-purifying and atmosphere-supplying respirator. ~ B. Any combination of supplied-air respirator and an SCBA Use minimum protection factor listed above for type of mode of operation, Exception: Combination supplied-air respirators, in pressure-demand or other positive pressure mode, with an auxiliary self-contained air supply, and a full facepiece, should use the PF for pressure-demand SCBA. NOTE: Table is not to be reproduced without the accompanying footnotes. Qv:A- 1 The overall protection afforded by a given respirator design {and mode of operation) may be defined in terms of its protection factor (PF). The PF is a measure of the degree of protection afforded by a respirator, defined as the ratio of the concentration of contaminant in the ambient atmosphere to that inside the enclosure (usually inside the facepiece) under condi tions of use. Respirators should be selected so that the concentration inhaled by the wearer will not exceed the appropriate limit. The recommended respirator PF's are selection and use guides, and should only be used when the employer has established a minimal acceptable respirator program as defined in Section 3 of the ANSI Z88.2-1969 Standard. 2 In addition to facepieces, this includes any type of enclosure or covering of the wearer's breathing zone, such as supplied-air hoods helmets, or suits. 3 Includes dusts, mists, and fumes only. Does not apply when gases or vapors are absorbed on particulates and may be volatilized or for particulates volatile at room temperature. Example: Coke oven emissions. *Any single-use dust respirator (with or without valve) not specifically tested against a specified contaminant. 5 Single-use dust respirators have been tested against asbestos and cotton dust and could be assigned a PF of 10 for these particulates. 6 Dust filter refers to a dust respirator approved by the silica dust test, and includes all types of media, that is, both nondegradable mechanical type media and degradable resin-impreg nated wool felt or combination wool-synthetic felt media. 7 Fume filter refers to a fume respirator approved by the lead fume test. All types of media are included. 8High-efficiency filter refers to a high-efficiency particulate respirator. The filter must be at least 99.97% efficient against 0.3 ptm DOP to be approved. 9To be assigned, based on dust or fume filter efficiency for specific contaminant. ,0For gases and vapors, a PF should only be assigned when published test data indicate the cartridge or canister has adequate sorbent efficiency and service life for a specific gas or vapor. In addition, the PF should not be applied in gas or vapor concentrations that arc: 1) immediately dangerous to life, 2) above the lower explosive limit, and 3) cause eye irritation when using a half-mask. nA positive pressure supplied-air respirator equipped with a half-mask facepiece may not be as stable on the.face as a full facepiece. Therefore, the PF recommended is half that for a similar device equipped with a full facepiece. I2A positive pressure supplied-air respirator equipped with a full facepiece provides eye protection but is not approved for use in atmospheres immediately dangerous to life. It is recognized that the facepiece leakage, when a positive pressure is maintained, should be the same as an SCBA operated in the positive pressure mode. However, to CHfpnfeMNlMrtt hinTHTFTRITrrTTHTr^fl lllj III! ilm II ii SAL. 0000 ,3The design of the supplied-air hood, suit, or helmet (with a minimum of 6 cfm of air) may determine its overall efficiency and protection. For example, when working with the arms over the head, some hoods draw the contaminant into the hood breathing zone. This may be overcome by wearing a short hood under a coat or overalls. Other limitations specified by the approval agency must be considered before using in certain types of atmospheres. l4The SCBA operated in the positive pressure mode has been tested on a selected 31-man' panel and the facepiece leakage recorded as less than 0.01% penetration. Therefore, a PF of 10,000+ is recommended. At this time, the lower limit of detection 0.01% does not warrant listing a higher number. A positive pressure SCBA for an unknown concentration is recom mended. This is consistent with the 10*000+ that is listed. It is essential to have an emergency device for use in unknown concentrations. A combination supplied-air respirator in pressuredemand or other positive pressure mode, wirh auxiliary self-contained air supply is also recommended for use in unknown concentrations of contaminants immediately dangerous to life. Other limitations, such as skin absorption of HCN or tritium, must be considered. breathing zone, and the dust concentration was found to be 5 mg/m3. The amount of crystalline silica (quartz) in the dust was 48%. The permissible quartz dust exposure limit in such conditions is 1.5 mg/m3. Now refer to Section II of the Respirator Decision Logic, Appendix F. Because the material is a par ticulate, statements 2, 4, and 6 are not pertinent. As to the other statements: (3) Silica is not known to be an eye irritant, (5) the IDLH concentration is far above the 5-mg/tn3 dust level found in this case, and (7) to date, there is no evidence of injury from silica through skin absorption. As the material is a par ticulate, we can proceed to Section III B, the specific .decision logic chart for respiratory protection against particulates. The restrictions under Routine Use do not apply, so we can proceed to Appendix 1, Section A, "Protection Factors for Particulate Filter Respirators." As the dust concentration is less than five times the permissible limit, we can choose any respirator from this list. A single-use respirator with a protection factor of 5 or a half-mask respirator with a protection factor of "10 probably would be chosen. 2. A womaivdoing^iifU^^enisg without any local exhaust ventilation i<w|riniiu il iiHii iiiliu jji i and nausea from the vapors and fumes. She was given a dust respirator customarily used by a sandblaster's helper, (Obviously a dust respirator for use against an organic vapor is a completely wrong choice.) The woman's continued complaints of headaches and nausea led to an OSHA inspection. Air sampling revealed 40 ppm of isophorone in her breathing zone. It was pointed out that this was above the permissi ble 25-ppm limit for isophorone. A local exhaust system was suggested. Management agreed, and while the local exhaust system was being installed supplied the employee with what type of respirator if any? Answer: The measured 40-ppm concentration is 1.6 times the 25-ppm permissible limit. In the Deci sion Logic, Section II, note that questions 2-6 and 7 are --unanswered. A review of the literature on isophorone will show that it can be detected well below the 25-ppm level and that 40 ppm presents a definite sensation to the eyes. This, using the Deci sion Logic interpretation, would be interpreted as eye irritation. The lower explosive limit and the con centration immediately hazardous to life are well above 40 ppm. Finally, there is no evidence of poor sorbent efficiencies or problems of skin absorption with this material. Proceed to Section III A, the Chart for Respiratory Protection Against Gases or Vapors. Item C, Eye Ir ritation, eliminates use of half-mask respirators. Protection factors for chemical cartridges and gas masks are listed in Appendix I B. Although the protection factor necessary is only 3, chemical cartridge half-mask respirators with protection fac tors of 10 are eliminated because of the eye irritation problem. A minimum of a chemical cartridge respirator with a full facepiece must be provided. 3. A sandblaster and his helper are working out doors on a 50-foot scaffold. Are respirators neces sary? If so, what type of respirators? Answer: To fully answer these questions, we must ask what abrasive is being used and what sur face is being treated. Let's assume that the abrasive is silica sand and the surface is granite. These create a silica dust problem, and the OSHA ventilation standards 1910.94 require that the employer furnish respiratory protection whenever silica sand is used as an abrasive. Furthermore, even if a different abrasive were used, silica dust would be produced from the granite. Therefore the operator must be furnished an approved abrasive blasting respirator, a Type AE, BE, or CE device. Another aspect of this problem which must be considered closely is the workplace geometry. The sandblaster and his helper are working on the scaf fold. We have specified protection for the sandblaster, but how about his helper? He is in the immediate vicinity of the blasting, so he should have the same degree of protection. However, he will probably have to leave the scaffold occasionally to perform some task. Then, having to remove the abrasive blasting hood will be a nuisance, and trying to climb down from the scaffold while wearing it will be dangerous. There are several solutions to this problem. The best would be to arrange that the helper stay on the ground, ascending to the scaffold only when ab solutely necessary. Then, a half-mask dust respirator would be adequate. If the helper must be on the scafffold with the sandblaster most of the time, work practices should specify that he must stay as far away from the sandblaster as the scaf folding allows. If this is done in conjunction with periodic air sampling to ensure that the airborne silica concentrations do not exceed the OSHA limits by more than 10 times, a half-mask dust respirator can be used. If this is impossible, the only recourse is to provide the helper the same protection as the sandblaster. Remember, the air supply system must meet the requirements for Gra.de D or better com pressed air. The point illustrated in this example is that it is not enough to abide only by the requirements of 29 CFR Part 1910.134 which is concerned with general use of respirators. There are other requirements within the OSHA regulations which may also affect respirator selection and use. Use of the Decision Logic was not mentioned in this example. The regulations requiring use of a sup plied air hood were made before assembly 0f the Decision Logic. You will note that the Deciai Logic Protection Factor Table lists a PF of 2000 f the supplied air hood. Considering the unknoj^ concentration of silica dust to which the sandblaster can be exposed, the protection required is consistent with the Decision Logic. 4. A man assigned to clean a large degreaser must occasionally go into the degreaser pit. He complains that the odor of trichloroethylene (trichlor) is so strong that it comes through his respirator cartridges after only a short time. Should he be as signed another type of respirator? Answer: The fact that the worker complains about the short lifetime of the sorbent cartridges warns that the trichlor concentrations may be high This brings up the dual hazards of toxicity and ox ygen deficiency. Degreaser pits are places where vapors may collect and, unless ventilated, actually reduce the oxygen below safe levels. Unless the pit is ventilated to prevent oxygen depletion, a positive pressure SCBA must be used. If the pit is ventilated, it will not be necessary to wear a respirator if tests show that the trichlor concentration is below the ex posure limit and that the oxygen has not been depleted. Again, the Decision Logic Section III A shows that for entry into and escape from unknown concentra tions, the only type of device that can be used is positive pressure self-contained breathing ap paratus. 5. A flagman for an aerial crop duster using Phosdrin dust is supplied a single-use disposable dust respirator. Is this adequate? Answer: Several points listed in the Decision Logic flow chart are pertinent here, Pesticides such as Phosdrin are noted for their ability to kill by absorbtion through the skin. The single-use respirator certainly does not provide complete skin protection. In such cases, protective clothing is as important as a proper respirator. The pesticide is mixed with the dust; however, some of it may vaporize from dust. This is one reason why the only respirators approved for pesticide use have organic charcoal in back of the dust filter. The Phosdrin concentration to which the flagman is exposed is not stated. Before a respirator can be 62 0 >j 'j 'J :./ / / assigned, we must know the approximate concentra tion expected. If the concentration cannot be es timated, the flagman will have to be provided with a self-contained breathing apparatus. 6. Hydrocyanic acid is used in a fumigation chamber. By state regulation, a full-face respirator or gas mask with a hydrocyanic acid canister is re quired. Is such protection satisfactory? Answer: To decide whether the respirator is ade quate, one must have some knowledge of the toxicity and potential concentration of the hydrocyanic acid. The TLV for hydrocyanic acid is listed as 10 ppm, with a warning that skin absorption is a problem. Regardless of the respiratory protection provided, there must be some protection for the skin in such an atmosphere. A review of the toxicity of hydrocyanic acid will show that a concentration of 270 ppm is immediate ly fatal and concentrations of 110 ppm are fatal within half an hour. Concentrations of hydrocyanic acid in fumigation chambers usually exceed 1% (10,000 ppm). The full-face gas mask is accorded a protection factor of only 50 in Table 6-1. Therefore, it would not be useful in concentrations above 500 ppm. Such a mask would not be satisfactory in this case. The Decision Logic offers a quicker solution. Section III A notes that when the contaminant con centration exceeds that immediately dangerous to life or health, only positive pressure self-contained breathing apparatus is acceptable respiratory protection. 7. A salvage company is to demolish a large openframework steel structure built in 1910 in a southern city. The job will require extensive use of cutting torches. Will respirators be required, and if so, of what type? Answer: Respirators definitely must be used. As the structure was built in 1910, it undoubtedly has many coats of lead-base paint, which when heated by the cutting torches will create a severe airborne lead problem. Therefore a respirator approved for protection against metal fumes can be used. Whether this will be a quarter- or half-mask or fullfacepiece respirator can be determined only after air samples are taken in the wearers' breathing zones. Because this is an outdoor operation, the concentra tions will vary widely. However, similar operations have shown that concentrations of 2 mg/m1 are not unusual. Considering the low protection factors for air-purifying respirators, the high temperatures in this climate, and the added heat loss from the cut ting torches, a continuous flow air line respirator should be considered. The trailing air hoses should not present much of a problem, as the workers will already be encumbered with the gas supply lines to the cutting torches. When equipped with a half mask facepiece to allow wearing of the necessary goggles, the air line respirator will provide a more than adequate protection factor of 2000. Providing this protection involves the expense and maintenance of the air supply system, plus the cost of the expensive air line respirator itself. However, in this example, these complications seem more than justified. 8. A large packing firm in Washington state stores apples in warehouses containing a nitrogen at mosphere with less than 3% oxygen. Inspectors must enter the storage areas periodically to examine'the apples. What type of protection do they need? Answer: Obviously with only 3% oxygen, the at mosphere inside the warehouse must be considered immediately hazardous to life. This fact seems to dictate use of a positive pressure supplied air device. This is not entirely true, as we are dealing only with reduced oxygen content of the air, not toxic materials in it. As discussed in Chapters Three and Four, the sea level oxygen content can be reduced, on a physiological basis--not a legal one, to about 14.5% without significant physiological effects. This amounts to reducing the partial pressure of oxygen in the air from a normal 160 mm Hg to about 110 mm. This 50-mm reduction is about 30% of the total normal oxygen (50/160 x 100 = 31%). Translated into respirator leakage, this means that the wearer could tolerate about 30% leakage of air containing no oxygen into the facepiece. On the basis of facepiece leakage alone, a half-mask with a protec tion factor of 10 would allow up to 10% leakage, and a full facepiece would allow up to 2% leakage with a protection factor of 50. Atmosphere-supplying devices with either of these facepieces would provide adequate protection and a reasonable margin of safety. Many choices could be made. If the inspec tors must remain inside for more than 30 minutes, an air line respirator with escape cylinder or a closed circuit SCBA should be used. The choice will de pend on whether the inspector can tolerate the trail ing air line or prefers to carry 35 pounds of breathing apparatus on his back. An oxygen-generating closed circuit SCBA could be used, but its useful lifetime is SPr\A\ ... . ^000'a 63 only one hour and once started it cannot be shut off. For less than a half hour, an open circuit SCBA could be used, as well as the device just mentioned. This example illustrates that a simple oxygendeficiency hazard is relatively easy to deal with. However, it must be classified as being immediately hazardous to life and the OSHA requirements for communications, standby men, lifelines, etc. during respirator use in such atmospheres must be met. Although the rationale for use of demand type atmosphere-supplying units is reviewed, they would not be allowed. Section III A states specifically that in concentrations immediately dangerous to life or health you must eliminate all but the positive pres sure self-contained breathing apparatus. We hope that these examples of respirator selec tion indicate the fundamental thought processes in volved. Without a knowledge of the degree and ex tent of the respiratory hazard and other possible physiological hazards, choosing the proper respirator can deteriorate into a potentially dangerous guessing game. The fact that the person selecting the respirator may not be an industrial hygienist or other knowledgeable individual is no ex cuse. The OSHA requirements state that the respirator "shall be selected on the basis of hazards to which the worker is exposed," which, freely translated, means by hazard evaluation. 64 il... 00005728:1 CHAPTER SEVEN RESPIRATOR USE LEGAL REQUIREMENTS OSHA 1910.134 states that the correct respirator shall be specified for each job and that a qualified individual supervising the respirator program usual ly specifies the respirator. Also, the person who is sues respirators shall be adequately instructed to en sure he issues the correct respirator. PRACTICALITIES OF RESPIRATOR ISSUE Issuance of respirators seems simple, but issue of an incorrect respirator may injure or even kill a worker, so the matter cannot be treated lightly. The person responsible for issuing respirators must be adequately trained to make sure that he issues the correct respirator for each job. Some firms have developed an elaborate system wherein each wearer is issued a card that specifies what type of respirator he can be issued for protection against a particular hazard. He is required to show this card to the is suer, who can issue only the type of respirator listed. Often, such a card lists a particular brand of respirator on the basis of fitting tests. When practical, a respirator should be assigned to each worker for his exclusive use, and should be per manently marked to indicate to whom it is assigned. Care must be taken to ensure that the marking does not hurt the respirator performance. If possible, records should be kept on the issuance and use of each respirator, To do so, each must be permanently identified. Records should include the date of initial issue, the dates of reissue, and a listing of repairs. are being used and that they are in good condition. Respiratory protection is no better than the respirator in use. Periodic monitoring of respirator use should include: Determination that the proper respirators are being used. Determination that respirators are being worn properly. Consultation with wearers about: Discomfort Resistance to breathing Fatigue Interference with vision Interference with communications Restriction of movement Interference with job performance Confidence in the respirator Problems discovered during the random inspec tions must be rectified. Employee Responsibility Proper supervision of respirator use should ensure that each worker understands that he has the follow ing responsibilities. He shall use the respirator as instructed. He shall guard against damaging the respirator. He shall go immediately to an area having respirable air if the respirator fails to provide proper protection. He shall report any respirator malfunction to a person responsible for the respirator program. SUPERVISION OF RESPIRATOR USE Determination of Wearer's Exposure to Hazards Random Inspection Respirators in use shall be randomly inspected frequently to ensure that those selected for the job Appropriate surveillance of work area conditions and of worker exposure to respiratory hazards shall be carried out. This means that the concentration of the respiratory hazard to which workers are exposed 65 shall be determined periodically and records shall be kept. The monitoring must cover conditions throughout a full work shift as activities in the work area vary during the shift and change the hazard concentration. The time-weighted average con centration and ceiling (peak) concentration of the hazard during the work shift must be determined. Preferably, the air in the work area should be sampled in the workers' breathing zones. Fit Testing Before Use atmospheres, so care should be taken in storing Filter elements. Performance also may deteriorate during use because of water vapor in the workplace at mosphere. Airborne liquid particles (aqueous and nonaqueous) and extremely small solid particles may deteriorate the functioning of these materials. Solid particles plug fibrous filter materials (including electrostatic felts), and, although this plugging increases the materials' efficiency in removing particles from air, it also increases resistance to air flow. Respirator facepieces shall be checked for fit each time they are worn. The wearer can make either the positive- or the negative-pressure test, discussed in Chap. Eight, before entering a hazardous at mosphere. but a qualitative check using either isoamyl acetate or irritant smoke is much preferred. FUNCTIONAL AND PHYSICAL CHARACTERISTICS AND USE LIMITA TIONS OF RESPIRATORS The various types of respirators and their func tional and physical characteristics and use limita tions are discussed in Chap. Five. As these factors are most important in respirator use, additional in formation is given here. Limitations of Particulate-Filter Elements As discussed in Chap. Five, the air flow resistance of a particulate-removing respirator filter element increases as the quantity of particles it retains in creases. This resistance increases the breathing resistance offered by a nonpowered respirator and may reduce the rate of air flojv in a powered respirator. Filter element plugging by retained par ticles may also limit the continuous use time of a particulate-filter type respirator. Rapid plugging means that the element must be replaced frequent ly. Elements should be replaced at least daily or more often if necessary. Filter elements designed to be cleaned and reused also should be cleaned at least daily. Performance of some fibrous filter materials (electrostatic felts) is hurt by storage in very humid Limitations of Vapor- and Gas-Removing Cartridges and Canisters It has been stated that if a vapor or gas lacks ade quate warning properties (odor, taste, irritation) in a' concentration above the established breathing timeweighted average concentration, a vapor- and gasremoving air-purifying respirator should not be used. Another limitation is limited capacity of the cartridges and canisters in these respirators to remove vapors and gases from air, or to catalyze a reaction that converts toxic vapors or gases to non toxic products or products that can be removed from air. Theoretically, cartridges and canisters contain ing sorbents are totally efficient against vapors and gases until their, capacity for adsorption or catalysis*, is exhauated.-Then, the vapor or gas passes through the sorbent bed of the cartridge or canister and into the respirator. If the wearer detects an odor or taste of gas in the inspired air, or feels eye or throat irrita tion, he should leave the hazardous area immediate ly and go to a safe area that contains respirable air. Then, he should replace the cartridge or canister. Because of the limited useful service time of canisters and cartridges, they should be replaced daily or after each use, or even more often if the wearer detects odor, taste, or irritation. If a respirator wearer detects an odor, taste, or ir ritation for a very short time and then the sensation disappears, penetration of an air contaminant into the respiratory-inlet covering has not necessarily ceased. The nerve endings that cause a sensation of odor, taste, or irritation often are fatigued or their response is dulled by low concentrations of sub stances. Thus, one may fail to detect low concentra tions of some substances in air. This often happens when the concentration increases very slowly. 66 Some sorbents used in cartridges and canisters are harmed by high humidity, whereas others are harmed by very dry atmospheres. Therefore, when replacing these elements, never use an unsealed one and remember that if the hazardous atmosphere is very moist or dry, the useful service time may be markedly reduced. Advantages and Limitations of Nonpowered AirPurifying Respirators In addition to those limitations imposed by respiratory-inlet coverings (see Chap. Five), particulate-filter elements, and sorbent cartridges and canisters, further limitations of nonpowered airpurifying respirators should be considered. An important disadvantage is the negative air pressure created inside the respiratory-inlet cover ing during inhalation which can cause air contami nants to penetrate the covering if it fits poorly. Care should be taken to provide each wearer with a respirator that fits him. This can best be ac complished by individual fittings. Other disadvantages of nonpowered air-purifying respirators include resistance to breathing, need for frequent replacement of air-purifying elements, and need for continual maintenance (except for single use respirators). Advantages and Limitations of Powered AirPurifying Respirators In addition to those imposed by respiratory inlet coverings, particulate-filter elements, and cartridges containing sorbents, other limitations of powered air-purifying respirators should be con sidered, A powered respirator's battery must be recharged periodically to ensure that the blower will deliver enough respirable air to the respiratory-inlet cover ing. A battery has a limited useful life and cannot be recharged indefinitely. Battery replacement can be expensive. The blower in most powered respirators has a high-speed motor whose parts eventually wear out. Therefore, the blower will have to be replaced periodically. If the blower fails, the wearer of a powered respirator must go to the nearest safe area immediately. Other disadvantages include weight, bulk, com plex design, the need for continual maintenance, high initial cost, cost of at least daily replacement of air-purifying elements, and cost of periodic replace ment of batteries and blowers. The great advantage of the powered air-purifying respirator is that the air inside the respiratory-inlet covering is normally at positive pressure which reduces the possibility of contaminated air entering, and that the wearer is continually being supplied with fresh air with no breathing resistance. Advantages and Limitations of Airline SuppliedAir Respirators Loss of the source of respirable air supplied to the respiratory-inlet covering of the air line supplied-air respirator eliminates any protection to the wearer. Such loss may be caused by cutting, burning, kink ing, or crushing the supply air hose, by air compres sor failure, or by depletion of the respirable air in a storage tank. Possible loss of respirable air prohibits air line respirator use in atmospheres immediately dangerous to life or health. However, an air line res pirator with an auxiliary self-contained air supply can be used in such atmospheres because the aux iliary self-contained air supply always can be used in escape. The trailing air supply hose of the air line respirator severely restricts the wearer's mobility. This may make the air line respirator unsuitable for those who must move frequently between widely separated work stations. A combination air line and self-contained breathing respirator may be suitable if the supply of self-contained breathing air is ade quate for the time required to move from place to place. Airline respirators that operate in the demand mode have negative air pressure inside the respiratory-inlet covering during inhalation which permits the contaminated atmosphere to leak into the respiratory-inlet covering if it Fits poorly. However, air line respirators that operate in the continuous-flow or pressure-demand mode always have positive air pressure inside the respiratoryinlet covering which keeps contaminated air from leaking in. Thus, an air line respirator operating in Al... 0 () ,;) Q . 67 the continuous-flow or pressure-demand mode provides much better protection than one that operates in the demand mode. A great advantage of the air line respirator is that it can be used for long continuous periods. Other ad vantages are minimal breathing resistance and dis comfort, light weight, low bulk, moderate initial cost, and relatively low operating cost. Advantages and Limitations of Hose Mask Type Supplied-Air Respirators Obviously, air pressure inside the respiratoryinlet covering of the hose mask with no blower is negative during inhalation, so contaminated air can leak in if the covering fits poorly. At present, 30 CFR Part 11 allows a hose mask with a blower that sup plies respirable air at a relatively low (50-lpm) flow rate to be approved for atmospheres immediately dangerous to life and health. Hose mask type supplied-air respirators, with and without blower, are not recommended in atmospheres immediately dangerous to life or health. ' The trailing air supply hose of the hose mask also severely limits mobility, so it may be unsuitable for those who must move frequently among widely separated work stations. A severe restriction of the hose mask without blower is that it is limited to a maximum hose length of only 75 ft. Also, it requires the wearer to in hale against the resistance to air flow offered by the air hose which may become significant during heavy work. Inhaling against this resistance strains the wearer and may cause fatigue. Advantages of the hose mask without blower are its theoretically long use periods and its simple con struction, low bulk, easy maintenance, low initial cost, and minimal operating cost. An advantage of the hose mask with blower isHts minimal resistance to breathing. Advantages and Limitations of Self-Contained Breathing Apparatus The bulk and weight of mo9t SCBAs make them unsuitable for strenuous work or use in a very con fined space. The limited service life makes them un suitable for routine use for long continuous periods. The especially short service life of open-circuit type devices may limit them to use where the wearer can go conveniently and quickly from a hazardous at mosphere to a safe atmosphere to change the tank of supply air, The demand type open-circuit SCBA and most closed-circuit SCBAs have negative air pressure in side the respiratory-inlet covering during inhalation, so contaminated air can leak in if they fit poorly. The pressure-demand type open-circuit SCBA and those closed-circuit SCBAs that are positivepressure devices provide very good protection because the air inside the respiratory-inlet covering is always at positive pressure which keeps the con taminated atmosphere from leaking in. Because the SCBA wearer carries his own supply of respirable air, he is independent of the sur rounding atmosphere. A great advantage of such ap paratus is that it allows comparatively free move ment over an unlimited area. RESPIRATOR USE UNDER SPECIAL CONDI TIONS In Dangerous Atmospheres Written procedures shall be prepared for safe respirator use in dangerous atmospheres that may occur in normal operations or emergencies. Person nel shall be familiar with these procedures and respirators. At least one standby man, equipped with proper rescue equipment including a SCBA shall be present in the nearest safe area for emergency rescue of those wearing respirators in a dangerous atmosphere. Communications (visual, voice, signal line, telephone, radio, or other suitable type) shall be maintained among all persons present (those in the dangerous atmosphere and the standby man or men). The respirator wearers shall be equip ped with safety harnesses and safety lines to permit their removal from the dangerous atmosphere if they are overcome. In Confined Spaces Confined spaces are enclosures that are difficult to get out of, such as storage tanks, tank cars, boilers; sewers, tunnels, pipelines, pits, and tubs. 68 The atmosphere in a confined space may be im mediately dangerous to life or health because of tox ic air contaminants or lack of oxygen. Before anyone enters a confined space, tests should be made to determine the presence and concentration of any flammable vapor or gas, or any toxic airborne par ticulate, vapor, or gas, and to determine the oxygen concentration. The confined space must be force-ventilated to keep the concentration of a flammable substance at a safe level. No one shall enter if a flammable sub stance exceeds the lower explosive limit, No one shall enter without wearing the proper type *of respirator if any air contaminant exceeds the es tablished breathing time-weighted average limit or if there is an oxygen deficiency. Even if the contami nant concentration is below the established breathing time-weighted average limit and there is enough oxygen, the safest procedure is to ventilate the entire space continuously and to monitor the contaminant and oxygen concentrations con tinuously if people are to work in the confined space without respirators. Air-purifying respirators and air line and hose mask type supplied-air respirators may be worn in a confined space only if tests show that the at mosphere contains adequate oxygen and that air contaminants are well below levels immediately dangerous to life or health. While people wearing these types of respirators are in a confined space, its atmosphere must be monitored continuously. If the atmosphere in a confined space is im mediately dangerous to life or health owing to a high concentration of air contaminant or oxygen deficiency, those who must enter the space shall wear a SCBA or a combination air line and self- contained breathing respirator that always main tains positive air pressure inside the respiratory- inlet covering. This is the best safety practice for confined spaces. ^ While personnel are in a confined space, at least one standby man with proper rescue equipment, in cluding a SCBA, must be present outside for emergency rescue. He must maintain -communica tions (visual, voice, signal line, telephone, radio, or other suitable type) with those inside. Also, those in side the space must be equipped with safety harnes ses and safety lines to allow their removal in case they are overcome. In Low and High Temperatures Low temperatures will fog respirator lenses. Coating the inner surface of the lens with an anti fogging compound will prevent fogging down to 32F, but severe fogging may occur below 0F. Full facepieces with nose cups that direct the warm, moist exhaled air through the exhalation valve without its touching the lens are available. They should provide satisfactory vision at as low as --30F. At very low termperatures, exhalation valves may freeze owing to moisture. Dry respirable air should be used with air line respirators and with the type of SCBA that has an air tank when they are used in low temperatures. A person working in high-temperature air is under stress. Wearing a respirator causes additional strain which should be minimized by using a light-weight respirator with low breathing resistance. The air line type supplied-air respirator is recommended. Such a respirator used in low- or high-temperature at mospheres may be equipped with a vortex tube to either warm or cool the air supplied. SPECIAL PROBLEMS IN RESPIRATOR USE Facial Hair Facial hair lying between the sealing surface of a respirator facepiece and the wearer's skin will pre vent a good seal. If the respirator permits negative air pressure inside the facepiece during inhalation, there will be excessive penetration by an air con taminant. Even a few days growth of stubble will permit excessive contaminant penetration. Respirators shall not be worn when conditions prevent a good seal of the facepiece to the face. Items such as beards and sideburns prevent satisfac tory sealing. Therefore, anyone who has stubble, a moustache, sideburns, or a beard that passes between his face and the sealing surface shall not wear a respirator that allows negative pressure in side the facepiece during inhalation. 69 Corrective Lenses Those who must wear spectacles present a problem in respiratory protection. Spectacle temple bars or straps that pass between the sealing surface of a full facepiece and the wearer's face prevent a good seal. Therefore, spectacles that have temple bars or straps shall not be used when a full-facepiece respirator must be worn. Spectacles with short tem ple bars that do not protrude between the sealing surface and the wearer's face, or spectacles without temple bars which are taped to the wearer's face may be used temporarily. Special corrective lenses to be mounted inside full facepieces are available and should be used by those who need them. These lenses shall be mounted in the full facepiece only by qualified persons to ensure good vision, comfort, and proper sealing of the facepiece. Spectacles or goggles may also interfere with quarter- or half-masks. They shall be worn so as not to interfere with the seal of the facepiece. If there is interference, a full facepiece respirator should be worn to avoid sealing problems. Contact lenses shall not be worn while weiuiagrespirator in a contaminated atmosphere. Cental that penetrate the respirator may get into the eyes and cause severe discomfort because of the con tact lenses. Miscellaneous Sealing Problems Scars, hollow temples, very prominent cheekbones, deep skin creases, and lack of teeth or dentures may cause respirator facepiece sealing problems. Dentures or missing teeth may cause problems in sealing a mouthpiece in a person's mouth. Full dentures should be retained when wear ing a respirator, but partial dentures may or may not have to be removed, depending upon the pos sibility of swallowing them. With full lower den tures, problems in fitting quarter-masks can be ex pected, as the lower part of the mask tends to unseat the denture. s. 70 >000572B/ CHAPTER EIGHT TRAINING AND FITTING ELEMENTS OF AN ADEQUATE TRAINING PROGRAM Selecting the respirator appropriate to a given hazard is important, but equally important is using the selected device properly. Proper use can be en sured by carefully training both supervisors and workers in selection, use, and maintenance of respirators. This implies that there should be a training program. Like the overall respirator program, the content of the training program can vary widely, depending on circumstances. However, OSHA 1910.134 requires that training of both workers and supervisors in clude the following, no matter what the circum stances: An opportunity to handle the respirator, Proper fitting, Test of facepiece-to-face seal, A long familiarizing period of wear in normal air. Furthermore, OSHA requires that the wearer receive fitting instructions including demonstra tions and practice in wearing, adjusting, and deter mining the Fit of the respirator. These requirements originated in ANSI Standard Z88.2-19G9. Section 7.4 of that Standard gives more details. Training of supervisors and workers also should include: Discussion of the engineering and ad ministrative controls in use and why respirators also are needed, ^ Explanation of the nature of the respiratory hazard and what happens if the respirator is not used properly, Explanation of why a particular type of respirator has been selected, Discussion of how to recognize and handle emergencies. Unfortunately, these training requirements apply to large and small organizations, with no differentia tion to meet individual needs. The training the supervisor needs may differ from that for the in dividual worker, and both may differ markedly from that needed by members of emergency response teams. This chapter summarizes methods for satisfying the OSHA requirements and suggests ways that respiratory protection training may be tailored to individual needs based on job function. The exact format of the training program will vary widely, depending upon the organization. The large user may need a full-time professional instructor. At the other extreme is the very small user who may be forced into a do-it-yourself training program. It^ must be emphasized again, however, that the OSHA requirements apply to large and small users alike. Supervisor Training Supervisors, those who oversee the daily activities of one or more workers who wear respirators frequen tly, should have a reasonably comprehensive knowledge of respirators and respiratory protection practices. Their training should include, but not necessarily be limited to, knowledge of the following. Basic respiratory protection practices, Selection and use of respirators to protect each worker against every respiratory hazard to which he may be exposed, The nature and extent of the respiratory hazards to which the workers may be exposed, The structure and operation of the entire respirator program. The supervisor should under stand his responsibility to facilitate functioning of the program, including maintenance that the worker may be expected to do himself, issuance of respirators, control of their use, and evaluation of the program's effectiveness. The legal requirements pertinent to use of respirators in his situation. These suggestions obviously apply to the large organization. A smaller organization may have to 71 combine the supervisor training with that of the workers. This benefits the workers as they receive more comprehensive training. Worker Instruction and Training The extent and frequency of the workers' training depends primarily on the nature and extent of the hazard. If the hazard is a nuisance particulate, for example, the danger from misuse of the respirator is not likely to be serious. However, against highly tox ic particulates, a single misuse may have serious consequences. The same holds true, of course, for gases and vapors. If the respirator is to be used in an emergency, training in its use should be very thorough and complete. In any case, the worker shall be given some instruction and training in respiratory protection practices. As a bare minimum, both worker and supervisor should be trained in basic respiratory protection practices. Also each should be trained in use of the respirator selected for his particular situation. Because proper respirator use depends especially upon the wearer's motivation, it is important that the need for the respirator be explained fully. ANSI Standard Z88.2, Sec. 7.4 lists the following points to be included in a minimal acceptable respirator program. "(1) Instruction in the nature of the hazard, whether acute, chronic, or both, and an honest appraisal of what may happen if the respirator is not used. (2) Explanation of why more positive control is not immediately feasible. This should include recognition that every reasonable effort is being made to reduce or eliminate the need for respirators. (3) Discussion of why this is the proper type of respirator for thparticular pur pose. (4) Discussion of the respirator's capabilities and limitations. (5) Instruction and training in actual use of the respirator (especially one for emergency use) and close, frequent super vision to ensure that it continues to be used properly. (6) Classroom and field training in recognizing and coping with emergencies. (71 Other special training as needed.* A major thrust is toward explaining && much u possible about the reasons for wearing a respirator. Tfahcist ,'thoaf ct opurrosete, cistioton misontievcaetesstahrey,usaenrdtotoacincesptitllthine him the desire to wear and maintain his respirator properly. Just throwing a respirator at a worker with orders that he wear it because OSHA says so is one of the easiest ways to ensure its misuse. At best, a respirator may cause discomfort and inconvenience, so there is a natural resistance toward wearing it conscientiously. Recent field studies have pointed this out. Much of this natural resistance can be overcome by taking the time and effort to inform the wearer as thoroughly as possible why he needs the respirator. This effort will create easier accep tance of respirators and contribute to subsequent correct use. RESPIRATOR FITTING METHODS / All the care that went into design and manufac ture of a respirator to give maximum efficiency will not protect the wearer if there is an improper match between facepiece and wearer or improper wearing practices. The problem is twofold. Assuming that more than one brand of a particular type of facepiece is available, the first problem is to deter mine which fits best. The second problem is to en sure that the user knows when the respirator fits properly. Both problems can be solved by use of some sort of fitting test, which is one of the OSHA requirements. Respirator Fitting Tests Determination of facepiece fit could involve both qualitative and quantitative tests. A qualitative test relies on the wearer's subjective response. A quan titative test uses some other means of detecting facepiece leakage. The general advantages and dis advantages are as follows. Qualitative Tests Advantages Usually, qualitative tests are fast, require no com plicated, expensive equipment, and are easily per formed in the field. 72 4./\ | () () () Q ."i / V;. o / Disadvantages Qualitative tests rely on the wearer's subjective response, so they are not entirely reliable. Quantitative Tests Advantages The greatest advantage of a quantitative test is that it indicates respirator fit numerically, and does not rely on a subjective response. The quan titative test is highly recommended when facepiece leakage must be minimized for work in highly toxic atmospheres or those immediately dangerous to life or health. Disadvantages Quantitative fitting tests require expensive (up to $10 000) equipment that can be operated only by highly trained personnel and is unsuitable for field use because of its complexity and bulk. Each test respirator must be equipped with a sampling probe to allow removal of a continuous air sample from the facepiece, so the same facepiece cannot be worn in actual service. the chances of properly fitting all workers are in creased. Equally important is the fact that having more than one facepiece to choose from gives the worker a better chance of finding a respirator that is reasonably comfortable while providing good protec tion. It is in this process of matching the respirator to the individual user that the fitting test, par ticularly the qualitative test, has the greatest im pact. Respirator Fitting Procedures One point must be kept in mind throughout the following discussions. The OSHA regulations re quire that workers be allowed to test the facepieceto-face seal of the respirator and to wear it in a test atmosphere. NOTE: During any fitting test, the respirator headstraps must be as comfortable as possible. Tightening the straps will sometimes reduce facepiece leakage, but the wearer may be unable to tolerate the respirator for any length of time. Selection of a qualitative or quantitative fitting test depends upon circumstances such as the severity and extent of the respiratory hazard and the size of the organization. Ideally, both qualitative and quantitative fitting tests should be used. A quantitative test can be used in selecting the best respirator for each worker during training. To sup plement the periodic quantitative fitting, a qualitative test can be used before each entry into a contaminated atmosphere. Again, this is only a sug gested procedure that can be modified on the' basis of an objective professional evaluation of the cir cumstances. As mentioned in Chap. Five, quarter- and half masks, and full facepieces have inherently different fitting characteristics. Moreover, several brands of each are marketed, each brand manufactured in only one size and style and each having slightly dif ferent fitting characteristics. Although every manufacturer designs his facepieces to fit as broad a section of the working population as possible, no respirator marketed will fit everyone. Therefore it is strongly suggested that many brands of a given type of respirator be purchased to take advantage of the different fitting characteristics of each. In this way, Qualitative Fitting Tests Negative Pressure Test. The wearer can per form this test by himself in the field. It consists merely of closing off the inlet of the canister, cartridge(s), or filter(s) by covering with the palm(s) or replacing the seal(s), or of squeezing the breathing tube so that it does not pass air; inhaling gently so that the facepiece collapses slightly; and holding the breath for 10 seconds. If the facepiece re mains slightly collapsed and no inward leakage is detected, the respirator is probably tight enough. This test, of course, can be used only on respirators with tight-fitting facepieces. Although this test is simple, it has severe draw backs, primarily that the wearer must handle the respirator after it has supposedly been positioned on his face. This handling can modify the facepiece seal. It is strongly recommended that this test be used only as a very gross determination of Fit when the respirator is to be used in relatively toxic at mospheres. The wearer should use this test (Fig. 8-1) just before entering any toxic atmosphere. b' AI... 0 0 0 0;-:j 7 9 () 73 Positive Pressure Test. This test is very like the negative pressure test, and it has the same advan tages and limitations. It is conducted by closing off the exhalation valve and exhaling gently into the facepiece. The fit is considered satisfactory if slight positive pressure can be built up inside the facepiece without any evidence of outward leakage. For some respirators, this method requires that the wearer remove the exhalation valve cover and then careful ly replace it after the test, often a most difficult task. Removing and replacing the exhalation valve cover often disturbs the respirator Fit even more than does the negative pressure test. Therefore, this test should be used sparingly if it requires removing and replacing a valve cover. The test is easy for respirators whose valve cover has a single small port that can be closed by the palm or a finger. The wearer should perform this test (Fig. 8-2) just before entering any hazardous atmosphere. .............................. Anyone who has ever built flying model airplanes has smelled banana oil, widely used in the dope for coating their fabric coverings. This chemical, isoamyl acetate, has a pleasant, easily detectable odor, so it also is used widely in qualitatively check ing respirator fit. This is the first test mentioned that gives the user the required opportunity to wear the respirator in a test atmosphere. Generally it consists of creating an atmosphere containing banana oil around the wearer of an atmosphere-supplying or air-purifying respirator with an organic vapor-removing cartridge(s) or canister. If the hazard is particulate matter or a nonorganic vapor or gas, the organic vapor cartridge(s) or canister must be replaced with a particulate filter(s) or proper cartridge(s) or canister after this test. There are several versions of the banana oil test. The simplest is to saturate a piece of cotton or cloth with the liquid and pass it close to the respirator near the sealing surface, taking care to avoid the skin. A second method is to use a stencil brush (Fig. 74 8-3) filled with isoamyl acetate in the same manner If the wearer smells banana oil, he returns to as the cotton or cloth. clean air and readjusts the facepiece and/or adjusts A more complex, and better, version of the test the headstraps without unduly tightening them. uses a room or small booth or a hood that covers the The wearer repeats the second step. If he does respirator wearer's head and shoulders. In this not smell banana oil, he is assumed to have obtained enclosure is generated a known concentration of a satisfactory fit. If he smells the vapor, an attempt vapor, usually 100 ppm, created by vaporizing 17.3 should be made to find the leakage point. If the leak j ml of isoamyl acetate liquid for each 1000 ft* (or cannot be located, another respirator of the same | about 28 m3) of enclosure volume. Use of a fixed type and brand should be tried. If this leaks, another } enclosure decreases the test's flexibility but provides brand of respirator with a facepiece of the same type a known vapor concentration that reduces the should be tried. number of variables involved. Most people can smell After a fit is obtained, if the respirator is an air- 1-10 ppm of isoamyl acetate; the permissible ex purifying device it must be equipped with the cor posure limit is 100 ppm. rect filter(s), cartridge(s), or canister for the an In general, the isoamyl acetate fitting test should ticipated hazard. be performed as follows. During the test, the subject should make move The wearer puts on the respirator in a normal ments that approximate a normal working situation. manner, if it is an air-purifying device, it must be These may include, but not necessarily be limited i equipped with a cartridge(s) or canister specifically to, the following. designed for protection against organic vapors. Normal breathing. The wearer enters the test enclosure, or the Deep breathing, as during heavy exertion. This saturated cloth or stencil brush is passed close to the should not be done long enough to cause hyperven- * i respirator sealing surfaces. tilation. - Side-to-side and up-and-down head move ments. These movements should be exaggerated, but should approximate those that take place on the job. Talking. This is most easily accomplished by reading a prepared text loudly enough to be under stood by someone standing nearby. Other exercises may be added depending upon the situation. For example, if the wearer is going to spend a significant part of his time bent over at some task, it may be desirable to include an exercise approximating this bending. If the test is used in training the worker and selecting the respirator that fits him best, he should perform the complete set of exercises. However, the number of exercises may be reduced when the test is used as a quick field check before routine entry into a contaminated atmosphere. of the isoamyl acetate test is that ^ gmnnfT in dividuals. Furthermore, the sense of smell is easily dulled and may deteriorate during the test so that the wearer can detect only high vapor concentra tions. Another disadvantage is that isoamyl acetate smells pleasant, even in high concentrations. Fig. 8-3. Banana oil test. Therefore, a wearer may say that the respirator fits although it has a large leak. This is usually because 75 S A!... 0 0 O 0 5 7 2,9 2 4 he likes the comfort of the particular respirator or is following the lead of someone else and selecting the same respirator. Conversely, a wearer may claim that a particular respirator leaks if it is uncomfor table, etc. Therefore, unless the worker is highly motivated toward wearing respirators, the results of this test must sometimes be suspect. Irritant Smoke Test. This qualitative test is similar to the isoamyl test in concept. It usually in volves exposing the respirator wearer to an irritating aerosol produced by commercially available smoke tubes normally used to check the quality of ventila tion systems. These are sealed glass tubes, approx imately 12 cm long by 1 cm in diameter (Fig. 8-4), filled with pumice impregnated with stannic chloride or titanium tetrachloride. When the tube ends are broken and air is passed through it, the material inside reacts with the moisture in the air to produce a dense, highly irritating smoke, consisting of hydrochloric acid adsorbed on small solid parti cles. As a qualitative means of determining respirator fit, this test has a distinct advantage in that the wearer usually reacts involuntarily to leakage, by coughing or sneezing. The likelihood of his giving a false indication of proper fit is reduced. On the other Fig. 8-4. Irritant smoke test. hand, the aerosol is very irritating and must be used carefully to avoid injury. Also, it is advisable to have The tester tells the wearer to close his eyes, even exhaust ventilation behind the subject to protect the if he is wearing a full facepiece respirator, and to person doing the testing. keep them closed until told to open them. This test can be used for both air-purifying and The tester lightly puffs smoke over the atmosphere-supplying respirators, but an air- respirator, holding the smoke tube at least 2 ft from purifying respirator must have a high-efficiency it. At this time, he should keep the amount of smoke filter(s). After the test, it may be necessary to minimal and pause between puffs to note the replace the high-efficiency filter(s) on the air- wearer's reaction. purifying respirator with another type of air- If the wearer detects no leakage, the tester may purifying element(s), depending upon the hazard to increase the smoke density and move the smoke which the respirator wearer is to be exposed. This tube progressively closer to the subject, still remain test can be used for worked training or respirator ing alert to his reactions. selection. When the smoke tube has been brought to The irritant smoke test must be performed with within about 6 in. of the respirator with no leakage proper safeguards because the aerosol is highly ir detected, the tester may start to direct smoke ritating. A suggested procedure is as follows. specifically at the potential sources of leakage, The wearer puts on the respirator normally, tak around the sealing surface and exhalation valve, ? ing care not to. tighten the headstraps uncomfor while the subject holds his head still. tably. He stands with his back to a source of exhaust ventilation, such as a chemical fume hood. SAL 000057293 76  At this point, if no leakage has been detected, the wearer may cautiously begin the head move ments mentioned in the isoamyl acetate test. The tester should remain especially alert and be prepared to stop producing smoke immediately. If leakage is detected at any time, the tester should stop the smoke and let the wearer readjust the facepiece or headstrap tension. The tester should then start the test at the second step. In all fairness, this test is not so time-consuming as it sounds. Also, because of its greater sensitivity and lesser reliance on subjective response, it is con sidered more reliable than the isoamyl acetate vapor test. If the wearer keeps his eyes closed and. the smoke is increased gradually, there is little danger or discomfort. Other Qualitative Tests. Other qualitative fit ting tests have been used, although not so extensive ly as those just described. Among these are tests in which a stream of talcum powder or coal dust is directed around the respirator sealing surface. The wearer then removes the respirator and any leakage is revealed by telltale streaks of the powder or dust. These tests have been used almost exclusively for in vestigative purposes rather than routine fitting. Another similar test, used very infrequently, in volves spraying fluorescein dye (uranine) around the sealing surface. The respirator is then removed, and the sources of leakage are detected with ultraviolet light. Obviously, this test is more for research than for routine fitting. In summary, qualitative easilyperfonaedwith, amtmmum^c#^p#ei8lequip-' mant, - and generally adequate for checking respirator fit before entering a contaminated'area. However, they have limitations that make them less useful than quantitative tests for initial selection of a brand of respirator that fits best. For that purpose, the following tests are preferred* . J. All quantitative respirator performance tests in volve placing the wearer in an atmosphere contain ing an easily detectable, relatively nontoxic gas, vapor, or aerosol. The atmosphere inside the respirator is sampled continuously through a probe in the respiratory-inlet covering. The leakage is ex pressed as a percentage of the challenge atmosphere outside the respirator, called "per cent of penetra tion," or simply "penetration." The procedures are relatively independent of the type of aerosol or gas. Appendix D details standar dized test procedures and shows a typical strip-chart recording of a quantitative fitting test and a sug gested format for recording and evaluating the data. Sodium Chloride (NaCl) Test. In the NaCl aerosol quantitative respirator fitting test, a liquid aerosol is generated continuously from an aqueous solution (salt water) by use of a nebulizer, dried to produce discrete submicron salt particles, and dis persed into a test chamber or hood. The resultant NaCl aerosol is called polydisperse because the par ticles vary in size. A means is provided for sampling the atmosphere in the chamber or hood and that in side the respirator. These samples are fed to the analyzing section where the aerosol's penetration in side the respirator is determined. The amount of penetration is displayed on a meter or recorder. Figure 8-5 shows a NaCl quantitative respirator fit ting test system. See Appendix E for details of the test system. Appendix D gives the procedures for conducting the NaCl quantitative test. Dioctyl Phthalate (DOP) Test. The dioctyl phthalate (DOP) quantitative fitting test made us ing an air-generated DOP aerosol differs from the NaCl test only in that the aerosol particle is liquid (see Appendix D). The aerosol is generated using a nozzle-type atomizer, but, being an oil, DOP does not dry into solid particles when injected into a diluting air stream. Figure 8-6 shows a DOP test system, and Appendix D gives a more detailed description. A second type of DOP system uses a thermally generated liquid aerosol. Liquid DOP is heated to boiling, and the vapor is passed to a cooling chamber where it condenses at a very closely controlled temperature, to produce a 0.3-/un ^ii8)l0cbpp^n J$ aerosol. That is, all the particles are 0.3 Mm in diameter. This aerosol has been used widely for quality control of high-efficiency respirator filters and for basic research on aerosol filtration. It was also used for quantitative fitting tests but has fallen into disfavor because the MHppMnannBl iiifintinlnr thint Ilium n iliiiiiiiniinliln irlm mill m fcicity. 77 Fig. 8-5. NaCl quantitative respirator-fitting system. test Fig. 8-6. DOP quantitative respirator-fitting test system. Freon 12 Teat. Freon 12, normally a refrigerant gas, has been used in quantitative respirator fitting tests. It is not so useful as NaCl or DOP because the slow response time of the analyzing instrumentation pre vents following the fluctuations in concentration of the gas that penetrates the respirator. .o 78 CHAPTER NINE RESPIRATOR. INSPECTION, CLEANING, MAINTENANCE, AND STORAGE ELEMENTS OF AN ADEQUATE RESPIRATOR INSPECTION, CLEANING, MAINTENANCE, AND STORAGE PROGRAM Scrupulous respirator maintenance must be made an integral part of the overall respirator program. Wearing poorly maintained or malfunctioning respirators is, in one sense, more dangerous than not wearing a respirator at all. The worker wearing a defective device thinks he is protected when, in reality, he is not. Emergency escape and rescue devices are particularly vulnerable to poor maintenance as they generally are used infrequent ly, and then in the most hazardous and demanding circumstances. The possible consequences of wear ing a defective emergency escape and rescue device are lethal. The OSHA standards strongly emphasize the im portance of an adequate maintenance program, but permit its tailoring to the type of plant, working con ditions, and hazards involved. However, all programs are required to include at least: Inspection for defects (including a leak check), Cleaning and disinfecting, Repair, Storage. A proper maintenance program ensures that the worker's respirator remains as effective as when it was new. % INSPECTION FOR DEFECTS Probably the most important part of a respirator maintenance program is continual inspection of the devices. If conscientiously performed, inspections will identify damaged or malfunctioning respirators before they can be used. The OSHA requirements outline two primary types of inspection, that while the respirator is in use and that while it is being cleaned. In a small operation where the worker probably maintains his own respirator, the two types of inspection become essentially one and the same. In a large organization with a central respirator maintenance facility, the inspections dif fer. Frequency of Inspection OSHA requires that "all respirators be inspected before and after each use," and that those not used routinely, i.e., emergency escape and rescue devices, "shall be inspected after each use and at least monthly..." In one case, the respirator is to be in spected both before and after each use. However, it is highly unlikely that anyone needing a respirator in a hurry, as during an emergency, is going to in spect it. In fact, it could be dangerous to take time to do so. Inspection Procedures Here we will divide inspection procedures into those for "field" inspection and those for use during routine cleaning, as well as into those for airpurifying and atmosphere-supplying devices. The OSHA standards state only that respirator inspection shall include: A check of the tightness of the connections. A check of the facepiece, valves, connecting tube, canisters. The standards also state that the regulator and warning devices on SCBAs shall be checked for proper functioning. 79 FIELD INSPECTION Air-Purifying Respirators Routinely used air-purifying respirators should be checked as follows before and after each use. (a) Examine the facepiece for; Excessive dirt, Cracks, tears, holes, or distortion from improper storage, Inflexibility (stretch and massage to restore flexibility). Cracked or badly scratched lenses in full facepieces, Incorrectly mounted full facepiece lens or broken or missing mounting clips. Cracked or broken air-purifying element holder(s), badly worn threads, or missing gasket(s) (if required). (b) Examine the headstraps of head harness for: Breaks, Loss of elasticity, Broken or malfunctioning buckles and attach ments, (Full facepieces only). Excessively worn serrations on the head harness which might permit slippage. (c) Examine the exhalation valve for the following after removing its cover: Foreign material, such as detergent residue, dust particles, or human hair under the valve seat, Cracks, tears, or distortion in the valve material. Improper insertion of the valve body in the facepiece. Cracks, breaks, or chips in the valve body, par ticularly in the sealing surface, Missing or defective valve cover. Improper installation of the valve in the valve body. (d) Examine the air-purifying elements for: Incorrect cartridge, canister, or filter for the hazard, Incorrect installation, loose connections, missing or worn gaskets, or cross-threading in holder, Expired shelf-life date on cartridge or canister, Cracks or dents in outside case of filter, cartridge, or canister. Evidence of. prior use of sorbent cartridge or canister, indicated by absence of sealing material, tape, foil, etc., over inlet. (e) If the device has a corrugated breathing tube, examine it for: Broken or missing end connectors, Missing or loose hose clamps. Deterioration, determined by stretching the tube and looking for cracks. (0 Examine the harness of a front- or back-mounted gas mask for: Damage or wear to the canister holder which mav prevent its being held securely in place. Broken harness straps or fastenings. Atmosphere-Supplying Respirators For a routinely used atmosphere-supplying device, use the following procedures. (a) If the device has a tight-fitting facepiece, use the procedures outlined above for air-purifying respirators, except those pertaining to the airpurifying elements. (b) If the device is a hood, helmet, blouse, or full suit, use the following procedures, Examine the hood, blouse, or full suit for rips ami tears, seam integrity, etc., Examine the protective headgear, if required, for general condition, with emphasis on the suspen sion inside the headgear, Examine the protective faceshield, if any, for cracks or breaks or impaired vision due to rebounding abrasive particles. Make sure that the protective screen is intact and secured correctly over the faceshield of abrasive blasting hoods and blouses. (c) Examine the air supply system for: Integrity and good condition of air supply lines and hoses, including attachments and end fit tings, Correct operation and condition of all regulators, valves, or other air-flow regulators. On SCBAs, determine that the high-pressure cylinder of compressed air or oxygen is sufficiently charged for the intended use, preferably fully charged (mandatory on an emergency device). On closed-circuit SCBAs, make sure that a fresh canister of CO sorbent is installed before use, or that the total use time on the canister is known. On opencircuit SCBAs, recharge the cylinder if less than 25% of the useful service time remains. All these 80 SAL 0000572.>997 I SCBAs are required to have a warning device that tor like that described in Chap. Eight. An aerosol indicates when this point is reached. However, it is stream is directed through a small-diameter tube much preferred that an open-circuit SCBA be fully around the potential leak points in the facepiece. charged before use. Any leaks are shown by the penetration meter or When an air-purifying or atmosphere-supplying recorder of the aerosol analyzing system, if it is set device is used nonroutinely, all the above procedures on the most sensitive scale. should be followed after each use. OSHA requires This procedure will detect leak sources and in that devices for emergency use be inspected once a dicate the magnitude of the leak. However, it must month and that "a record shall be kept of inspection be considered a qualitative, rather than quan dates and findings for respirators maintained for titative, test. Some installations have built a small emergency use." test chamber around the headform. Instead of the If defects are found during any field inspection, aerosol's being passed around the facepiece, the two remedies are possible. If the defect is minor, chamber contains an aerosol-laden atmosphere that repair and/or adjustment may be made on the spot. permits actual quantitative determination of If it is major, the device should be removed from ser leakage in a manner similar to a quantitative fitting vice until it can be repaired. Under no circum test. stances should a device that is known to be defective This test requires use of the expensive aerosol be used. system which is practical only for large organiza tions. The small respirator user is in a difficult posi tion as he cannot afford this sophisticated equip Inspection During Cleaning ment but is bound by the same requirements as the large user. The best advice for the small user, which Because respirator cleaning usually involves some is of little help, is to use his ingenuity and devise a disassembly, it presents a good opportunity to ex method that will satisfy the basic purpose of the leak amine each respirator thoroughly. The procedures check, assurance that the reassembled respirator is outlined above for a field inspection should be used, leak-free. but a precleaning check would not normally include an operational check, which obviously should be done just before the device is returned to service. CLEANING AND DISINFECTING Therefore, it is suggested that the inspection be made after the respirator is cleaned. The OSHA requirements are not specific about During this inspection, the respirator should be cleaning and disinfecting procedures, stating that leak checked, as OSHA requires. The exact meaning "routinely used respirators shall be collected, of "leak check" has been much discussed, but no un cleaned, and disinfected as frequently as necessary iversal definition has emerged. Generally, a "leak to insure that proper protection is provided..." and check" is an examination of the freshly cleaned and that emergency use respirators "shall be cleaned and reassembled respirator to determine that the com disinfected after each use." plete assembly is gastight. In a large respirator program in which respirators Several methods could be devised for meeting this are used routinely, they should be exchanged daily requirement. One is worthy of mention as it is being for cleaning and inspection. In a small program in used in several extensive respirator programs. It in volving only occasional respirator use, this period volves use of a machined metal head form with an could be weekly or monthly. If each worker is to inflated sealing surface over which a full facepiece maintain his own respirator, he should be may be placed. The respirator facepiece is placed thoroughly briefed on its cleaning and disinfecting. over the headform, the straps are fastened down, Although a worker may not be required to maintain and the inflatable seal built into the headform is his own respirator, briefings on the cleaning pressurized to provide a gastight seal between the procedure will encourage his acceptance of the headform and the facepiece. A continuous air sam respirator by providing assurance that he always ple is withdrawn from inside the facepiece through receives a clean, disinfected, properly maintained the headform and passed through an aerosol detec device. This is particularly important where ."M'-'il- r. -y '"j i. 11.} 'J V *.J / 81 respirators are not individually assigned. Where respirators are individually assigned, a practice to be encouraged, they should be durably identified to ensure that the worker always receives the same device. Identification markers must not penetrate the facepiece or block filter or cartridge ports or ex halation valves. In a small respirator program, or where each worker cleans his own respirator, washing with detergent in warm water using a brush, thorough rinsing in clean water, and air drying in a clean place is generally accepted as sound procedure. Precautions should be taken to prevent damage from rough handling during this procedure. In a large program, there may be a centralized cleaning and maintenance facility with specialized equipment and personnel trained in respirator maintenance. Figure 9-1 shows a typical, hypothetical, large respirator maintenance facility. Good features are the separate areas for disassembly of used respirators and assembly of freshly cleaned and maintained devices which ensure that the clean respirators do not become contaminated. Also, there is ample storage space for the clean respirators, and spare parts (filters, exhalation valves, headbands, etc.) are readily available. There is also a test bench for checking the operation of SCBA regulators, as well as a leak test system. A facility of this type would take up about 500 ft2. In the following discussion of cleaning and maintenance procedures, reference to Fig. 9-1 should help in understanding the overall process. The following procedure may be used: Disassembly The used respirators are collected arid deposited in a central location, (A) of Fig. 9-1. They are taken to an area (C) where the* filters, cartridges, or canisters are removed and discarded. Canisters should be damaged to prevent accidental Teuse. If the facepieces are equipped with reusable dust filters, they may be cleaned with compressed air in a hood (B) that prevents dust from getting into the room and affecting the maintenance personnel. The air tanks from SCBAs are removed and connected to Fig. 9-1. Typical large respirator maintenance facility. the charging station (-J), and the rest of the unit is sent to the SCBA test bench (I) where the regulator is tested. SCBA facepieces are cleaned like airpurifying respirator facepieces. CAUTION: Improper disposal of an oxygen generating canister from a closed-circuit SCBA is dangerous. Mine Safety Appliances Company sug gests the following procedure for disposing of their "Chemox" oxygen-generating canister. "Punch a hole in the front, back, and bottom of the canister, and gently place it in a bucket of clean water deep enough to cover it by at least 3 in. When bubbling stops, any residual oxygen has been dis sipated and the canister is expended. Pour the water, which is caustic, down a drain or dispose of it in any other suitable manner." This procedure is safe. Not following this procedure, particularly neglecting to punch holes in the canister, can cause a violent explosion. ,, ... ,, i;:' --O Q (MA.'U.J - - 82 Cleaning and Sanitizing The actual cleaning may be done in a variety of ways. In Fig. 9-1, it is assumed that a commercial dishwasher (D) is used. Figure 9-2 shows a unit of this type. A standard domestic-type clothes washer also may be used if a rack is installed around the agitator to hold the facepieces in fixed positions, If the facepieces are placed loose in a washer, the agitator may damage them. A standard domestic dishwasher also may be used. Any good detergent may be used, but cleaner and sanitizer solutions that clean effectively and contain a bactericide are available. The bactericide is generally a quaternary ammonium compound, which has some disadvantages, because its con centration must be adjusted to the composition of the local water to provide a constant degree of dis infection. Also, there is a possibility of dermatitis if the quaternary ammonium salts are not completely rinsed from the respirator. An alternative is to wash the respirators in detergent, followed by a disinfecting rinse. Disinfec tion is not absolutely necessary if the respirator is reused by the same worker. However, where in dividual issue is not practiced, disinfection is man datory. Reliable, effective disinfectants may be made from readily available household solutions, in cluding: Hypochlorite solution (50 ppm of chlorine) made by adding approximately 2 ml of Clorox to 1 liter of water or, in kitchen language, 2 tablespoons per gallon, A 2-min immersion disinfects the respirators. Aqueous solution of iodine (50 ppm of iodine) made by adding approximately 0.8 ml tincture of iodine per liter of water. The iodine is approximately 7% ammonium and potassium iodide, 45% alcohol, and 48% water. An equivalent expression is approx imately 1 teaspoon of tincture of iodine per gallon of water. Again, a 2-min immersion is sufficient. If the respirators are washed by hand, a separate disinfecting rinse may be provided. If a washing machine is used, the disinfectant must be added to the rinse cycle, and the amount of water in the machine at that time will have to be measured to determine the correct amount of disinfectant. To avoid damaging the rubber and plastic in the respirator facepieces, the cleaner and disinfectant temperatures should not exceed 140F, but they should not be less than 120QF to ensure adequate cleaning. Rinsing The cleaned and disinfected respirators should be rinsed thoroughly in clean water (140F maximum) to remove all traces of detergent, cleaner and sanitizer, and disinfectant. This is very important to prevent dermatitis. Fig. 9-2. Commercial dishwasher used for respirator cleaning. Drying The respirators may be allowed to dry by themselves on a clean surface. They also may be hung from a horizontal wire, like drying clothes, but 83 care must be taken not to damage the facepieces. A better method is to equip a standard steel storage cabinet. Fig. 9-1 (E), with an electric heater that has a built-in circulating fan, and to replace the solid shelves with steel mesh. Appendix C gives instruc tions for these modifications. Reassembly and Inspection The clean dry respirator facepieces should be reas sembled and inspected in an area, Fig. 9-1 (F), separate from the disassembly area to avoid con tamination. The inspection procedures have been discussed, but there may be more things to look for because of the cleaning. The most common is detergent or soap residue left by inadequate rinsing. This appears most often under the seat of the ex halation valve, and can cause valve leakage or stick ing. At this time, the respirators should be thoroughlyinspected and ail defects corrected. New or retested filters, or new cartridges and canisters should be in stalled, and the completely reassembled respirator should be tested for leaks, Fig. 9-1 (M). The facepiece of a SCBA can now be combined with the tested regulator from (I) and a fully charged cylinder from the storage rack (K), and an operation check can be performed. MAINTENANCE AND REPAIR The OSHA standards state that "replacement or repairs shall be done by experienced persons with parts designed for the respirator." Besides being con trary to OSHA requirements, substitution of parts from a different brand or type of respirator in validates approval of the device. Therefore, the user would be wearing an unapprovedjdevice, in violation of the OSHA requirement. Maintenance personnel must be thoroughly trained. They must be aware of their limitations and never try to replace components or make repairs and adjustments beyond manufacturer's recommenda tions, unless they have been especially trained by the manufacturer. These restrictions apply primarily to maintenance of the more complicated devices, especially closedand open-circuit SCBAs, and even more specifically their reducing or admission valves (reeul which "...shall be returned to the manufacturer^- a trained technician for adjustment or repair*^ words "trained technician" permit on-site ren . the maintenance personnel are trained mv* ** should be no problems in repairing and maintain6"* most other respirators, particularly the most c ^ monly used air-purifying types. COrn` An important aspect of any maintenance progTa is having enough spare parts on hand. Only tinual surveillance of replacement rate will dete ' mine what parts in what quantities must be kept i' stock. It is desirable to have some sort of record keeping system to indicate spare parts usage and the inventory on hand. STORAGE All the care that has gone into cleaning and maintenance of a respirator can be negated by improper storage. OSHA requires that respirators be stored to protect against; Dust, Sunlight, Heat, Extreme cold, Excessive moisture, Damaging chemicals. What is omitted, though implied in a later state ment, is protection against mechanical damage. Leaving a respirator unprotected, as on a workbench, or in a tool cabinet or tool box among heavy wrenches, etc., may damage it. It is strongly recommended that freshly cleaned respirators be placed in heat-sealed or reusable plastic bags until reissue. They should be stored in a clean, dry location away from direct sunlight. They should be stored in a single layer with the facepiece and exhalation valve in a more or less normal posi tion to prevent the rubber or plastic from taking a permanent distorted "set." Air-purifying respirators kept ready for non routine or emergency use should be stored in a cabinet in individual compartments. A steel wallmounted cabinet, with six compartments is shown in Fig. 9-3. Note that each compartment is clearly labeled with the user's name and that the respirators are in plastic bags. Note also that the respirator in the lower right compartment is stored 84 Fig. 9-3. Air-purifying respirator storage. improperly. Another acceptable method of storage in a standard steel storage cabinet is shown in Fig. 94. Note that the respirators are stored in a single layer. The storage cabinet should be readily accessible, and all workers should be made aware of its location, as is done for fire extinguishers. Avoidance of serious injury from inhalation of a toxic substance may de pend entirely on how quickly workers can get to the emergency respirators. This type of storage should be encouraged for routinely used respirators if it does not interfere with the norma} work routine. A little inconvenience here i9 justified to prevent use of a respirator damaged by improper storage. A chest, Fig. 9-5, or wall-mounted case, Fig. 9-6, may be purchased from the respirator manufacturer for storing a SCBA for use in emergencies. Again, the locations of SCBAs should be well known and clearly marked. Unlike fire extinguishers, however, they should be located in an area that will predic tably remain uncontaminated. Even highly trained Fig. 9-4. Standard storage cabinet used for respirator storage. Fig. 9-5. Storage chest for a SCBA. 00O0U/3O2 85 Fig. 9-6. Wall-mounted storage cabinet for a SCBA workers take 30 seconds to 1 min to put on the*''; devices. In a highly contaminated atmosphere such . as might be created by massive release of a toxic material, this may be too long a time to stay safely , the area Therefore, the first reaction should be to escape to an uncontaminated area, then put on the SCBA which should be located there and re-enter the hazardous area for whatever task must be done There are undoubtedly exceptions to this general rule, and only thorough evaluation of the potential hazard, taking into account the physical configuyation of the work area, will permit a final decision about the correct storage location for a SCBA. Routinely used respirators may be stored in a variety of ways if they are protected against the sub stances and conditions listed at the beginning of this section. This means that when a respirator is not in use, it should be stored in a plastic bag inside a rigid container. The OSHA requirements suggest that respirators be stored in the cartons in which they came, but these usually would provide only minimal protection from mechanical damage. If the worker is trained adequately, he should develop a respect for his respirator which will automatically give him incentive to protect it from damage. Besides providing better assurance of ade quate protection, this training will lower maintenance costs because of decreased damage. SAL 0000L7 CHAPTER TEN PHYSIOLOGICAL AND PSYCHOLOGICAL LIMITATIONS ON RESPIRATOR USE PHYSIOLOGICAL LIMITATIONS Wearing any type of respirator imposes some physiological stress on the wearer. Air-purifying respirators resist inhalation because the filter or cartridge restricts free air flow, and also resist ex halation because the expired air must force open a valve. The special exhalation valve on an opencircuit pressure-demand SCBA, designed to ensure that the air pressure inside the facepiece is always positive, requires the wearer to exhale against significant resistance. The bulk and weight (up to 35 lb) of some SCBAs are a significant burden. Wearers of air line respirators and hose masks must drag around up to 300 ft of air supply hose. Any or all of these factors significantly increase the work load. If the worker's cardiovascular or pulmonary function is significantly impaired, wear ing a respirator could constitute an unacceptable risk. The OSHA standards suggest that the local physician determine whether a worker can wear a respirator and perform useful work safely. As there is so little information on the physiological effects, it may be difficult for the local physician to determine whether or not a worker should wear a specific type of respirator. How is the person responsible for overseeing the physical well-being of those who must wear respirators supposed to make decisions? The only practical approach is to treat eafch case individually, using the best medical advice available, and to con sider the physical burdens imposed by the various types of respirators. Pulmonary The individual should be examined for evidence of respiratory impairment such as emphysema, chronic pulmonary obstructive disease, or bronchial asthma. Historical and x-ray evidence of significant pulmonary disease, if substantiated by reduced vital capacity or reduced forced expiratory volume may justify forbidding a person to wear a respirator that restricts inhalation and exhalation, and limiting him to powered air-purifying or continuous flow air line respirators. Breathing difficulties should not necessarily prohibit a worker from wearing airpurifying respirators, if he is reasonably comfor table. because such prohibition might deprive him of his livelihood. Workers in occupations, such as installing asbestos insulation, coal mining, and sand blasting, which cause high incidence of pulmonary diseases, should be given particular attention. In any case, if difficulties are experienced, the local physician shall make the final determination. Cardiovascular Cardiovascular impairment must be treated with much more concern than pulmonary impairment because of its potentially catastrophic conse quences. Workers who have indications of coronary artery disease or angina pectoris, probably should not wear nonpowered air-purifying respirators or the heavy (35-lb) SCBAs. The same restrictions are recommended for those who have myocardial infarc tion or progressive or severe hypertension. Those whose duty is to respond to emergencies should not wear any type of respirator if they have any cardiovascular deficiency. Or, if emergency response duty absolutely requires use of respirators, those wearing them should be completely free of car diovascular impairment. Such people include firemen and mine rescue team members, who might have to rescue an unconscious 200-lb man from an extremely hazardous environment while wearing 35 lb of self-contained breathing apparatus. ''0/ Or-. 8' -*o Other Physiological Considerations Other physical conditions such as diabetes, or grand mal epilepsy may limit wearing of respirators. Skin sensitivity to certain organic compounds may prevent some workers from entering certain environ ments at all, let alone wearing respirators in them. A perforated eardrum, allowing air passage through the eustachian tube into the respiratory tract, may keep a person from working in a toxic environment unless he wears a respirator with a full head enclosure, such as a supplied-air hood, helmet, or suit. Deep facial scars or blemishes, hollow temples, or an abnormally receding chin may spoil the seal of certain types of respirator facepieces. Also, full or partial dentures may prohibit wearing of certain types of facepieces or mouthpieces. In summary, physiological conditions that may determine whether an individual should wear a respirator or not are varied. Pending more research on this problem, specific guidelines cannot be stated, and one must rely on the best judgement of the local physician. PSYCHOLOGICAL LIMITATIONS Psychological conditions that may prevent a worker from wearing a respirator are, if anything, less clearly defined than physical limitations. However, those who experience claustrophobia or anxiety when confined in a small space should not be given jobs that require respirators. In this category are firefighting, which frequently requires entering smoke-filled rooms with poor visibility, and mine rescue, which necessitates crawling through small passages containing highly toxic gases. A more subtle psychological consideration is com fort. Obviously, if a respirator with an ill-fitting or irritating facepiece causes continual discomfort, it is bound to have an adverse psychological effect. .. ->o.O-5 000^'" 88 CHAPTER ELEVEN PROGRAM ADMINISTRATION Unfortunately, respirators generally are misused or taken too much on faith, primarily because of' lack of knowledge. Such misuse can be avoided by establishing written procedures for respirator selec tion and use and through proper supervision of all aspects of the respirator program. This chapter pre sents detailed methods for ensuring that a respirator program remains effective. WRITTEN STANDARD OPERATING PROCEDURES The importance of written standard operating procedures is emphasized in OSHA Part 1910.134 which gives the first requirement for a "minimal ac ceptable (respirator) program" as establishment of "written standard operating procedures governing the selection and use of respirators." Part 1910.134 does not provide any guidance on preparation of these procedures and does not differentiate between large and small users. However the general content of written procedures can be established, and from that information, any user, large or small, can for mulate procedures for his own circumstances. General Content The written standard operating procedures should contain all information.needed to maintain an effective respirator program'lo meet the user's in dividual requirements. They should be written so as to be useful to those directly involved in the respirator program, the program administrator, those fitting the respirators and training the workers, respirator maintenance workers, and the supervisors responsible for overseeing respirator use on the job. It is not necessary that the operating procedures be written for the wearer himself, although in a very small program it may be desirable to direct their corrent to the wearer. Only analysis of the individual program will show to what extent information for the wearer should be in cluded. The procedures should contain all information needed to ensure proper respiratory protection of a specific group of workers against a specific hazard or several particular hazards. The hazard(s) must have been assessed thoroughly; otherwise the written procedures will have only limited validity. Generally, the procedures should contain the follow ing. Guidance for selection of the approved respirator(s) for protection against particular * hazard(s). Detailed instructions for training workers in proper use of the respirator(s), including respirator fitting. Detailed maintenance procedures for: Cleaning and disinfecting, Drying, Inspection, Repair or replacement of worn or defective com ponents, Storage. Administrative procedures for: Purchase of approved or accepted respirator(s), Control of inventory of spare parts, new respirators, and respirators ready for reissue af ter maintenance. Issuance of respirators to ensure use of the proper one for a given hazard, Guidance of supervisory personnel in continued surveillance of respirator use and determina tion of workers' exposure to respiratory hazards. Instructions for respirator use during emergen cies, including fire, which can create an atmosphere immediately hazardous to life and health. Guidelines for medical surveillance of workers, including preemployment physical examinations to eliminate those physically or psychologically unfit to wear respirators, and periodic physical examina tions to review the overall effectiveness of the 89 1 I respirator program on the basis of physiological fac ministrator's technical and profaaim, ,, tors. should enable him or her to niafc ^d *' Procedures for evaluating the respirator based on hazard evaluation input program's effectiveness. workplace. She or he may be a safety Vl Obviously, the above essentially restates the dustrial hygienist, health physicist J^***'i- OSHA requirements for a minimal acceptable or she should have the full support of ^SV"lan' respirator program. The point is that all the infor mation needed to establish and maintain an ade quate respirator program must be written down. The exact format of written standard operating management; without it, an effective level program is difficult to initiate and mm^'**1** It may seem strange that respirator P*L . should be controlled by the program admin- h ,n* procedures may vary widely. The large user who has many workers wearing respirators and, perhaps, several respiratory hazards to consider may for mulated separate procedures for selection and use of There are good reasons related to r' and selection. Several respirator manufact produce a wide variety of devices for proteTTM against specific hazards. Unfortunately'^ respirators for each hazard. For a small user, who has only a few workers to protect from only one or very few hazards, a much simplified document may serve; but it must cover the same subjects. In general, the complexity of the procedures increases facepiece of each device generally is made in | one size that may fit only 50-75% of a ground workers. However, if more than one brandP of respirator is purchased, thus providing a variety of facepiece sizes, it is possible to fit over 95% 0f as respirator use increases. The procedures also become more extensive as the toxicity of the respiratory hazard(s) increases, demanding better and more reliable protection, It is better to be overly detailed in developing written operating procedures than not detailed enough. Particularly important are procedures for respirator use during emergencies such as fire, large spillage of toxic material, accidental release of a potentially lethal substance, or failure of a ventila tion system. All possible emergencies must be con working population. Sometimes more than one type of respirator may be adequate against a particular hazard. The program administrator should select what he considers to be the best types of devices and ensure that they are purchased. As the price spread among the various brands of respirators for a par ticular type of hazard is not great, it is foolish to select a respirator on the basis of price alone. The program administrator, with his comprehensive knowledge, should have a strong influence on, if not absolute control over, respirator purchases. sidered in advance and prepared for in the written procedures because in the stress of an emergency memories may be faulty. Furthermore, these emergency procedures should be used in training emergency response teams. What about the small user who cannot afford (and may not need) to involve several people specifically in a respirator program? Does he not have to meet the same requirements that the program administrator does for the large user? Because the OSHA regulations do not differentiate for Pn res div THE PROGRAM ADMINISTRATOR between large and small users, the answer is yes! In a small firm, where only a few workers must wear respirators for protection against one or very few dif TI AI Without a definite chain of supervision, there is no assurance that written standard operating procedures will be followed. Therefore, respon sibility for the entire respirator program should be assigned to one person. The large user may find it practical and ferent hazards, the program administrator may be a foreman or other supervisor. Where only one or two workers wear respirators, the entire program may be the responsibility of the company owner. In an ex tremely small operation, the entire program may be the responsibility of the worker himself, if he is the vis ev acfoi economical to have a staff of personnel involved in the respirator program, each with his own area of only person who must wear a respirator. In summary, the program administrator can be a pr< responsibility as shown in Fig. 11-1. Each of these highly trained professional who oversees several em people should report to the one administrator who ployees responsible for specific phases of the has overall responsibility for the program. The ad- respirator program, or a single employee responsible I 90 V.573'0" OOOU ftV- i l (t 5 for his own respirator. Like the written operating procedures, the exact administration of the respirator program must be tailored to the in dividual situation. THE DUTIES OF ADMINISTRATOR THE PROGRAM s The program administrator is generally a super visor and coordinator. He receives workplace hazard evaluations, medical information, reports on worker acceptance of particular devices, etc., which he uses for guidance. The administrator should keep the respirator program as flexible as possible. Although the writ ten operating procedures meet today's situation, they may not meet tomorrow's. New hazards are continually being identified, and allowable exposure limits often are revised as more knowledge becomes available. The program administrator must stay abreast of these changes by subscribing to pertinent publications, and must not hesitate to modify his program to meet changing conditions. Thus, the administrator, of a large or small program, must establish a respirator program that meets current needs, ensure that it is carried out satisfactorily, and ensure that it remains effective by continual examination and modification to meet changing conditions. 91 CHAPTER TWELVE SURVEILLANCE AND PROGRAM EVALUATION SURVEILLANCE Surveillance of Work Area Conditions and Worker Exposure OSHA 1910.134 and Sec. 3.5.8 of ANSI Z88.2 state that surveillance of conditions in the work area and of worker exposure to respiratory hazards shall be maintained. This necessitates periodic monitor ing of the air contaminant concentration to which the respirator wearer is exposed. Many things such as changes in the operation or process, air move ment, temperature, or humidity, affect the concen tration of a substance in the work area atmosphere. Therefore, the air contaminant should be sampled. Preferably, sampling should be in the respirator wearer's breathing zone. Both the time-weighted average and peak concentrations of the contaminant should be determined. Comparing the measured time-weighted average concentration with the max imum use concentration determined for the type of respirator being used is a means of checking that the proper respirator has been selected. Medical Surveillance OSHA 1910.134 and Sec. 3.7 of ANSI Z88.2 state that no one should be assigned to tasks requiring use of respirators unless he has been found physically able to do the work while paring the respirator. Both standards declare that a'physician shall deter mine what health and. physical conditions are perti nent, and that respirator wearers' medical status should be reviewed periodically. Pre-employment medical examinations should screen out those who are physically or psy chologically unfit to wear respirators. As another part of this examination, medical tests pertinent to the respiratory hazards that workers may encounter should be made to get baseline data against which to assess physiological changes in respirator wearers. Periodic routine medical examinations shall be made to determine whether respirator wearers have been exposed to harmful levels of respiratory hazards. Examination frequency should be tailored to particular situations. Tests to determine whether harmful amounts of hazardous substances have been taken into the body should be used. The results of the periodic examinations should be compared with those of the pre-employment examinations and previous periodic examinations to determine " whether the respirators used are adequate. If possi ble, periodic biochemical tests of body tissues and wastes should be made to measure respirator wearers' exposures to respiratory hazards. EVALUATION OF RESPIRATOR PROGRAM EFFECTIVENESS OSHA 1910.134 and Sec. 3.5.9 of ANSI Z88.2 state that respirator program effectiveness shall be inspected and evaluated regularly. Periodic monitoring is necessary to ensure that workers are adequately protected. The program should be evaluated at least annually, and the written operating procedures should be modified to reflect the evaluation results if necessary. Frequent inspection of respirator use will deter mine whether the correct respirators are being used and worn properly. Examination of respirators in use and in storage will indicate how well they are maintained. Wearers should be consulted periodically about their acceptance of respirators, including the discomfort, resistance to breathing, fatigue, interference with vision and communica tion, restriction of movement, and interference with -> H L ^000o73()9 92 job performance, and their confidence in the respirator's effectiveness. The results of periodic inspections of respirator use, consultations with wearers, measurements of hazard levels in work areas, and medical sur veillance of wearers should be reviewed, studied, and analyzed to determine the effectiveness of the respirator program. Evidence of excessive exposure to hazards should be followed up to determine why inadequate protection was provided, and action should be taken to remedy the problem. The results of the program evaluation should be presented in a written report that should list plans to correct faults and the target dates for their implementation. ACKNOWLEDGMENTS Alamos Scientific Laboratory, and especially to Kasha Thayer, who edited the many drafts of the Guide. Thanks also must be given to the National Institute for Occupational Safety and Health (NIOSH) whose sponsorship of this project has made this Guide possible, and whose patience has been appreciated. Appreciation is also expressed to Darrel D. Douglas and William H. Revoir who contributed original material for this Guide in areas where they had particular expertise lacked by the author. Special thanks must be given to the Zia Com pany, Los Alamos, New Mexico, for their time and assistance in obtaining photographs of various types of respirators being used in typical work situations. The respirator manufacturers were also of great assistance in providing photographs of respirators. The author wishes to extend particular thanks to the Information Services Department of the Los 3 A0 0 0 0 5 7 310 93 APPENDIX A &CFRPART lftlfeia? ? 1910.134 Respiratory protection. () Permissible practice. (1) In the control of those occupational diseases caused oy breathing air contaminated with harmful dusts, fogs, fumes, mists, gases, smokes, sprays, or vapors, the pri mary obiective shall be to prevent at mospheric contamination. Tills shall be accomplished as far as feasible by ac cepted engineering control measures (for example, enclosure or confinement of the operation, general and local ventilation, and substitution of less toxic materials). When effective engineering controls are not feasible, or while they are being in stituted. appropriate respirators shall be used pursuant to the following require ments. (2) Respirators shall be provided by the employer when such equipment is necessary to protect the health of the emnlovee The emplover shall provide the respirators which are applicable and suitable for the purpose Intended. The employer shall be responsible for the establishment and maintenance of a res piratory protective program which shall include the requirements outlined In paragraph <b> of this section, (3) The employee shall use the pro vided respiratory protection in accord ance with instructions and training received. (Mr. TTjWWln nyil"*1 I'nr ft Tnfttfnrrf ^SiflSM>4>iSMSft<l) Wrltten standard operating procedures governing the se lection and use of respirators shall be established. (2) Respirators shall be selected on the basis of hazards to which the worker is exposed. i3) The user shall be Instructed and trained m the proper use of respirators and their limitations. (4) Where practicable, the respirators should be assigned to individual workers for their exclusive use. (5) Respirators; shall be regularly cleaned and disinfected. Those issued for the exclusive use of one worker should be cleaned after each day's use. or more often if necessary. Those used by more than one worker shall be thoroughly cleaned and disinfected after each use. () Respirators shall be stored In a convenient, clean, and sanitary location. (7) Respirators used routinely shall be inspected during cleaning. Worn or deteriorated parts shall be replaced. Res pirators for emergency use such as selfcontained devices shall bo thoroughly Inspected at least once a month and after each use. (8> Appropriate surveillance of work area conditions and degree of employee exposure or stress shall be maintained. 94 (9) There shall be regular Inspection and evaluation to determine the con tinued effectiveness of the program. (10) Persons should not be assigned to tasks requiring use of respirators un less it has been determined that they are physically able to perform the work and use the equipment. The local physician shall determine what health and physical conditions are pertinent. The respirator user's medical status should be reviewed periodically (for Instance, annually). (11) Approved or accepted respirators shall be used when they are available. The respirator furnished shall provide adequate respiratory protection against the particular hazard for which it is designed In accordance with standards established by competent authorities. The U.S. Department of Interior. Bureau of Mines, and the U,S. Department of Agri culture are recognized as such authori ties. Although respirators listed by the U.S. Department of Agriculture continue to be acceptable for protection against specified pesticides, the U.S. Department of the Interior. Bureau of Mines, is the agency now responsible for testing and approving pesticide respirators. (c> Selection of respirators. Proper selection of respirators shall be made ac cording to the guidance of American National Standard Practices for Respira tory Protection Z88.2-1969. .* <WT^^^.^l> Compressed alrf compressed oxygen, liquid air, and liquid oxygen used for respiration shall be of high purity. Oxygen shall meet the re quirements of the United States Pharma copoeia for medical or breathing oxygen. Breathing air shall meet at least the re quirements of the specification for Grade D breathing air 2s described in Com pressed Gas Association Commodity Specification G-7.1-1966. Compressed oxygen shall not be used in supplied-air respirators or in open circuit selfcontained breathing apparatus that have previously used compressed air. Oxygen must never be used with air line respirators. (2) Breathing air may be supplied to respirators from cylinders or air compressors. (1) Cylinders shall be tested and main tained as prescribed in the Shipping Container Specification Regulations of the Department ox Transportation (49 CFR Part 178). (ii) The compressor for supplying air shall be equipped with necessary safety and standby devices. A breathing air- type compressor shall be used. Compres sors shall be constructed and situated eo as to avoid entry of contaminated air SAL 0000 Into the system and suitable In-line air 01) When cell-contained breathing purifying sorbent beds and filters in apparatus or hose masks with blowers stalled to further assure breathing air are used in atmospheres immediately quality. A receiver of sufficient capacity dangerous to life or health, standby men to enable the respirator wearer to escape must be present with suitable rescue from a contaminated atmosphere In equipment. event of compressor failure, and alarms (iii> Persons using air line respirators to indicate compressor failure and over In atmospheres immediately hazardous heating shall be installed in the system. to life or health shall be equipped with If an oil-lubricated compressor is used, safety harnesses and safety lines for lift it shall have a high-temperature or car ing or removing persons from hazardous bon monoxide alarm, or both. If only a atmospheres or other and equivalent high-temperature alarm Is used, the air provisions for the rescue of persons from from the compressor shall be frequently hazardous atmospheres shall be nsc-ci, A tested for carbon monoxide to insure that It meets the specifications in sub paragraph (1) of this paragraph. standby roan cr men with suitable selfcontained breathing apparatus shall be at the nearest fresh air base for emer (3) Air line couplings shall be incom gency rescue. patible with outlets for other gas sys (4) Respiratory protection is no bet tems to prevent inadvertent servicing of air line respirators with nonresplrable gases or oxygen. ter than the respirator in use, even though it Is worn conscientiously. Fre quent random inspections shall be con (4) Breathing gas containers shall be ducted by a qualified individual to as marked in accordance with American sure that respire tors ere properly se National Standard 'Method of Marking lected. used, cleaned, and maintained. Portable Compressed Gao Containers to (5> For safe use of any respirator, it Identify the Material Contained, 248.1- is essentia! that Ihe user be properly In 1954; Federal Specification BU-A-1034?., structed in its selection, use, and main June 21. 1SS8. Air, Compressed for tenance. Both supervisors and workers Breathing Purposes; or Interim Federal shall be so instructed by competent per Specification GG-B-00675b. April 27. sons. Training shall provide the men an ISGj. Breathing Apparatus, Self-Con opportunity to handle the respirator, tained. have it fitted properly, test its face-piece- m Standard to-face seal, wear it in normal air for procedures shall be developed for respi a long familiarity period, and. finally, rator use. These should include all infor to wear it in a test atmosphere. mation and guidance necessary for their (i) Every respirator wearer shall re proper selection, use, and care. Possible ceive fitting Instructions Including dem emergency and routine uses of respira onstrations and practice in how the res tors should be anticipated and planned pirator should be worn, how to adjust it, for. and how to determine if it fits properly. (2) The correct respirator shall De Respirators shall not be worn when con specified for each Job. The respirator ditions prevent a good, face seal. Such type is usually specified in the work pro conditions may be a growth of beard, cedures by a Qualified individual super sideburns, a skull cap that projects under vising the respiratory protective program. The individual Issuing them shall be the facepiece, or temple pieces on glasses. Also, the absence of one or both dentures adequately Instructed to insure that the can seriously affect the fit of a facepiece. correct respirator Is issued. Each respira The worker's diligence in observing these tor permanently assigned to an. indi vidual should be durably marked to In dicate to whom it was assigned. This factors shall be evaluated by periodic check. To assure proper protection, the facepiece fit shall be checked by the mark shall not affect the respirator per wearer each time he puts on the respira formance In any way. The date of issu tor. This may be done by following the ance should be recorded! manufacturer's facepiece fitting instruc (3) Written procedures shall be pre tions. pared covering safe usfcof respirators In (ii) Providing respiratory protection dangerous atmospheres that might be for individuals wearing corrective glasses encountered in normal operations or in is a serious problem. A proper seal cannot emergencies. Personnel shall be familiar be established if the temple bars of eye with these procedures and the available glasses extend through the sealing edge ( respirators. of the full facepiece. As a temporary (i) In areas where the wearer, with measure, glasses with short temple bars failure of the respirator, could be over or without temple bars may be taped to come by a toxic or oxygen-deficient the wearer's head. Wearing of contact atmosphere, at least one additional man lenses in contaminated atmospheres with shall be present. Communications (visual, 1 a respirator shall not be allowed. Sys voice, or signal line) shall be maintained tems have been developed for mounting between both or all Individuals present. corrective lenses inside full facepieces. Planning shall be such that one individ When a workman must wear corrective ual will be unaffected by any likely inci lenses as part of the facepiece, the face- dent and have the proper rescue equip piece end lenses shall be fitted by quali I ment to be able to assist the other(s) in case of emergency. fied individuals to provide good vision, comfort, and a gas-tightseal. 95 AL 0000577} m (HI 1/ corrective spectacles or goggles light, heat, extreme cold, excessive 4 are required, they shall be worn to as not to affect the fit of the facepiece. moisture, or damaging' chemicals. Res pirators placed at stations and work 3 vl Pn),:--r selection of equipment will mini__ - - or avoid this problem. areas for emergency use should be quickly accessible at - all times and should be stored in compartments built Sof4?Trw^ro5T%-'rn''for maintenance an'd for the purpose. The compartments cam cf respirators shall be adjusted to should be clearly marked. Routinely the type ci plant, working conditions, and hazards Involved, and shall include used respirators, such as dust respira tors, may be placed in plastic bags. Res the following basic services: pirators should not be stored in such (1) Inspection for defects. (Including places as lockers or tool boxes unless aleak check), they are in carrying cases or cartons. (il) Cleaning and disinfecting, <ii) Respirators should be packed or MU) Repair, stored so that-the facepiece and exhala (iv) Storage tion valve will rest in a normal position Equipment shall be properly maintained to retain its original effectiveness. (2) (i) All respirators shall be in spected routinely before and after each use. A respirator that Is not routinely used but is kept ready for emergency use shall be inspected after each use and at least monthly to assure that it la in satisfactory working condition. (il) Self-contained breathing appara tus shall be inspected monthly. Air and oxygen cylinders shall be fully charged according to the manufacturer's instruc tions. It shall be determined that the regulator and warning devices function properly. (ill) Respirator inspection shall In clude a check of the tightness of con nections and the condition of the facepiece, headbands, valves, connecting tube, and canisters. Rubber or elastomer parts shall be inspected for pliability and signs of deterioration. Stretching and manipulating rubber or elastomer parts with a massaging action will keep them pliable and flexible and prevent them from taking a set during storage. (iv) A record shall be kept of inspec tion dates and findings for respirators maintained for emergency use. (3) Routinely used respirators shall be collected, cleaned, and disinfected 3 frequently as necessary to insure that proper protection is provided for the wearer. Each worker should be briefed on the cleaning procedure and be assured that he will always receive a clean and and function will not be impaired by the elastomer setting in an abnormal position. (ill) Instructions for proper storage of emergency respirators, such as gas masks and self-contained breathing apparatus, are found in "use and care" instructions usually mounted inside the carrying case lid. (g) Identification of gas mask canis ters. (I) The primary means of identify ing a gas mask canister shall be by means of properly worded labels. The secondary means of identifying gas mask canister shall be by a color code. (2) All who issue or use gas masks fall ing within the scope of this section shall sec that all gas mask canisters purchased or used by them are properly labeled and colored in accordance with these require ments before they are placed in service and that the labels and colors are prop erly maintained at ail times thereafter until the canisters have completely served their purpose. (3) On each canister shall appear in bold letters the following: (U -- Canister for___________ ____ _ (Name for atmospheric contaminant) or Type N Gas Canister (11) In addition, essentially the fol lowing wording shall appear beneath the appropriate phrase on the canister label: "For respiratory protection in at mospheres containing not more than disinfected respirator. Such assurances percent by volume of are of greatest significance when respira tors are not Individually assigned to workers. Respirators maintained for emergency use shall be cleaned and dis infected after each use. (4) Replacement or repairs shall be done only by experienced persons with parts designed" for the respirator. No attempt shall bo made* to replace com ponents or to make adjustment or re pairs beyond the manufacturer's recom mendations. Reducing or admission valves or regulators shall be returned to the manufacturer or to a trained technician for adjustment or repair. (5) (i) After inspection, cleaning, (Name of atmospheric contaminant) (iii) All of the markings specified above should be placed on the most conspicuous surface or surfaces of the canister. (4) Canisters having a special hlghefficiency filter for protection against radionuclides and other highly toxic par ticulates shall be labeled with a state ment of the type and degree of protec tion afforded by the filter. The label shall be affixed to the neck end of, or to the gray stripe which is around and near the top of, the canister. The degree of protection shall be marked as the per cent of penetration of the canister by a 0.3-micron-diameter dioctyl phthalate and necessary repair, respirators shall (DOP) smoke at a flow rate of 85 liters be stored to protect against dust, sun per minute. 96 > o c: (5) Each canister shall have a label warning that gas masks should be used only In atmospheres containing suffi cient oxygen to support life (KFte&st 1* percent since gas mask canisters are only designed tc neutralize or remove contaminant:, from the air. (S) Each gas mask canister shall be painted a distinctive color or combina tion of colors indicated in Table 1-1. All colors used shall be such that they are clearly identifiable by the user and clearly distinguishable from one another. The color coating used shall offer a high degree of resistance to chipping, scaling, peeling, blistering, fading, and the effects of the ordinary atmospheres to which they may be exposed under normal con ditions of storage and use. Appropri ately colored pressure sensitive tape may be used for the stripes. Tabu 1-1 Atmospheric contaminants to be protected against Acid gases................ ........... Hydrocyanic acid gas Chlorine gas......______________________.... Organic vapors_____________________________ Ammnnlp gas____ Acid gases and ammonia gas___ ............. Carbon monoxide.. Acid gases and organic vapors_____________ Hydrocyanic acid gas and chloroplcrln vapor. Acid gases, organic vapors, and ammonia gases. Radioactive materials, excepting tritium and noble gases. Particulates (dusts, fumes, mists, fogs, or smokes) in combination with any of the above gases or vapors. All of ths above atmospheric contaminants_ Colors assigned* White. White with %-lnch green stripe completely around the canister near the bottom. White with Vj-luch yellow stripe completely around the canister near the bottom. Black. Creen. Green with >/3-lnch white stripe completely around the canister near the bottom. Blue. Yellow. Yellow wtth W -Inch blue stripe completely around the canister near the bottom. Brown. Purple (Magenta). Canister color for contaminant, as designated above, with H-lnch gray stripe completely around the canister near the top. Red with %-lnch gray stripe completely around the canister i-oar the top. 'Gray shall not he assigned as the main color for a canister designed to remove acids or vapors. Nora: Orange shall be used as a complete body, cr stripe color to represent -gases uot included in this table. The user wtU need to refer to the canister label to determine the degree of protection the canister will afford. f i j. SAL. 00005731A APPENDIX B Title 30--MINERAL RESOURCES Chop+er J--Bureau of Min*, SUICHAFTM B--RSSXIRATORY FROTtCTlVl AffARATUS, TESTS FOR NRMlSSIBIUTYi FCCS PART 11--RESPIRATORY PROTEC TIVE DEVICES; TESTS FOR PER MISSIBILITY; f Eil5 PART 12--SUPPUED-AIR RESPIRATORS PART 13--GAS MASKS PART 14--FILTER-TYPE DUST, FUME, AND MIST RESPIRATORS PART 14a--NONEMERGENCY GAS RESPIRATORS (CHEMICAL CAR TRIDGE RESPIRATORS, INCLUDING PAINT SPRAY RESPIRATORS) Pursuant to the authority vested In the Secretary of the Interior under 39 Stat. 399, u amended 37 Stat. 681 (3Q U-S.C. 3, 5, and 7), and the authority vested In the Secretary of the Interior ih-ih the Secretary of Health, Education, and Welfare under sections 202(h). 204, and 508 of the Federal Coal Mine Health and Safety Act of 1999 (30 H.S.C. 842 (h). 844, and 957), there was published In the Pzderal Bxoistzx for March 10, 1971 (36 Pit 4652) a notice- of proposed rule making wherein It was proposed to revoke Farts 11, 12, 13, 14. and 14a of Subehapter B, Chapter I, Title 30, Code of Federal Regulations (Bureau of Mines Schedules 13B, 14F, lfiB. 21B, and 23B), and to sub stitute therefor a new Part 11, prescribing the approval procedures, establishing the lees, and consolidating and extending the requirements for obtaining Joint approval of respirators by the Bureau of Mines, Department of the Interior and the Na tional Institute for Occupational Safety Health, Department of Health, Edu cation, and Welfare. Interested persons were afforded a period of 45 days from the date of pub lication of the notice within which to submit written comments, suggestions, or objections to the proposed amendments. Approximately 15 associations, com panies, labor organizations, individuals, and State and Federal agencies sub mitted comments, suggestions, or objec tions. m addition Interested parties In formally conferred, with officials of the Department of the Interior and the De partment of Health, Education, and Wel fare in March, April, October, and No vember 1971 in order to discuss the pro posed amendment*. Some of the regulations have been revised as suggested; In other instances revisions have been made In view of the comments received. The proposed regulations specified that protection factors for certain types of respirators would be determined by the Bureau during the course of testing. A suggestion was received that protection factors be determined for all types o9 respirators. After thorough considera tion of this issue, the Bureau and the Institute have decided that although the concept of protection factors is valid, present technology in this area Is In sufficient to produce reliable data upon which to base such factors. Therefore, references to protection factors have been deleted from the regulations, with a view toward working to improve relevant technology and data in order to incorpo rate requirement* for protection factors Into Part 11 at a later date. Other significant technical revisions are: (IJ Performance requirements have replaced certain design specifications; and (2) tests have been Included for powered air-purifying respirators. Certain procedural revisions have also been made. The arrangement and num bering system of the proposed amend ments has been totally redesignated so as to place all procedural requirements at the beginning of Part 11 (Subparts A through F), followed by all technical requirements (Subparts O through M3, Expanded and more stringent quality control requirements have been estab lished (Subpart E). Examples of causes which may result in revocation of the certificate of approval have been speci fied. The time limit for phasing out respirators approved under revoked Parts 11. 12, 13, 14. and 14a of this Title 30 has been clarified (see 4 11.2). A suggestion was received that models submitted for testing and approval be made only on regular production tooling with no operations included which would not be incorporated In regular produc tion processing in order to Insure that commercially produced respirators would be Identical In all respects to those tested and approved under these regulations. This suggestion was carefully considered. However, it was determlned.by the Bu reau and the Institute that such a re quirement might well operate to obstruct advances in respirator technology, since substantial investment would be neces sary to build production models with no adequate assurance of ultimate approval. Consequently it was decided to continue the testing of soundly designed and con structed prototype models: however, upon completion of such testing the Bu reau and the Institute may require the applicant to resubmit a production model for additional testing prior to issuance of a certificate of approval (see SS 11.11 (e) and 11.30), Subchapter B of Chapter I. Title 30, Code of Federal Regulations, amended by revoking Parts 11, 12. 13, 14, and 14a, and substituting therefor a new Part 11-- Respiratory Protective Devices; Testa for Permissibility; Pees, as set forth below Is herewith promulgated and'shall become effective 80 days following publication In the Fxnxiuu. Racism. W. T. Pxcoaa, Acting Secretory of the interior. Fxbrtmxt 17, 1972. Elliot L. Richaxdsow, Secretary of Health, Education, and Welfare. Uucb 10, 1972. flee. 112 1U UJ-1 IS I. 4 Sttbport A-- -Oenerol Previtien* Purpose. Approted respirators. Selection, lit. uee, ta4 mainte nance of approved' respirators, Definitions. Incorporation by reference. Subpert Application for Approval II. lb ll.ll 11.13 Application procedures, Contents of application. Delivery of respirators by appli cant; requirements. 11.20 1121 1122 Subpart C--Frit Examination, Inspection, and testing of complete respirator assemblies; fees. Examination, Inspection, and testing ol respirator compo nents or eubaasembUee; feet. Unlisted fees; additional fees; payment by applicant prior to approval. Subporl D--Approval and Disapproval 11.30 1121 1122 1123 1124 1125 11.36 Certificates of approval; scope of approval. Certificates of approval; contents. Notice of disapproval. Approval labelsand markinga^ap proval of contents; use. Revocation of certificates of ap proval. Changes or modifications of ap proved respirators; Issuance of modification of certificate of approval. Delivery of changed or modified approved respirator. 11.40 v 11.41 11.42 11.49 Subpart f--Ouollty Control Quality control plans; filing requirements. Quality control plans; contents. Proposed quality control plana; aproval by the Bureau and the Institute. Quality oontrot records; review by the Bureau and the Institute; revocation of approval. Subperl E ClenlHtotlen of Approved Roiplrolert; Seeps of Approval; Almotpfieric Herordt; Service Time 11.60 Types of respirators to be ap proved; scope of approval. 1121 1123 Sntry and escape, or escape only: classification. Respiratory hazards; classifica 1128 tion. Ssrrtoe time; classification. lubpdrtO Oenerol Csnih-volon end PerformsrKi Requirements 1120 Construction and performance re 1121 quirements; general. Qeneral construction require 1123 ment*. Component parti; minimum re 1121 quirements. Test requirements; general. 1124 Pretesting by applicant; approval of test methods by the Bureau. 1128 Conduct of examinations, Inspec tions, and taste by the Bureau and the Institute; assistance by applicant: observers; raoorded 1128 data; public demonstrations. Withdrawal of applications; re funded fees. c AL 0 0 0 o 15 Iglipwt H Svlf-Cenlolned Srwotfiirvs Apperatet W. 1LT0 11,71 11.73 11.73 11.74 11.78 11.78 11.77 11.78 11.TO 11.79-1 11-80 1141 1143 11-83 1144 1186 1183-1 1148-2 1143-8 11.86-4 11.86-0 1148-9 1146-7 U-sa-a 1148-9 1148-10 1148-11 1148-13 1146-13 1146-14 1148-10 1140-10 1146-17 1148-10 1148-19 Self-contained breathing *pp*r- > tue; deecrtptlon. Self-oontalAed breathing appara tus; required component*. Breathing tube*; minimum re quirements, Harnesses; Installation and con struction; minimum require ment*. Apparatus container*; minimum requirements. Half-meek facepieces, full faoe- pleces, mouthpieces; At; mini mum requirements. Fooepleces; eyepieces; minimum requirements. Inhelation and exhalation valves; minimum requirements. Head, harnesses; minimum re quirements. BreathIns sa*; minimum re quirements. Interchangeability of oxygen and air prohibited. Compressed breathing gas and liquefied breathing gas con tainer*; minimum require ments. Oas pressure gage*; minimum re quirement*. Timers; elapsed time Indicators; remaining service life fndice- tors; minimum requirements. Band-operated valves; minimum requirements. Breathing bags; minimum re quirements. Self-contained breathing appara tus; performance requirements; general. Component parte exposed to oxy gen pressures; minimum re quirements. Compressed gas Utters; minimum requirements. Breathing bag test. Weight requirement. Breathing resistance test; Inhala tion. Breathing resistance teat; exhala tion. Exhalation valve leakage test. Oas flow teat; open-circuit ap paratus. Ga* flow test; closed-circuit ap paratus. Service time test; open-circuit apparatus. Service time test; doaed-dretdt apparatus. Test for carbon dioxide lu In spired gas; open- and closed- circuit apparatus; imviinim allowable limits. Tests during low temperature op eration. Man testa; testing conditions; general requirements. Man tests I, 3. 3, aa4; require? meats, ^ Man test 0; requirements. Man test 6; requirements. Man tests; performance require ments. Gas tightness test; minimum re quirements. 1140 1141 1143 1143 1144 Sebperi 1--Get Medl Gas masks; description. Gas masks; required components. Canister* arid cartridges In paral lel; resistance requirements. Cenlstera and carCrtdges; eolor and marking*; requirements. Filter* used with canister* and cartridges; location; replace ment See. UJS Breathing tubes; re quirements. 11.90 TTemras^r and con struction; minimum require ments. 11.97 Oas ****** containers; minimum requirements. 11J)1 Half-mask facepieces, full face pieces, end mouthpieces; fit; minimum requirements. 11.H Facepieces; eyepieces; minimum requirements. 11.100 Inhalation and exhalation valves; minimum requirements. 11.101 Bead harnesses; minimum re quirements. 11.103 Oas masks; performance require ments; general. 11.103- 1 Breathing resistance test; mini mum requirements. 11.103- 2 Exhalation valve leakage test. 11J 03-3 Facepiece teste; minimum re quirements. 11.103- 4 Dust, fume, mist, and unoke tests; canister* containing fil ters; minimum requirements, 11.103- 3 Canister bench tests; minimum requirements. Sebpart J--Swpplied-AIr Respirator* li.110 11.111 11.113 11.113 11.114 11.118 11.110 11.117 11.118 11.119 11.120 11.121 11.133 11.123 11.134 11.134-1 11.134-3 11.134-3 11.134-4 11.134-8 11.134-0 11434-7 11.134-8 Supplled-alr respirators; descrip tion. aupplled-alr respirators; required components, Breathing tubes; minimum re quirements. Harnesses; installation and con struction; minimum require ments. Respirator containers; minimum requirements. Half-mask facepieces, full face- pieces, hoods, and helmets; fit; minimum requirements. Facepleoes. hoods, and helmets; eyepieces; minimum require ments. Inhalation and exhalation valvcw; check valves; minimum require ments. Bead harnesses; minimum re quirements. Head and neck protection; svipplled-alr respirator*; miniw..M requirements. Air velocity and nolas levels; hoods add helmets; miwi-nwii requirements. Breathing gas; minimum require manta. Air supply source; hand-operated or motor driven air blowers; Type A supplled-elr respirators; mitiimruT) requirements. Terminal fittings or chambers; Type B supplled-alr respirators; minimum requirements. Supplled-alr respirator*; perform ance requirements; general. Hand-operated blower test; mini. mum requirements. Motor-operated blower test; min imum requirements. Method of measuring the power and torque required to operate blowers. Type B supplled-alr respirator; requirements. Type C supplled-alr respirator, continuous flow -'***; mini mum requirements. Type O supplled-alr respirator, demand and pressure class; aaiTiitniim requirements. Air-supply line teste; minimum requirements. Berness test; miaiwnm require ments. lee. 1.134-0 1.134-10 .1.134-11 11.124-13 11.124-14 11.134-13 11.134-13 11.134-17 11.134-18 11.124-19 11.134-30 11.134-21 11.134-33 11.134-33 11.134-34 Bntthinf tub* toft: nifiisiiiB requirements. Airflow resistance test, Type A and Type AS supplled-alr res pirators; minimum require ments. Airflow resistance test: Type B and Type BE supplled-alr res pirators; minimum require ments. Airflow resistance test; Type C supplled-alr respirator, con tinuous flow class and Type CE supplled-alr respirator; minimum requirement*. Airflow resistance test; Type C supplled-alr respirator, demand class; minimum requirements. Airflow resistance test; Type C supplled-alr . respirator, pres- IUT4"d4QlAlKl ml nltmim requirements. Exhalation valve leakage teat. Man tests for gases and vapors supplled-alr respirator*: gen* cral performance requiremeote. Man tests for gases and vapors; Type A and Type AS respira tors; test requirements. Man tests for gaaee and vapors; Type B and Type BE respira tors; test requirements. Man test for gases and vapors; Type C respirator*, eontlnuoue- flow class and Type OS sup- plled-aix respirators; test re quirements. Man test for gases and vapors; Type C supplled-elr respirators, demand and pressure-demand classes; test requirements. Teats for protection during abra sive blasting; Type AS, Type BE. and Type CE supplled-alr respi rators; general performance re quirements. Test for protection during abra sive blasting; Type AS sup plled-alr respirator; test re quirements. Test for'protection during abra sive blasting; Type BE sup- plled-alr respirator; test re quirements. Test for protection during abra sive blasting; Type CE sup plled-alr respirator; test re quirement*. Sebpert K--^v*l, Feme, end Mist Respirators 11.130 11.131 11.133 11483 Dust, fume, and mist respirators: description. Dust, firms and mist respirators; required components. Breathing tubes; minimum re quirements. Harnesses; Installation and con struction; minimum require ments. 11.194 Respirator containers; minimum 11.184 requirements. Half-mask facepiece*, full face pieces. hoods, helmet*, and mouthpieces; fit; minimum 11.130 11.197 requirements. Facepieces, hoods, and helmets: eyepieces; minimum require ments. Inhalation and exhalation valves; minimum requirement*. 11499 Head harnesses, minimum re quirements. 11.199 Air velocity and rules levels; hood* and helmets; mlnlmnm requirement*. 11.140 Dust, fume, and mist respirators; performance general. requirements; 99 kAL, 0000573X6 11.146-1 Xeoamyl cuti tlghtaew test; dun. fume, asd mist neptrator* designed for respiratory protection against Jubm of various metal* having an Air contamination level not lew than o.OO milligram per cubic meter; minimum requirement*. 11.140-9 leoamyl acetate tightness test; respirator* designed for reapIratory protection against dusts, fumes, end mitts baring en elr eontemlnetlon level leu then 0.04 milligram per cubic meter, or against radionuclides; mini mum requirement*. 11.140-3 Alr-puritylng filter tests; per formance requirements; gen eral. 11.140-4 SIUca dust test; tingle-use or re usable filters; minimum re quirement*. 11.140-4 BUlca dust test; single-use dust respirator*; minimum require ments. 11.140-0 Lead fume test, minimum re quirements. 11140-7 Silica mist test; minimum re quirements. 11.140-0 Tests for respirators designed for respiratory protection against mors tbair one type of dlepertotd; minimum requirements. 11.140-9 Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements. 11.140-10 Exhalation valve leakage test; minimum requirements. 11.140-11 DOP filter test; respirators de signed M respiratory protection against dusts, fumes, asd mlsti baring an air contamination level lew than 0.04 milligram per cubic meter and agalnsl radionuclides; minimum re quirements. 11440-12 Silica dust loading test; respira tors designed as proteotloc against dusts, fumes, and mlsti having an air eontamlnatlor level leas than 0.06 mllUgrap per cubic meter and agalnsi radionuclides; minimum re quirement*. fabpert l--Chemkel Cartridge Kstplroler* 11.140 H-iAi 11.181 11,168 11.164 11.164 11.184 11407 11.164 11464-1 11464 Chemical cartridge respirator* description. Chemical cartridge respirator* required components. Cartridges In parallel; reelstano requirements. Cartridges; color and markings requirements. Filter* used with chemical cart ridges; location; replacement. Breathing tubes; minimum re quiremants. Harness**; Installation axfe con struction; minimum require ments. Beeplrator container*; minimum requirements. Half-mask facepieces, full face pieces. moutbpleose, hoods, and helmets; fit; minimum require ments. Facepieces, hoods, and helmets; eyepieces; require ments. Inhalation and exhalation valves; minimum requirements 11440 11441 Heed hem*****; minimum re quirements, Air velocity and note* level*; fcwnS. wyl heUnStS; minimum requirement*. M. and the Matlon&l Institute for Occupa 1.183 Chemical ewtrldg* respirator*: tional Safety and Health of respirators 1.186-1 performance requirements; gen eral, Breathing resistance tmt; mini mum 'requirements. or changes or modifications of approved respirators; (b) to establish a schedule of fees to be charged each applicant for 1.163- 3 Exhalation valve leakage teet; the inspections, examinations, and test minimum requirement*. ing conducted by the Bureau under the 1483-3 Facepiece test; minimum requlre- provisions of this part; (c) to provide for ments, the Issuance of certificates of approval or 1463--4 1.163- 8 Lacquer and enamel mist tests: respirators with filters; mini mum requirements; general. Lacquer mist test; minimum re modifications of certificates of approval for respirators which have met the ap plicable construction, performance, and quirements. respiratory protection requirements set 1.183- 8 Enamel mist teet; minimum re forth in this part; and (d) to specify quirements. minimum requirements and to prescribe 1.183- 7 Dust, fume, and mist t*ete; res methods to be employed by the Bureau pirator* With filters; minimum and by the applicant In conducting in 1.183- 4 Bench tests; gas and vapor tests; minimum requirements; gen eral. 1470 1471 Swbpori M--PeaHdde 8e*p(rater* Pesticide respirator*; description. Pesticide respirators; required spections, examinations, and tests to determine the effectiveness of respirators used during entry into or escape from hazardous atmospheres. 8 11.2 Approved respirator*. (a) Until March 30, .1874, respirators 1473 1473 1.174 components. Canister* and cartridge* In paral lel; resistance requirements. Canisters and cartridge*; color and markings; requirements. Filters used with canisters and cartridges: location; replace ment. or combinations of respirators shall be considered to be approved for use during entry into hazardous mine atmospheres, escape from * hazardous mine atmos pheres, or both, where such respirators or combinations of respirators are; (1) The same In all respects as those respi 1.178 .1.178 .1.177 11.178 Breathing tubes; minimum re quirements. Harnesses; installation and con struction; minimum require ment*. Respirator oontalners; minimum requirement*. Half-m**k facepieces, full face pieces. hoods and helmets, and rators which have been approved after meeting the minimum requirements for * performance and respiratory protection set forth in this Part 11; or (2) fabri cated, assembled, or built under any approval, or any modification thereof, issued by the U.S. Bureau of Mines, De partment of the Interior, in accordance 11.179 11.1B0 11.101 mouthpieces; fit; minimum re quirements. Pacepleoes, hoods and helmets; eyepieces; minimum require ment*. Inhalation and exhalation valves; minimum requirements. Head harnesses; minimum re with the schedules set forth below; and (3) maintained in an approved condi tion: U) Self-contained Breathing Appa ratus, Bureau of Mines Schedules 13, March 5, 1919; 13A, January 21, 1930; 13B, August 12, 1935; 13C. July 9. 1946; 11483 11488 11.183-1, 11483-3 quirements. Air velocity and noise levels; hood* fTM1 helmet*; minimum requirement*. Pesticide reeplratonrpwrformanoe requirements; general. Breathing resistance test; mini mum requirements. Exhalation valve leakage test; 11.183-8 11483-4 11.183-6 11483-4 11433-7 Facepiece test; minimum require ments. Silica dust test; minimum re quirements. Lead fume test; minimum re quirements. Dtoctyl-phthalat* test; minimum requirements. Beneh tests; minimum require ments. Aomoairr; The provision* of this Part 11 Issued under sections 303(h), 304, and 604 of the Federal Coal Min* Health and Safety Act erf 1049 (30 U.S.O. 343(h), 344. And 987) and 34 Stat. 348, as *m*nd*rt 37 Stat. 481 (30 13D, September 22, 19S6; and 13E, July 29, 1948. (11) Oas Masks, Bureau of Mines Schedule 14P, April 23. 1955. (ill) SuppUed-air Respirators, Bureav of Mines Schedule 19B, April 19, 1965. (lv) Filter-type Dust, Fume, and Mist Respirators, Bureau of Mines Schedule 21B, January 19. 1945. () Nonemergency Gas Respirators, Bureau of Mines Schedule 23B, August 4, 1959. (b)After March 30, 1974, respirators or combinations of respirators shall be considered to be approved for use during entry Into hazardous mine atmospheres, escape from hazardous mine atmos pheres, or both, only where such respi rators or combinations of such respira tors are: (l)The same in all respects as those respirators which have been ap proved after meeting the minimum re quirements for performance and respira HB^.8,3, and 7). tory protection prescribed In this Part Subpart A--Gonerat Provisions 911.1 Purpose The purpose of the regulations con tained in this Part 11 Is: (*> To establish procedures and prescribe requirements 11; and (2) maintained in an approved condition. 9 11.2--1 Selection, fit, use, and mainieauee of approved respirator*. In order to Insure the maximum -which must be met in flung applications amount of respiratory protection, ap for Joint approval by the Bureau of Minos proved respirators shall be selected, 100 SAL. 0000573:17 fitted, used, and maintained In accord (n) A `facepiece" or "mouthpiece" Is Insect, rodent, nematode, fungus, weed, ance with the provisions of the American a respirator component designed to pro or other form of plant or ftn<rr>i uf9 w National Standard Practices for Respir vide a gas-tight or dust-tight fit with the virus, and (2) any substance or mixture atory Protection, Z88.2, obtainable from face and may include headbands, valves, of substances (including solvents nd American National Standards Institute, and connections for canisters, cartridges, impurities) intended for use as a plant Inc., 1430 Broadway, New York. NY filters, or respirable gas source!' regulator, defoliant, or desiccant, as de 10018. | ILferDeferitfam*- (o) "Final Inspection" means that ac fined in the-Federal Insecticide, Fungi tivity carried out on a product after all cide, and Rodentldde Act of 1947, as manufacturing and assembly operations amended (7 U.S.C. 135-13Sk), excluding 7^ V As v-(a) used "Air In this part-- Contamination Level* means are completed to Insure completeness and `adherence to performance or other speci fumigants which are applied as gases or vapors or in a solid or liquid form as the standards of contaminant levels pre fications, including satisfactory appear pellets or poured liquids for subsequent scribed by the Secretary of Labor in ac ance. release as gases or vapors. cordance with the provisions of the Occu (p) "Fume" means a solid condensa <cc> "Powered alr-purifytng respira pational Safety and Health Act of 1970 tion particle, generally less than 1 mi tor" means a device equipped with a lace- (Public Law 91-590; 84 Stat. 1590). crometer In diameter. piece, hood, or helmet, breathing tube, >LL'; fb) "Applicant" means an individual, (q) "Gas" means an aeriform fluid canister, cartridge, filter, canister with partnership, company, corporation, asso which Is in a gaseous state at ordinary filter, or cartridge with filter, and_a ciation, or other organization that de temperature and pressure. blower. signs, manufactures, assembles, or con (r) "Hazardous atmosphere" means: (dd) "Radionuclide" meani an atom trols the assembly of a respirator and <1) Any atmosphere containing a toxic Identified by the constitution' of its nu who seeks to obtain a certificate of ap or disease producing gas, vapor, dust, cleus. (specified by the number of pro proval for such respirator. fume, mist, or pesticide, either immedi tons Z, number of neutrons N, and en (c) "Approval" means a certificate or ately or not Immediately dangerous to ergy. or, alternatively, by the atomic formal document Issued by the Bureau life or health; or (2) any oxygen-defi number Z, mass number A= (N-fZ), and and the Institute stating that an individ cient atmosphere. atomic mass) which exists for a measur ual respirator or combination of respi <s> A "hood" or "helmet" is a respira able time; decays or disintegrates spon rators has met the minimum require tor component which covers the wearer's taneously, emits radiation, and results In ments of this Part 11, and that the appli head and neck, or head, neck, and the formation of new nuclides. cant Is authorized to use and attach an shoulders, and is supplied with Incoming (ee) "Respirable dust" means a dust approval label to any respirator, respira respirable air. for the wearer to breathe. particle aerodynamically capable of tor container, or instruction card for any It may Include a headhamess and con reaching the terminal airways of the respirator manufactured or assembled nection for a breathing tube. lung. In conformance with the plans and spec (t) "Immediately dangerous to life or (ff) "Respirator" means any device ifications upon which the approval was health" means conditions that pose an designed to provide the wearer with based, as evidence of such approval. immediate threat to life or health or con respiratory protection against Inhala (d) "Approved" means conforming to ditions that pose an Immediate threat of tion .of a hazardous atmosphere. the minimum reouirements of this severe exposure to contaminants, such (gg) "Smoke" means the products of Part ll. as radioactive materials, which are likely Incomplete combustion of organic sub (e) "Auxiliary equipment" means a to have adverse cumulative or delayed stances In the form of solid and liquid self-contained breathing apparatus, the effects on health. particles and gaseous products In air, use of which Is limited In underground (u> "Incoming inspection" means the usually of sufficient concentration to per mine rescue and recovery operations to activity of receiving, examining, and ac ceptibility obscure vision. situations-where the wearer has ready cepting only those materials and parte (hh) "Vapor" means the gaseous state access to fresh air and at least one crew whose quality conforms to specification of a .substance that is solid or liquid at equipped with approved self-contained requirements. ordinary temperature and pressure. breathing apparatus of 2 hours or longer rating, is In reserve at a fresh-alr base. (v) "In-process inspection" means the control of products at the source of pro 11.4 Incorporation bj; reference. (f) "Bureau" means the U.S. Bureau duction and at each step of the manu In accordance with 5 UB.C. 552(a)(1), of Mines, Department of the Interior. facturing process, so that departures the technical publications to whleh (g) "Compressed breathing gas" from specifications can be corrected be reference Is made In this Part 11, and means oxygen or air stored In a com fore defective components or materials which have been prepared by organiza pressed state and supplied to the wearer are assembled into the finished product. tions other than the Bureau of Mines, are In gaseous form. (w> "Institute" means the National hereby incorporated by reference' and (h) "Concentration limits for radio Institute for Occupational Safety and made a part hereof. The Incorporated nuclides" means the concentration limits Health. Department of Health, Educa technical publications are available fot set forth In Appendix B. Table 1, Column tion, and Welfare. examination at Approval and Testing, I of Title 10 CFR Part 20. by the Atomic (x) "Liquefied breathing gas" means Health and Safety Technical Support Energy Commission. oxygen or air stored In liquid form and Center, Bureau of Mines, 4800 Forbes (1) "dJBA" means sound pressure levels supplied to the wearer in a gaseous form. Avenue, Pittsburgh. Pa. In sedition, In decibels, as measured with the A- (y) "Mist" means a liquid condensa copies of the American National Stand weighted network of a standard sound tion particle with a size ranging from ard Practices for Respiratory Protection, level meter using slow response. ** submlcroscoplc to macroscopic. Z88.2, are available for examination In (j) "DOP" means a homogenous liquid (z) "Not immediately dangerous to life every Coal Mine Health and Safety Dis aerosol, having a particle diameter of or health" means any hazardous atmos trict and Subdistrict Office. 0.3 micrometer, which Is generated by phere which may produce physical dis vaporization and condensation of dloctyi comfort Immediately, chronic poisoning "aShtilj___ ...__ phthalate. after repeated exposure, or acute adverse 11.10 Application procedures. (k) "Dust" means a solid mechanically produced particle with a' size ranging from submlcroecopic to macroscopic. (l) Respirators "for entry Into and escape from" means respiratory devices providing protection during entry into and escape from hazardous atmospheres. Cm) Respirators "for escape only" means respiratory devices providing pro tection only during escape from hazard ous atmospheres. physiological symptoms after prolonged exposure. w atmosphere which contains an oxygen partial pressure of less than 148 millimeters of mercury (194 percent by volume at sea level). <bb> "Pesticide" means (1) any sub stance or mixture of substances (Includ ing solvents and Impurities) intended to prevent, destroy, repel, or mitigate any (a) Inspection, examination, and test ing leading to the approval of the types of respirators classified in Subpart 7 of this part shall be undertaken by the Bu reau only pursuant to written applica tions which meet the minimum require ments set forth in this Subpart B. (b) Applications shall be submitted to Approval and Testing, Bureau of Mines, 4800 Forbes Avenue, Pittsburgh, FA A L 0 o" oXJ> >'S')-/ >slj (V 0 18313. and shall ba accompanied by a bank draft, or money order la the amount specified Is Subpart C of thl* part payable to- tbs order of the UA Bureau of Mines, (e) Except as provided is i 11.64, the ten request within 30 days after notice respirator assemblies which are not listed of approval. If no such request Is made, in | 11.20, or for the examination. In the respirators will be disposed oC by spection, and testing of respirator com the Bureau In such manner as it deems ponents or subassemblies which are not appropriate. listed in 111.31, shall be accompanied (e) Where a respirator falls to meet' by the following deposits: examination. Inspection, and testing of the requirements for approval set forth (1) Complete respirator assem all respirators shall be conducted by Ap in this part, all respirator* and compo bly ................................................. *1,600 proval and Testing, Bureau of Mines, nents delivered In accordance with this (2) Each individual component or Pittsburgh, Pa. 19213. section may. be returned to the appli subassembly ________________ 900 (d) Applicants, manufacturers, or thetr representatives may visit or com municate with Approval and Testing In order to rfisctws the requirements for ap proval of any respirator or the proposed designs thereof. No charge shall be made for such consultation and no written re port shall be Issued to applicants, manu facturers, or their representatives by the Bureau as a result of such consultation. 911.11 Contents of application. cant at his own expense, upon written request within 30 days after notice of disapproval. If no such request is made, the respirator* will be disposed of by the Bureau in such manner as it deem* appropriate. Subpart C--Fee*. 11.20 Examination, Inspection and testing of complete respirator assem blies; fees. <b) The Bureau reserves the right to conduct any examination, inspection, or test it deems necessary to determine the quality and .effectiveness of any listed or unlisted respirator assembly or respirator component or subassembly, and to assess the1 cost of such examinations, Inspec tions, or tests against the applicant prior to the issuance of any approval for the respiratory equipment examined, in spected, or tested. (a) Each application for approval shall contain a complete written description of the respirator for which approval is re quested together with drawings and spec ifications (and lists thereof) showing full details of construction of the respi rator and Of the materials used. Draw ings and specifications (and lists thereof) shall be submitted >n triplicate. 4b) Drawings shall be titled, num bered, and dated; any revision dates shall be shown on the drawings, and the pur pose of each revision being sought shall be shown on the drawing or described on an attachment to the drawing to which it applies. <c) Each application for approval shall contain a proposed plan for quality con trol which meets the minimum require ments set forth In Subpart E of this part. (d) Each application shall contain a statemaxt that the respirator has been pretested by the applicant as prescribed In 111.64, and shall include the results of such tests. (e) Each application for approval shall contain a statement that the respirator and component parts submitted for ap proval are either (1) prototypes, or (2) made on regular production tooling, with Except as provided in i 11-22, the fol lowing fees "halt be charged by the Bureau for the examination. Inspection and testing of complete respirator assemblies: (a) Bstf-coDUlned breathing ap paratus-- (1) Entry and escape, 1 hour or more............................... 63,900 (3) Entry and escape, less than 1 hour _________............ (3) Escape only...........----.- (b) Oas masks. Including pssd- dde gas masks-- (X) Single hseard....... (2) Type N..................................-........... (e) Supplied-air respirator*...-- (d) Dust, !ums and mdst rsspt- i*tor*-- (1) Single particulate hazard hav ing an Air Contamination Devei more than 0.06 mg./ m.a oc 3 million particles per cuble toot...------------------------- (2) Combination particulate haa- ards having an Air Contami nation Level more than 0.09 mg/m.1 or 3 par. tdcles per cubic foot__________ (9) Particulate hasards having an Air Contamination Live! lesa than 0.09 ng/n.* or t million particles per cubic 3.750 3,000 1,100 4,100 790 900 790 (c) The fees charged for the exami nation, inspection, and testing of un listed respirator assemblies, unlisted In dividual respirator components or subassemblies, and for the additional exam ination, inspection, and testing of listed respirator assemblies and components or subassemblies shall be at the rate of 6100 per day for each man-day required to be' expended by the Bureau. (d) Upon completion of all examina tions, inspections, and testa of unlisted respirator assemblies or components, or following the completion of any addi tional examination. Inspections, or tests of listed assemblies, or components or subassemblies, lncludlngretesting subse quent to disapproval, the Bureau shall advise the applicant in writing of the total cost assessed and the additional amount, if any, which must be paid to the Bureau as a condition of approval. (e) In the event the amount assessed by the Bureau for unlisted assemblies, or components or subassemblies Is lees than the amount of the deposit sub mitted In accordance with paragraph (a) of this section, the Bureau h*ii refund the overpayment upon the l.vwixno* of any approval or notice of disapproval. no operation Included which win not be foot, radon daughter*.... 1,350 Subpart D--Approval and Incorporated In regular production processing. 9 11.12 Delivery of respirators by appllcant; requirements. (a) Each applicant shall, when an ap plication Is filed pursuant to 111.10, be advised by the Bureau of the total number of respirator* and component parts required for testing, i? (b) The applicant deliver, at his own expense, the number of completely assembled respirators and component parts required for testing, to Approval and Testing, Bureau of Mines, Pitts burgh, Pa. 15213. (c) Respirators and component parts submitted for approval must be made from materials specified In the applica tion. (4) All dosts, fumes ami mists.. () Cbemloal cartridge respfcw tor* ......__.............. (f) Paint spray respirator*_______ (g) Pesticide respirator*......... 3,000 1,190 1,900 2,900 9 11.21 Examination, inspection and testing of respirator components or subassemblies; fees. Except u provided in I 11.22, the fol lowing fees shall be charged by the Bureau for the examination, inspection and testing of the Individual respirator components or subassemblies: (a) Pacepleoes _____ (b) Canisters ...........____..... (c) Cartridges__ ____________ ____ (d) Filters__ ___________ (*) Hoaes________________________ (f) Blow*** 390 (g) Harnesses ___________________ 94S0 000 600 eso 390 100 Disapproval 9 11.39 Certificate* of approval; scope of approval. (a) The Bureau and the Institute shall Issue certificates of approval pur suant to the provisions of this subpart only for Individual, completely as sembled respirator* 'which have been examined, inspected, and tested, and which meet the minimum requirements set forth In Subparts H through M of thu part, as applicable. <b> The Bureau and the Institute will not issue certificates of approval for any respirator component or for any respira tor subassembly. <c) The Bureau and the Institute shall not issue an Informal notification of approval. However, If the application (d) One completely assembled respira tor approved under the provisions of this part may be retained by the Bu reau as a laboratory exhibit, the remain ing respirators may be returned to the 9 11.22 Unlisted fees; additional fees; payment by applicant prior to ap. provaL (a) Applications for the examination. for approval, submitted In accordance with 111.11, states that the submitted respirator and component parts are only prototypes, the Bureau will examine, in spect, and test such respirator and com applicant at his own expense, upon writ Inspection and testing ` of complete ponent parts in accordance with the . 102> \ SAL 0000573. I i i 5i * >| i provisions of this Part 1L If, upon com respirator for which approval was sought pletion of such examinations, lnspectitm* with a view to the possible correction of arid tests, It Is found that the prototype any such defects. meets the mtniTwum requirements set (c) The Bureau and the institute shall forth m this part, the Bureau and the not disclose, except to the applicant or Institute may Inform the applicant. In as required by statute or regulation, any writing, of the results of the examina data, findings, or other information with tions, inspections, and tests, and may respect to any respirator for which a require him to resubmit respirators and notice of dlsappovai is issued. cocnponoit parts made on regular pro duction tooling, with no operations in cluded which will not be Incorporated in regular production processing, for fur ther examination, inspection, and test ing. prior to Issuance of the certificate of approval. (d) Applicants required to resubmit respirators and component parts made on regular production tooling, with no operation Included which will not be incorporated In regular production proc essing. shall be charged fees in accord ance with Subpart C of this part. g 11.31 Certificate* of approval; con tents. |1LM- Approval laBifla imd'jiMrfaiTifj; approval of contents; <a> Full-scale reproductions of ap proval labels and markings, and a sketch or description of the method of applica tion and position on the harness, con tainer, canister, cartridge, filter, or other component, together with instructions for the use and maintenance of the respirator shall be submitted to the Bu reau and the Institute for approval. (b) Approval labels shall bear the seals of the UB. Bureau of Mines and the Department of Health, Education, and Welfare, the applicant's name and ad dress. an approval number assigned by (a) The certificate of approval shall the Bureau, and, where appropriate, re contain a classification and a description strictions or limitations placed upon the of the respirator or combination of use of the respirator by the Bureau and respirators for which It Is Issued, as the Institute.. provided in this part. <c) .The Bureau shall, where neces <b> The certificate of approval shall sary, notify the applicant when addi specifically set forth any restrictions or tional labels, markings, or Instructions limitations on the respirator's use In will be required. hazardous atmospheres. (d) Approval labels and markings (c) Each certificate of approval shall shall only be used by the applicant to be accompanied by the drawings and whom they were issued. specifications (and lists thereof) sub Ce) Legible reproductions or abbrevi mitted by the applicant in accordance ated forms of the label approved by the with } 11.11. These drawings and Bureau and the Institute for use on each specifications shall be incorporated by respirator shall be attached to or printed reference in the certificate of approval, at the following locations: and shall be maintained by the applicant. The drawings and specifications Usted in each- certificate of approval shall set forth Respirator type label type Location In detail the design and construction requirements which shall be met by the applicant during commercial production of the respirator. (d) Each certificate of approval shall be accompanied by a reproduction of the Self-contained Entire....... Harness assembly breathing appe- TStll*. (where applicable). Gh mut................... Entire.... ,. Mast container and canister. 8upplled-elr respi- Entire.......... . Respirator container rater. or Instruction approval label design to be employed by the applicant with each approved respirator, as provided In }U-33. <e> No test data or specific laboratory findings will accompany any certificate of approval, however, the Bureaq will re lease pertinent test data and specific findings upon written request by the ap plicant, or as required by statute or regulation. Duft, hnn*. And Entire.......... . Respirator container mist respirator. and (liter con tainer. Abbrevi- Filters. ated. Chemical-cartridge - Entire........... Respirator oon- respirator, LncJudInj paint ipray talner, cartridge respirator. filter containers (where appli- Abbrevtated. Cartrldges and 11ter* and filler (f) Each certificate of approval shall, also contain the approved quality.control; plan as specified in } 11.42. 11.32 Notice of disapproval. Pwticid* rplrator. Entire....... Respirator am- talner, end car tridge and filter containers. Abbrerl* ated. Cartridges and filter*. (a) if, upon the completion of the ex aminations, inspections, and testa re quired to be conducted In accordance with the provisions of this part. It Is found that the respirator does not meet the minimum requirements set forth in this part, the Bureau and the Institute shall Issue a written notice of disapproval to the applicant. (b> Each notice of disapproval shall be accompanied by sU pertinent data or findings with respect to the defects of the (f) The use of any Bureau and Insti tute approval label obligates the appli cant to whom It is Issued to maintain or cause to be maintained the approved quality control sampling schedule and the acceptable quality level for each charac teristic tested, and to assure that It Is manufactured according to the drawings and specifications upon which the certi ficate of approval Is based. <g) Bach respirator, respirator com ponent, and respirator container shall, as required by the Bureau and the Institute to assure quality control and proper use of the respirator, be labeled distinctly to show the name of the applicant, and the name and letters or numbers by which the respirator or respirator component Is designated for trade purposes, and the lot number, serial number, or approxi mate date of manufacture. g 11.34 Revocation of certificate* of ap proval. The Bureau and the Institute reserve the right to Jointly revoke, for cause, any certificate of approval Issued pursuant to the provisions of this part. Such causes include, but are not limited to, misuse of approval labels and markings, mislead ing advertising, violations of section 109(e) of the FederafCoeJ Mine Health and Safety Act of 1969 (30 U.8.C. 619 (e)), and failure to maintain or cause to be maintained the quality control re quirements of the certificate of approval. 11.35 Changes or modification of ap proved respirators; issuance of mod ification of certificate of approval. (a) Each applicant may. If he desires to change any feature of an approved respirator, request a modification of the original certificate of approval Issued by the Bureau and the Institute for such respirator by filing an application for such modification In accordance with the provisions of this section. (b) Applications shall be submitted as for an original certificate of approval, with a request for a modification of the existing certificate to cover any proposed change. (c) The application shall be accom panied by appropriate drawings and specifications, and by a proposed quality control plan which meets the require ments of Subpart E of this part. (d) The application for modification, together with the accompanying mate rial, shall be examined by the .Bureau to determine whether testing will be required. (e) The Bureau shall inform the ap plicant of the fee required for any addi tional testing and the applicant will be charged for the actual cost of any exami nation. inspection, or test required, and such fees shall be submitted In accord ance with the provisions of Subpart C of this part. (f) If the proposed change or modifi cation meets the requirements of this part, a formal certificate of modifica tion will be issued, accompanied, where necessary, by a list of new and revised drawings and specifications covering the change(s) and reproductions of revised approval labels. S 11.36 delivery of changed or modified approved respirator. An approved respirator for which a formal certificate of modification' has been Issued shall be delivered, with proper markings and containers, by the applicant to the Bureau of Mines, Ap proval and Testing, 4800 Forbes Avenue, Pittsburgh, PA 15213, as soon as it is commercially produced. Svbpart E--Ovality Control 111.40 Quality control pits*, filing Ai a port of each application for ap proval or modification of approval sub mitted pursuant to this port, each appli cant shall file with the Bureau and the Institute a proposed Quality control plan which shall be designed to assure the Quality of respiratory protection pro vided by the respirator for which ap proval Is sought. I 11.41 (Quality control plant; content*. (a) Bach Quality control plan sh*n contain provisions for the management of Quality, Including: Cl) Requirements for the production of Quality data and the use of quality control records; (2) control of engineering drawings, docu mentations, and changes; (3) control and calibration of measuring and test equipment; (4) control of purchased material to Include Incoming Inspection; (B) lot identification, control of proc esses, manufacturing, fabrication, and assembly work conducted in the appli cant's plant; (6) audit of final Inspec tion of the completed product; and, (?) the organizational structure necessary to carry out these provisions. (b) Each provision for Incoming and final inspection In the quality control plan shall include a procedure for the selection of a sample of respirators and the components thereof for testing, In accordance with procedures set forth in Military Standard MIL-STD-105D, "Sampling Procedures and Tables for Inspection by Attributes," or Military Standard MXL-BTD-414, "Sampling Procedures and Tables for Inspection by Variables for Percent Defective," or an approved equivalent sampling proce dure, or an approved combination of sampling procedures. Incoming bulk raw materia] Inspection or verification of specification, and in-process Inspection shall be sufficient to ensure control of product quality through the manufac turing cycle. (c) The sampling procedure shall In clude a list of the characteristics to be tested by the applicant or his agent. (d) The characteristics listed In ac cordance with paragraph (c) of sec tion shall be classified according to the potential effect of such defect and grouped Into the following classes: (1) Critical. A defect that Judgment and experience Indicate is likely to re sult in a condition immediately hazard ous to life or health for individuals using or depending upon the respirator; (2) Major A. A defect, other than critical, that is likely to result In failure to the degree that the respirator does not provide any respiratory protection, or-a defect that reduces protection and is not detectable by the user; (9) Major B. A defect, other than Ma jor A or critical, that Is likely to result In reduced respiratory protection, and is 'detectable by the user; and (4)Minor. A defect that Is not likely to mstrrlsfly reduce the usability of the respirator for its intended purpose, or a defect that is a departure from estab lished standards and has little bearing on the effective use or operation of the respirator. (e> The quality control Inspection test method to be usM by the applicant or his agent for each characteristic re quired to be tested shall be described In detail. (f) Each Item manufactured shall be 100 percent Inspected for defects In all critical characteristics and all defective items shall be rejected. (g) The Acceptable Quality Level <AQL) for each major or minor defect so classified by the applicant shall be: (1) Major A. 1.0 percent; (2) Major B. 2.6 percent; and (3) Minor. 4.0 percent. (h) Except as provided in paragraph Cl) of this section, inspection level n as described In iflL-8TD-103D, or Inspec tion level IV as described In 1CL-STD414, shall be used for major and minor characteristics and 100 percent Inspec tion for critical characteristics. <1) Subject to the approval of the Bureau and the Institute, where the quality control plan provisions for raw material, processes, manufacturing, and fabrication Inspection are adequate to In sure control of finished article quality, destructive testing of finished articles may be conducted at a lower level of in spection than that specified In 'para graph (b) of thlj section. g 11.42 Proposed quality control plans; approval by the Bureau and the Insti tute. (a) Each proposed quality control plan submitted In accordance with this subpart shall be reviewed by the Bureau and the Institute to determine its effec tiveness in Insuring the quality of res piratory protection provided by the respirator for which an approval Is sought. <b) If the Bureau and the Institute de termine that the proposed quality control plan submitted by the applicant will not Insure adequate quality control, the Bu reau and the Institute shall require the applicant to modify the procedures and testing requirements of the plan prior to approval of the plan and Issuance of any certificate of approval. (c) Approved quality control plans shall constitute a part of and be incor porated into any certificate of approval Issued by the Bureau and the Institute, and compliance with such plans by the applicant shall be a condition of ap proval. g 11.43 Quality control records; review by the Bureau and the Institute; rev ocation of approval. (a) The applicant hri keep quality control Inspection records sufficient to carry out the procedures required In MXLf-STl>-lQ&D or MXL-8TD-414. or an approved equivalent sampling procedure. (b) The Bureau and the Institute re serve the right to have their representa tives inspect the applicant's quality con trol test methods, equipment, and rec ords, and to Interview any employee or agent of the applicant in regard to quali ty control test methods, equipment ..... records. ' *** (e) The Bureau and the Institute ^ serve the right to Jointly revoke fZ! cause, any certificate of approval whe*I It is found that the applicant's queut? control test methods, equipment, orre/ ords do not insure effective quality con" trol over the respirator for which thl approval was Issued. Mie Subpart F--Classification of Approved Respirators; Scope of Approval; At- mospherk Hazards; Service Tims 9 11.50 Types of respirators to be proved; scope of approval. Approvals shall be issued for the types of respirators which have been pursuant to this Bubpart P, have been Inspected, examined and tested by the Bureau In accordance with the provi sions of Subparts O through M of this part, and have been found to provide respiratory protection for fixed periods of time against the hazards specified In such approval. g 11.51 Entry and escape, or escape only; classification. Respirators described In Subparts h through M of this part shall be classified for use as follows: (a) Entry and escape. Respirators de signed and approved for use during entry Into a hazardous atmosphere, and for escape from a hazardous atmosphere; or. (b) Escape only. Respirators designed and approved for use only during escape from a hazardous atmosphere. g 11.52 Respiratory Hazards; elauifica. lion. Respirators described in Subparts R through M of this part shall be classified as approved for use against any or &U of the following respiratory hazards: (a) Oxygen deficiency; (b) Oases and vapors; (c) Particles, including dusts, fumes and mists; and (d) Pesticides. g 11.53 Service lime; classification. (a) Respirators described In Subparts H through M of this part shall be classi fied, where applicable, as approved for use during the following prescribed service times: (1) Pour hours; (2) Three hours; (3) Two hours; (4) One hour; <5) Porto-five minutes; (6) Thirty minutes; (?) Fifteen minutes; (8) Ten minutes; (6) Five minutes; (10) Three minutes. (b) Other service times may be pre scribed by the Bureau and the Institute. Subparl G--General Construction and (a) The Bureau and the Institute shall issue approvals for the topes of respira tors described In Subparts H through M r* ii<5 -404 ^ J % '<> A L 0000 5 7 3 p ( ma. . ^ pan which have met the mini-.mi requirements set forth for such SSSJi in this Part 11 fb> In addition to the types of respiraspecified In Stibparta H through M, r"Bureau and the Institute shall Issue "rovals for other respiratory protec tive devices not specifically described in this Part 11 suoject to such additional requirements as may be imposed in ac cordance with g 11.63(c). 11.61 General compaction require ments. (a) Respirators will not be accepted by the Bureau for examination, Inspec tion and testing unless they are designed on sound engineering and scientific prin ciples, constructed of suitable materials and evidence good workmanship. (b) Respirator components which come into contact with the wearer's skin .hall be made of nonirritating materials. (c> Components replaced during or after use shall be constructed of mate rials which will not be damaged by nor mal handling. (d) Mouthpieces, hoods, helmets, and facepieces, except those employed In sin gle-use respirators, shall be constructed of materials which will withstand re peated disinfection as recommended by the applicant in his instructions for use of the device. (e) The components of each respira tor approved by the Bureau and the In stitute for use where permissibility Is re quired shall meet the requirements for permissibility and Intrinsic safety set forth In Part 18, Subchapter D of this chapter (Bureau of Mines Schedule 20). S 11.62 Component parts; minimum re quirements. (a) The component parts of each respirator shall be: (1) Designed, constructed, and fitted to insure against creation of any hazard to the wearer: (2) Assembled to permit easy access for inspection and repair of functional parts; and (3) Assembled to permit easy access to parts which require periodic cleaning and disinfecting. (b) Replacement parts shall be de signed and constructed to permit easy installation and to maintain the effec tiveness of the respirator. 11.63 Teal requirements; general. (a) Each respirator and respirator component shall' when tested by 4}ie applicant and by the Bureau, meet the applicable requirements set forth in Subparts H through M of this part. (b) Where a combination respirator Is assembled from two or more types of respirators, as described In this part, each of the individual respirator types which have been combined shall, as applicable, meet the minimum require ments for such respirators set forth in Subparts H through M of this part, and such combination respirators, except as specified In 111.70(b) (2), will be classi fied by the type of respirator in the com bination which provides the least pro tection to the user. (c) In addition to the minimum re quirements set forth in Subparts H through M of tht part, the Bureau and the Institute reserve the right to re quire, as a further condition of approval, any additional requirements deemed nec essary to establish the quality, effec tiveness, and safety of any respirator used as protection against hazardous atmospheres. (d) Where it is determined after re ceipt of an application that additional requirements will be required for ap proval, the Bureau will notify the appli cant in writing of these additional re quirements, and necessary examinations. Inspections, or tests, stating generally the reasons for such requirements, ex aminations, inspections, or tests. 11.64 Pretesting by applicant; ap proval of lest method* by the Bureau. (a) Prior to making or filing any ap plication for. approval or modification of approval, the applicant shall conduct, or cause to be conducted, examinations, in spections, and tests of respirator per formance which are equal to or exceed the severity of those prescribed In this part. (b) With the application, the appli cant shall provide a statement to the Bureau showing the types and results of the examinations, inspections, and tests required under paragraph (a) of this section and state that the respirator meets the minimum requirements of Subparts H through M of this part, as applicable. Complete examination. In spection, and test data shall be retained on file by the applicant and be sub mitted, upon request, to the Bureau. (c) The Bureau may, upon written request by the applicant, provide draw ings and descriptions of its test equip ment and otherwise assist the applicant In establishing a test laboratory or se curing the services of a testing agency. <d) The Bureau will not issue an ap proval to the applicant until It has vali dated the applicant's test results. 11.65 Conduct of examinations, in spections, and tests by the Bureau and trie Institute; assistance by applicant; observers; recorded data; public demonstrations. (a) All examinations, inspections, and tests conducted pursuant to Subparts 5 through M of this part will be under the sole direction and control of the Bureau and the Institute. (b) The Bureau and the Institute may, as a condition of approval, require the assistance of the applicant or agents of the applicant during the assembly, dis assembly, or preparation of any respira tor or respirator component prior to test ing or in the operation cf such equip ment during testing. . (c) Only Bureau and Institute person nel, persons assisting the Bureau pur suant to paragraph (b) of this section, and such other persons as are requested by the Bureau, the Institute, or the appli cant to be observers, shall be present dur ing any examination. Inspection, or test conducted prior to the Issuance o&an ap proval by the Bureau and the Institute for the equipment under considerstico. (d> The Bureau and the Instituteahall hold as confidential any analyses, draw ings, specifications, or materials sub mitted by the applicant and shall not dis close any principles or patentable fea tures of such equipment, except as re quired by statute or regulation. (e) As a condition of each approval is sued for any respirator, the Bureau and the Institute reserve the right, following the Issuance of such approval, to conduct such public tests and demonstrations of the approved respiratory equipment as is deemed appropriate. 11.66 Withdraws! of applications; re fund of fees. (a) Any applicant may, upon a writ ten request submitted to the Bureau or the Institute, withdraw any application for approval of any respirator. <b) Upon receipt of a written request for the withdrawal of an application, the Bureau shall determine the total mandays expended and the amount due for services already performed during the course of any examinations, inspections, or tests conducted pursuant to such ap plication. The total amount due shall be determined In accordance with the pro visions of ! 11.22 and assessed against the fees submitted by the applicant. If the total amount assessed is less than- the fees submitted, the Bureau shall refund the balance together with a statement of the charges made for services rendered. Subport H--Self-Contained Breathing Apparatus 11.70 Self-contained breathing appa ratus; description. (a) Self-contained breathing appara tus. Including all completely assembled, portable, self-contained devices designed for use as respiratory protection during entry into and escape from or escape only from hazardous atmospheres, are de scribed as follows: (1) Closed-circuit apparatus. An ap paratus of the type in which the exhala tion is rebreathed by the wearer after the carbon 'dioxide has been effectively removed and a suitable oxygen concen tration restored from sources composed of: (1) Compressed oxygen; or (ill Chemical oxygen; or Oil) Liquid-oxygen. (2) Open-circuit apparatus. An appa ratus of the following types from which exhalation is-vented to the atmosphere and not rebreathed: (i) Demand-type apparatus. An appa ratus in which the pressure inside the facepiece In relation to the immediate environment Is positive during exhala tion and negative during Inhalation. (il) Pressure-demand-type apparatus. An apparatus In which the pressure in side the facepiece in relation to the im mediate environment Is positive during both inhalation and exhalation. (b) The following respirators may be classified as designed arid approved for use during emergency entry into a haaardooa atmoephera: A combination rexpl- where applicable, provide lor holding a full facepiece ln the ready position when ^equate teraioe nd an eves dlstribSLi^?* rater which Includes a self-contained not In use. the entire pe^SJ breathing appeuratu* and a Typo "C* or Type "CE" supplied air respirator, where (1) the self-contained breathing appara tus is classified for 3-, S-, or 10-minute service time and the air line supply is used during entry, or (3) the selfcontained breathing apparatus is classi fied for 16 minute* or longer service time and not more than 30 percent of the rated capacity of the air supply is used during entry. (cl Self-contained breathing appara tus classified for lees than 1 hour serv ice tim* will not be approved for .use during underground mine rescue and recovery operations except as auxil iary equipment. <d) Self-contained breathing appara tus classified for lees than 30 minutes' 811.74 Appsritus container*; minimum requirements. (a) Apparatus may be equipped with a substantial, durable container bearing markings which show the applicant's name, the type and commercial desig nation of the respirator it contains, and all appropriate approval labels. (b) Containers supplied by the appli cant for. carrying or storing selfcontained breathing apparatus will be Inspected, examined, and tested as com ponents of the respirator for which ap proval Is sought. (e> Containers for self-contained breathing apparatus shall be designed and constructed to permit easy removal of the apparatus. wrehpelarceeaabplpeUhcaarnbIu*TBetiLE***,,2i structed to hoW ^ 811.79 BreeihJnc u, . ***. quirement*. * (a) Breathing gas um paratus shall be ^KSh* *. no leas than 18.6 (?n- TOS?e^rcentof <h> Oxygen, Including yaifW shaU meet the alnimiuu iSii0****. for medical or breathim,^?1**** forth in the Xr.8. PhanniSJp*?*"*** (c) Compressed. gaseo^vS^^ shah meet the ** grade rfeoqruthireImn ethnet* for TroCoLJ service time will not be approved for 8 11,75 Half-mask facepiece*, fuH_ face- soetation Commodity SmSE.*?* ** use as auxiliary equipment during un derground mine rescue and recovery piece*, mouthpiece*; fits minimum Air. 0-7.1 (Grade D or requirement*. (d) Compressed. llquelto bSSS*; operations. | 11.71 Selfcontained breathing appara tus; required component*. (a) Each self-contained breathing apparatus described In I 11.70 shall, where its design requires, contain, the following component parts t (?) Facepiece or mouthpiece, and nosechp; (3) Respirable breathing gas con tainer; (3) Supply of respirable breathing gas; (a) Half-mask facepieces and full facepieces shall be designed and con structed to fit persons with various facial shapes and sizes, either (1) by providing more than one facepiece size, or <31 by providing one facepiece size which will fit varying facial shapes and sizes. (b) Tun facepieces shall provide for the optional use of corrective spectacles or lenses which shall not reduce the respiratory protective qualities of the apparatus. (0) Apparatus with mouthpieces shall air shall meet the applicable gTade requirements for Typen5f^ set forth to the Compr^ gTM* ciatloa Commodity Speclficatlon^T?* G-7.1 (Grade B or higher quality) 11.79-1 tm*h.ng*l,mi7 *f ana ir prohibited. w"^ Approvals shaU not be Issued w *_ Bureau and the Institute for in* iJl* ratus, combination of respirator uZZr biles,or any apparatus or resplratoreST ponent which Is designed or construct!! to permit the Interchangeable mE3 (4) Gas pressure or liquid level gagee; be equipped with nosecllpe which are oxygen and air, w (5) Timer;- (0) Remaining- service life indicator or warning device; (7) Hand-operated valves; (8) Breathing bag; (fi> Safety relief valve or safety relief system; and (Id) Bameee. (b) The components of each self- coatalned breathing apparatus shall securely attached to the mouthpiece or apparatus and provide an airtight seaL (d) Facepieces shafi be designed to prevent eyepiece, spectacle, and lens fogging. 8 11.76 Facepiece* ; eyepiece*; mini mum requirement*. (a) Facepieces shall be designed and constructed to provide adequate vision 8 11.80 Compressed breathing p ..i liquified breathing gas conUioan, minimum requirement*. * (a) Compressed breathing gas ud liquefied breathing gas containers >-q meet the minimum requirements of the Department of Transportation for etate shipment of such container whm fully charged. meet the wHn<ntT construction require which Is not distorted by the eyepiece. (b) Such containers shall be perma ments set forth in Subpart a of this part. 8 11.72 Breathing tub**; minimum re quirements. (a) Flexible breathing tubes lued In conjunction with breathing apparatus shall be designed and constructed to prevent: (l> Restriction of free bead move ment; (3) Disturbance of the fit of fdeepiecee and mouthpieces; (3) Interference with the wearer's aeUvtUee; and. (4) Shutoff of airflow due to Unking, or from chin or arm pressure. | 11.73 Harnesses t Installation and eon* traction('minimum requirement*. (a) fitch apparatus shall, where neceesary, be equipped with a suitable harness designed and constructed to hold the components of the apparatus In pay swan against the wearer's body. (b) Harnesses shah be designed sad constructed to permit easy removal and (b) All eyepieces shall be designed and constructed to meet the Impact and pen etration requirements specified In Fed eral Specification, Mask. Air Line, and Respirator. Air Filtering, Industrial, OOG-M-125d. October 11, 1866. This Federal Specification is available from the Government Printing Office or the General Services Administration. 8 11,77 Inhalation and exhalation valve*; minimum requirement*. (a) Inhalation and exhalation valves shall be provided where necessary and protected against damage and distortion. (b> Exhalation valves shall be: (1) Protected against external influ ence. and - (3) Destined and constructed to pre vent Inward leakage of contaminated air. 8 11.78 Head himeMo; minimum re quirement*. (a) Facepieces shall ba equipped with adjustable and replaceable head har nently and legibly marked to Identity their contents, e.g., compressed breath ing air, compressed breathing oxygen, liquefied breathing air, or Uqueflad breathing oxygen. (c) Containers normally removed from apparatus for rdUllng (hall ba equipped with a dial indicating gage which shows the pressure to the con tainer. <d) Compressed breathing iu con tained valves or a separate charging system or adapter provided with each apparatus shall be equipped with outlet threads specified for the service by the American National Standard for Com pressed Gaa Cylinder Valve Outlet nd Inlet Connactions, B87.1 (IMS), obUtn able from American National standards Institute, Inc.. 1430 Broadway, New York. NT 100X8. -.^5 | 11.81 Ga* prcMwre gage*; arfnlw requirement*. , (a) Gas pressure gages employed co compressed breathing gas cmtalnsrt , hall be calibrated In pounds per squat* ' - replacement of apparatus parts, and. nesses designed and constructed to pro- Inch. 106 8 4 ? If @5 I v 9 0 a 0>) Liquid-level gages shall be cali brated In fractions of total container capacity, or In units of liquid volume. <e> Gas pressure gages other than those specified In paragraphs (a) and (b) of this section shall be calibrated In: (1) Pounds per square Inch, or U) In fractions of total container capacity, or <3> Both In pounds per square Inch Inch and fractions of * total contsiner capacity. (d) (1) Dial-Indicating gages shall be reliable to within 5 percent of full scale when tested both up and down the scale at each of 5 equal Intervals. (2) The full scale graduation of dialindicating gages shall not exceed 1BQ percent of the maximum rated cylinder pressures specified for the container in applicable Department of Transportation specifications or permits. (e) (1) Stem-type gages shall- be readable by sight and by touch and shall have a stem travel distance of not less than one-fourth Inch between each graduation. (2) a minimum of five graduations shall be engraved on the stem of each gage and these graduations shall Include readings for empty, one-quarter, one- half, three-quarters, and full. (3) Stem gage readings shall not vary from true readings by more than onesixteenth Inch per Inch of stem travel. (f) The loss of gas through a broken gage or severed gage connection shall not exceed 70 liters per minute when the cylinder pressure is 6,900 kN/m.*'(l,000 pounds per square Inch gage) or when the liquid level Is at one-half. (g> Where gages are connected to the apparatus through a gage line, the gage and line shall be capable of being Iso lated from the apparatus except where the failure of the gage or line would not impair the performance or service life of the apparatus. (h) Oxygen pressure gagee shall have the words, "Oxygen" and `Use No OH," marked prominently on the gage. (1) (1) Apparatus using compressed breathing gas, except apparatus classi fied for escape only, shall be equipped with gages visible to the wearer which Indicate the remaining gas content In the container. (2) Apparatus using liquefied breath ing gas, except apparatus classified for escape only, shall be equipped with gages visible to the wearer which Indicate the remaining liquid content in the cefi- talner; however, where , the liquid con tent cannot be rapidly vented, and the service time of the device begins Imme diately alter - filling, a timer be provided In place of a visible gage. | 11.82 Timers; elapsed time indicators; remaining service life indicator; min imum requirements, (a) Elapsed time indicators shat! be provided for apparatus with a chemical oxygen source, except: (1) Apparatus used for escape only; or, (2) liquefied breathing gas apparatus quipped with gages visible to the wearer which Indicate the remaining liquid con tent in the container. (b) The timer or other indicator shall be accurately calibrated in minutes of remaining service life. (c) Timers shall be readable by sight snd by touch during use by the wearer. (d) Timers shall be equipped with au tomatically preset alarms which will warn the wearer for a period of 7 sec onds or more after the preset time has elapsed. (e) Remaining service-life indicators or warning devices shall be provided in addition to a pressure gage on "com pressed gas self-contained breathing ap paratus, except apparatus used for escape only, and shall operate automat ically without preadjustment by the wearer. Cf) Bach remaining servlce-llle indi cator or warning device shall give an alarm when the remaining service life of the apparatus Is reduced within a range of 20 to 2S percent of Its rated service time. 9 11.83 Hand-operated valves; minimum requirements. () Hand-operated valves shall be de signed and constructed to prevent re moval of the stem from the valve body during normal usage to insure against a sudden release of the full pressure of the container when the valve is opened. (b) Valves shall be designed or posi tioned to prevent accidental opening and closing, and damage from external forces. (c) Valves operated during use of the apparatus shall be Installed in locations where they can be readily adjusted by the wearer. (d) Main-line valves, designed and constructed to conserve gas in the event of a regulator or demand valve failure, shall be provided In addition to gas con tainer valves, except when such failure will not affect performance. ie) Hand-operated bypass systems designed and constructed to permit the wearer to breathe and to conserve his gas supply In the event of a regulator or demand valve failure, shall be provided where necessary. (f) Valves installed on apparatus shall be dearly distinguishable from one another by sight and touch. (g) The bypass system valve control shall be colored red. (h) A main-line or bypass valve or system will not be required on apparatus for escape only. (1) Safety relief valves or systems, de signed and constructed to release excess pressure in the breathing circuit, shall be provided an closed-circuit apparatus, add shall meet the following requirements: (1) The relief valve or system operate automatically when the pressme In the breathing circuit on the Inhala tion side of the breathing bag reaches 13 mm. (one-half inch) water-column height of pressure above the minimum pressure required to HU the breathing bag. within the breathing resistance re quirements for the apparatus. (2) The relief valve or system be designed to prevent external atmes- phexee from entering the breathing circuit. (3) The relief valve or system han be designed to permit manual overriding for test purposes and In the event of a failure In the valve or system. 9 11,84 Breathing hags; iwlwtwmwi re quirement*. (a) Breathing bags shall "have suffi cient volume to prevent gas waste during exhalation and to provide an adequate reserve for inhalation. (b) Breathing bags than be con structed of materials which are flexible and resistant to gasoline vapors. (c) Breathing bags shall be Installed In a location which will protect them from damage- or collapse by external forces, except on apparatus classified for escape only. 9 11.85 Self-contained breathing appa ratusi performance requirement* t general. Self-contained breathing apparatus and the individual components of each such device shall M applicable meet the requirements gpeoifled in || 11.86-1 through 11.86-19. | 11.85-1 Component parts exposed to oxygen pressure*; minimum require ment*. Each applicant shall certify that the materials employed In the construction of component parts exposed to oxygen pressures above atmospheric pressure are safe and compatible for their Intended use. 9 11.8S-2 Compressed gas filters; mini mum requirements. Ail self-contained breathing apparatus using compressed gas shall hare a filter downstream of the gis source to effec tively remove particles from the gas stream. } 11.85--8 Breathing bag test. (a) Breathing bags will be tested In an air atmosphere saturated with gasoline vapor at'room temperature (24"-30* c./ 76*-88* F.) for a continuous period of twice the rated time of the apparatus (except for apparatus for escape only where the test period shall be the rated time of the apparatus). (b) The beg will be operated during this test by a breathing machine with 24 respirations per minute and a minutevolume of 40 liters, (c) A breathing mxehfne cam with a work rate of 622 kg.-mymin. will be used.1 <d) The air within the bag(s> *h*ri not contain more than 100 parts per mil lion of gasoline vapor at the end of the test. laavenoao, 1*. O. Lae, T. Retain. L. Amory, sad A. lb Tanoey, Fundamental Factor* In Design of Protective Zqulpaent. OBJLD. Ispert Wo. 57X3. Issued Apr. 1. IMS. me dlmeatioas cf the breathing earn are available from the Bureau upon request. 107 mar* than 15.kg. KBmiiil: however, where the weight decrease* by more than 35 percent of Its Initial charge weight during its rated serviee life, the maxi mum allowable weight of a completely assembled and fully charged apparatus shall be 15 kg. (40 pounds). (b> Where an apparatus employs equipment which contributes materially to the wearer's comfort, e.g., a cooling system, the completely assembled and fully charged apparatus shall not weigh more than is kg. (40 pounds) regardless of the-decrease in weight during use. 11.85-5 Breathing resistance test; in halation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is oper ated by a breathing machine as de scribed in } 11.85-3. (b) The Inhalation resistance of opencircuit apparatus shall not exceed 32 mm, (1.25 Inch) water-column height (at a flow rate of 120 liters per minute). (c> The Inhalation resistance of closed-circuit apparatus shall not ex ceed the difference between exhalation resistance <5 11.85-6(e)) and 10 cm. (4 Inches) water-column height. 11.85--6 Breathing resistance test; ex halation. (a) Resistance to exhalation airflow will be measured In the facepiece or mouthpiece of open-circuit apparatus with air flowing at a continuous rate of 85 liters per minute. (b) The exhalation resistance of de mand apparatus shall not exceed 25 mm. (1 inch) water-column height. (c) The exhalation resistance of pres sure-demand apparatus shall not ex ceed the static pressure In the facepiece by more than 51 mm. (2 Inches) waterolumn height. <d) The static pressure (at zero flow) in the facepiece shall not exceed 38 mm. (1.5 Inches) water-column height. (e) Resistance to exhalation airflow will be measured in the facepiece or mouthpiece of closed-circuit apparatus with a breathing machine as described in J 11.85-3, and the exhalation resistance ffhaJj not exceed 51 mm. (2 inches) water-column height. S 11.85--7 Exhalation valve leakage letL (a) Dry exhalation valves and 'valve seats will be subjected to a suction of 25 "ITM (i inch) water-column height while in a normal operating position. (b) Leakage between the valve and the valve seat shall not exceed 30 milli liters per minute. 11.85--8 Cat flow lest; open-circuit ap paratus. (a) A static-flow test wd be per formed on all open-circuit apparatus. (b) The flow from the apparatus shall be greater than 200 liters per minute when the pressure In the facepiece of demand-apparatus Is lowered by 51 mm. (2 Inches) water-column height when full container pressure is applied. (c) Where pressure demand appara tus are tested, the flow will be measured at 2ero gage pressure in ` he facepiece. (d) Where apparatus with com pressed-breathing-gas containers are tested, the flow test shall also be made with 3,450 kN/m.' (500 pj.l.g.) container pressure applied. 11.85--9 Gas flow test', closed-circuit apparatus. (a) Where oxygen Is supplied by a constant-flow device only, the rate of flow shall be at least 3 liters per minute for the entire rated service time of the apparatus. (b) Where constant flow is used in conjunction with demand flow, the con stant flow shall be greater than 1.5 liters per minute for the entire rated service time. (c) All demand-flow devices shall pro vide at least 30 liters of oxygen per minute when In the fully open position. 11.85--10 Service time test; open-cirouit apparatus. (a) Service time will be measured with a breathing machine as described in } 11.85-3. (b) The open-circuit apparatus will be classified according to the length of time It supplies air or oxygen to the breathing machine. (c) The service time obtained on this test will be used to classify the opencircuit apparatus In accordance with 5 11.53. 11.35--11 Service time test; closed-cir cuit apparatus. (a) The closed-circuit apparatus will be classified according to the length of time it supplies adequate breathing gas to the wearer during man test No. 4 described in Table 4. (b) The service time obtained on man test No. 4 will be used to classify the closed-circuit apparatus in accordance with l 11.53. 11.85--12 Teat for carbon dioxide in inspired gas; open- and closed-circuit apparatus; maximum allowable limits. (a) Open-circuit apparatus: (1) The concentration of carbon dioxide in inspired gas In open-circuit apparatus will be measured at the mouth while: the apparatus mounted on a dummy head Is operated by a breathing machine.' (2) The breathing rate will be 14.5 respirations per minute with a minutevolume of 10.5 liters. (3) A sedentary breathing machine cam will be used. (4) The apparatus will be tested at a temperature of 27*2` C. (80*5* F.>. * Klooe, X. J., and J. Lamontea, A MachinoTeat Method for Measuring Carbon Dioxide In the Inspired Air of Sell-Contained Breathing Apparatus. Bureau of Mines Report of In vestigations eses. 1966. if pp. (5) A concentration of 5 pen-.,. carbon dioxide In air will be exhaled tom the facepiece. w (b). Closed-circuit apparatus: (1) The concentration of carbon dio* lde In Inspired gas In closed-circuit apparatus will be measured at the mouth while the parts of the apparatus con tributing to dead-air space are mounted on a dummy head and operated by the breathing machine as in paragraphs (&) (1) through (5) of this section. (c) During the testing required by paragraphs (a) and (b) of this section, the concentration of carbon dioxide in Inspired gas at the mouth will be con tinuously recorded, and the maximum average concentration during the inhala tion portion of the breathing cycle shall not exceed the following limits: SfoTfmvm allowable Where the service average concentration 0/ carbon dioxide in inspired air. time is: percent by volume Hot loot* tban 30 minutes.......____ j. 5 1 hour.---------------------------------------------- j, a 3 hour*..... j. B 3 hours 1.0 4 hours 1.0 (d) In addition to the tests require ments for closed-circuit apparatus set* forth in paragraph (b) of this section, gas samples will be taken during the course of the man testa described in Tables 1, 2, 3, and 4. These gas samples will be taken from the closed-circuit ap paratus at a point downstream of the carbon dioxide sorbent, and they shall not contain more than 0.5 percent car bon dioxide at any time. 11.8^-13 Teals during low tempera ture operation. (a) The applicant shall specify the minimum temperature for safe opera tion and two persons will perform the tests described In paragraphs (c) and (d) of this section,-wearing the appa ratus according to applicant's directions. At the specified temperature, the appa ratus shall meet all the requirements de scribed In paragraph (e) of this section. (b> The apparatus will bo precooled at the specified minimum temperature for 4 hours. (c) The apparatus will be worn In the low temperature chamber for 30 min utes, or for the service time of the ap paratus, whichever Is less. (d) During the test period, alternate 1-mlnute periods of exercise and rest will be required with the exercise periods consisting of stepping onto and off a box 21.5 cm. (8% Inches) high at a rate of 30 cycles per minute. (e> U> The apparatus shall function satisfactorily at the specified minimum temperature on duplicate tests. (2) The wearer shall have sufficient unobscured vision to perform the work. (3) The wearer shall not experience undue discomfort because of airflow re striction or other physical or chemical changes bn the operation of the apparatus. 108 (f) Auxiliary low-temperature parts which are commercially available to the user may be used on the apparatus to meet the requirements described in par agraph <e) of this section, 9 11.85-14 Man tesU; testing eondl. liona; general requirements. (a) The man tests described In Tables 1, 2, 3. and 4 represent the workload per formed In the mining, mineral, or allied industries by a person wearing the appa ratus tested. (b) The apparatus tested will be worn by Bureau personnel trained in the use of self-contained breathing apparatus, and the wearer will, before participating In these tests, pass a physical examina tion conducted by a qualified physician. (c) All man tests will be conducted by the Bureau. (d) The apparatus will be examined before each man test to ensure that It Is in proper working order. (e) Breathing resistance will be meas ured within the facepiece or mouthpiece and the wearer's pulse and respiration rate will be recorded during each 3 min ute sample period prescribed in tests 1, 2. 3. and 4. (f) Man tests 1. 2, 3, 4, 5, and 6 will be conducted in duplicate. (g> If man tests are not completed through no fault of the apparatus, the test will be repeated. 9 11.8^15 Man tesla 1, 2, 3, and 4; requirements. (a) Man tests 1, 2, 3. and 4, set forth In Tables 1, 2, 3, and 4 respectively, pre scribe the duration and sequence of spe cific activities. These tests will be conducted to: <1) Familiarize the wearer with the apparatus during use; (2) Provide for a gradual Increase In activity; (3) Evaluate the apparatus under dif ferent types of work and physical ori entation; and (4) Provide information on the op erating and breathing characteristics of the apparatus during actual use. 11.85--16 Man test 5; requirements. (a) Test 5 will be conducted to deter mine the maximum length of time the apparatus will supply the res piratory needs of the wearer while he Is sitting at rest. (b) The wearer will manipulate the devices controlling the supply of breath ing gas to the advantage of the apparatus. (c) Samples of inspiration from within the apparatus facepiece or mouthpiece shall be taken once every 15 minutes, and shall meet the minimum requirement for oxygen specified in $ 11.79(a) of this part, and the maximum allowable average concentration of carbon dioxide specified in | U.85-12(c). (d) One sample of inspiration will be taken In the case of 3-, 5-, and 10-mlnute apparatus. 11.05--17 Man test 6i requirements. (a) Man test 6 will be conducted with respect to liquefied breathing gas appara tus only. (b) This test will be conducted to eval uate operation of the apparatus In other than vertical positions. (c) The wearer will lie face downward for one-fourth the service life of the ap paratus with a full charge of liquefied breathing gas, and then a one-quarter full charge of liquefied breathing gas. (d) The test will be repeated with the. wearer lying on each side and on his back. (e) The oxygen content of the gas sup plied to the wearer by the apparatus will be continuously measured. 11.85--18 Mas tests; performance re quirements. (a) The apparatus shall satisfy the respiratory requirements of the wearer for the classified service time. (b) Fogging of the eyepiece shall not obscure the wearer's vision, and the wearer shall not experience undue dis comfort because of fit or other charac teristics of the apparatus. (c) when the ambient temperature during testing is 24*6' C. (75*10* F.), the maximum temperature of In spired air recorded during man tests shall not exceed the following, after correc tion for deviation from 24* C. (75* F.): Whcn serrlct JUt o( apparatus la-- When nranl Muboum permit- relatlre tibia temperature humidity o oduplndalr Inspired air shall not ue**d-- r. c. V hour or 1b. . h hour to hour... ] to 3 hour*............... 3 hour*........................ 4 hour*........................ 0-50 50-100 0-40 50-100 0-50 90-100 0-50 94-LOO 125 i no 115 110 1 100 104 >M 53 <a 45 a 41 >35 i When percent relatlr* humidity Is 40-100 and appa ratui U designed lot escape only, Chase maximum per missible temperature* will be Increased by 4* C. (10* 7.). 9 11.85--19 Gat tightnesa teat; minimum requirements. (a) Each apparatus will be tested for tightness by persons wearing It In an atmosphere of 1,000 p,pm. tsoamyl acetate. (b) Six persons will each wear the ap paratus In the test concentrations spec ified in paragraph (a) of this section for 2 minutes and none shall detect the odor or taste of the test vapor. Tittl 1,--DUSATIOK AKb Sti)t7INCC Of SrCCUlf ACTtVtrlka fOB TUT 1, Itf MlHPTX* (30 C7R Part 11, Subpan H, I 11.85, ttetQ.) Actlrtty * minute* 8 minute* Barrie* Urn* 10 minute* 15 minute* 30 minute* 45 rnlnut** 1 hour 3,1, and t boon Sampling and reedtnp Walk* at *J km. (3 miles) par hour................................... j Sampling and raadlags.................................................................. .................... Walk* at 4.8 km. (3 mils*) par hour................................................................ Sampling and reading!_____ __________________ ...................... Walk* at 4.8 km. (3 tnilei) par hour............. ......... ............... .... ... Rampling and reading!................................... .................................... < 3 3 3 3 Pat/lain I boor te* 3.3. or 4 time* re*p*eUraly. 4 8 13 IS 3 3 13 2 13 3 13 333 3 8 s 13 a 1a8 SfVu .. ....... . O I. : O 'J -) / T*aua.--puneaow*jtpimwaor BncgsAmiiiuifoiTtw2,mMaror** . (SO CFJt Part 11, Babpart H, | 11.86, et *eq.) Activity I minutes I minute Sampling and reading.................... ............................ ............... .. Walk* at 44 fan. 13 mlla)p*r boar....................-------- Curl* S4(H pound) weight aver.................................... OTKOlt, Walks at 4.5 km. (3 mil**) per boor............................................ Climb* vertical treadmill (or squlva- l................... .. 1. lent). Walks at 44 km. (3 mil**) per boar........................................ 1. Climbs vertical treadmill (or equivalent)............................ 1. Sampling and reading*............................................................... Walks at 4.S km. (3 mile*) per boor................................................. Climb* vertical treadmill (or ecuivalent)........___________ Carrie* 33 kg. (50 pound) walgbt orer ........ .......................... overcast. Sampling and reading*.................. .................................................... Walk* at 18 bn. (3 miles) pr hour. ................................ .. CUmb* vertical treadmill (or equivalent)............................. .. Walk* at 4.8 km. (3tn0) per hour. .................................... CUmbeverUsel treadmill (orequivalent)....................... ............. Carries 20 kg. <36 pound) weight and I 1................................ walk* at 44 km. (3 mile*) per boor. Welks at 44 fan. (SmllM) per hour. 1............... 3. Sampling and readings___________________________________ ... 10 minute Berrios Time-- 16 minute 30 minute 45 minntu j boat 1............ lUmeln J Dinatea. 1 5............ 1............ 1 Clm In 3 i..S..ll.&..1.l.t4..fl. . i.................. 2.................. 2 limes In 4 minutes. 31.............................. .. 3............ 4.................. StlmMlnfl minutes. 31...,.......................... 2a.........,............. 4 dm** In I 31....m....i..n....u..t..e....*..... ..1....................................................................................................................................................11.............................................13..................................... ............................................................. 2............................ 2.............................2...................... . ..............................3.............................2.............................8............................ t..................... .............................. 1.......................... 1.......................... 1.......................... 1..................... .............................. 1 time In 2 3 times In 6 4tlmesin8 SHmeelnlO minute*. minute*. minute*. minute*. 3............................ ............................................................ 2............................ 2.................... . .............................. 1.......................... 3.......................... 3.......... r............... 3.................. ......................................... ................. 1............................. 4____ 3.......................... 2.............................2............................ 3___ t a, x ^ KiTM " X10. time* In 10 minute*. 51.. 1. 2. 5 time* In lOminutw. Then repeat above activities once. i Total leet time lor Test 2 (or 2-hour, 3-hour, and 4-hour apparatus la 1 hours, i Treadmill shall be Inclined 15* (rom vertical and operated at a speed of 1 foot par second. TiBLX 3.--DUXitlOM 5J* flZQPXKCX 02 SHC31C ACTIYlTIIS TO* TlSI 3, IM MwtJTI* (30 C7R Fart 11. Subpart S, l 11.35, at seq.) Activity 3 minute 5 minutes 10 minate* Service time-- 16 minute* So minute* 45 minutes I boar 2, 3 end 4 hour* < Sampling and readings.....................___ Walks at 44 km. (3 miles) per hour................ Run* at 9.T km. (8 miles) per hour...... l..,,. Pull* 3 kg. (45 pound) weigbt to 5 feet........ .. Lie* on sld.........-............................... Lie* on back.. tt Crawl*on band* and knee*............. 1.. Sampling and reeding*______________ .... Run* at P.7 fan. (fi miles) per boor...... Walk* at 44 fan. (3 miles) per boor...... Full* kg. (45 pound) weight to 6 feet.. Sampling and readings................ ..... WLaklko*oatd4d4sk..m._._(3.m..il_e_s_) _pe..r.b_e_a_r_... Lit* on beck.............................................. Sampling and reading*................ .. ............. ............................................ 2.................. 2....................................... 2.......................... 2...................... ............... 1........................... 1.............................2............................ 2.......................... 3..................... 1......................... 1.......................... 1.......................... 1.......................... 1.......................... 1...................... 15 times in l .............................. 30 time* la 2 30 Umee In 2 30 times In T 60 times la 5 minute. minutes. minutes. minutes. minutes. 1........... 1........................... 2..........................3............................ 4...........................5...................... 1............................ 1........................... 2...............................2............................ 3........................... 3...................... L....................... 1......................... 3.............................2........................... 2......................... 2.................... 2..........................................................2...............................2.......................... 3...................... .............................. 1.......................... 1........................... 1.......................... 1...................... ............................................. 2............................ 8................... 10....,........ 30 times Ln 2 .............................. 80 elms* la 5 50 times In 4 60 times la 6 minute*. minute*. minutes. minute*. .............................. 2.4........................................................ *.............................2........................ 1......................................................... 3.............................4.......................... 10.................... .............................................................................................2............................ 4....................... .............................................................................................3............................ I.........-........... ............................................................. 2............................ 2............................ 2........................ "V*4 UWWLUJ, > Total tact time [or T*t 3 for 2-boor, 3-boor; and 4boar apparatus 1* 2 boors. :> R! j 7 no t.. 4.--DoKi.BOW-AM flmvbtcz or Spkjvk Acrrrmxa iqx Tsat 4, cUnw (M C7B Part U, Subpart H, 11LS6, at 1*4-) Aettrlty Bwrtuetime Iminote* I mlmila yn minnw u mlnalee JO minutes 46 minutes l bear Shows Shows 4 bows 3amplint end rsarllnp________ .... ... ............ 1.............................................. 3.....-------- 3.......... 3.......... Perform test No. 1 tor 80- Walks at 4.8 tan. (3 mflss) par hoar......................................................................... 1...................*-................... 3..................... 3..................... minute apparatus; then perform Perform Utt No. 1 tor l- hoar appara tus; than per* torra tost Perform test No. 1 tor 1hour appara tus; then per form teel Climbs Turtles] treadmill1 (or ......... I.......... 1......1.......... I-------..... 1.......... 1.......... aqulTslant). Walk* at 4.8 tan. (3 miles) per hour.......................... 1.................. 1..................1............. --..2............ -- 3........... .. 3................... Pulls 20 kg. (44 pound) weight to 1 leet. 30 tlm ao times 30 time* M times 60 time* 64 time* In 3 In 2 in 2 In'8 In E Is 6 minute*, minutes- minutes, minutes, minute*, minutes. test No. 4 for 1-hour apparatus: then perform teat No. 1 iw30-iaate appara tus. No. 4 tor 1boui appara tus: then per form test No. 1 tor 14)oor apparatus. No. 4 tx ! hour appara tus; then per form test No. t tor 1- hour apperv tua twice (l.e., two one-hour testa). Walks at 4.8 km. (Smiles} per hour... Carries 23 kg. (60 pound) welgnt orer oTercaet. Sampling and readings.......................... Walks at 43 km. (Smiles) per hour... Buna at 8.7 km. (4 miles) per hour... Carrie? ZB kg, (60pound) welghtoaer orereaat. Pulls 20 kg. (46 pound) weight to 5 IS times 1 miaat*. 1 time in 1 m(a- 2 times (a 3 mloStM. 1................... *................... i cim*s la .................................. --............................... 8 min0(4*. a............................................................ ,......................... 4......................................................................................... 1 time In 2 times la 4 time* la 6 time* In .............................. ..................................... 3 min- B min- 9 min- ut*. utes. at**. IS llmu In 1 la 6 In 2 In I mlnut*. minutes. mlrunes. minutes. Samplliig and readings......................... Walks at 4.8 km. (3 miles) per hour.. Pulls 20 kg. (46 pound) weight to 4 loet. In S la 6 minute*. minutes. Carries20kg. (44 pound) weight and walks at 4.8 km. (3 milts) per hour. Sampling and readings 2.......................2. i Treadmill shall be Inclined 13* from TerClcal and operated at a *peod of 30 cm. (1 foot) per second. df Subpart I--Gas Masks 11.90 Gas sneaks; description. ifextmum t*j< concentration, per cent by volume (a) Gas masks including all completely assembled air purifying masks which are designed for use as respiratory protection during entry into and escape or escape only from hazardous atmos pheres containing adequate oxygen to support life are described as follows: (1) Front-mounted or back-mounted gas mask. A gas mask which consists of a full facepiece, a breathing tube', a canister at the front or back, a canister harness, and associated connections. (2) Type "ff" front-mounted or backmounted gas mask. A gas mask specif ically designed to protect against add gases, ammonia, carbon monoxide, or ganic vapors, and particulate contami nants which consists of a full facepiece, breathing tube, a canister at the front or back, a canister' harness, and asso ciated connections. (3) Chin-style gas mask. A gas mask which consists of a full facepiece, a can* lster which is usually attached to the facepiece, and associated connections. (4) Escape pas. mask. A gas mask de signed for use during escape only from hazardous atmospheres which consists of a half-mask facepiece or mouthpiece, a canister, and associated connections. (b) Gas masks shall be further de scribed according to the specific gases or vapors against which they are designed to provide respiratory protection, as follows: Typ of :tront-mouDted or backmounted gas mask: Acid gu1' 1--------Ammonia * ---------------------------------------Carbon monoxide *_____________________ Organic vapors * *----------------------------- *2 9 3 *2 Maximum u* concentration, per cent by volume Type of chin-style gas mask: Acid g** * ----------------------------------------Ammonia ...................... Organic vapors*- * o. a .6 *.5 Maximum use concentration, parts per million Type of escape gas mask: Acid gas * * ___....._________ *1,000 Ammoola * 8, 000 Carbon monoxide.___......... 10,000 Organic vapor* * * . 8,000 * Approval may be for acid gases or organic vapors as a claas or for specific add gaeee, ammonia, or organic vapors. Approval may alar* be granted for combinations of acid gaeee, organic vapora, and other gases and vapor*. * Not for use against acid gaeee or organic vapor* with poor warning propertie* or which, generate high heat* of reaction with eorbent materials In the < enlster. * Suggested maximum nee concentrations ar* lower than these for eome add gases and organic vapors. 1 Eye protection may be required In certain concentration* of add gaaea, huimbi*, and organic vapors. Cc) Gas masks for respiratory protec tion against gases and vapors other than those specified in paragraph (b) of this section may be approved. The applicant shall submit a request for approval. In writing, to the Bureau of Mines, Approval and Testing, 4800 Forbes Avenue, Pitts burgh, PA 15213, listing the gas or vapor and suggested maximum use concentra tion for the specific type of gas mask. The Bureau and the Institute will con sider the application and accept or reject the application on the basis of effect on the wearer's health and safety and any field experience in use of gas mask* for such exposures. If the application Is ac cepted the Bureau will test such gas mask in accordance with the requirements of this subpart. S 11-91 Gas masks; required compo nents. (a) Each gas mask described in } 11.90 shall, where its design requires, contain the following component parts: (1) Facepiece or mouthpiece and nosecllp; (2) Canister or cartridge; (3) Canister harness; <4) External check valve: and (5) Breathing tube. (b) The components of each gas mask shall meet the minimum construction re quirements set forth in Subpart G of this part. 000057328 ir | 11.92 Cubten and exrtridjew in par. by providing one facepiece size which (b) The maximum allowable resist Del; resistance rcqniraacnta will fit varying facial shapes and sizes. ance requirements for gas masks are as Where two or more canisters or car tridges are used in parallel, their resist ance to airflow shall be essentially equal (b) Full facepieces shall provide for optional use of corrective spectacles or lenses, which shall not reduce the respi ratory protective qualities of the gas follows: ( 11.93 Canister* and cartridge*; eolor mask. and narking*; requirements. (c) Half-mask facepieces shall not in The color and markings ot all can- . terfere with the fit of common industrial triers and cartridges or labels shall con safety spectacles, as determined by the Typ* of |U muk 1 IOnill- rtnJi Uttoo form with the requirements of the Ameri can National Standard for Identification of Gas Mask Canisters, K13.1, obtainable from American National Standards In stitute, Inc., 1430 Broadway, New York, NY 10018. 8 11.94 Filter* used with canister* and cartridges; location; replacement. (a) Particulate matter filters used in conjunction with a canister or cartridge shall be located on the Inlet side of the Bureau's facepiece tests In i 11.102-3. (d) Gas masks with mouthpieces shall be equipped with noseclips which are securely attached to the mouthpiece or gas mask and provide an airtight seal. (e) Facepieces shall be designed to preven t eyepiece fogging. 811.99 Facepiece*; eyepiece*; minimum requirement*. (a) Full facepieces shall be designed and constructed to provide adequate Tront-tooanted or book-mounted (without portoulote Alter).............. to Vrout-moanted or bock-moanted Jwttb *pproved porticuUte Iter)....................................................... CblnntyU (without particulxU Alter)..............-............... ......... ............. 70 *0 Chin-tv] (with *pproTtd porUoulote Alter)______________ ________ u Escape (without parOcolaU Alter).. 60 Btcspe (With approved particulate filter).... .................................................. * * 3 470 7* U H U 74 IS i Measured at end of the terries Ilia specified In Ttblu t. 6, and T. canister or cartridge. <b) Filters shall be Incorporated In or firmly attached to the' canister or car vision which Is not distorted by the eye piece. (b) All eyepieces shall be designed and 8 11.102--2 teat. Exhalation valve leakage tridge and each filter assembly shall, constructed to meet the Impact and (a) Dry exhalation valves and valve where applicable, be designed to permit penetration requirements specified In seats will be subjected to a suction of 25 its easy removal from and replacement Federal Specification, Mask, Air Line: mm. water-column height while tn s in the canister or cartridge. 8 11.95 Breathing tubes; minimum re quirement*. (a) Flexible breathing tubes used in conjunction with gas masks shall be de signed and constructed to prevent: (1) Restriction of free head move ment; (3 > Disturbance of the fit of facepieces and Respirator, Air Filtering, Industrial, GOG-M-125d, October 11. 1965. 8 11.100 Inhalation and exhalation valve*; minimum requirement*. (a) Inhalation and exhalation valves shall be provided where necessary and protected against damage and distortion. <b) Inhalation valves shall be designed and constructed to prevent excessive ex normal operating position. (b) Leakage between the valve and valve seat shall not exceed 30 milliliter* per minute. 11.102--3 Facepiece tests; mimrauni requirement*. (a) The complete gas mask will be fitted to the faces of persons haring varying facial shapes and sizes. or mouthpieces; haled air from adversely affecting car (b) Where the applicant specifies a (3) Interference with the wearer's tridges, canisters, and filters. facepiece size or sizes for the gas mask, activities; and, (c) Exhalation valves shall be pro together with the approximate measure (4) Shutoff of airflow due to kinking, or from chin or arm pressure. | 11.96 Harnesses; Installation, and eon. traction; minimum requirements. (a) Each gas marie shall, where tected against external influence, and designed and constructed to prevent In ward leakage of contaminated air. 8 11.101 Heed hiniMKt; minimum re quirement*. ments of faces they are designed to fit. the Bureau will Insure that test subjects suit such facial measurements. (c) Any g&s mask parts which must be removed to perform the facepiece or mouthpiece fit teat shall be replaceable necessary, be equipped with a suitable (a) Faceplecee shall be equipped with without special tools and without dis harness designed and constructed to hold adjustable and replaceable head har turbing the facepiece or mouthpiece fit, the components of the gas mask In posi nesses, designed and constructed to pro (d) The facepiece or mouthpiece fit tion against the wearer's body. vide adequate tension during use and an test, mring positive or negative pressure <b) Harnesses shall be designed and even distribution of pressure over the recommended by the applicant and de constructed to permit easy removal and entire area In contact with the face. scribed in his.instructions will be used replacement of gas mask parts, and (b) Mouthpieces shall be equipped, before each test specified In paragraph where applicable, provide for holding a where applicable, with adjustable and (e) of this section, and In 111.103-4. fun facepiece In the ready position when replaceable harnesses designed and con <e> (1) Each wearer will enter a cham- not in use. structed to hold the mouthpiece in place. her containing 100 p.pm. Isoamyl acetate 8 11.97 Co* muk container*; minimum requirement*. (a) Gas muk* shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type and commercial designa 8 11.102 C* mask*; performance re quirement* ; general. Gas mnritw and the individual com ponents vaf each such device shall, as appropriate, meet the requirements for performance and protection specified In vapor for a half-mask facepiece and 1,000 p.pjn. Isoamyl acetate vapor for a full facepiece or mouthpiece. <3) The facepiece or mouthpiece may be adjusted, if necessary, in the test chamber before starting the testa (3) wearer will remain In the tion of mask It contains and all appro* the tests described in II 11.102-1 through rfiunhw for 8 minutes while performing priate approval labels. 11.10*2-5. the following activities: (b) Containers for gas masks shall 811.102--1 Breathing resistance test; <1) Two minutes, nodding and tim be designed and constructed to permit easy removal of the mask. 111.98 Half-mask facepieces, full face- piece* and mouthpieces; fit; mini mum I (a)Half-mask facepieces and full facepieces shall be designed and con structed to fit persons with various facial shapes and ilses either: (1) By provid ing more than one facepiece size, or (3) minimum requirement*. (a) Resistance to airflow will be meas ured In the facepiece or mouthpieoe of a gas mask mounted on a breathing nschine both before and after each test conducted in accordance with || 11.1023. 11.102-4, and 11.102-5, with air flow ing at a continuous rate of 85 liters per minute. ing bead; (A) Two minute*, callsthenlo ana movements; (111) Two minutes, running to anQd r) Two minutes, pumping with a a..re, pump into a 28 liter (1 cubic foot) tainer. (4) Each wearer shafi net detect e odor of isoamyl acetate during tbs to* -tt? SAL 000Q'j'7329 | 11.102--4 Dust, fane, mist, end smoke tests; canisters containing filters; minimum requirements. (a) Gas made canisters containing filters for protection against dusts, fumes, mists, and smokes In combination with gases, vapors, or gases and vapors, will be tested as prescribed in > 11.140. (b) Gas mask canisters designed for protection against smokes will be tested In an atmospheric concentration of 100 micrograms of dioctyl phthalate per liter of air at continuous flow rates of <1) 32 liters per minute, and (2) 85 liters per minute for a period of 5 to 10 seconds, and the DOF leakage through the canis ter shall not exceed 0.03 percent of the test concentration. 11.102--5 Canister bench tests; mini mum requirements. (a) (1) Bench tests, except for carbon monoxide tests, will be made on an ap paratus that allows the test atmosphere at 505 percent relative humidity and room temperature <25*:fc2.5* C.) to enter the canister continuously at concentra tions and rates of flow specified in Tables 5, 6, and 7. (2) Three canisters will be removed from containers and tested as received from the applicant. (3) Two canisters, other than those described In paragraph (a)(2) of this section, will be equilibrated at room tem perature by passing 25 percent relative humidity air through them at 64 liters per minute for 6 hours. (4) Two canisters, other than those described in paragraphs (a) (2) and (3) of this section, will be equilibrated at room temperature by passing 85 percent relative humidity aJr through them at 64 liters per minute for 6 hours. (5) The equilibrated canisters will be resealed, kept in an upright position at room temperature, and tested within 18 hours. (b) Front-mounted and back-mounted gas mask canisters will be tested and shall meet the minimum requirements set forth In Table 5. (c) (1) Front-mounted and backmounted canisters designated as Type N canisters shall have a window or other Indicator to warn the gas mask wearer when the canister will no longer satis factorily remove carbon monoxide from the inhaled air. (2) Other types of front- and back- mounted canisters may also be equipped with a window or other Indicator to warn of Imminent leakage of other gases br vapors. (3) The window indicator canisters will be tasted as regular canisters, but shall show a satisfactory Indicator change or other warning before the allowable canister penetration has occurred. (d) Chin-style gas mask canisters shall meet the minimum requirements set forth in-Table 6. (e) Escape gas mask canisters meet the minimum requirements set forth In Table 7. Tam i.__cuwtt Boa Tun uro Rxqviumxhts <ab era n. Bubpe x, \ u.ic*-*> Canister type Teet eondltten Teet atmosphera Oas or vapor Concentredon, p.pjn. TJnw reaa, 1p.m. Umbls Number pen#Wa of tte, taste p.pjn. Ulul-HM service life, minute* ' . At received............... ... so. Cl, NO. Equilibrated........... ... SO] Clt NO . Ax received............... ... CCU Equilibrated....... ... ecu . As received....... ... NH, Equilibrated...... ... NH, . As received............. ... CO CO CO ... so, Cl, NOi CC1, NH, CO CO CO Equilibrated........... . 30, Cl, No, ecu NH, 30.000 30,000 30.000 30.000 30,000 30.000 30,000 64 a M M3 4 33 4 M3 1 S 6 * 6 * 30,000 30,000 20,000 6,000 5.000 30,000 20.000 20,0(0 30,000 30,000 30,000 6,000 5.000 20.000 M 33 64 M 64 64 M 4 S3 132 33 3 2 A) 1R 1 3 a 3 52 3 3 4i 20,000 20.000 30,000 S3 4 33 4 S3 4 60 12 13 12 12 13 13 13 13 52 00 0 fl 6 0 00 00 00 0 0 0 0 i Minimum 111* will be determined at the Indicated peneWaBon. i Relative humidity of tiwt atmosphere will be 963 percent; ternjxratur* of teet atmospben vUl b 2S19*C. i Maximum allowable CO penetration will be 366 ee. during the minimum Ufa. Tbe penetrationihail not exceed 500 p.p.m. during tbla time. Relative humidity ot test etmoepbere will be 961 percent; temperature o( test atmosphere entering tb* teet fixture will be 0+1.4* C.-tr* C. Tuu 6.--Cajcstib Bixcs Tuts axd Riqctxxmihts to* CnSmt Gas Wan Camxstsu (SO era Part 11, Subpart I, i 11,103-4) Canister type Test condition Oas or vapor Teat atmoepbera Concentretion. p.p.m. Flow l.pjn. Martmtm Number allowable of peuetra- teats tloa, p.pjn. Minimum eervioe Ilf*. minute* i Add gas. Organic vapors. JUnrnoets. BO, Equilibrated................... SO, cu NO, As received........... ecu Equilibrated............... ecu As-retailed. -- NH* Equilibrated.....--... 6,000 6. OOP 6.000 6.000 6.000 A. 000 , ) ( AN 04 64 04 n 33 33 04 33 04 33 3 3 1 4 4 4 3 4 3 4 4 12 6 13 3 12 6 12 S 13 12 8 12 8 U M ( l*-", 40 i Minimum llle will be determined at tbe Indicated penetration. Tabu* 7.--Canistxb Bxkch l'MH awp Rbqudicmxmt* bo* Skats Oas Mask CAPnanax (M CPU Part U, Subpart I, | n.103-5) Canister type Teet condition Test atmosphere Oas or vapor Concent?*fltm, P-PJU. new lute, 1 p-m- l/r. Ilium, Number allowable of penetra tests tion, P-P-m- Xftntmnm service Ufe, vHnnte* 1 .. As received............... __ Equilibrated.......... .. Organic vapors.--. .. As received............... Equilibrated_______ --- k mwAidi __ As received________ __ Equilibrated............. .. Carbon monoxide.. .. As received............... .. BO, Cl, NO, SO, Cl, NO, eeccuu NH, NH, CO CO CO Aon A oon AOOO AOOO AMO A000 Aooo AOOO AOOO Aooo 10,000 AOOO AOOO 64 64 64 S3 33 13 64 83 6343 13 *33 31 16 3 6 46 43 6 3 46 4 30 3 aa n5)j 11 13 13 13 13 13 13 13 19 ii * 60 60 M i Minimum life will be determined at tba Indicated penaWaOoa. > Relative humidity ot teat atmosphere will be U1 percent; tamperatar* of teat atmosphere will be 362^ c. > Maximum allowable CO penetnSloa will be 384 ee. during tbe wiinnmmi uj*. Tbe penetration shall net exeeed 100 p.pA during this ttma. , If efUoeot tempesaturs exceeds 10CT C. during this teat, tbe seaepe gM mask shag be equipped with an <*ottv* beat exohanrw. RdaWve humidity of teet atmosphere will be 96AI percent; tampwatnra of teet atmospMs entering B>* teet fixture will be 0+3J* C.-0* C. I do not unduly interfere with the wearer's (e) Hoods and helmets shall be de vision and permit easy access to the ex signed and constructed to fit persons 9 ll.llff Supplied-air respirators* do- ternal surface of such wlndow(s) for with various head sizes, provide for the lalptioiL cleaning. optional use of corrective spectacles or <a) Supplled-alr respirators, including ell completely assembled respirators de signed for use as respiratory protection ( 11.111 Sapplled-air respirator** quired component*. re lenses, and insure against any restriction of movement by the wearer. <d> Facepieces, hoods, and helmets during mtry Into *n,1 escape from () Each supplled-alr respirator de shall be designed to prevent eyepiece hazardous atmospheres are .described as scribed In ! 11.110 shall, where Its design fogging. follows: (1) Type "A" tupplied-air respirators. A b06e mask respirator, for entry into and escape from hazardous atmospheres, which consists of a motor-driven or requires, contain the following compo nent parts: (1) Facepiece, hood, or helmet; (2) Air supply valve, orifice, or de mand or pressure-demand regulator; 11.116 Facepieces, hoods, and helmeU* eyepieces; minimum require, ments. (a) Facepieces, hoods, and helmets hand-operated blower that permits the (3) Hand operated or motor driven shall be designed and constructed to pro free entrance of air when the blower Is airblower; not operating, a strong large-diameter <4> Air supply hose; vide adequate vision which is not dis torted by the eyepiece. hose having a low resistance to airflow, a (3> Detachable couplings; (b) All eyepieces except those an harness to which the hose and the life () Flexible breathing tube; and Types B, BE, C, and CE supplled-alr line are attached and a ttght-flttlng facepiece. (7) Respirator harness. respirators shall be designed and con (b> The component parts of each structed to meet the Impact and pene (2) Type "AT* supplled-air respira supplied-alr respirator shall meet the tration requirements specified In Federal tort. A Type "A" supplled-alr respirator minimum construction requirements set Specification, Mask. Air Line, and Res equipped with additional devices designed forth in Subpart O of this part. pirator, Air Filtering, Industrial OGQ- / to protect the wearer's head and neck against impact and abrasion from re bounding abrasive material, and with shielding material such as plastic, glass, woven wire, sheet metal, or other suitable material to protect the window(s) of facepieces, hoods, and helmets which do not unduly Interfere with the wearer's viedan and permit easy access to the ex ternal surface of such wlndow(s) for cleaning, (3) Type mpplied-air respirators. A hose mask respirator, for entry Into and escape from atmospheres not im mediately dangerous to life or health, which consists of a strong large- diameter hose with low resistance to air flow through which the user draws Inspired air by means of his lungs alone, a hamaaa to which'the hose Is attached, and a ttght-flttlng facepiece. <4) Type supplied-air respira tors. A type "B" supplied-air respirator equipped with additional devices de signed to protect the wearer's head and neck against Impact and abrasion from rebounding abrasive material, and with bidding material such as plastic, glass, woven wire, sheet metal, or other suit able material to protect the wlndow(s) of facepieces, hoods, and helmets which 11.112 Breathing tubes; minimum re quirements. (a) Flexible breathing tubes used In conjunction with supplled-alr respirators shall be designed and constructed to prevent: (1) Restriction of free head move ment; (2) Disturbance of the fit of facepieces, mouthpieces, hoods, or helmets; (3) Interference with the wearer's ac tivities; and (4) Shutoff of airflow due to kinking, or from chin or arm pressure. 11.113 Harnesses; installation and construction* minimum require ment*. (a) Each supplied-air respirator shall, where necessary, be equipped with a suitable harness designed and con structed to hold the components of the respirator In position against the wear er's body. (b> Harnesses shall be designed and constructed to permit easy removal and replacement of respirator parts, and where applicable, provide for holding a full facepiece In the ready position when not in use. M-125d, October 11, 1063. (c) (1) The eyepieces of AE, BE, and CE type supplled-alr respirators shall be shielded by plastic, glass, woven wire, sheet metal, or other suitable material which does not Interfere with the vision of the wearer. (2) Shields shall be mounted and at tached to the facepiece to provide easj access to the external surface of the eye piece for cleaning. 11.117 Inhalation and exhalation valves * check valves * minimum re quirement*. (a) Inhalation and exhalation vslves shall be provided where necessary and protected against distortion. <b) Exhalation valves shall be: (1) Protected against damage and ex ternal influence; and <2) Designed and constructed to pre vent Inward leakage of contaminated air. (c) Check valves designed and con structed to allow airflow toward the face piece only shall be provided In the con nections to the facepiece or in the hoee fitting near the facepiece of all Type A, AE, B, and BE supplled-alr respirators. ( 11.118 Head harnesses* minimum re quirements. i do not unduly interfere with the wearer's vision and permit easy access to the external surface of such wlndow(s) for cleaning. (i> Titp*2C" suppHed-a&respiraton. An airline respirator, for entry Into and escape from atmospheres not immedi 11.114 Respirator containers; mini mum requirements. Supplled-alr respirators shall be equipped with a substantial, durable con tainer bearing markings which show the applicant's name, the type and commer cial designation of the respirator It con Facepieces shall be equipped with ad justable and replaceable head harnesses which are designed and constructed to provide adequate tension during use, and an even distribution of pressure over the entire area In contact with the face. ately dangerous to life or health^ which tains, and all appropriate approval labels. fi 11.119 Head and neck protection; sup- consists of a sourcesof respirable breath plied-air respirator*; minimum re ing air, a hose, a detachable coupling, 11.115- Half-mask facepieces, full quirements. a control valve, orifice, a demand valve or pressure demand valve, an arrange ment for attaching the'-hose to the wearer, and a facepiece, hood, or helmet. (6) Type "CE" tuppUed-air respira tors. A type MC" supplled-alr respirator facepieces, hoods, and nelmets; fit* minimum requirements. (a) Half-mask facepieces and full facepieces shall be designed and con structed to fit persona with various facial shapes and sines either (1) by providing Type AE, BE, ahd CE supplied-air respirators shall be designed and con structed to provide protection against Impact and abrasion from rebounding abrasive materials to the wearer's head equipped with additional devices de more than one facepiece size, or (2) by and neck. signed to protect the wearer's head and neck against Impact and abrasion from rebounding abrasive material, and with htddtng material such as plastic, glass, woven wire, sheet metal, or other suit providing one facepiece size which will fit varying facial shapes and sires. (b) Full facepieces shall provide for optional use of corrective spectacles or lenses, which shall not reduce the res 8 11.120 Air velocity and noise level** hoods and helmets* minimum re quirements, Holse levels, generated by the respira able material to protect the window (s) piratory protective qualities - of the tor will be measured inside the hood or of facepieces, hoods, and helmets which respirator. helmet at maximum airflow obtainable SAL 00005733:!. minute through each completely as sembled respirator. Each respirator shall 911.121 Breathing |u; minfariin re quirement*. (a) Breathing gas used to supply supplied-ali respirators shall be respirable breathing air and contain no less than 19.5 volume-percent of oxygen. <b) Compressed, gaseous breathing air be equipped with the wwimnm length of hofMt with which the device Is to be ap proved and the hose be connected to each blower or manifold outlet de signed for hose connections. (b) The crank speed of the hand- operated blower shall not exceed 50 revolutions par minute in order to de shall meet the applicable minimum grade requirements for Type I gaseous air set forth In the Compressed Gas Associa tion Commodity Specification for Air, 0-7.1 (Grade D or higher quality) <e) Compressed, liquefied breathing liver the required 50 liters of air per minute' to each facepiece. (cl The power required to deliver 50 liters of air per minute to each wearer through the maximum length of hose shall not exceed one-fiftieth horsepower, air meet the applicable minimum and the torque shall not exceed a force grade requirements for Type H liquid air set forth in the Compressed Gas Association Commodity Specification for Air. G-7.1 (Grade B or higher quality). of 2.3 kg. (5 pounds) on a 20 cm. (8-Inch) crank, as defined In ! 11.124-3. (d) The blower shall operate through out the period without failure or Indica 9 11.122 Air *upply source; hand-oper tion of excessive wear of bearings or ated or motor driven air blower*; other working parts. Type A *upplid-air respirator*; min | 11.124--2 Motor-operated blower teat; imum requirements. minimum requirements. (a) Blowers shall be designed and constructed to deliver an adequate amount of air to the wearer with either direction of rotation, unless constructed to permit rotation in one direction only, and to permit the free entrance of air to the hose when the blower is not operated. <b) No multiple systems, whereby more than one user is supplied by one blower, will be approved, unless each hose line Is connected directly to a manifold at the blower. (a) Motor-operated blowers shall be tested by operating them at their speci fied running speed 8 to 8 hours dally for a period of 100 hours when assembled with the kind and maximum length of hose for which the device Is to be ap proved and when connected to each, blower or manifold outlet designed for hose connections (b) The connection between the motor and the blower shall be so constructed that the motor may be disengaged from the blower when the blower is operated 9 11.123 Terminal fittings or chambers; Type B snpplied-air respirator*; min imum requirements. by hand. (c) The blower shall operate through out the period without failure or indica (a) Blowers or connections to air supplies providing positive pressures shall not be approved for use on Type B supolied-alr respirators. <b) Terminal flttinft or chambers employed In Type B supplied-air respi rators. shall be; (1) Installed in the inlet of the hose; tion of excessive wear of bearings or other working parts. (d) Where a blower, which is ordi narily motor driven, la operated by hand, the power required to deliver 50 liters of air per minute to each wearer through the maximum length of hose shall not exceed one-fiftieth horsepower, and the torque shall not exceed a force of 2.3 kg. (3) Designed and constructed to pro (5 pounds) on a 20 cm. (8-inch) crank, vide for the drawing of air through cor as defined In f 11.124-3. rosion resistant material arranged so as (e) Where the respirator la assembled to be capable of removing material larger with the facepiece and 15 m. (50 feet) than 0.149 mm. In diameter (149 mi of the hose for which It is to be approved, crometers, 100-mesh. 7.3. Standard and when connected to one outlet with sieve). all other outlets closed and operated at (3) Installed to provide a means for a speed not exceeding 50 revolutions of fastening or anchoring the fitting oi the crank per minute, the amount of air chamber In a fixed position in a zone of delivered Into the respiratory-inlet cov respirable air. ering shall not exceed 150 liters per ^minute. 9 11.124 Supplled-air respirator*; per formance requirement*; general. 9 11.124--3 Method of measuring the Supplied-air respirators anH the in dividual components of each such device shall, as appropriate, meet the require ments for performance and protection specified In the tests described In If 11.124-1 through 11.124-24. 9 11-124-1 Hand-operated blower teet{ minimum requirement*. (a) Hand-operated blowers shall be tested by attaching them to a mechanical drive and operating them 6 to 8 hours dally for a period of 100 home at a speed necessary to deliver 50 liters of air per Sower and torque required to operate lower*. As shown In Figure 1, the blower crank is replaced by a wooden drum, a (13 cm. (5 inches) in diameter Is convenient). This drum Is wound with about 12 m. (40 feet) of No. 2 picture cord. t>. A weight, c, of sufficient mass to rotate the blower at the desired speed Is suspended from this wire cord. A mark is made on the cord-about 3 to 4.5 a. (10 to 15 feet) from the weight, c. Another mark Is placed at a measured distance (6-Q m./ 20-30 feet is convenient) from the first. These are used to facilitate timing. To determine the torque or horsepower re quired to operate the blower, the drum is started in rotation manually t or slightly above the speed at which the power measurement is to be made. The blower is then permitted to aasnmg con stant speed, and then as the first mark on the wire leaves the drum, a stopwatch is started. The watch is stopped when the second mark leaves the drum. From these data the foot-pounds per minute and the torque may be calculated. 11.124-4 Type B supplied-air respira tor ; minimum requirement*. No Type B supplled-air respirator shall be approved for use with a blower or with connection to an air supply de vice at positive pressures. 11.124--5 Type C supplied.air respira tor, continuous flow da**; minimum requirement*. (a) Respirators tested under this sec tion shall be approved only when they supply respirable air at the pressures and quantities required. (b) The pressure at the inlet of the hose connection shall not exceed 883 kN/m*. (125 pounds per square inch gage). (c) Where the pressure at any point In the supply system exceeds 863 kN/m.1 (128 pounds per square Inch gage), the respirator shall be equipped with a pres sure-release mechanism that will prevent the pressure at the hose connection from exceeding 883 kN/m.1 (125 pounds per square Inch gage) under any conditions. 11.124--5 Type C *upplied-air respira tor, demand and pm<nre demand da**; minimum requirements. (a) Respirators tested under this sec tion shall be approved only when used to supply respirable air at the pressures and quantities required. (b) The manufacturer, shall specify the range of air pressure at the point of attachment of the air-supply hose to the air-supply system, and the range of hose length for the respirator. For example, he might specify that the respirator be used with compressed air at pressures ranging from 280-550 kN/m.* (40 to 80 pounds per square Inch) with from 8 to 76 m. (15 to 250 feet) of air-supply hoee. (c) The specified air pressure at the point of attachment of the hose to the air-supply system shall not exceed 863 kN/m.* (125 pounds per square inch gage), (d) (1) Where the-pressure in the air, supply system exceeds 863 kN/m.* (125 pounds per square inch gage), the res pirator shall be equipped with a pres sure-release mechanism that will pre vent the pressure at the point of attach ment of the hose to the air-supply sys tem from exceeding 863 kN/m.* (125 pounds per square Inch gage). (2) The pressure-release mechanism shall be set to operate at a pressure not more than 20 percent above the manu facturer's highest specified pressure. For example, if the highest specified pres sure Is 863 kN/m.* (123 pounds per square inch), the pressure-release mechanism O0005733L SAL 115 would be set to operate at a maximum of 1,035 kN/m.' <150 pounds per square Inch) g 11.124--7 Air-supply lin teats; minimum rwpiirtmenla. Air supply line* employed on Type A, Type B, and Type C supplled-alr respi rators shall meet the minimum test re quirements set forth in Table 8. | 11.124-3 Hmtu lest; minimum re quirements. <a) (1) Shoulder straps employed on Type A supplied-air respirators shall be tested for strength of material, joints, and seams and must separately with stand a pull of 113 kg. (250 pounds) for 30 minutes without failure. (2) Belts, rings, and attachments for life tinea must withstand a pull of 138 kg. <300 pounds) for 30 minutes without failure. (3) The hose shall be firmly attached to the harness so as to withstand a pull of 113 kg. <250 pounds) for 30 minutes without separating, and the hose at tachments shall be arranged so that the pull or drag of the hose behind an ad vancing wearer does not disarrange the harness or exert pull upon the facepiece. (4) The arrangement and suitability of all harness accessories and fittings will be considered. <b) <1) The harness employed on Type B supplled-alr respirators shall not be uncomfortable, disturbing, or Interfere with the movements of the wearer. (2) The harness shall be easily adjust able to various sizes. (3) The hose shall be attached to the harness In a manner that will withstand a pull of 45 kg. <100 pounds) for 30 min utes without separating or showing signs of failure. <4) The design of the harness and attachment of the line shall permit drag ging the maximum length of hose con sidered for approval over a concrete floor without disarranging the harness or exerting a pull on the facepiece. <5) The arrangement and suitability of all harness accessories and fittings will be considered. <c) The harness employed on Type C respirators shall be similar to that re quired on the Type B respirator, or, Jt may consist of a simple arrangement for attaching the hose to a part of the wear er's clothing In a practical manner that prevents a pull equivalent to dragging the maximum length of the hose over a concrete floor from exerting puQ upqji the respiratory-inlet covering. (d> Where supplled-alr respirators have a rigid or partly rigid head covering, a suitable harness shall be required to assist in holding this covering in place. 111.124-9 Breathing taha test; mini mum requirements, (a) (1) Type A and Type B supplledalr respirators shall employ one or two flexible breathing tubes of the nonkinking type which extend from the facepiece to a connecting hose coupling attached to the belt or harness. <2) The breathing tubes employed shall permit free head movement, insure against closing off by kinking or by chin or arm pressure, and they shall not create a pull that will loosen the facepiece or disturb the wearer. <b> Breathing tubes employed on Type C supplled-alr respirators of the con tinuous flow class shall meet the mini mum requirements set forth In paragraph <a) of this section, however, an exten sion of the connecting hose may be em ployed In heu of the breathing tubes required. (c) (1) A flexible, nonklnking type breathing tube shall: (1) Be employed on Type C supplied-air respirators of the demand and pressure-demand class: and <11) extend from the facepiece to the de mand or pressure-demand valve, except where the valve Is attached directly to the facepiece. <2) The breathing tube shall permit free bead movement, Insure against clos ing off by kinMng or by chin or arm pres sure, and shall not create a pull that will looeen the facepiece or disturb the wearer. 11.124--10 Airflow resistance test. Type A and Type AE supplied-air res pirators i minimum requirements. (a) Airflow resistance will be deter mined when the respirator Is completely assembled with the respiratory-inlet covering, the alr-supply device, and the maximum length of air-supply hose colled for one-half Its length In loops 1.5 to 2.1 m. (5 to 7 feet) in diameter. <b) The Inhalation resistance, drawn at the rate of 85 liters (3 cubic feet) per minute when the blower Is not operating or under any practical condition of blower operation shall not exceed the following amounts: Maximum length si has* (or irblch respirator is approved Maximum rastsUnea, water column height Psst KltM Xnhs MUllmsUrt IS 9 LI ss ISO M IS 94 2A0 79 S.S M too n 4.0 UB <e) The exhalation resistance shall not exceed 25 mm. (1 inch) of water-column height at a flow rate of 85 liters <3 cubic feet) per minute when the blower Is not operating or under any practical condi tion of blower operation. 9 11.124-11 Airflow resistance test; Type B and Type BE supplied-str res pirators ) minimum requirement*. (a) Airflow resistance shall be deter mined when the respirator is completely assembled with the respiratory-inlet covering and the bose In the maximum length to be considered for approval, colled is loops 1.5 to-2.1 m. <5 to 7 feet) In diameter. (b) Airflow resistance shall not exceed 38 mm (1.5 inches) of water-column height to air drawn at the flow rate of 85 liters <3 cubic feet) per minute. <o> The exhalation resistance shall not exoeed 2ft mm. (l inch) of water-col umn height at this flow rate. 9 11.124--12 Airflow resistance lest; Type C supplied-sir respirator, eon. tinuous Row class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the respirator shall not exceed 35 mm q Inch) of water-column height when the air flow Into the respiratory-inlet cover ing U115 liters (4 cubic feet) per minute. 9 11.124-13 Airflow resistance test; Typ C supplied-air respirator, de mand class; minimum requirements. (a) Inhalation resistance shall not ex ceed 50 millimeters (2 Inches) of water at an air flow of 115 liters (4 cubic feet) per minute. (b) The exhalation resistance to a flow of air at a rate of 85 liters (3 cubic feet) per minute shall not exceed 25 milli meters (1 inch) of water. 11,124--14 Airflow resistance lest; Type C supplied-air rsepirator, pressure-demand class; minimum requirements. <a) The static pressure in the facepiece shall not exceed 38 mm. (1.5 Inches) of water-column height. (b) The pressure In the facepiece shall not fall below atmospheric at Inhalation airflows less than 115 liters <4 cubic feet) per minute. (c) The exhalation resistance to a flow of air at a rate of 85 liters (3 cubic feet) per minute shall not exceed the static pressure In the facepiece by more than 51 mm. (2 Inches) of water-column height. 11.124--13 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be subjected to a suction of 25 mm. water-column height while in a nor mal operating position. (b) Leakage between the valve and valve seat shall not exceed 30 milliliters per minute. 9 11.124--16 Man tet* for gases and vapors; supplied-air respirators; gen eral performance requirements. (a) Wearers will enter a chamber con taining a gas or vapor as prescribed In ff 11.124-17, 11.124-18, 11.124.19, and 11.134-20. (b) Each wearer will spend 10 minutes in work to provide observations on free dom of the device from leakage. The freedom and comfort allowed the wearer win also be considered. (c) Time during the teat period win be divided as follows; (1) five minutes. Walking, turning head, dipping chin; and (3) five minute*. Bumping air with a tire pump into a 28-llter Cl eublo foot) container, or equivalent work. (d) !?o odor of the test gas or vapor shall be detected by the wearer in the air breathed during any such test, and the wearer shall not be subjected to any undue discomfort or encumbrance be cause of the fit, air delivery, or other features of the respirator during the testing period. 116  11.124-17 Mon tot for {** uJ npon< Type A and Type AE respira tor* ; tot requirement*, (a) The completely assembled respi rator will be worn In a chamber contain ing 0.1 0.025 percent Isoamyl acetate vapor, and the blower, the Intake of the hose, and not more than 25 percent of the hose length will be located in isoamyl acetate-free air. (b) The man In the lsoamyl acetate atmosphere will draw his Inspired air through the hose, connections; and all parts of the air device by means of his lungs alone (blower not operating). (c> The 10-mlnute work test will be repeated with the blower In operation at any practical speed up to 50 revolu tions of the crank per minute, { 11,124--18 Man tet for gate* and vapor*; Type B and Type BE respira tor* ; test requirements. (a) The completely assembled respi rator will be worn in a chamber contain ing 0,10.025 percent lsoamyl acetate vapor, and the intake of the hose, and sot more than 25 percent of the hose length will be located in lsoamyl acetatefree air. (b) The man in the lsoamyl acetate atmosphere will draw his inspired air through the hose and connections by means of his lungs alone. 11.124--19 Man let for gase* and vapor* i Type C respirator*, eontinaoa*.flow class and Type CE supplied- air respirator* ; lest requirement*. (a) The completely assembled respi rator will be worn in a chamber contain ing 0 1 0.025 percent lsoamyl acetate vapor, the intake of the hose will be connected to a suitable source of respi rable air, and not more than 2ft percent of the hose length will be located In lsoamyl acetate-free air. (b) The minimum flow of air required to TrtfllT,tAin a positive pressure In the respiratory-inlet covering throughout the entire breathing cycle will be sup plied to the wearer, provided however, that airflow shall not be less than 115 liters per minute for tight-fitting and not leas than 170 liters per minute for loosefitting respiratory inlet-coverings. (c) The test will be repeated with the mn.Tjmiim rate of flow attainable within specified operating pressures. 11.124--20 Man test for gasee and vapor* i Type C nipplied-air respire*tor*, demand and preuaiedeminS classes; lest requirement*. (a) The completely assembled respi rator will be worn In a chamber contain ing O.lmO.025 percent lsoamyl acetate vapor, the Intake of the hose will be con nected to a suitable source of respirable air, and not more 25 percent of the hose length will be located in lsoamyl acetate free air. (b) The test will be conducted at the minimum pressure with the maximum hose length and will be repeated at the maximum pressure with the minimum hose length. | 11.124-21 Test* for protection during abrasive blasting; Type AE, Type BE, and Type CE supplied-air respirator*; gener*rperforwiance requirement*. (a) Tests will be mads under condi tions of typical abrasive blasting opera tion. (b) The tests prescribed In }S 11.124- 22, 11.124-23, and 11.124-24 will be con ducted under the following conditions: (1) A suction-feed abrasive blasting outflit will be used by the wearer; (2) The diameter of the air Jet shall be 5 mm. (A inch); (3) Air pressure will be 276--483 kN/ m.' (40-70 pounds per square inch); (4) The abrasive used will contain a composition of 99+ percent free silica (810,); (5) The size properties of the abrasive used will be a mixture of 90 percent by weight of essentially No. 1 sandblast sand and 10 percent air-floated fines; and (6) The No. 1 sand used will meet a size specification of not more than 10 percent on a 20-mesh sieve and not more than 10 percent through a 35-mesh sieve; 99+ percent of the fines will be able to pass through a 270-mesh sieve. All size determinations will be made by standardmesh sieves. <c) Tests will be conducted for 30 min utes continuously. (d) (1) The person wearing the res pirator will sandblast the inside surface of a common Iron kettle of approximate hemispherical shape (about 76 cm. (30 inches) In diameter, and 113.6 liters (30 gallons) capacity). (2) The kettle will be placed with the plane of the opening inclined 45* from a vertical position and with the lowest point of the rim at about the height of the person's hips. (3) The wearer will stand at one posi tion In front of the kettle and lean over until the upper part of the body is In clined to parallel the face of the kettle. (4) The wearer will blast the entire Inner surface of the kettle with the blast at all times directed approximately at right angles to the surface with the noz zle of the gun approximately 15 cm. (6 Inches) from the surface, and with his head approximately 46 cm. (18 Inches) from the nozzle. (5) The wearer will move his head for ward, backward, and sideways during each blasting operation. (e> (1) Air will be withdrawn continu ously diming the test at the rate of 32 liters (1.19 cubic feet) per minute from the respiratory-inlet covering at a point a* near as convenient to the wearer's nostrils. (2) Simultaneously air will be drawn at the same rate from the source of In take air to the respirator. (f) Respirators tested In accordance with || 11.124-23, 21.224-33, and 11.124-24 shall meet the following mini mum requirements: (1) The amount of particulate matter tti the air withdrawn from the resplratory-lnlet covering shall not exceed the amount of particulate matter supplied to the respirator by more than 0.5 mg. for the 30-minute test period; (2) The wearer of .the respirator in this test shall not experience undue en cumbrance and discomfort because of the fit. air delivery, or other features of the respirator; and. (3) The head and shoulder covering shall adequately protect the wearer from `discomfort or injury due to im pact or abrasion from the rebounding material during the test. 11.124--22 Teal for protection during abrasive blasting; Type AE supplied* air respirator; lest requirements. (a) The respirator will be arranged as prescribed In I 11.124-l7(a), and the tests prescribed in ] 11.124-21 will be performed. (b) The wearer will draw his In spired air through the hose, connec tions. and all parts of the air device by means of his lungs alone (blower not operating), (c) The test will be repeated with the blower in operation at any practical speed up to 50 revolutions per minute of the crank. 11.124--23 Test for protection during abrasive blasting; Type BE supplied* air respirator; teat requirement*. (a) The respirator will be arranged as prescribed In | 11.124-18(a), and the tests prescribing in { 11.124-21 will be performed. (b) The wearer will draw his Inspired air through the hose, connections, and all parts of the air device by means of his lungs alone. 11.124--24 Test for protection during abrasive blasting; Type CE supplied* air respirator; teat requirements. (a) The respirator will be arranged as prescribed In ! 11.124-19(a), and the tests prescribed in 111.124-21 will be performed. Hgur* 1.--Apparatus for measuring power required to operate blower, (80 CTR Part 11, Subpart J, 111.134-3) c; j () 0 0 0 5 / 3 o 117 Ti>lx g.--Ara-8trm.T-LiNx Hbquuzkknts ind Tun (30 CFR Fart II, Subpart J, { 11.124-7} flpeolfle requirement* Requirements tor the elr-supply lines o( the Indicated type of supplied-air resplratori Type A Type B Type C Length of bose... Maximum ol 91 tn. (300 feet). In multiple* of 7.6 m. (24 feet). Maximum of 23 m. (76 feet) Id multiple* of 7.6 id. (24 feet). Airflow...................None.......................................... None. Air-regulating None.... .................................. Non*. valve. Maximum of 91 m. (J00 feet) la multiple* of 7.6 m. (24 feel). It will be permissible for the applicant to supply hose of the approved type of shorter length then 7.6 m. (26 feet) provided It meet* the requirement* of the pert. The sir-supply hose with sir regulating velve or orifice shell permit e flow of not less than 116 liters (4 cubic feet) per minute to tight-fitting end 170 liters (6 cubic feet) per minute to loosefitting resplretory-lolet covering* through the maximum length of hose for which approval Is granted end at the minimum specified air-supply pressure. The maximum flow shall not exceed 426 liters (16 cubic feet) per minute at the maxi mum specified air-supply pressure with the mini mum length of hosefor which approval Is granted. The air-supply hose, detachable coupling, and de mand valve of the demand class or pressuredemand valve of the pressure-demand class for Type C suppUed-alr respirators, demand and pressure-demand classes, shall be capable of delivering respirable air at a rate of not less than 116 liters (4 cubic feet) per minute to the resplratory-lnlat coveting at an Inhalation resistance not exceeding 60 millimeters (2 Inches) of watercolumn height measured In the respiratory-inlet covering with any combination of air-supply pressure and length of hose within the applicant's specified range of pressure and hose length. The air-flow rate and resistance to Inhalation shall be measured while the demand or pressure-demand valve Is actuated 20 times per minute by a source of Intermittent suction. The maximum rats of flow to tbs resplratory-Inlct covering shell not exceed 426 liters (16 cubic feel) per minute under the specified operating conditions. If an alr-regulallog valve Is provided, It shell be so designed that It will remain at b specific adjustment, which will not be affected try the ordinary movement of the wearer. The valve must be so constructed that the air supply with the maximum length of hose and at the minimum specified air-supply pressure will ot be less than 116 liters (4 cubic feet) of afr per minute to tight-fitting and 170 liters (6 cubic feet) of air per minute of loose-fitting respiratory Inlet coverings for any adjustment of the valve. If a demand or pressure-demand valve replaces the air-regulating valve, It shall be connected to the alr-aupply at the maximum air pressure for which approval Is sought by means of tbs minimum length of alr-eupply hose for which approval is sought. The outlet of the demand or pressuredemand valve shall be connected to a source of Intermittent suction so that the demand or Sressure-demand valve Is actuated approximately ) times per minute for a total of 100,000 inhala tions. To expedite this test, the rate of actuation may be Increased If mutually agreeable to the applicant and the Bureau. During this test the valve shall function without tallure and without excessive wear of the moving parts. The demand or prassure-demand valve shell not be iamsgtd tn any w*y when subjected et the outlet to pressure or suction of 24 cm. (10 Inches) of water gage lor 2 minutes. s SAL 0000b 118 < Tiblz 8---Ar-Surn.T-LlNx RxqpUBXBtm snd Tun-Continned (30 CFR Put 1!, Subput I, 111.194-7) Specific requirement! Requlrements-lor the air-supply Unas of Uiindicated type, QUoppUtd-Ur respirator. TypeA Type B ' Typed '--------- NoncoHspsibllllj. NonYlnkabillty. Strength of hose end couplings. Tfghtnoss. Permeation ot hose by gasoline. Detachable coupling. The hose shell act collapse oi exhibit permanent defonnalion when e (ores ot 90 kg. (TOO pounds) is applied (or S minutes between 2 planes 7.6 cm. (3 inches) wide on opposite sides of the hose. None................................... Bose end couplings shell not separate or fell when tested with a pull of 113 kg. (260 pounds) (or fi minutes. No air leakage shall occur when the hose and couplings are Joined aud the Join t(s) are immersed In water and subjected to an Internal air pressure of 36 kN/m.1 (S pounds per square loch) gage. The permeation of the hose by gasoline will be tested by Immers ing 7,9 m. (26 feet) of hose and one coupling In gasoline, with air flowing through the hose at the rate of t liters per minute for 6 hours. The air from the hose shall not contain more than 0.01 percent by volume of gasoline vapor at the end of the Cast. None.......................... Batne as Type A.- None. None........................... A 7.6 m. (25 foot) section of the hose will be placed on a borliontal-plaoe surface and shaped Into a - one-loop coll with pne and of the hose connected to an airflow meter and the other end of the hose supplied with air at the minnmim specified supply pressure. The connection shall be In tbs plane of tbs loop. Tbeotber end of the hose will be pulled tangentially to the loop and la the plane oi the loop until the hose straightens. To meet the requirements of this test the loop sball maintain a uniform near-circular shape and ultimately unfold as a spiral, without any local ised deformation that decreases the flow of air to less than SO percent of the flow w.ben the hose Is tested while remaining in a straight line. Same as Type A.. Hose and couplings sball not exhibit any separation or failure when tested with a pull of 46 kg. (100 pounds) far 6 minutes and when tested by *ul> JectiDg them to an internal air pressure of 2 times the maximum respirator-supply pressure that Is specified by the applicant or at 173 kN/m.' <26 pounds per square Inch) gage, whichever Is higher. None........................... Leakage of air exceeding 60 cc. per minute at each coupling shall not be permitted when the bosoand couplings are Joined and are Immersed In water, with air flowing through the respirator under a pressure of 173 kN/m.1 -(26 pounds per square inch) gaga applied to the Lillet end of the sir-sup ply hose, or at twice the rnarlmum respiratorsupply pressure that la specified by the applicant, whichever Is higher. Same as for Type Same as for Type A, except the test period shall be A. 1 hour. None........................... A hand-operated detachable coupling by which the wearer can readily attach or detach the con necting bose (hall be provided at a convenient location. This coupling shall be durable, remain connected under all conditions of normal res pirator use, and meet the prescribed tests for strength and tightness of boseand couplings. S 1 0 0 0 0 :/ 7 3 3 119 td dusts, or dusts and mists. Including but not limited to aluminum, asbestos, coal, g 11.130 IhisL, fame, and miat respira tor.; description. Dust, fume, and mist respirators, in cluding all completely assembled respi rators designed for use as respiratory protection during entry Into and escape flour, iron ore, and free silica. more than one facepiecei2,w**3E (1) The types of dust, fume, and mist providing one facepleiT.u ' w U>h! respirators in paragraphs (a) through facia! (g) of this section may also be classified Cb) Full laceplecessti?,4 ^ according to their design as follows: optional use of eorJJctW?1. ****** 1 (1) Air-purlfylng respirators; and lenses, which * (2) Powered air-purlfylng respirators. Jtory protective quaiitlC ^^ from hazardous particulate atmospheres 11,131 Dual, fume end mi*t respira which contain adequate oxygen to sup tors; required components. port life, are described as follows: (a) Respirators, either with replace able or reusable filters, designed as res piratory protection against dusts <l) having an air cnnta.mi'nw.tlon level not less than. O'JIS milligram per cubic meter of air, including but not limited'to coal, arsenic, cadmium, chromium, lead, and manganese; or (2) dusts having an air contamination level not less than 2 mil lion particles per cubic foot of air, in cluding but not limited to aluminum, flour, iron ore, and free silica, resulting principally from the disintegration of a solid, e.g., dust clouds produced In min (a) Each dust, fume, and mis respi rator described in 5 11.130 shall, where its design requires, contain the following component parts: i (1) Facepiece, mouthpiece with nose- clip. hood, or helmet; (2) Filter unit; (3) Harness; (4) Attached blower; and (5) Breathing tube, (b) The components of each dust, fume, and mist respirator shall meet the minimum construction requirements set forth in Subpart O of this part- (c) Hoods and helmets 5h.n v signed and constructed to fit * **' various head sises, pro"Je ^ tional use of corrective sDeet^!?* lenses, and insure against anY^S? ,<* of movement by the wearer tr1cUi (d) Mouthpieces shall fe- , with nosecltps which are Wei^Pc^ tached to the mouthpiece or SjL?' and provide an airtight seal pLmf (e) Facepieces, hoods, and SU*des^ ** 5SS terfere with the'fit??commontosSSS] safety corrective spectacles, a* ing, quarrying, and tunneling, and in 11.132 Breathing tubes; minimum re mined by the Bureau's facepiece testTi* dusts produced during industrial opera quirements. }! 11.140-1 and 11.140-2. 10 tions, such as grinding, crushing, and the general processing of minerals and other materials. <b> Respirators, with replaceable fil ters, designed as respiratory protection against fumes of various metals having an air contamination level not less than 0.05 milligram per cubic meter, includ ing but not limited to aluminum, anti mony, arsenic, cadmium, chromium, cop per, iron, lead, magnesium, manganese, mercury (except mercury vapor), and xlnc. which result from the sublimation or condensation of their respective vapors, or from the chemical reaction between their respective vapors and gases. (c) Respirators, with replaceable Al tera, designed as respiratory protection against mists of materials having an air contamination level not less than 0.05 milligram per cubic meter or 2 million particles per cubic foot, e.g., mists pro duced by spray coating with vitreous enamels, chromic acid mist produced during chromium plating, and other mists of materials whose liquid vehicle does not produce harmful gases or vapors. Cd) Respirators, with replaceable fil ters, designed as respiratory protection gainst dusts, fumes, and mists having an air contamination level less than 0.05 milligram per cubic meter, Including but not limited to lithium hydride artti iJeryl- Uum, and against radionuclides.' (e) Respirators, with replaceable fil ters, designed as respiratory protection against: radon daughters, and ration daughters attached to dusts, fumes, and mists, <f> Respirators, with replaceable fil ters, designed as respiratory protection against asbestos-containing dusts and mists. <g) Respirators, with replaceable fil ters, designed as protection against var ious combinations of particulate matter. (h) Single-use dust respirators de signed as respiratory protection against pneumoconiosis- and fibrosis-producing (a) Flexible breathing tubes used In conjunction with respirators shall be de signed and constructed to prevent: (1) Restriction of free head move ment: <2) Disturbance of the fit of facepieces, mouthpieces, hoods, or helmets; <3> .Interference with the wearer's ac tivities: and (4) Shutoff of airflow due to kinking, or from chin or arm pressure. 11.133 Harneese*; installation and conatruction; minimum require ments. (a,) Each respirator shall, where nec essary, be equipped with a suitable har ness designed and constructed to hold the components of the respirator in po sition against the wearer's body- lb) Harnesses shall be designed and constructed to permit easy removal and replacement of respirator parts, and, where applicable, provide for holding a full facepiece in the ready position when not in use. 11.134 Respirator containers; mini mum requirements. (a) Except as provided In paragraph (b) of this section each respirator shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type of respira tor Is contains, and all appropriate ap proval labels. (b) Containers for single-use respira tors may provide for storage of more than one respirator, however, such con tainers shall be designed and construct ed to prevent contamination of respira tors which are not removed, and to pre vent damage to respirators during trans it, 11.135 Half.ma.k facepieces, fuQ facepieces, hoods, helmets, and mouthpieces; fit; minimum require ments. (a) Half-mask facepieces and fuB facepieces shall be designed and con- 11.136 Facepieces, hoods, and h*l met.; eyepieces; minimum r*TMifT menu. ^ p^ Facepieces, hoods, and helmets shall h* " designed and constructed to provide ade quate vision which Is not distorted by tsi eyepieces. 11.13? Inhalation and exhalation valve.; minimum requirements (a) Inhalation and exhalation valves shall be protected against distortion. (b) Inhalation valves shall be designed and constructed and provided where nec essary to prevent excessive exhaled air from adversely affecting filters, except where filters are specifically designed to resist moisture as prescribed in I 11.140-5. (c) Exhalation valve* shall be: (l) Provided where necessary: (2) protected against damage and external influence; and < 3> designed and constructed to prevent inward leakage of contaminated air. 11.138 Head harnesses; minimum re quirement.. (a) All facepieces shall be equipped with head harnesses designed and con structed to provide adequate tension during use and an even distribution of pressure over the entire area in contact with the face. (b) Facepiece head harnesses, except those employed on single-use respirators, shall be adjustable and replaceable. (c) Mouthpieces shall be equipped, where applicable, with adjustable and replaceable harnesses, designed and con structed to hold the mouthpiece In place. 11,139 Air velocity and noiM level.; hood* and helmets; minimum re quirements Noise levels generated by the respira tor will be measured inside the hood or helmet at maximum airflow obtainable and shall not exceed 30 dBA. BAL 0000573 $ 11.140 Dust, fume, ind mi*t reapira- lorti perform*.nce requirements; general. Dust, fume, end mist respirators and the Individual components of each such device shall, as appropriate, meet the requirements for performance and pro tection specified In the tests described in t! 11.140-1 through 11.140-12 and pre scribed In Tables 9 and 10. 11.140--1 Isoamyl acetate lightness teat; dust, fume, and mist respirators designed for respirator? prolection against fumes of various metals hav ing an sir contamination level noi less than 0.05 milligram per cubic meter; minimum requirements. (a) The respirator wlll.be modified In such a manner that all of the air that normally would be inhaled through the inhalation port(s) Is drawn through an efficient activated charcoal-filled can ister, or cartrtdge(s), without Interfer ence with the face-contacting portion of the facepiece. (b) The modified respirator will be worn by persons for at least 2 minutes each In' a test chamber containing 100 parts (by volunie) of isoamyl-acetate vapor per million parts of air. <c) The odor of isoamyl-acetate shall not be detected by the wearers of the modified respirator while in the test atmosphere. S 11.14^--2 Isoamyl acetate lightness test; respirators designed for respira tory protection against dusts, fumes, and mists having an air contamina tion level less than 0.05 milligram per cubic meter, or against radio nuclides; minimum requirements. (a) The applicant shall provide a charcoal-filled canister or cartridge of a size and resistance similar to the filter unit with connectors which can be at tached to the facepiece In the same man ner as the filter unit. (b) (1) The canister or cartridge will be used In place of the filter unit, and persons will each wear a modified half mask facepiece for 6 minutes in a test chamber containing 100 parts (by volume) of Isoamyl-acetate vapor per million parts of air. (2) The following work schedule will be performed by each wearer In the test chamber: (I) Two minutes walking, nodding, and shaking head in normal movements; and (II) Three minutes exercising ^nd running In place. (3) The facepiece shall be capable of adjustment, according to the applicant's Instructions, to each wearer's face, and the odor of Isoamyl-acetate shall not be detectable by any wearer during the test. (e) Where the respirator Is equipped with a full facepiece, hood, helmet, or mouthpiece, the canister or cartridge will be used In place of the filter unit, and persons will each wear the modified res piratory-inlet oovering for 5 minutes in a test chamber containing 1,000 parts (by volume) of isoamyl-acetate vapor per million parts of air, performing the work schedule specified In paragraph (b) (2) of thi section. 911.14&-3 Air-purifying filler tests; performance requirements; general. Dust, fume, and mist respirators will be tested In accordance with the schedule set forth in Table 10 to determine their effectiveness as protection against the particulate hazards specified therein. 11.140--4 Silica dust lest; single-use or reuseable filters; minimum require ments. (a) Three respirators with single-use filters will be tested for periods of 90 minutes each at a continuous airflow rate of 32 liters per minute for alr-purifylng respirators^ and for periods of 4 hours each at a flowrate not less than 115 liters per minute to tight-fitting facepieces, and not less than 170 liters per minute to loose-fitting hoods and hel mets for powered air-purifying respira tors. (b) The relative humidity in the test chamber will be 20-80 percent, and the room temperature approximately 25* C. (c) The test suspension in the chamber will not be less than 50 nor more than 60 milligrams of flint <99+ percent free silica) per cubic meter of air. (d> The flint In suspension will be ground to pass 99+ percent through a 270-mesh sieve. (e) The particle-size distribution of the test suspension will have a geometric mean of 0.4 to 0.6 micrometer, and the standard geometric deviation will not exceed 2. (f) The total amount of unretained test suspension in samples taken during testing shall not exceed 1.5 milligrams for an air-purlfylng respirator, 14.4 mil ligrams for a powered alr-purlfylng res pirator with tight-fitting facepiece, and 21.3 milligrams for a powered alr-purifylng respirator with loose-fitting hood or helmet. (g) Three respirators with reusable fil ters will be tested and shall meet the requirements specified in paragraphs (ak through (f) of this section; each filter shall be tested three times: Once as re ceived; once after cleaning; and cnee after recleaning. The applicant's instruc tions shall be followed for each cleaning. 11.140-5 Silica-dual teat; single-use dust respirators; minimum require ments. (a) Three respirators will be tested. (b) As described In S 11.140-4, airflow will be cycled through the respirator by a breathing machine at the rate of 24 respirations per minute with a minute volume of 40 liters; a breathing machine cam with a work rate of 622 kg.-m.'/min ute shall be used. (c) Air exhaled through the respirator will be 35* +2 C. (95* 3* P.) with 94 rb3 percent relative humidity. (d) Air inhaled through the respira tor will be sampled and analyzed for respirator leakage. (e) The total amount of unretained test suspension, after drying, In samples taken during testing, shall not exceed 1.8 milligrams for any single test. 11.140--6 Lead fume test; minimum requirements, (a) Three respirators will be tested for a period of 312 minutes each at a continuous airflow rate of 32 liters per minute for air-purifying respirators, and for periods of 4 hours each at a flow rate not less than 115 liters per minute to tight-fitting facepieces, and not leas than 170 liters per minute to loose-fitting hoods and helmets for powered airpurifying respirators. <b) The relative humidity in the test chamber will be 20--80 percent, and the room temperature approximately 25* C. (c) The test suspension in the test chamber will not be less than 15 nor more than 20 milligrams of freshly gen erated lead-oxide fume, calculated as lead (Pb). per cubic meter of air. (d> The fume will be generated by impinging an oxygen-gas flame on molten lead. (e) Samples of the test suspension will be taken during each test period for analysis. (f) The total amount of unretained test suspension in the samples taken dur ing testing, which is analyzed and calcu lated as lead (Pb), shall not exceed 1.5 milligrams of lead for an air-purifying respirator, 4.2 milligrams of lead lor a powered air-purifying respirator with tight-fitting facepiece, and 6.2 milli grams of lead for a powered air-purify ing respirator with loose-fitting hood or helmet. 11.140--7 Silica mist test; minimum requirements. (a) Three respirators will be tested for a period of 312 minutes each at a continuous airflow rate'of 32 liters per minute for air-purifying respirators, and for periods of 4 hours each at a flow rate not less than 115 liters per minute to tight-fitting facepieces, and not less than 170 liters per minute to loose-fitting hoods and helmets for powered alrpurlfylng respirators. (b) The room temperature in the test chamber will be approximately 25* C. (c) The tost suspension in the test chamber will not be less than 20 nor more than 25 milligrams of silica mist, weighed as silica dust, per cubic meter of air. (d) Mist will be produced by spraying an aqueous suspension of flint (99+ per cent free silica), and the flint shall be ground to pass 99+ percent through a 270-mesh sieve. <e) Samples of the test suspension will be taken during each test period for analysis. (f) The total amount of silica mist un retained In the samples taken during testing, weighed as silica dust, snail not exceed 2.5 milligrams for an air-purify ing respirator, 6.9 milligrams for a pow ered air-purifying respirator with tightfitting facepiece, and 10.2 milligrams for a powered air-purifying respirator with loose-fitting hood or helmet. g 11.140--8 TMi for respirator* do- ipd for mpirtUi7 protection against more duo one type of dia- pr*oid; minimum requirement*. Respirators designed as respiratory protection against more than one partic ulate hazard (dust, fume, or mist) shall comply with all the requirements of this part, with respect to each of the specific hazards Involved. 11.14(^9 Airflow resistance tests; all dost, fume, and mist respirators; minimum requirements. (a) Resistance to airflow will be meas ured In the facepiece, mouthpiece, hood, or helmet of a dust, fume, or mist res pirator mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both before and after each test conducted in accordance with 13 11.140-4 through 11.140-7. (b) The maximum allowable resistance requirements for dust, fume, and mist respirators are as follows: M, TTtfrrH RxmatHa (mm. wtUr-oolornn height) Type of respirator TntM.I Final Bxfcale- Inhala tion Inbale rt,*. tloa Sloele-oae........................ Dost, turns, sad mist, with stnelvewe filter.... Dust, fume, and mist, wits reusable filter..... dust and mist... IS 16 30 to ao 40 18 28 18 U X X > *-r------1 alter illlea dost test described In } 11.140-4. } 11.140--10 Exhalation valve leakage teal; minimum requirements. (a) Dry exhalation valves and valve seats will be subjected to a suction at 25 mm water-column height while In a normal operating position. (b> Leakage between the valve and valve seat shall not exceed 30 milliliters per minute. { 1L140--11 DOF filter teal; respirator* designed as respiratory protection against dusts, fumes, and mists her. inf an air contamination level less than 0.05 milligram per cubic meter and against radionuclides; minimum requirements. (a) AH single alr-purlfying respirator filter units will be tested In an atmos phere concentration of 100 mlcrograxns of OOP per liter of air at continuous flow rates of 32 and 85 liters per minute for a period of 5 to 10 seconds. (b) Where filters are to be used In pairs, the flow rates will be 16 and 42.5 liters per minute, respectively, through each filter. (c) The filter will be mounted on a connector in the same manner as used on the respirator, and the total leakage for the connector and filter shall not ex ceed 0.03 percent of the ambient DOP concentration at either flow rate. 11.144^12 Silica dust loading test; respirator* designed as protection against dusts, fumes, and mists hav ing an air contamination level less than 0.05 milligram per cubic meter and against radionuclides; minimum requirements. Three respirators will be tested In accordance with the provisions of I 11.140-4 and shall meet the minimum requirements of S3 11.140--4 and 11.140.9. Txsta firtTitct Tier RxqvszxxNv* {30 OFB rsrt U, Subpart K, | U.140-1, t seq.) Respirator typas hwin tightness 11.140-1 1L 140-3 Tyw.fa11 tr Contamination Level not lam than 0.06 mg/VP or 2 mppcf______ romac Air Contamina tion Lsval not Isas than 0.04 mg/Mi___ _____ ..... lusts: Air Contamination lsval not lass than 0.M mt/M* or 2 mpp=f_ _ Dusts, Fumes. sod Mists: Air Contamination Lsval lea tban 0M mg/ IP or 3 mopef, sod radionuclides._________ Redon daoghtan...,...,. Aibestca-eooUlnlsg dusts and mists_______________ X X X X X X > Test 1* requital only vrbas* appileabU. Tabl* 10--Aia-Fuatrrwo am Fowxaap Axa-FTramwo BxsniuiOB Furs* Tans Rwjuraxp to* Amoral. {JOCTB Part 11, Snbpsrt X. I lLMCt-4, at ssq.) Respirator types Sflloa dust tots Lead fame aiw mist DOF um 1L140-4 11.140-6 U. MO-13 11.140-6 1L140-7 1L M0-11 Busts: Air Contamination Level not less than (LOO mg/ M> or 2 mpprt. Fuats: Air Contamination Lsval sot las than 0.06 mg/ 14*. Mists: Air Coutamlaadoa Lrrsl net ]ss than 0,06 tag/ H> <r 2 tappet. Dusts, Fumes, and MJstr. Air Lewi Isa than 0.06 mg/M' or 3 mppef, and radtoopnHdsa- x tl X X X x* X x ' For resistance only. > For penetration only. * Tasi reqnlnd only whsr* appMoatlas 11.150 Chemical cartridge v*spii-i0_,. description. n> Chemical cartridge respirators lndud lag all completely assembled respirators which are designed for use as respiratory protection during entry into or escao* from atmospheres not immediately dangerous to life and health, are de scribed according: to the specific ga^es or vapors against which they are designed to provide respiratory protection, as follows: Maximum use Type of obecalcal ccmoentraftoa, parts cartridge respirator: per million Chlorine ________________ Hydrogen chloride____............................... SO Organic vapor7....--. Sulfur dioxide_____.... ' M4DS W*against organic vapor* wtth poo* wanting properties or those which gencrate high heats of reaction with acrbent material tn the cartridge. Maximum use concentrations are lower lor organic vapors which produce atmos pheres Immediately hazardous to life or health at concentrations equal'to or lower than this concentration. Non: Chemical cartridge respirators for respiratory protection against gases or vapors, which are not specifically listed with their ma-T-tm nwi use concentration except peatl- deles, may be approved If the applicant submite a request for such approval, In writing, to the Bureau. The Bureau and the Institute shall consider each such application and ac cept or reject the application after a review of the effects on the wearer's health and safety and In the light of any field experience In use of chemical cartridge respirators as protection against such hazards. 11.151 Chemical cartridge respirators; required components. (a) Each chemical cartridge respira tor described in 3 11.150 shall, where its design requires, contain the following component parts: (l> Facepiece, mouthpiece, and noeecllp, hood, or helmet; (2) cartridge: (3) Cartridge with filter; (4) Harness; (5) Breathing tube; and (8) Attached blower. (b) The components of each chemical cartridge respirator shall meet the mini mum construction requirements set forth In Subpart O of this pert. 11.152 Cartridge* in parallel; resist ance requirements. Where two or more cartridges are used in parallel, their resistance to airflow dull be essentially equal. 11.153 Cartridge*; color and mark ings; requirement*. The color and markings of all car tridges or labels shall conform with the requirements at tbe American Rational Standard for Identification of Gee Mask ^OcUfLJjrJ > J/rd/ ^"7 S A L 0 00 0 ':> 7 3 3 9 Canister*. K13.1, obtainable from Amer ican National Standards Institute, Inc^ 1430 Broadway. New York, NY 10018. 8 11.154 FUtera nied with chamleal ear* trid|| location ; replacement (a) Particulate matter filter* used tn conjunction with a .chemical cartridge shall be located on the inlet side of the cartridge. (b) Filter* ahall be Incorporated in or firmly attached to the cartridge and each filter assembly shall, where applicable, be designed to permit Its easy removal from and replacement on the cartridge. | 11.1SS Breadline tubes; minimum re* qalremenl*. (a> Flexible breathing tubes usod In conjunction with respirators shall be designed and constructed to prevent: (1) Restriction of free head move ment; <3> Disturbance of the fit of facepieces, mouthpieces, hoods, or helmets; (3> Interference with the wearer's activities; and (4) Shutoff of airflow due to kinking, or from chin or arm pressure. | 11.154 Bimeiiet; Installation and conalructioni menu. minimum rtqui'r*. (a) Each respirator shall, where nec essary, be equipped with a suitable harness designed and constructed to hold the componements of the respirator In position against the wearer's body. (b> Harnesses shall be designed and constructed to permit easy removal and replacement of respirator parts and, where applicable, provide for holding a full facepiece in the ready position when not in use. | 11.157 Respirator container* ; mini, nmm requirements. Respirators shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type and commercial desig nation of the respirator It contains and lH appropriate approval labels. 811.158 H*lf-maik facepiece*, full facepiece*, mouthpiece*, hood*, and helmet*; fit; minimum requirement*. fa) Half-mask facepieces and fun facepieces shall be designed and con structed to fit persons with various facial shapes and sizes either: (1) By provid ing more than one facepiece size, or (3) by providing one facepiece size which will fit varying facial shapes and size*. (b> Hoods and helmets shall be de signed and constructed to fit persons with various head sizes, provide for the optional use of corrective spectacle* or lenses, and Insure against any restriction of movement by the wearer. <e) Mouthpieces shall be equipped with noeedlps which are securely at tached to the mouthpiece or respirator and provide an airtight fit. (d) Full facepieces shall provide for Kaxqtou S****jrc* optional use of corrective ^ectadee or -* ntnrnn Mfht) lenses which dull not reduce the respi ratory protective qualities of the respi rator. (e) Facepieces, hoods, and helmet* TTP* ti b**nfcti *rtrMll napirtier Inkels Hm Sxbti*. InlUti Until shall be designed to prevent eyepiece fogging. 8 11,158-1 Facepiece*, hood*, and hcL met* | eyepiece*; minimum require ment*. Facepieces, hoods, and helmets shall be designed and constructed to provide ade Tor mn, v*pon, at pm iaa vepen.................................... Tor mhi, npori.orc**** ad vtpon, *od dwt. aim**, tad mitt* Jar cm**, vapor*. or gum *od Ttpon, *ad muu or ptiott.keoquan, tod tok....................................... 0 ID H 41 70 30 so 30 quate vision which Is not distorted by tite eyepieces. i M*ar*d ti lad of mttIo* IUi ip*dS*d la TbU 1L 811.162--2 Exhalation valve leakage g 11.159 Inhalation apd exhalation minimum requirement*. (a) Inhalation and exhalation valves shall be provided where necessary and protected against distortion. <b) Inhalation valves ahxii he de signed and constructed to prevent exces sive exhaled air from entering cartridges or adversely affecting canisters. (c) Exhalation valves shall be: (1) Protected against damage and external test; minimum requirement*. (a) Dry exhalation valves and valve seats will be subjected to a suction of 25 mo. water-column height while In a normal operating position. (b) Leakage between the valve ant; valve seat shall not exceed 30 milliliters per minute. 8 11.162--3 Facepiece test; minimum re quirement*. influence, and (2) designed and con (a) The complete chemical c&rti.dge structed to prevent Inward leakage of respire.tor_will be fitted to the lu:*a of contaminated air. persons having varying facial sha*^ and 8 11.160 Head harnesses; minimum re* qulrement*. (a) Facepieces shall be equipped with adjustable and replaceable head har nesses designed and constructed to pro vide adequate tension during use and aa even distribution of pressure over the entire area in contact with the face. (b) Mouthpieces shall be equipped where applicable, with an adjustable and replaceable harness designed and con structed to hold the mouthpiece m place. sizes. (b) Where the applicant epeck.es a facepiece size or sizes for the respirator together'with the approximate measure ment of faces they are designed to fit, the Bureau will provide test subjects to suit such facial measurements. <c> Any chemical cartridge respirator part which must be removed to perform the facepiece or mouthpiece fit test shall be replaceable without special toots and without disturbing facepiece or mouth piece fit. 8 11.161 Air velocity end noUe level*; (d> The facepiece or mouthpiece fit hood* and helmet*; minimum re test using the positive or negative pres quirement*. sure recommended by the applicant and Noise levels generated by the respira tor will be measured inside the hood or helmet at maximum airflow obtainable and shall not exceed 80 dBA. 8 11.162. Chemkal cartridge respirator*; described In his Instructions will be used before each test. (e) (1) Each wearer will enter a cham ber containing 100 p.pm. Isoamyl acetate vapor for half-mask facepieces, and 1,000 p.pm-. for full facepieces, mouthpieces, performance requirement*; general. hoods, and helmets. Chemical cartridge respirators and the Individual components of each such de vice shall, as appropriate, meet the min imum requirements for performance and protection specified In the tests described tn (i 11.163-1 through 11.163-8. (3) The. facepiece or mouthpiece may be adjusted, IX necessary, in the test chamber before starting the test. (3) Each wearer will remain in the chamber for 8 minutes while performing the following activities: 8 11.162--1 Breathing resistance test; minimum requirements. * (a) Resistance to airflow will be meas ured In the facepiece, mouthpiece, hood, or helmet of a ehemioal cartridge respi (I) Two minutes, nodding and turning head; (II) Two minutes, callsthenlc arm movements; (ill) Two minutes, running in place; rator mounted on a test fixture with air and flowing at a continuous rate of 85 IKen per minute, both before and after each test conducted In accordance with 8111.163-5 through 11.163-8. (b) The maximum allowable resist ance requirements for chemical cartridge (It) Two minutes, pumping with a tire pump Into a 28-11ter (l cubic-foot) container. (4) Each wearer shall not detect the odor of laeamyl-acetate vapor during the respirator* are as follows: teat. c ,A| l... Q () 0 0 7 3 4 0 a 11.162--4 Lacquer and enamel nI*t lMu; mpinton with filter*; mini* mum requirement*; general. (a) Three respirators with cartridges containing or having attached to them, filters lor protection against mists of paints, lacquers, and enamels shall be in accordance with the provisions Ol } 11.162-6. (b) In addition to the test-require ments set forth In paragraph (a) of this section, three such respirators will be tested against each aerosol in accordance with the provisions of {{ 11.162-5 and 11.162-6. 11.162--5 Lacquer mist test; minimum requirements. (a) Temperature in the test chamber will be approximately 25* C. (b) Continuous airflow through the respirator will be 32 liters per minute for air-purifying respirators, and not less than ns liters per minute to tight fitting facepieces and 170 liters per minute to loose-fitting hoods and helmets of pow ered air-purifying respirators. (c) Airflow through the chamber will be 20-25 air changes per minute. (d) The atomizer employed will be a No. 64-5 nozzle with setup 3, or equiv alent, operating at 69 kN/m*. (10 pounds per square inch gage). (e) The te3t aerosol will be prepared by atomizing a mixture of one volume of clear cellulose nitrate lacquer and one volume of lacquer thinner. (f) The lacquer used will conform es sentially to Federal Specification TT-L31. October 7, 1953. (g) The concentration of cellulose nitrate in the test aerosol will be 95-125 milligrams per cubic meter. (hi The test aerosol will be drawn to each respirator for a total of 156 minutes for alr-purifylng respirators and 240 minutes for powered air-purifying respirators. (D The total amount of unretalned mist In the samples taken during testing, weighed as cellulose nitrate, shall not ex ceed 5 milligrams for an air-purifying respirator. 28 milligrams for a powered alr-purifylng respirator with tight- fitting facepiece, and 41 milligrams for a powered air-purifying respirator with Loose-fitting hood or helmet. 11.162--6 Enamel mi*l lest; minimum requirement*. (a) Temperature In the test chamber will be approximately 25* C. Cb) Continuous airflow through the respirator will be 32 liters per minute for alr-purifylng respirators, and not less than 115 liters per minute to tight-fit ting facepieces and 170 liters per minute to loose-fitting hoods and helmets of powered air-purifying respirators. (c) Airflow through the chamber will be 20-25 air changes pier minute. (d) The atomizer employed win be * No. 64 nozzle with setup 1A, or equiv alent. operating at 69 kN/m*. (10 pounds per square Inch gage). (e) The test aerosol will be prepared by atomizing a mixture of 1 volume of white enamel and 1 volume of turpentine. (f) The enamel used will conform es sentially to Federal Specification TT-E489b, Majr 12, 1953 (an enamel having a phthalic 'slkyd resin vehicle and a titanium dioxide pigment). (g) The concentration of pigment In the test aerosol, weighed as ash, will be 95-125 milligrams per cubic meter. (h) The test aerosol will be drawn to each respirator for a total of 156 minutes for air-purifying respirators and 240 minutes for power air-purifying respirators. (1) The total amount of unretalned mist In the samples taken during testing, weighed as ash, shall not exceed 1.5 milligrams for any air-purifying respi rator, 8.3 milligrams for a powered airpurifying respirator with tight-fitting facepiece, and 12.3 milligrams for a powered air-purifying respirator with loose-fitting hood or helmet. 11.162--7 Dull, fume, and mist tests; respirators with fillers; minimum re quirement*; general, (a) Three respirators with cartridges containing, or having attached to them, filters for protection against dusts, fumes, and mists, except the mists of paints, lacquers, and enamels, will be tested in accordance with the provisions of 5 11.162-8. (b) Id addition to the test require ments set forth in paragraph (a) of this section, three such respirators will be tested, as appropriate, In accordance with the provisions of $3 11.140-1 through 11.140-14. however, the maxi mum allowable resistance of complete dust, fume, and mist, and gas, vapor, or gas and vapor chemical cartridge res pirators not exceed the maximum allowable limits set forth in 111.162-1, 811.162--8 Bench teeU; ga* and vapor lost*; minimum requirement*; gen eral. (a) Bench tests will be made on an apparatus that allows the test atmos phere at 50 5 percent relative humid ity and room temperature, approximately 25* C., to enter the cartridges contin uously at predetermined concentrations and rates of flow, and that has means lor determining the test life of the cartridges. (b> Where two cartridges are used In parallel on a chemical cartridge respi rator. the bench test will be performed with the cartridges arranged in parallel, and the test requirements will apply to the combination rather than to the in dividual cartridges. (c) Three cartridges or pairs of cartridges will be removed from con- tainers and tested as received from the applicant. <d) Two cartridges or pairs of cart ridges will be equilibrated at room tem perature by passing 25 percent relative humidity air through them at the fol lowing flow rates (expressed in liters per minute (l.pm.)) for 6 hours: Type of cartridge: Airflow rate, l.p.m. Air purifying ___________.___._______ 23 Powered air purifying with tightfitting facepiece_______________________ Powered air purifying with looaefittlng hood or helmet.________________ US 170 (e) Two cartridges or pairs of car tridges will be equilibrated by passing 85 percent relative humidity air through them at the flow rates stated In para graph (d) of this section. if) All cartridges will be resealed, kept in an upright position, at room tempera tures, and tested within 18 hours. (g) Cartridges will be tested and shall meet the minimum requirements set forth In Table 11. T**u H.--Canmisox Baxes Txeta ixi> (BO C7B Pari 11, Sobpart L, 111,10-0 Cartridge Te*t condition Taet atmoaphere Gee or vapor Concenttte Hon (P-PJB.) Flowr&U G.p.m.) Number oi feet* fane- Minimum tratlon life (p.pjn.) (mlB.) A mmarria A-EZLQO&li ,,. - Aj received....... NH, . Xqiimbmted...... NS, Chiortne...................... . Aj received______ . Cli Chlorine............ . Equilibrated___ _ - Cli Hrdrocen chloride.. - Aareceived..___ . HC1 Hrdrocen chloride. . Equilibrated.___ . HC1 Mettryl - a* received....... CH, NHi Methyl amine._____ . Equilibrated......... . CHiNHi Organic Taper*..... . ii reowlwd ___ . CCli Organic Tenon..... _ Equilibrated..... - ecu Bailor dioxide..... . SO) Sulfur dioxide............ . Equilibrated.___ SO) 11000000 500 600 31 600 1500000 M 11000000 54 <00 a * 30 i Minimum 111* will be determined at the Indicated penetration. * Where a respirator 1* dealreed for maplratnry protection agelnet men than one tjp4 of iu or vapor, a* for oe* In ammonia and in chlorine, the niainiin life be one-half that ahown for each type of fa* or vapor. When a reaptrmtor le designed for raplratorj protection again** mlifoemahtahlalnapopnley. gaa of a type, a* for net la chlorine and Hlfar dioxide, the Rated minimal i 0 0 0 015 7 3 3 '1. 124 9 11.170 Peatieide re*plr#tor 5 descrip tion. Pesticide respirators. Including all completely assembled respirators which are designed lor use as respiratory pro tection during entry into and escape from atmospheres which contain pesti cide hazards, are described according to their construction as follows: (a) Front-mounted or back-mounted gas masks: (b) Chin-style gas mask; (c) Chemical cartridge: (d) Air-purifying respirator with at tached blower: and, <e) Other devices, including combina tion respirators. 11.171 Pesticide respirators; required components. (a) Each pesticide respirator described in ! 1'1.170 shall, where its design re quires, contain the following component parts: (1) Facepiece, mouthpiece, and noseclip, helmet, or hood; <2) Canister with Alter; (3) Cartridge with Alter; (4) Harness; (5) Attached blower; and, (6) Breathing tube. (b) The components of each pesticide respirator shall meet the minimum construction requirements set forth in Bubpart G of this part. 9 11.172 Canisters and cartridges in par allel; resistance requirements. Where two or more canisters or cartiidges are used in parallel, their resist ance to alrAow shall be essentially equal. 9 11,173 Canisrer* and cartridge*; color and markings; requirements. The color and markings of all canis ters and cartridges or labels shall con form with the requirements of the American National Standard for Identi fication of Gas Mask Canisters, K13.1. S 11.174 Filters used with canister* and cartridgea; location; replacement. (a) Particulate matter Alters used in conjunction with a canister or cartridge Han be located on the inlet Bide of the canister or cartridge. (b) Filters shall be incorporated into or. firmly attached to the canister or car tridge and each filter assembly shall, where applicable, be designed to permit Its easy removal from and replacement on the canister or cartridge. ^ 9 11.175 Breathing tube*; minimum re quirement*. (a) Flexible breathing tubes used in conjunction with'respirators shall be de signed and constructed to prevent: (1) Restriction of free head move ment; (2) Disturbance of the fit of facepieces, mouthpieces, hoods, or helmets; (3) Interference with the wearer's ac tivities; and, (4) Shutoff of airflow due to kinking, or from chin or arm pressure. 9 11.176 Harnesses; inataUalion and construction; minimum require ments. (a) Each respirator shall, where nec essary, be equipped with a suitable har ness designed and constructed to hold the components of the respirator In po sition against the wearer's body. (b) Harnesses shall be designed and constructed to permit easy removal and replacement of respirator parts, and, where applicable, provide for holding a full facepiece in the ready position when not in use. 9 11.177 Respirator container*; mini mum requirement*. (a) Respirators shall be equipped with a substantia], durable, container bearing markings which show the applicant's name, type, and commercial designation of the respirator It contains, and all ap propriate approval labels. (b) Containers for gas masks shall be designed and constructed to permit easy removal of Che mask. 11.178 Half-mask facepiece*, full facepiece*, hood* and helmet*, and mouthpieces; At; minimum require ment*. (a) Half-mask facepieces and full facepieces shall be designed and con structed to fit persons with various facial shapes and sizes either: (1) By providing more than one facepiece size, or (2) by providing one facepiece size which will fit varying facial shapes and sizes. * (b) Full facepieces shall provide for optional use of corrective spectacles or lenses, which shall not reduce the respiratory protective quality of the respirator, (cl Hoods and helmets shall be de signed and constructed to fit persons with various head'Slzes, permit optional use of corrective spectacles without re ducing the respiratory protective quali ties of the respirator, and insure against any restriction of movement by the wearer. (d) Pesticide respirators with mouth pieces shall be equipped with nosecltpa which are securely attached to the mouthpiece or respirator and provide an airtight seal. (e) Facepieces, hoods, and helmets shall be designed to prevent eyepiece fogging. (f) Half-mask facepieces shall not Interfere with the fit of common Indus trial safety corrective spectacles as deter mined by the facepiece tests in } 11.1833. 9 11.179 Facepiece*, hood*, and hel met*; eyepiece*; minimum require ment*. fa) Facepieces, hoods, and helmets shall be designed and constructed to pro vide adequate vision-which is not dis torted by the eyepiece. (b) All eyepieces of gas masks shall be designed and constructed to meet the Impact and penetration requirements specified in Federal Specification, Mask, Air line: and Respirator, Air Filtering, Industrial. GGG-M-l25d. October 11, 1965. S 11.180 Inhalation and exhalation valve*; minimum requirement*. (a) Inhalation and exhalation valves shall be protected against distortion. (b) Inhalation valves shall be designed and constructed and provided where necessary to prevent excessive exhaled air from adversely affecting cartridgea, canisters, and filters. (c)Exhalation valves shall be: (l) Provided where necessary; (21 Protected against damage and ex ternal Influence; and, (3) Designed and constructed to pre vent Inward leakage of contaminated air. 11.181 Head harnesses; minimum re quirement*. (a) Facepieces shall be equipped with adjustable and replaceable head har nesses designed and constructed to pro vide adequate tension during use and an even distribution of pressure over the entire area in contact with the face. (b) Mouthpieces shall be equipped, where applicable, with adjustable and replaceable harnesses designed and con structed to hold the mouthpiece in place. 11.182 Air velocity and noise level*; hood* and helmet*; minimum re* quiremenU. Noise levels generated by the respira tor will be measured Inside the hood or helmet at maximum obtainable alrAow and shall not exceed 80 dBA. 11.183 Pesticide respirator*; perform, ance requirement*; general. Pesticide respirators and the individ ual components of each such device shall, as appropriate, meet the requirements for performance and protection specified in the tests described In H 11.183*1 through 11.183-7. 9 11.18^-1 Breathing resistance test; minimum requirements. (a) Airflow resistance will be meas ured in the facepiece, mouthpiece, hood, or helmet of a pesticide respirator mounted on a test fixture with air flow ing at a continuous rate of 85 liters per minute, both before and after each test conducted In accordance with SS 11.183-4 and 11.183-7. (b) The maximum allowable resist ance requirements for pesticide respira tors are as follows: Manvvx Rx*at*Mcx (hub. wiiv-oohmm height) IfibalaQoB Zzh* iatloo Ptaait Treat* * baak-moonUd fM Chin-styla t>* mate___ ..._____ Pownd klr-poriiyins----......... Chemical eartrld(..... TO a M u so 70 70 30 30 30 1 Ma*ond *t tod of th* serrlo* tm spaolflad la Tabl* 13. Rwistane* of filtar(*>, eanridcift), sad brottbtac rtiboti) only with blowar not opsrmUog. 1 112.183--3 Exhalation valve leakage t--; minimum requirements. (*) Dry exhalation valves and valve eats will be subjected to a suction of 25 mm. water-column height while In a normal operating position. (b) leakage between the- valve and valve seat shall not exceed 30 milliliters per minute. 3 11.183-3 Facepiece teat; minimum reqnireinent*. (a) The complete pesticide respirator will be fitted to the 'aces of persons hav ing varying facial shapes and sizes. (b) Where the applicant specifies a facepiece size or sizes for his respirator together with the approximate measure ments of faces they are designed to fit, the Bureau' will provide test subjects to suit such facial measurements. (c) Any pesticide respirator part which must be removed to perform the facepiece fit test shall be replaceable without special tools and without disturbing face piece fit. (d) The facepiece or mouthpiece fit test u^Tig positive or negative pressure recommended by the applicant and de scribed In his instructions will be used dining each test. (e) (1) Each wearer will enter a cham ber containing 1,000 p.pm. isoamylacetate vapor for a respirator equipped with a full facepiece, mouthpiece, hood, or helmet and 100 p.p.m. isoamyl-acetate vapor for a respirator equipped with a half-mask facepiece. (2) The facepiece, mouthpiece, hood, or helmet may be adjusted, if necessary, in the test chamber before starting the test. (3) Each wearer will remain in the chamber while performing the follow ing activities: (1) Two minutes, nodding and turn ing head: (li> Two minutes, calisthenic arm movements; (ill) Two minutes, running in place: and, Uv) Two minutes, pumping with a tire pump into a 28-llter (1 cubic foot) container. (4) Each wearer shall not detect the odor of isoamyl-acetate during the test. 11.183-4 Silks dual lest; minimum re quiremenu. Three completely assembled pesticide respirators will be tested with a mechanical-testing apparatus as. fol lows: ''j (a) Temperature in the test chamber will be approximately 25* C. (b) Continuous airflow through the respirator will be 32 liters per minute for front-mounted, back-mounted, and chin-style gas mask pesticide respirators and chemical cartridge pesticide respira tors, ar>d not less than ns (4 cubic feet) liters per minute to tight-fitting face pieces and 110 liters (8 cubic feet) per minute to loose-fitting hoods and hel mets of powered air-purifying respira tors. <) The test aerosol will contain 50-80 milligrams of M-f percent free silica per cubic meter of air. (d) The particle size distribution of the test suspension will have a geometric mean diameter of 0.4 to 0.6 micrometer, with a standard geometric deviation less than 2. ( ) Front-mounted, back-mounted, and chin-style gas mask pesticide res pirators and chemical cartridge pesti cide respirators will be tested for 90 minutes and powered alr-purlfying res pirators will be tested for 4 hours. 11.183--5 Lead fume teet; minimum requirement*. Three completely assembled pesticide respirators will be tested with a mechanical-testing apparatus as follows: (a) Continuous airflow through the respirator will be 32 liters per minute for front-mounted, back-mounted, and chin-style gas mask pesticide respirators and chemical cartridge pesticide res pirators and not less than 115 liters (4 cubic feet) per minute, for powered airpurifying respirators with tight-fitting facepieces, and not less than 170 liters <6 cubic feet) per minute for powered air-purifying respirators with loosefitting hoods and helmets. (b) The test aerosol will contain 1520 milligrams of freshly generated leadoxide fume, calculated as lead, per cubic meter of air. <c> The fume will be generated by im pinging an oxygen-gas flame on molten lead. (d) Front-mounted, back-mounted, and chin-style gas mask pesticide res pirators and chemical cartridge-pesticide respirators will be tested for &0 minutes and powered air-purifying pesticide res pirators will be tested for 4 hours. (e) The total amount of unretalned test suspension, which Is analyzed and calculated as lead, shall not exceed: (1) 0,43 milligram for any 90-mlnute test; (2) 4.8 milligrams for any 4-hour test made at 115 liters (4 cubic feet) per minute: or (3) 6.2 milligrams for any 4-hour test made at 170 liters (6 cubic feet) per minute. 11.183--6 Dioctyl-phihalale teal; min imum requirements. Ca) All canisters submitted for use with front-mounted and back-mounted gas mask pesticide respirators win h* tested In an atmospheric concentration of 100 micrograms of dloctyl-phthalau per liter of air at continuous flow ratei of 32 and 65 liters per minute for a test period of 5 to 10 seconds. (b) The DOP leakage through the canister shall not exceed 0.03 percent of the ambient DOP concentration. 11.18^7 Bench teat*; minimum r*. quiremen t. (a) (1) Bench tests will be made on an apparatus that allows the test atmos phere at 505 percent relative humidity and at room temperature (25*m2.o' c.) to enter the canister or cartridge at pre determined concentrations and rates of flow, and that has a means for determin ing the test life of the canister or car tridge against carbon tetrachloride, (2) Canisters and cartridges will be tested as they are used on each pesticide respirator, either singly or in pain. (3) Three canisters or cartridges or pairs of cartridges will be removed from containers and tested as received from the applicant. (4) Two canisters, cartridges, or pairs of cartridges will be equilibrated at room temperature by passing 25 percent rela tive humidity air through them at the following flow rates (expressed as liters per minute (l.p.m.)) for 6 hours; Type of canister or cartridge Air-purlfylng cejilater___________ Alr-purlfying cartridge________ Powered alr-purlfying with fitting facepiece............ Powered alr-purlfying with fitting hood or helmet_______ Airflow rate, ____l.p.m0. 4 _______ 28 tlght- ________ looae- 115 ________ 170 (5) Two canisters, cartridges, or pairs of cartridges will be equilibrated at room temperature by passing 85 percent rela tive humidity air through them at the flow rates stated in subparagraph (4) of this paragraph for 6 hours. (6) The equilibrated canisters or car tridges will be rese&led, kept in an up right position at room temperature, and tested within 18 hours. (b) Canisters and cartridges tested In accordance with the provisions of t.hi section shall meet the requirements spec ified In Table 12. Tabu is,--Caxbon TftTucaLOKiox Braca Tim ajtd Riannunra rot Clmuiiu int> CiXTtmotj (30 CrB Ptrt 11, Subpert U. 1 11.183-7) Type of pesticide respirator Testoooceatr*. Flow rate Ulnlmom life, tfoet^g-p.m. l,pjB. Number of test* minuter1 Chat-mounted or beck.moonted [ mut (er received)..................... ............. ................................. Chest-mounted or bars-mountort pi milt (eqal> ibrtM).............................................................................. Chio-etyle fee mask (u reedved).............._................. Chin-stylepimiit(equilibrated) ................. ChcmJeal-cirtrldee respirator (m received)------------Chemical oartrtds respirator (equilibrated).............. Fevered elr-pnrifytm raptrakr (ttfht-Atttng facepiece, as received) .....__________.......... Powered tir-purifrlai reaplrster CtUbt-fltUng Powered eir-punfyinfnaplrstor (louee fitting hood or helmet as received)...--........................................... Powered eli-purlfying rer$lraisr Ocui fitting hood or helmet, equilibrated).......... .................................... ; 20,000 70,000 6,000 LOCO LOCO 1,000 L000 1,000 1,000 L000 M 82 M 32 04 82 111* 111* 170 in 2 4 I 48 4 S 8 4 >Matmum m vffl be detvmtned ttip.p.gv. 1takere. ^ .... i The flow rateeball be the elective flow reteoitbedevice, bat ihefi be not tew than lULpjBi * The flov rate than be the effective fiov rate ol the device, bat (bell be net Ian than 170 Lpmu [m Doc.73-4116 Piled 9-34-70:8:46 am] 13 U 9 9 M M* 3 M 91 ,,OOC>S73A3' 126 QAt i i Title 30--Mineral Resources CHAPTER I--BUREAU OF MINES, DEPARTMENT OF THE INTERIOR PART 11--RESPIRATOR*^- PROTECTIVE DEVICES, TESTS FOR PCTVfSSIBILTTY: FEES Accordingly. It has been determined, after consultation with the Occupational Safety and Health Administration and the Atomic Energy Commission, that it is necessary to amend Part 11 as set forth below. The amendments provide that on or before September 30. 1974, respirators Respirator Used in Hazardous approved under Part 11 or a Bureau of Atmospheres The Secretary of the Interior, through the Mining Enforcement and Safety Ad ministration (MESA), and the Secretary of Health. Education, and Welfare, through the National Institute for Occu pational Safety and Health (KIOSK), conduct a testing and approval program for respirators used in hazardous atmos pheres pursuant to the regulations con tained in 30 CFR Part 11 issued Jointly by the Secretaries on March 25, 1972 f37 PR 6244). as amended on March 15, 1973 (38 FR 6993) Section 11.2 provides that until March 30, 1974. respirators shall be considered to be Approved for use in hazardous atmospheres if approved under either Part 11 or those Bureau of Mines respirator approval schedules in effect prior to Part 11, but that after March 30, 1974, only respirators tested and ap proved under Part 11 shall be considered to be approved. After receiving a written request for a two year extension of the March 30.1974, deadline from the Industrial Safety Equipment Association, a trade associa tion of respirator manufacturers. MESA and NIOSH decided to conduct a public meeting to consider this request. Notice of the public meeting was pub lished in the Federal Register for Octo ber 18.1973 (38 FR 23961), and the meet ing was held on November 14,1973. in the Department of Health, Education, and Welfare's Parklawn Building, 5600 FLshers lane, Rockvilie. Maryland. Presenta tions were made by the following organi zations: Industrial Safety Equipment Association. American Iron and Steel In stitute. Boston Fire Department. Manu facturing Chemists Association,'and Tenneco. Inc. A verbatim transcript of the meeting Is available for public inspec tion at the National Institute for Occu pational Safety and Health. Parlclawn Annex Room. 3-32, Parklawn Drive. ilines respirator approval schedule wiL be approved for use in hazardous atmos pheres. The effect of this amendment ito extend the period for complying with the requirements of Part n for six months. The amendments further pro vide that after September 30. 1974, only respirators approved under Part 11 or manufactured pursuant to a quality con trol plan approved under Part 11 will be approved for such use, except that if a respirator Is purchased on or before Sep tember 30. 1974, and at the time of pur chase was approved under a Bureau of Mines inspirator approval schedule, it shall be approved for use until the dates specified in } 11.2(b). Finally, the amend ments provide that after March 31. 1975. only respirators approved under Part 11 will be approved for use except that if a respirator is purchased on or before March 31, 1975 and at the time of pur chase was approved under a Bureau of Mines respirator approval schedule and manufactured pursuant to a quality con trol plan approved under Part 11. it shall be approved for use until the dates speci fied in 111.2(c). The effect of this amendment is to clarify that users of equipment previously approved under Bureau of Mines schedules may continue to use such equipment, and to permit a gradual phasing out of such equipment in a manner consistent with the ability of these devices to provide effective res piratory protection. Notice of proposed rulemaking, public rulemaking procedures, and postpone ments of effective date have been omit ted in the Issuance of the amendments to section 11.2 because the public has had an opportunity to present its views in the public meeting, and to delay the de cision In this matter would be contrary' to the public interest. Accordingly these amendments will be effective on April 9, 1974. Rockville. Maryland, and at the office of Dated: March 29.1974. the Assistant Administrator-Technical Support, MESA. Room 927. 4015 Wilson Boulevard. Arlington. Virginia. On the basis of information presented William A. Voccur. Acting Deputy Assistant Secretory of the Interior, at the hearing, numerou* written -com Dated: April 3,1974. ments, and information developed by NIOSH and MESA, it has been deter mined that only approximately 35 of the 400 currently approved types of respira tors will have been certified under Part II by March 30. 1974. Additionally, Frank Caritjcct. Acting Secretary of Health, Ed ucation, and 'Welfare. Section 11.2 is revised to read u follows: among the 35 certified types of respira tors. there are not enough units manu factured or in process to supply the needs of those who would be required to use approved respirators. Moreover, It ap pears that manufacturers, particularly 112 Approved respirator*. (a) Until September 30. 1974. respira tors or combination of respirators shall be approved for use in hazardous atmos pheres where such respirators or combi nations of respirators are maintained in the smaller ones, need additional time to an approved condition and are the same establish and Implement the formal quality control procedures required by Part 11. In ail respects as those respirators: (1) For which a certificate of approval been issued under his part: or *2) Fabricated, assembled, or built under any approval or any modification thereof, issued by the U.S. Bureau of Mines. Department of the Interior, in accordance with the schedules set forth in this paragraph; (i) Self-contained Breathing Appara tus. Bureau of Mines Schedules 13. March 5. 1919; 13A. January 21, 1930: ;J3, August 12. 1935; 13C, July 9. 1946; !3D. September 22. 1950, and 13E, July 19. 1968. (ii) Gas Masks, Bureau of Mines Schedule 14F, April 23. 1955. tiii) Supplied-air Respirators. Bureau of Mines Schedule 19B, April 19. 1555. <ivj Filter-type Dust. Fume, and Mist Respirators, Bureau of Mines Schedule 21B. January 19. 1965. (.v) Nonemergency Gas Respirators. Bureau of Mines Schedule 23B, August 4. 1959. (b) After September 30/1974, respira tors or combinations of respirators shall be approved for use in hazardous atmos pheres where such respirators or'combinations of respirators are maintained in an approved condition and are the same in all respects as those respirators: (1> r or which a certificate of approval has been issued under this part; or (2) fab ricated. assembled, or built under any approval or any modification thereof is sued by the U-S. Bureau of Mines in accordance with the schedules set forth in paragraph (a) and in accordance with a quality control plan approved under this part: Provided, That if a respirator is purchased on or before September 30, 1974 and at the time of purchase was the same in all respects as a respirator approved under a Bureau of Mines Schedule, it shall be approved for use until the following dates: Until March 31, 1979, for self-contained breathing apparatus approved under Bureau of Mines Schedules 13-13E: Until March 31. 1977. for gas a:asks ap proved under Bureau of Mines Schedule 14F, Until March 31. I960, for supplied-alr respirators, approved under Bureau of Mines -Schedule 19B, Until March 31, 1976. for filter-type dust, fume, and mist respirators approved under Bureau of Mines Schedule 21B and for non- emergency gas respirators approved under Bureau of Mines Schedule 23B. (c) After March 31, 1975. respirators or combinations of respirators shall be approved for use in hazardous atmos pheres where such respirators or com binations of respirators are maintained in an approved condition and are the same in all respects as those respirators for which a certificate of approval has been issued under this part: Provided, That If a respirator is purchased on or before March 31, 1975, and at the time of purchase was the same in all respects as a respirator approved under a Bureau of Mines Schedule and was manufac tured pursuant to a quality control plan approved under this part, it shall be ap proved for use until the following dates: Until March 31. 1979, for self-contained breathing apparatus approved under Bu reau of Mines Schedule 13-13E; ;i I... 0 0 0 0.5 7 /) 4 4 127 --Btll Mircti 31. 1977. for gu mask* ap- pr^vd under Bureau o/ Mines Schedule 1*F; XJttU March 31. 1980. for &upplicd-alr respirators approved under Bureau of Mines Schedule 19B: Until March 31. 1973. for liter-type dust, fucie, al'd nLst respirators approved under Bureau of Mines Schedule 21B ar.d for nonemergtQcy gas resp'.ritors approved under Bureau of Mines Schedule 2JB. (Secs. 202 Ihl, 204. tCS. S3 Slat. 733, 764. 603 (30 U S C- S42i b). 814. 957): secs. 2, 3, 5. 3d Slat. 373, as amended 37 Slit. 881 (30 U.S.C. 3. 5. 7): see. S(^), 84 Sui, 1500 (29 Following adoption of the April 9 amendments, respirator manufacturers submitted quality control plans for NIOSH review and approval. While some plans were submitted In a timely manner, a number was not received un til after July 1974, and a substantial number has not yet been received. Due to the complexity of the plans and tho shortage of Qualified manpower to reHC*r these detailed plans, there are de vices for wldch a quality contrcl plan has been submitted but not reviewed and approved. Tho result b that, gas masks shall be approved tor use i,, hazardous atmospheres where * , rtwplrafora or combinations of retnu, tors are maintained In an approved cTM dltlon and arc the some In nu respiL ^ those respirators: "u (1) For which a certificate of approval has been issued under thlsparf or ^ M (2) Fabricated, assembled or built on der any approval or any modification thereof issued by the U.3. Bureau <3 Mines, Department of the Interior m accordance with the schedules set forth In this paragraph; 1 U.S.C. 657(g))) (rn Doc.74-8100 Filed 4-8-74;8:45 am] the regulations are amended, after Sep tember 30 these devices will no longer be permitted to be sold as approved <t) Self-contained Breathing Appara tus. Bureau of Mines Schedules March 5, 1919; 13A. January 21 1930 equipment. Moreover. It is anticipated 13B, August 12. 1935; 13c, July 9 194a that A similar situation will develop with 13D, September 22.. 1956, and nr respect to the March 31, 1975 deadline. July 19. 1963. ^ The purpose of these amendments Is (II) Suppiied-air Respirators. Bureau to eliminate September 30. 1974 as a of Mines Schedule 10B. April 19, 1955 Tit!130--Mineral Resources deadline date and to extend the March (III) Filter-type Dust'. Fume, and Mist 31, i975 date described above to June 30, Respirators. Eureau of Mines Schedule pKAFTER I--MrNING ENFORCEMENT 1975. By that time NIOS3 will have had 21B, January 19. 1965.- ANO SAFETY ADMINISTRATION, DE an opportunity to review all of the qual <i7) Nonemergency Oas Respirators, PARTMENT OF THE INTERIOR ity control plans previously submitted as Bureau of Mines Schedule 23B, August 4' SmCHAP7ER B-- lESPIATOfV FBOTECTIVE APPARATUS; TESTS FOR PERMISSIBILITY; na PART 31--RESPIRATORY PROTECTIVE DEVICES; TESTS FOR PERMISSIBILITY; FEES Deadline Extension The Secretary of the Interior, through well as those anticipated to be received. Respiratory equipment already in the possession of industrial users or acquired on or before June 30, 1975 and previous ly approved under Bureau of Mines res pirator approval schedules will continue to be approved for use In accordance with the dates adopted In the April 9, 1959. <b) After June 30, 1975. respirators or combinations of respirators other than gas masks shall be approved for use in hazardous atmospheres where such respirators or combinations of respirators are maintained In an approved condi tion and ore the same in alt rejects as the Mining Enforcement and Safety Ad 1974 amendments 139 FR 12864). ministration (MESA) ar.d the Secretary Finally, since the requirements for the iff Health, Education, and Welfare, approval and certification of gas masks through the National Institute for Oc are under revision, the deadline date for cupational Safety and Health, iNIOSH), the approval of those devices has not been conduct a testing and approval program established and those devices have been for respirators used in hazardous atmos excepted from the June 30, 1975 dead phere pursuant to the regulations con line date. A deadline date for approval tained In 30 CFR Part 11 issued Jointly and certification of gas masks under by the Secretaries i3T FR 6244). Part 11 will be adopted In the future. On April 9. 1974, following a public Since It Is essential that approved bearing on tire Issue. Part 11 was respiratory protective devices remain amended <39 FR 12864) to provide that available to Industrial users, the Depart until September 30, 1974 respirators ap ments find that good cause erfsts for proved under Part 11 or a Eurean of omitting notice of proposed rulemaking Mines respirator schedule would be ap* and postponement of the effective date proved for use in hazardous atmospheres. in the Issuance of the omendments^to those respirators for which a certificate has been Issued under this part; Provided, That LI a respirator is purchased on or before June 30. 1 ST5 ar.d at the time of purchase was the same in all re spects as a respirator approved under a Bureau of Mines Schedule, It shall be approved for use until the following dates: Until March 31, 1079. for Mlf-cociAlned breathing apporatue approved under Bump Ot Mines Schedules 13-137. Until March 31. 1930, for supplled-elr rwptratora approved under Bureau of Mines Schedule 190. Until March 5t, 1978. for flller-type dust, fume, and mist respirators approved under Bureau of Mines Schedule 2IB and for non- The amendments provided that after September 30. 1074. only respirators Ap proved under Part 11 or manufactured Part 11. Accordingly, these amendment*, as set forth below, will be effective a September 30,1974. emergency ga* respirators approved under Bureau of MLnea Schedule 23B. | 11.2--1 Approved las masks. pursuant to a quality control plan ap proved under Part 11 would be approved for such use except that if a respirator was purchased before September 30,1974 and at the time of purchase was ap proved for use under a Bureau of Mines respirator schedule. It would be approved for use until the dates specified In the regulation. The amendment further pro vided that after March 31. 1975 only respirators approved under Part 11 would be approved for use except that If a res pirator was purchased before March 31 and at that time was approved under a Bureau of Mines respirator schedule and manufactured pursuant to an approved quality control plan. It would be approved for use until the dates specified in the regulation. Part 11 of Title 30. Code of Federal 0*3 masks shall be approved for u** Regulations is amended and revised a* to hazardous atmospheres where ch set forth below. gas masks nre malutcincd in an on-* Dated: November 12,1974. proved condition and nrc the same in all Jack V/. Cahlsok, Assisfanf Secretary of the Interior respects ar. tho:<* gas mp.-f's: (o) For wine!) a certificate of ap proval has been Issued under this part; or Dated: November IS, 1974. (b) Fabricated, assembled or bull*, un Caspar \v. WrrxncRcr*. Secretary of Health, Education, and Welfare. der any approval or any modification thereof Issued by tire U.3. Bureau of Mines, Department of the Interior la ac cordance with Bureau of M5r.es Sched In Part 11, * new I 11.2-1 Is added a&d ule J4F, April 23, 1950. j 11.2 Is revised to read os follows; roa. 303(h), 204. 003. 0) i'lat. 7C3. 764. 80S 9 11.2 Approves! respirator* other than pu masks* s use. cu(h). 84*. son; 3- *C 370. as amended 27 Kiat. flit (33 u-3-O. *;t): . B(g), 0-1 two (23 UJ*C* (a) Until June 30, 1975. respirators or combinations of respirators other than 7(C))) 128 Title 30---Mineral Resources CHAPTER I--MINING ENFORCEMENT AND SAFETY ADMINISTRATION, DE PARTMENT OF THE INTERIOR PART 11--RESPIRATORY PROTECTIVE DEVICES; TESTS FOR PERMISSiaiUTY; FEES Respiratory Protection Against Exposure to Vinyl Chloride The Secretary of the Interior, through the Mining Enforcement and Safety Ad ministration. and the Secretary of Health. Education, and Welfare, through the National Institute for Occupational Safety and Health, conduct a testing and approval program for respirators used In occupationally hazardous atmospheres pursuant to regulation contained in this part. On October 4, 1974, the Occupational Safety and Health Administration, fol lowing a public hearing on the matter, promulgated a standard for the control of employee exposure to vinyl chloride. The standard provides that respiratory protection shall be provided at the re quest of employees exposed to 25 ppm or less vinyl chloride ar.d requires that respirators shall be selected from those approved under Parc 11. Soeciflcally, the standard requires, among other things, that where the atmospheric concentra tion of vinyl-chloride is not over 25 ppm. any gas mask with front- or backmounted canister or powered air-purify ing respirator with canister which pro vides a service life of at least four hours may be used, and where the concentra tion is r.ot over 10 ppm. any chemical cartridge respirator with an organic \apor cartridge which provides a service life of at least one hour may be used. The standard further requires a program to assure timely replacement of canisters or cartridges. The purpose of the amendments t forth below is to establish special pro cedures for testing vinyl chloride res pirators and to adopt a requirement that any canister or cartridge used to protect employees against exposure to vinyl chlo ride, have au end-of-service-life Indi cator. Unlike many other gases, vinyl chloride has no Inherent warning prop erties. Where a gas has an odor and %-here a canister or cartridge Is nearing or U si the end of its useful life, tha worker is aware because he can smell the gas. Vinyl chloride is odorless and color less. Thus, with due regard for"? the wearer's health, any cartridge or can ister should possess an end-of-servicclife Indicator. Section 11.205 provide* that after June 30. 1975, each canister or cartridge submitted for approval must have an end-of-service-llfe Indicator. The delay In this requirement is to giro the Institute an opportunity to test the effectiveness of the Indicators. Section 11.205 further provides that after De cember 31. 1975--when respiratory pro tection at 25 ppm or less becomes manda tory--.respirators without an end-ciservice-Ufe indicator wilt not be consid ered approved for use by employee* exposed to vinyl chloride. There la no delay in the effective date for the special tests adopted for vinyl chloride (b) The .components of each vinyl respirators. chloride respirator shah meet the mini Since It is essential that there are mum construction requirements set forth available approved respiratory devices in Subpart G of this part. for protection against exposure to vinyl chloride the Departments find that good cause exists for omitting notice of pro posed amendments to Part H. Accord ingly, these amendments, as set forth below, will be effective on December 30, 1974. Dated; Deceniber24,1971 11.202 Cat mask*; requirement* and teste. (al Except for the tests prescribed In 11.102-5, the minimum requirements and performance tests for gas masks, pre scribed in Subpart I of this part, are applicable to vinyl chloride gas masks. (b) The following bench tests are ap JacxW. Carlson, Secretary plicable to canisters designed for use with gas masks for entry into and escape o/ the Interior. Dated: December 10,1974. from vinyl chloride atmospheres con taining adequate oxygen to support life: (1) Four canisters will be equilibrated Caspar W. Wetnbercer, atSSmS* C bypassing 85m5 percent rela Secretary of Health, Education, tive humidity air through them at 64 end Welfare. liters per minute for six hours. In Part IT a new Subpart N for special ase respirators is established and Sec tions 11.200-11.203 applicable, to vinyl chloride respirators are added to read as follows: Subpart N--Special U*a Respirator* (2) The equilibrated canisters will be resealed, kept in an upright position at room temperature, and tested accord ing to subparagraph (3) of this para graph within 18 hours. (3> The canisters equilibrated and stored as described in subparagraphs <1> 3ec. and (2) of this paragraph will be tested 11.200 11.201 11.202 11.203 11.204 Vinyl chloride respirators; descrip tion. Required components. Qcj masks; requirements end tests. Chunlcal-carcridge respirator*; re quirements and tests. Powered eir-purUying respirators; on an apparatus that allows the test atmosphere at 85m5 percent relative humidity and 255* C to enter the canls-* ter continuously at a concentration of 25 ppm vinyl chloride monomer at a total flow rate of C4 liters per minute. fl-205 11.205 11207 requirements and tests. Requirement* for eud -of-senrlee-Ilf* indicator. Quality control requirements. Labeling requirements. (4) The maximum allowable penetra tion after six hours of testing according to subparagraph (3) of this paragraph ahall not exceed 1 ppm vinyl chloride. ll.20fl Pee*. <C) Where canisters are submitted for AtrrKoarrt: Secs. 202(h). 204. 508. 83 SUt. >03. 704, 803 (30 OS.C, 812(h), 844. 057); oe. 2. J. 5, 38 Slat. 370. as amended J7 Stat. ! (30 33 C. 3. 5. 7); aec. 8(g), 84 8twt. 1800 testing and approval with a service life of more than four hours, the period of time for testing for vinyl chlonde pene tration will be performed at 15094 of (20 US.C. 857(g)). the service life specified In the manu 5 11.200 Vinyl chloride resptralor*) de(CripUou. Vinyl chloride respirators. Including aB completely assembled respirator* *hlch arc designed for use ns respira tory protection during entry Into and escape from vinyl chloride Atmosphere* facturer's application. Example; If a manufacturer requests approval of a, respirator for six hours use against ex posure to vinyl chloride, the maximum allowable penetration after nine hours of testing shall not exceed 1 ppm vinyl chloride. containing adequate oxygen to support 11,203 C!icniic3l-carlrid;;e -respirators; ^fe. are described according to their con requirement* ond duction as follows: (a) Except for the tests prescribed In 11.162--8, the minimum requirement* (a) Front-mounted or back-mounted gas masks; and performance tests for chemical-car (bl Chin-style gas masks; tridge respirators prescribed in Subpart (c) Chemical-cartridge respirators; I of this part are applicable to vinyl (d> Powered air-purlfytng respirators; chloride chemical-cartridge respirators. and. fb) The following bench tests are ap (e) Other devices. Including combina plicable to cartridges designed for use tion respirators. with chemical-cartridge respirators for 11.201 R-rqnLrcd component*. entry Into and escape from vinyl chloride atmospheres containing adequate oxygen (a) Each vinyl chloride respirator de to support life: scribed in 11.200 shah, where its design .(1) Where two cartridges ere used in requires, contain the following compo parallel on a chemical-cartridge respira nent parts: tor. the bench test requirements will ap (1) Facepiece; ply to the combination rather than the (2) Canister with end-of-servlee-life Individual cartridges. indicator; (2) Four cartridges or palm of car (3) Cartridge with end-of-service-life tridges will be equilibrated at 255? C Indicator; by passing 85+5 percent relative hu (4) Harness; midity air through them at 25 liters per (5) Attached blower; and. minute for six hours. () Breathing tube. 129 <3> The equilibrated cartridges will be resealed, kept In an upright position, at room temperature, and tested accord ing to subparagraph (,4) of this para (4) The maximum allowable peuetra- - Such tests shall be performed la - ' tlon after six hours of testing according quantity necessary to assure continued to subparagraph <3) of this paragraph satisfactory confoi-mar.ee of the canisters shall not exceed 1 ppm vinyl chloride. and cartridges to the requirements of tills Eubpart. graph within 18 hours. (4) The cartridges equilibrated and stored as described In subparagraphs (1), (21, and (31 of this paragraph wiU be tested on an apparatus that allows the test atmosphere at 85=5 percent relative humidity and 25 = 5* C. to enter the cartridges or pairs of cartridges continuously at a concentration of 10 ppm vinyl chloride monomer at % total flow rate of 64 liters per minute. ' <51 The maximum allowable penetra tion after two hours o/ testing according' to subparagraph (4) of this paragraph shall not exceed 1 ppm vinyl chloride. 11.204 Powered air-purifying respira tor*; requirements and tests. (a! Biccept for the tests prescribed In 11.162-8, the minimum requirements and performance tests for powered sirpurifying respirators prescribed In Subpart Lof this part are applicable to vinyl chloride powered alr-purifylng respira tors. <b> The following bench tests are ap plicable to cartridges designed for use VSth powered aiT-purifying respirator* for entry Into and escape from vinyl 11.203 lloi{iiiri'r.cni fur servke-Ufe indicator. end-of* (a) After June 30, 1975, each canister or cartridge submitted for testing ami approval In accordance with JS 11.202. and 11.203, and 11.204 shall be equipid with a canister or cartridge end-offiCrvlce-liie Indicator wliich shows a satisfactory indicator change or other obvious warning before l ppm vinyl chloride penetration occurs. The Indi cator shall show such change or aSocd such warning at 60=10 percent of the total service life to l ppm. Leakage, as de termined by continuing each test de scribed in paragraphs (b> of each of $3 11.202. 11.203, and 11.204 of this Sub part until a l ppm leakage of vinyl chloride occurs. After December 3], 3975, a cartridge or canister without an endof-scnice-life indicator will not be con sidered approved for use by employees exposed to vinyl chloride. <b) The applicant sliall provide suf ficient pretest data to verify the per formance of the end-of-seiYlce-llfe Indi cator required, in paragraph, (a) of this Section. (.d) Final performance qua'fiy wa. trcl tests on the complete canisters and cartridges shall be accomplished uaiivthe bench tests and procedures pret scribed In 33 11.202, 11.203, 11.204, and 11.203 of this Subpart. 11.207 Labeling requironu-ut*. A warning shall be placed on the label of each gas mask, chemical-cartridge respirator, and powered air-purifying respirator and on the label of each can ister and cartridge, aierting the wearer to the reed for a fitting test In accord ance with the manufacturer's facepiece fitting instructions, providing service life information, providing specific Instruc tions for disposal, and advising tint the wearer may communicate to hTOSK any difficulties that may be experienced In the design and performance of any gas mask, chemical-cartridge respirator, oc powered air-purifying respirator ap proved under the requirements of Uus Subpart. The service lives of respirators meeting the test requirements of this Subpart shall be specified as follows: (a) Chemical-cartridge } hour chloride atmospheres containing ade quate oxygen to support Hie. <1> Four cartridges will be equili brated at 25=5' C by passing 85 = 5 percent relative humidity atf through them at 115 liters per minute for tightfitting facepieces and 170 liters per min ute for loose-fitting hoods and helmets, for six hours. (2) The equilibrated cartridges will be 11.206 Quality control requirements. (a) In addition to the construction and performance requirements specified In Sections 11.201, 11.202, 11.203. 11.204, and 11.205 of this Subpart, the quality control requirements in paragraphs (b), (c) .-and <d> of this section apply to ap proval of gas masks, chemical cartridge respirators, and powered air-purlfytng respirators for entry into and escape 4respirator. (t) Ohj mask ________ ________ tour* (c) Powered aU-purUying res. pirator. 4 tour* (d> Where the service life of a res pirator is approved for more than four hours, the service life for which the respirator has been approved will be specified. 11.208 Fees. resealed, kept in an upright position at room temperature and tested according to subparagraph <3> of this paragraph within 18 hours. (3> The cartridges equilibrated and ftored as described in subparagraphs (1) and (2) of this paragraph will be tested cn an apparatus that allows the test atmosphere at 85 = 5 percent relative humidity and 25 i 5* C to enter the cart ridge continuously at a concentration of 25 ppm vinyl chloride monomer at a total flow rate of 115 liters per minute for tight-fitting facepieces and 170 liters Per minute for loose-fitting hoods and helmets. from vinyl chloride atmospheres contain ing adequate oxygen to support life. (b) The respirators submitted for ap proval as described in paragraph (a) of this Section shall be accompanied by a complete quality control plan meeting The following fees shall be charged for the examination. Inspection, and testing of complete assemblies and com ponents of respirator* described in 53 11.200 and 11.201 of this Subpart. the requirements of Subpart E of this (a) Complete gu tuask____... *1.100 Part. (c) The applicant shrril specify in the plan that a sufficient number of samples Will be drawn from each bulk container of iorbent material and tliat where acti (b) Complete eli-niicat-cartrldga respirator. (c) Complete powered altpurUylug respirator. (d) C&nlater or cartridge only. 1,150 1,500 760 vated carbon ts used, the following spe JFR Doc.74-00362 rued 12-37-8:45 m) cific tests will be performed; 1. Apparent density, 2. Iodine number, 3. Moisture content, 4. Carbon tetrachloride number, and, 5. Mesh size. Iv-u. nO0 a / 130 I appendix c RESPIRATOR DRYING CABINET One 18 by 36 by 78-in. three-shelf cabinet with dou ble doors Three 15-3/4 by 35-3/4-in, pieces of 1/4-in. stainless steel mesh for shelves One 10 by 10-in. piece of window screen for exhaust port One small portable electric heater with fan, 115 V ac, 1650 W Thirty-two size 10 eyebolts Thirty-two clothespins with metal hanging clips Thirty-two spring clips 0 to 180F thermometer Size 20 nuts and bolts. CABINET MODIFICATION On one side, near the bottom, cut a hole and bolt the heater in place. Make sure the heater has a three-wire (grounded) plug. In the top of the cabinet, cut an 8 by 8-in. exhaust port and cover it with window screen. Cut away each shelf, leaving 1-1/2 in. at each edge, and bolt the stainless steel mesh in place. On the bottom and second shelves screw the small eye bolts into this mesh about 3 in. apart, and spaced so that 16 masks can hang in a double row from each shelf without touching each other. The clothespins hang from the eyebolts by specially fabricated metal clips. The thermometer is suspended by a small clamp. The temperature inside the cabinet is kept at 120 to 140F. After the cabinet has been loaded with masks, the temperature averages about 125F on the top shelf to 135F at the bottom of the lowhanging masks. The normal cabinet load is 10 to 15 full-face and 24 half-mask respirators and their filter holders. The greatest practical capacity, using both hangers and shelves, is 30 full-face or 60 half-mask respirators. The average drying time is 1 to 1-1/2 h. The total cost of materials and labor is less than $150.00. Figures C-l through C-3 show this cabinet. S' A i. 0 0 O 0 5 / 3 4 G 131 '/' o ovwc. 132 Fig. C-3. Cabinet loaded with masks. i'-l a! 00 u 0 o o 133 * ti APPENDIX D QUANTITATIVE RESPIRATOR FITTING TEST PROCEDURES Except for procedures peculiar to instrument operation and calibration, quantitative respirator fitting tests are practically identical. The following is a suggested procedure for use in all types of test systems. I. PRELIMINARY CHECKOUT PRO CEDURES A. Start up and calibrate the test system ac cording to manufacturer's instructions. Be sure that the system is stable and that the aerosol or gas con centration in the enclosure has reached equilibrium. B. Inspect all respirators to be used in the tests for defects and cleanness according to the procedures described in Chap. Nine. II. QUANTITATIVE FITTING TEST PROCEDURES A. Recheck the respirator before handing it to the test subject, paying particular attention to the sam pling probe and line attached to the facepiece. B. Describe the test to the subject, making sure that he fully understands its purpose, the procedures, and the actions expected of him. C. If the subject is not familiar with wearing respirators, demonstrate correct wearing procedures. The subject's level of expertise usually becomes apparent as he puts on the respirator. The untrained or poorly trained subject will put the respirator on incorrectly or be hesitant in his move ments. D. Have the subject put ori the respirator, ac cording to manufacturer's instructions. Be sure he does not tighten the headstraps to the point of dis comfort. Remember that this test should approx imate working conditions in which the subject might have to wear the respirator continuously for an hour or two at a time. In testing a half- or quarter-mask, check its com patibility with safety glasses. If the subject's safety glasses interfere, try other brands of respirators of the same type. The subject may have to wear a full facepiece, which provides eye protection, if a half- or quarter-mask compatible with safety glasses cannot be found. E. Once it has been determined that the respirator is worn properly, the fit can be checked quickly using a qualitative fitting test. Make sure that the correct filter, cartridge, or canister for the particular test is installed in the respirator. Also make sure that the subject pinches off the^sampling hose. If leakage is detected, try to determine its source and cause. If the leakage is from a poorly fitting facepiece, try another brand of the same type of respirator. In fact, several different brands of respirators should be made available so the subject can choose the most comfortable, a very important aspect of fitting respirators. F. After the best possible qualitative fit has been obtained, the subject enters the test enclosure and connects the sampling hose. If necessary, and without disturbing the facepiece fit, replace the filter, cartridge, or canister used during the qualitative test with the air-purifying element re quired for the quantitative test, To minimize filter leakage, use high-efficiency particulate filters when the test agent is an aerosol. Allow enough time (2-3 min) at this point for the test enclosure concentra tion to stabilize. Then recheck the test system calibration. G. In response to verbal instructions, the subject begins head and facial movements simulating those made during normal work. (1) Normal breathing with head motionless for 1 min; (2) Deep breathing (simulating that during hard work) with head motionless for 30 seconds. Do not prolong this exercise because of the danger of hyper ventilation; 134 OOOOOS / _l (3) Turning head slowly from side to side while breathing normally, pausing for at least two breaths before changing direction. Continue for at least 1 min; (4) Moving head slowly up and down while breathing normally, pausing for at least two breaths before changing direction. Continue for at least 2 min; (5) Reading from a prepared text, slowly and clearly, and loudly enough to be heard and un derstood by the test operator. Continue for 1 min; (6) Normal breathing with head motionless for at least 1 min. These exercises are more or less "standard" and have been found to provide a meaningful evaluation of respirator performance. Therefore, if they are used, the data can be compared with published informa tion. The times suggested for each are minimal and may be extended if needed to obtain better data, H. After the test, the subject leaves the test en closure and removes the respirator. The operator should then ask about the respirator comfort and note any marks on the subject's face which indicate pressure points. If the test indicated a good fit, any discomfort may be due to a mismatch between the subject and the facepiece or to headstraps that are too tight. Every effort should be made to provide the most comfortable respirator possible. I. The test results may be analyzed and the protection level determined by one of two methods. The first involves watching a meter during the test to determine that penetration does not exceed a cer tain value. On the basis of a protection factor (PF) of 10 for respirators with half- and quarter-mask facepieces and 50 for those with full facepieces, maximum penetrations by the test agent should not significantly exceed 10 and 2%, respectively. A cer tain amount of professional judgment is involved in using this method. The second, much preferred, method is to record the entire test using a strip-chart recorder operated at a chart speed of about 2 in. per min. Figure D-l is a simulated recording that illustrates most of the things likely to occur in a test. Starting at the bottom of Fig. D-l, the first infor mation should uniquely identify the test by number, date, subject, and type of respirator. Next comes the test system calibration after the subject has entered the test enclosure, to establish the maximum span of the penetration-measuring instrument ("100%" Fig. D-l. Typical quantitative fitting test strip-chart recording. calibration). This should be done at least twice to ensure that the calibration is correct. Next follow the five exercises, separated by horizontal lines across the chart. As the penetration measuring instrument has several ranges, the range should be shown next to the right margin of the chart. When it becomes necessary to change the penetration range, as in the example under turning 135 1 L S R L. '..a> o; o o > y head from side to side (TH), make a short mark where the change was made and indicate the new scale setting. Each exercise should be identified by some nota tion. In Fig. D-l the following were used. Normal breathing NB Deep breathing Turning head from side to side DB TH Moving head up and down UD Talking T These are suggested notations; others may be used, but they should be consistent. All the above notations should be made during the test. However, it is neither necessary nor desirable to calculate the penetrations until later. The operator should pay full attention to running the equipment and noting the subject's actions dur ing the test. The cyclic nature of the recorder trace is a func tion of the subject's breathing cycle. As this exam ple shows, in an air-purifying respirator with a half mask, negative air pressure created in the facepiece during inhalation increases the leakage. Exhalation creates slightly positive air pressure, reducing the leakage. Also, the lungs absorb some of the test agent, especially if it is an aerosol, thus reducing the quantity of test agent in the exhaled breath. Conse quently, the maximum penetration during inhala tion indicates the fraction of ambient concentration which has penetrated the facepiece. Therefore respirator performance is based on the average of the peak penetrations. After the test, the operator may analyze the recording. This is done, treating each exercise separately, by drawing a line through the inhalation peaks to approximate their average. The midpoint of each line is the "average peak penetration" for the exercise. This number should be entered on the chart for each exercise. Where the penetration changes abruptly, efe in Fig. D-l during the moving head up and down (UD) exercise, it is usally advan tageous to split the data into more than one section and treat each separately. In the example, five chart divisions under UD showed a penetration of 2.55% and three showed 3.75%. The average peak penetration for the entire exercise is calculated as follows. 5 divisions x 2.55 = 12.75 3 divisions x 3.75 - 11.25 8 divisions 24.00 24.00/8 = 3.00% peak average penetration. After the average peak penetration has been calculated for each exercise, the data may be en tered on the fitting test record, shown in Fig. D-2. This form is only a suggestion, other formats may be devised to better meet individual needs. Shown in Fig. D-2 on lines (1)-{3), is the informa tion from the recorder chart which uniquely iden tifies the test. Lines (4) and (5) show the results of the qualitative pretest. In this case, the subject did not have a qualitative fit and had to readjust the respirator or tighten the headstraps. As line (5) shows, he then obtained a satisfactory seal. Line (6) indicates that the subject was able to wear safety glasses with the particular respirator without inter ference. This is important information as most workers are now required to wear eye protection. m Tent HO. / *7 3 QUANTITATIVE FITTING TOST (;i subject____ C). Smt h_______________________ (Ji ftesplralor__ ABC JT7 C. . . Jr/(\ l f Mg ">k (O evaluative Priest: TypeJTrr. 9ngK> Tit: (51 Boiit: (6J Compatible with $ies*** r<i y res_________________________ res V __ \0 no TEST JttSUlTS Exercise Peak Average Per (?) Forrnal ar^Aihin? (ft) Deep Breelhin? to19) Turning u?Ad 'ron Side Side (10) Kovin9 Head Up and Dovn (11) Talking (0.7(-> MJL5,, 3. OO 4. 25 (131 AVIR.V.C: Allowable /C? t: Tct Average / J5 > (131 TIT: satisfactory /<* llnaatl ifaetory (30 Coafort Mllrtgr i * <D * * Fig. D-2. Fitting test record. 136 000057353 Lines (7) -(11) show the average peak penetrations calculated for each exercise. Line (12) shows the test criterion expressed as the maximum allowable average peak penetration, This is 10%, as the test involved an air-purifying respirator with a half mask facepiece. Line (12) also shows the test average peak penetration of 1,95% obtained by averaging the average peak penetrations for each ex ercise. Line (13) shows whether the overall perfor mance was satisfactory or not. This determination is based on the qualitative fit, compatibility with safety glasses, and average penetration, which in this example had to be less than 10%. The subjective evaluation of the comfort of the particular respirator, shown on line (14), is based on the criteria shown in Fig. D-3. All other factors be ing equal, final choice of a respirator should be based on comfort. A worker should not be required to wear a device he considers "uncomfortable" or "in tolerable." He may wear a "barely comfortable" respirator if the proposed usage is intermittent for short periods. In summary, the above is a suggested procedure for conducting a quantitative respirator fitting test, evaluating the results, and recording the data meaningfully, without laborious record keeping. Moreover, the data will be compatible with those from other work. 1. VERT COMFORTABLE HASK CAN BE WORN FOR AN UIDEFINITE PERIOD WITHOUT BECOMING UNBEARABLY BOTHERSOME OR PAINFUL. NO PA 111 POINTS: MASK FEELS COf-PORTABLE. 2. COHORT APLE HASH CAN BE WORN FOR 2 TO A HOURS WITHOUT IT.TIUl DISCOMFORT. SOKE PRESSURE POINTS WITH SLIGHT DISCOMFORT. J. BARFLY CUUIUKTASLE HASH CAN BE WORN FOR APPROXIMATELY 1/2 HOUR TO 1 HOUR WITHOUT INTOLERABLE disco:oukt. som disco:tost r?.o:: pressure. . UNCOMFORTABLE MASK CA'I BE TOLERATED FOR THE PERIOD OF THE TEST ONLY. 5. INTOl.ERJ.PI.E MASK CANNOT BE WORN AT ALL WITHOUT DISCOMFORT. HOYT: This table can be used aa the prepared teat far the ''Talking" eaerclse during Che quantlcetIre fleeing ceac. This vill rave the tine for the subject to acquaint htcaelf trith this table alter the ceac. Fig. D-3. Respirator comfort ratings. 137 APPENDIX E QUANTITATIVE RESPIRATOR-FITTING TEST EQUIPMENT Both NaCl and DOP aerosol systems are commer cially available (1975) from Air Techniques, Inc., 1717 Whitehead Road, Baltimore, ME) 21207 and Frontier Enterprises, Inc., Box 30041, Albuquerque, NM 87110. The systems these concerns make differ little from the basic designs developed by the Los Alamos Scientific Laboratory (LASL). The cost may vary, depending upon accessories, but it is generally about $8-10,000. Both the NaCl and DOP systems consist of an aerosol generation and dilution air system, an analyzing system, and a test en closure. Figure E-l illustrates a typical NaCl. test system consisting of an internal or external compressed air source (1) that provides clean air at 50-100 psig to the aerosol generators (2) and combustion air to the burner (12). A Wright-design nebulizer is used in all commercial systems and has been adopted as the standard means of generating an NaCl aerosol. Operated at 24 psi with a 1% NaCl solution, it produces an aerosol with an aerodynamic mass me dian diameter (AMMD) of 0.6 ^m. Two nebulizers are provided in most systems, although the output from one is sufficient for most purposes. The aerosol generator injects the liquid droplets perpendicularly into the air stream flowing through the mixing and drying chamber (3), in Fig. E-l. The air for drying the aerosol ('-4 cfm) is supplied by an internal blower ahead of which is mounted a highefficiency filter. In passing through the mixing and drying chamber, the liquid NaCl droplets dry into discrete solid particles that are carried in the aerosol stream to the test enclosure. In this instance, the en closure (5) is a test hood that covers the subject Fig. E-l. NaCl quantitative fitting test system schematic. 138 A 00 OO down to his waist, but particles also could be delivered to a small chamber. This test hood, based on a Harvard School of Public Health design, is commercially available. The aerosol is delivered to the center top of the hood. Directly below the inlet is a small circular plate that helps distribute the aerosol stream evenly inside the hood. Even dis tribution is further ensured by a large perforated plate that forms the bottom of the aerosol distribu tion section. The chamber part of the hood is made of two, slightly separated, cylindrical walls of thin, transparent plastic. At the bottom of the outer wall is a cloth skirt that can be drawn snugly around the subject's waist to minimize leakage into the sur rounding area. The aerosol is exhausted through the annular space between the inner and outer walls, As Fig. E-l shows, two sampling tubes lead from the hood to the aerosol-analyzing system. One tube (6) samples the concentration of NaCl aerosol parti cles in the chamber atmosphere, and it is used in calibrating the flame photometer. The other tube (7) samples the NaCl aerosol particles in the air in side the respirator. A peristaltic (tubing) pump (9) is used to inject the sample into the flame photometer burner (10). On the inlet side of this pump are connected the sampling tubes from the test hood as well as a third sampling tube which is connected to a small highefficiency filter. This tube and filter (8) supply clean sampling air to the burner to calibrate the photometer. Combustion air for the burner (10) is supplied from the external or internal compressed air source (1), and the propane fuel is supplied from an exter nal tank (11). The amount of NaCl in the sample stream is determined by vaporizing the NaCl parti cles in the burner and detecting the emitted yellow light characteristic of sodium by using a sensitive photomultiplier tube (12) aheadsof which is placed an optical filter (13) that passes only the sodium emission lines. The light intensity is directly related to the concentration of NaCl aerosol particles. The photomultiplier tube output is fed into the electronics (14) of the test system analyzing section, and the amount of aerosol in the sampled air is dis played as percentage of the ambient concentration in the hood, either on a meter or a separate strip chart recorder (15). The DOP quantitative respirator fitting test system is very like the NaCl system. As Fig. E-2 shows, an internal or external compressed air source (1) supplies 3- to 5-psig air to the Naval Research Laboratory Model III design DOP generator (2) and LASL-designed round jet impactor (3). The equivalent generator and impactor are found in commercial systems, but external construction details may differ. The output from the generator and impactor assembly is injected into the dilution air chamber (4), perpendicularly to the air flowing through this chamber. The purpose is not to dry the aersol, as it is an oil mist, but to reduce the aerosol mass concen tration to an acceptable level and maintain ade quate air flow to the test enclosure. The test en closure (6) is identical to that for the NaCl system, and two sampling tubes sample the DOP aerosol in the hood and the interior of the respirator, A third sampling tube outside the test hood is connected to a small high-efficiency filter (9) to provide clean air to the forward light-scattering photometer (10). The amount of DOP aerosol in the sample stream is determined by the intensity of the light scattered forward from particles passing through the center of the conical scattering chamber. This light strikes the photomultiplier tube (12), and the tube output is fed into the electronic section (13) of the analyzer which is almost identical to that used in the NaCl system. The DOP concentration in the sample stream from the respirator, expressed as a percentage of the concentration in the test hood is displayed either on a meter or on a separate strip chart recorder (14). This description applies primarily to the prototype units designed and built at LASL, upon which the commercial systems are based. Improve ments and changes are made continually, so presen tly available systems may not look like those described. The important point is that the hearts of these systems, the aerosol generators, are identical in all respects. fit. 00005 73' 139 1 Fig. E-2. DOP quantitative fitting test system schematic. In summary, these quantitative respirator fitting test systems provide the ultimate method for deter mining respirator fit. However, it is unrealistic to suggest that every respirator program have this capability. These systems are expensive and com plex and require trained operators. Therefore, they are most widely used by industrial firms that have very comprehensive respirator programs. On the other hand, if a small industrial firm must protect workers against highly toxic contaminants, the ex penditure for a quantitative respirator fit test system may be justified. 000c 7 140 APPENDIX F JOINT NIOSH/OSHA STANDARDS COMPLETION PROGRAM RESPIRATOR DECISION LOGIC AUGUST 2, 1976 L INTRODUCTION The purpose of the Respirator Decision Logic is to assure technical accuracy and uniformity between substances in the selection of respirators and to provide necessary criteria to support this selection. The Decision Logic is a step-by-step elimination of inappropriate respirators until only those which are acceptable remain. Judgment by persons knowledgeable of inhalation hazards and respiratory protection equipment is essential to en sure appropriate selection of respirators. The primary technical criteria for what con stitutes a permissible respirator are based on the technical requirements of 30 CFR Part 11 (Depart ment of the Interior, Bureau of Mines, Respiratory Protective Devices and Tests for Permissibility). The proposed substance health standards will allow only respirators approved by the Bureau of Mines (or Mining Enforcement and Safety Administration (MESA)) and NIOSH under 30 CRF 11. Classes of respirators are included only if at least one device has been approved. Protection factors are criteria used in determining what limiting concentrations are to be permitted for each respirator type that will afford adequate protection to the wearer. Thg referenced subparts of 30 CFR 11 give technical descriptions of each type or class of respirators referenced in the Decision Logic. 30 CFR 11 should be used with the Decision Logic in order to properly understand the criteria for the specification of allowable respirators. II. GENERAL FLOWCHART DECISION LOGIC Step 1 - Assemble Information on Substance Assemble necessary toxicological safety, and research information for the particular contami nant. Typically the following are required: (1) Permissible exposure limits specified in 29 CFR 1910.1000 (Tables Z-l, Z-2, and Z-3). These are the former 29 CFR 1910.93 tables. (2) Warning properties if the substance is a gas or a vapor. Refer to Part IV(8) of this logic. (3) Eye irritation potential of the substance. Refer to Part IV(D) of this logic. (4) LFL (Lower Flammable Limit) for the sub stance. Refer to Part IV(F) of this logic. (5) Immediately dangerous to life and health (IDLH) concentration for the substance. See Part IV(E) of this logic. (6) Any possibility of poor sorbent efficiency at IDLH concentration and below. Refer to Part IV(C) of this logic. (7) Any possibility of systemic injury or death resulting from absorbance of the substance (as a gas or vapor) through the skin. Refer to Part IV(A) of this logic. (8) Any possibility of severe skin irritation resulting from contact of the skin with corrosive gases, vapors, or particulates (see Part IV A of this logic). (9) The vapor pressure of the substance (and equivalent ppm). (10) Any possibility of high heat of reaction with sorbent material in cartridge or canister. (11) Any possibility of shock sensitivity of sub stance sorbed on cartridge or canister sorbent. (A) Gas or vapor, (B) Particulate (dust, fume or mist), or (C) Combination of (A) and (B). Step 3 Assemble a Table of Permissible Respiratory Protection for Substance Step 2 - Determine Physical State of Substance Determine the physical state(s) of the substance as it is likely to be encountered in the occupational environment. It will be either: This is done using the material from Step 1 and the appropriate specific decision logic chart from Part III of this logic and the respirator protection factors in Appendix I. Classes of respirators are in cluded only if at least one device has been approved. III.A. SPECIFIC DECISION LOGIC CHART FOR RESPIRATORY PROTECTION AGAINST GASES OR VAPORS Condition Routine Use Entry and Escape From Unknown Concentrations Firefighting Escape Selection Sequence (A) Consider irritation and sorption of the material through the skin, (See IV A). (B) Poor warning properties - eliminate all air purfiying respirators (see IV B). (C) Eye irritation - eliminate or restrict use of half-mask respirators (see IV D). (D) IDLH or LFL - above this concentration eliminate all but positive pressure self-contained breathing apparatus and combination positive pressure supplied air respirator with auxiliary positive pressure self-contained breathing apparatus (see IV E and F). (E) List all allowed respirators by condition of use and type. Use positive pressure self-contained breathing apparatus or combination positive pressure supplied air respirator with auxiliary positive pressure self-contained breathing apparatus. Use positive pressure self-contained breathing apparatus. Gas mask or escape self-contained breathing apparatus (see IV C). 142 SAL. j 0 0 0 s III.B. SPECIFIC DECISION LOGIC CHART FOR RESPIRATORY PROTECTION AGAINST PARTICULATES Condition Routine Use Entry and Escape From Unknown Concentrations Firefighting Escape Selection Sequence (A) Consider skin irritation or sorption of the material through the skin (see IV A). (B) Eye irritation - eliminate or restrict use of half mask respirator (see IV D). (C) Systemic poison - eliminate single-use respirator. (D) For permissible exposures less than 0.05 mg/cu.m, - eliminate DFM respirators except with high efficiency particulate filter. (E) IDLH or LFL - above this concentration eliminate all but positive pressure self-contained breathing apparatus and combination positive pressure supplied-air respirator with auxiliary positive pressure self-contained breathing apparatus (see IV E). (F) List all allowed respirators by condition of use and type. Use positive pressure self-contained breathing apparatus or combination positive pressure supplied air respirator with positive pressure self-contained breathing apparatus: Use positive pressure self-contained breathing apparatus (see IV F). Use any dust, fume, or mist respirator, except single use, or any escape self-contained breathing apparatus. til 0()(. W 360 143 III.C. SPECIFIC DECISION LOGIC CHART FOR RESPIRATORY PROTECTION AGAINST COMBINATION OF GAS OR VAPOR AND PARTICULATES Condition Routine Use Entry and Escape From Unknown Concentration Firefighting Escape Selection Sequence (A) Consider skin irritation or sorption of material through the skin (see IV A). (B) Poor warning properties or inadequate sorbent efficiency - eliminate all air purifying respirators (see IV B & C). (C) Eliminate all respirators except with combination sorbent/particulate filter. (D) Eye irritation - eliminate or restrict use of half mask respirator {see IV D). (E) For permissible exposures less than 0.05 mg/m3, - eliminate all respirators except with sorbent/high efficiency particulate filter. (F) IDLH or LFL - above this concentration eliminate all but positive pressure self-contained breathing apparatus and combination positive pressure supplied-air respirator with auxiliary positive pressure self-contained breathing apparatus, (see IV E). (G) List all allowed respirators by condition of use and type. Use positive pressure self-contained breathing apparatus or combination positive pressure supplied air respirator with positive pressure self-contained breathing apparatus. Use positive pressure self-contained breathing apparatus (see IV F). Gas mask or escape self-contained breathing apparatus (see IV C). o ) 1... () () Q () 5 7 ';> /. 144 IV.A. SKIN ABSORPTION Personal protection requirements for protection against exposure to substances which may cause in jury by absorption through the skin from materials splashed or spilled on the skin are covered in Section (F) of each substance standard. Respirator selection criteria are based primarily on the inhalation hazard of the substance. A supplied-air suit may provide skin protection for extremely toxic sub stances which may be absorbed through the skin, or substances that may cause severe skin irritation or injury. Where information is available indicating systemic injury or death resulting from absorbance of a gas or vapor through the skin or where severe skin irritation or injury may occur from exposure to a gas, corrosive vapor, or particulate, the following statement is included as a footnote to the respirator tables and both the employee and employer are cautioned in the appendices concerning their use: "Use of supplied-air suits may be necessary to pre vent skin contact and respiratory exposure from airborne concentrations of (specific substance). Supplied-air suits should be selected, used, and maintained under the immediate supervision of persons knowledgeable in the limitations and potential life endangering characteristics of supplied-air suits. Where supplied-air suits are used above a concentration which may be im mediately dangerous to life and health, (concen tration) an auxiliary positive-pressure selfcontained breathing apparatus must also be worn." The supplied-air suit statement is an advisory foot note. The decision whether or not to include the footnote is made by the NIOSJH/OSHA review com mittees based on available information. Since most information concerning skin irritation is not quantative, but rather presented in commonly used descriptive terms, such as "a strong skin irritant, highly irritating to the skin", "corrosive to the skin", etc., the decision made by the committees concern ing skin irritation is a judgmental decision often based on non-quantitative information. As a guideline for inclusion of the supplied-air suit state ment for substances which are sorbed through the skin, a single skin penetration LD50 of 2 grams/kilogram for any species is used. The footnote is advisory in nature and its inclu sion does not make the use of supplied-air suits mandatory. Further, employers may use suppliedair suits in any situation where they provide ade quate protection, whether there is an advisory foot note in the respirator table or not. To assure the health and safety of persons using supplied-air suits, it is imperative that they be used under the im mediate supervision of persons knowledgeable in the limitations and potential life endangering charac teristics of supplied-air suits. IV.B. POOR WARNING PROPERTIES It is important to realize that 30 CFR 11 NIOSH/MESA approvals for air-purifying (organic vapor) devices prohibit use against organic vapors with poor warning properties. Specifically, 30 CFR 11.90(B) (Note 4) covers gas masks (canister respirators) and 30 CFR 11.150 (Note 7) covers chemical cartridge respirators. Thus these ap provals are only for those organic vapors with ade quate warning properties and not all organic vapors. Warning properties relying upon human senses are not foolproof, however, they provide some in dication to the employee of possible sorbent exhaus tion or of poor facepiece fit or other respirator malfunction. Warning properties include odor, eye irritation, and respiratory irritation. Adequate warning properties can be assumed when the substance odor, taste, or irritation effects are detectable and persistent at concentrations "at" or "below" the permissible exposure limit. It is expected that environmental concentrations will vary considerably and, therefore, warning of a respirator failure would soon be perceived at con taminant concentrations somewhat above the per missible exposure limit. If the odor or irritation threshold of a substance is more-than three times greater ;than the permissible , exposure-limit, this substance should be considered to have poor warning properties. If the substance odor or irritation threshold is somewhat above the permissible exposure limit (not in excess of three times the limit) and there is no ceiling limit, con sideration is given as to whether or not undetected 145 exposure in this concentration range could cause serious or irreversible health effects. If not, the sub stance is considered to have adequate warning properties, Some substances have extremely low thresholds of odor and irritation in relation to the permissible exposure limit. Because of this, these substances can be detected by a worker within the facepiece of the respirator even when the respirator is functioning properly. These substances are, therefore, considered to have poor warning proper ties. Though 30 CFR 11 does not specify eliminating air purifying respirators for pesticides with poor warning properties, the SCP respirator review com mittee believes the standard completion program should not allow pesticide respirators for gases and vapors with poor warning properties. and should be kept away from oxidizable material. Some cartridges and canisters may contain ac tivated charcoal and shall not be used to provide protection against (specific substance). Only nonoxidizable sorbents are allowed." Where the ox idizable material may be an oxidizable filter, the footnote reads; "(specific substance) is a strong ox idizer and should be kept away from oxidizable sub stances. Only air purifying respirators with nonoxidizable filters are allowed. Where there is reason to suspect that a substance sorbed on a sorbent of a cartridge or canister is shock sensitive, use of air purifying respirators is dis allowed. IV.D. EYE IRRITATION IV.C. SORBENT EFFICIENCIES ^ Where supporting evidence exists on immediate (less than three minutes) breakthrough time at the IDLH concentration and below for a cartridge or canister sorbent, air-purifying devices shall not be allowed for any use, escape or otherwise. Where there is reason to suspect that the com monly used sorbents (e.g., activated charcoal) do not provide adequate sorption efficiency against a specific contaminant, use of such sorbents shall not be allowed. However, where another sorbent material has been demonstrated to be effective against a specific contaminant, approved respirators utilizing the effective sorbent material shall be allowed. The statement in the respirator table shall read, "Any chemical cartridge respirator providing protection against (specific substance)", and "any gas mask providing protection against (specific substance)". Where there is reason'to suspect that a sorbent has a high heat of reaction with a substance, use of that sorbent is not allowed. In such cases, only sor bents providing safe protection against (specific substance) may be used. For such substances, a footnote is added to the respirator table which reads as follows: "(specific substance) is a strong oxidizer For routine work operations, any perceptible eye irritation is considered unacceptable. Therefore, only full facepiece respirators are permissible in contaminant concentrations which produce eye irritation. Note that 30 CFR 11.90(B) (Note 6) specifies that eye protection may be required in cer tain concentrations of acid gases and organic vapors. For escape, some eye irritation is permissi ble if it is determined that such irritation would not inhibit escape and such irritation is reversible. Where quantitative eye irritation data cannot be found in literature references, and theoretical con siderations indicate the substance should not be an eye irritant, half facepiece respirators are allowed. Where a review of the literature indicates a sub stance causes eye irritation but no eye irritation threshold is specified, the data will be evaluated to determine whether quarter or half-facepiece respirators are to be included in the respirator tables. When a table is developed for such sub stances, the respirators with quarter- and half facepieces shall be footnoted as follows: When an employee informs his employer that he is experienc ing eye irritation from ** NAME ** while wearing a respirator allowed in Table 2, the employer shall provide and ensure that the employee use an equivalent respirator with a full facepiece, helmet or hood. 146 IV.E. IDLH The deffi IDLH' provided in 30 CFR 11.3(T) is as follows: "Immediately dangerous to life or health" means conditions that pose an immediate threat to life or health or conditions that pose an immediate threat of severe exposure to contaminants, such as radioactive materials, which are likely to have ad verse cumulative or delayed effects on health." 2. Chronic exposure data may have no relevance to the acute effects and should be used in determining the IDLH concentration only upon competent toxicologic judgment. 3. Where there is no toxicologic evidence of an IDLH concentration, 500 times the permissible exposure limit shall determine the upper limit above which only highly reliable breathing ap paratus providing maximum worker protection is used. The purpose of establishing an IDLH exposure concentration is to insure that the worker can escape without injury or irreversible health effects from an IDLH concentration in the event of failure of the respiratory protective equipment. The IDLH is con sidered a maximum concentration above which only highly reliable breathing apparatus providing max imum worker protection is permitted. Since IDLH values are conservatively set, any approved respirator may be used up to its maximum use con centration below the IDLH. In establishing the IDLH concentration, the following factors are considered: 1. Escape without loss of life or irreversible health effects. Thirty minutes is considered the max imum permissible exposure time for escape. 2. Severe eye or respiratory irritation or other reactions which would prevent escape without injury. IDLH should be determined from the following sources: 1. Specific IDLH provided in the literature such as the AIHA Hygienic Guides. 2. Human exposure data. 3. Acute animal exposure data. 4. Where such data are lacking toxicological data from analogous substances may be considered. The following guidelines should be used to inter pret toxicological data reported in the literature for animal species: 1. Where acute exposure animal data are available (30-minute to 4-hour exposures), the lowest exposure concentration causing death or irreversible health effects in any species is determined to be the IDLH concentration. IV.F. LOWER FLAMMABLE LIMIT AND FIRE-FIGHTING Contaminant concentrations in excess of the LFL are considered to be immediately dangerous to life or health. At or above the LFL, the use of respirators is limited to those devices which provide the max imum protection, i.e., positive-pressure SCBA, and combination positive-pressure supplied-alr respirators with positive pressure SCBA. Firefighting is defined by ANSI Z88.5-1971 as be ing immediately dangerous to life. For firefighting, the only device providing adequate protection is the positive pressure self-contained breathing apparatus. IV.G. PROTECTION FACTORS Protection factors are a measure of the overall ef fectiveness of a respirator. Filtering efficiency is a part of the protection factor and becomes a signifi cant consideration for less efficient air purifying respirators, The protection factors used in the preparation of the standards are based on quantitative fit tests per formed at Los Alamos Scientific Laboratory and elsewhere, and in some instances on professional judgment. In Appendix I, the protection factors for each class of respirators listed in the checklists are shown. The entries in each list are for an entire class of respirators, and are assigned the protection factor of the lowest performing device within each class, 8 AI... 0 0 0 0 5 7 3 6 4 147 IV.H. VARIATIONS WITH 30 CFR 11 1. The type A supplied-air respirator is allowed in 30 CFR 11 for use in immediately dangerous to life and health atmospheres. However, air supply re quirements of 50 1/min are insufficient to maintain a positive pressure in the facepiece under all working conditions. Therefore, this device should have the same protection factor as applied to other airpurifying and atmosphere supplying respirators having a negative pressure in the facepiece (see Ap pendix I). 30 CFR 11 will require a revision to eliminate approval of type A supplied air respirators for TDLH atmospheres. 2. 30 CFR 11 does not contain protection factor requirements. Protection factors are used in the decision logic. An amendment to 30 CFR 11 is plan ned to include protection factor requirements for DFM respirators. Future amendments are contem plated for other types of respirators. 3. 30 CFR 11 does not permit the use of an escape gas mask against acid gases or organic vapors with poor warning properties. A change to 30 CFR 11 is necessary to permit the use of an escape gas mask against substances with poor warning properties. IV.I. ESCAPE employer shall provide and ensure that employees carry an escape respirator where exposure to ex tremely toxic substances may occur. (An extremely toxic substance is defined as a gas or vapor having a RAT LC50 of less than 10 ppm.) The following statement is added to the introduc tion to the respirator table for these substances: Employers shall provide each employee working in areas where **name** may be released into the workplace air with an approved escape respirator as specified in Table 2. The employer shall ensure that each employee carry the escape respirator in the area where "name** may be released into the workplace, IV.J, "ENTRY INTO TANKS OR CLOSED VESSELS, OR . . Item (D)(4)(IV) is a variable provision in the in troductory statements to the respirator tables which lists the specific operations where a respirator is considered to be an acceptable means of control. Ex amples of where this may occur are for operations which require occasional entry into tanks or other closed vessels. Where escape respirators are provided, they shall be selected from the escape category in Table 2. The APPENDIX I A. PROTECTION FACTORS FOR PARTICULATE FILTER RESPIRATORS Protection Factor Permissible respiratory protection 5X 5X 10X 10X 10X 50X 1000X 148 Any dust and mist respirator (30 CFR 11.130) Any dust and mist respirator, except single use (30 CFR 11.130). Any dust and mist respirator, except single-use or quarter-mask respirator (30 CFR 11.130). Any fume respirator (30 CFR 11.130). Any high efficiency particulate filter respirator (30 CFR 11.130). A high efficiency particulate filter respirator with a full facepiece (30 CFR 11.130). A powered air-purifying respirator with a high efficiency particulate filter (30 CFR 11.130). SAL 00003 73 B. PROTECTION FACTORS FOR CHEMICAL CARTRIDGES AND GAS MASKS Protection Factor (Minimal) Permissible respiratory protection 10X Any chemical cartridge respirator with a `NAME** cartridge(s) (30CFR 11.150) 50X A chemical cartridge respirator with full facepiece and **NAME** car- tridge(s) (30 CFR 11,150) 50X A gas mask with a full facepiece and ** NAME "* canister (30 CFR 11.90 (A)) 1000X A powered air-purifying chemical cartridge respirator with a ** NAME ** cartridge (unlisted device).* Escape Any gas mask providing protection against ** NAME ** vapors (30 CFR 11.90) "Classes of respirators are included only if at least one device has been approved. NOTE: The approval ** NAME ** may consist of acid gases or organic vapors as a class nr specific acid gases, am monia, or organic vapors. It may also consist of combinations of acid gases, organic vapors, and other gases and vapors. C. PROTECTION FACTORS FOR COMBINATION CHEMICAL CARTRIDGES AND PARTICULATE FILTERS AND GAS MASKS AND PARTICULATE FILTERS Protection Factors Permissible respiratory protection 10X Any chemical cartridge respirator with ** NAME ** cartridge(s) and ** NAME ** filter(s) (30 CFR 11.150 and 11.1300) 50X A chemical cartridge respirator with a full facepiece, ** NAME ** car- tridge(s) and high efficiency filter(s) (30 CFR 11.150 and 11.130) 50X A gas mask with a full facepiece and ** NAME ** canister and high ef ficiency filter (30 CFR 11.90(A) and 11.130). 1000X A powered air purifying chemical cartridge respirator with a ** NAME ** cartridge and high efficiency particulate filter. Escape Any gas mask providing protection against ** NAME ** and particulates (30 CFR 11.90 and 11.130) ** NAME ** refers to any acid gas, akaline gas, organic vapor, or other specific gas or vapor. ** TYPE ** refers to dust and mist, fume, or high efficiency particulate. NOTE: A pesticide respirator is a special type of chemical cartridge respirator or gas mask with a combination sorbent and particulate filter. Where a substance is a pesticide the following phrase is added as a footnote to the respirator tables. "Including pesticide respirators which meet the requirements of this class." D. PROTECTION FACTORS FOR SUPPLIED-AIR RESPIRATORS Protection Factor 10X 50X Permissible respiratory protection Any supplied-air respirator (30 CFR 11.110(A)) Any supplied-air respirator with a full facepiece, helmet, or hood. (30 CFR 11.110(A)) 149 SAL. ' lj () i 7 , , 1000X 2000X *A type C supplied-air respirator operated in pressure-demand or other positive pressure of continuous flow mode {30 CFR 11.110(A)) A type C supplied-air respirator with a full facepiece operated in pressuredemand or other positive presssure mode or with a fuil facepiece, hood, or helmet operated in continuous flow mode (30 CFR 11.110(A)) "This category is not fully covered by preceding category. E. PROTECTION FACTORS FOR SELF-CONTAINED BREATHING APPARATUS Protection Factor 10X 50X 10,000+X or Fire Fighting 10,000+X Escape Permissible respiratory protection Any self-contained breathing apparatus (30 CFR 11.70(A)) Any self-contained breathing apparatus with a full facepiece (30 CFR 11.70(A)) Self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive pressure mode (30 CFR 11.70(A)) A combination respirator which includes a Type C supplied-air respirator with a full facepiece operated in pressure-demand or other positive pressure or continuous flow mode and an auxiliary self-contained breathing apparatus operated in pressure-demand or positive pressure mode (30 CFR 11.70(B)) Any escape self-contained breathing apparatus (30 CFR 11.70(A)) * APPENDIX II LITERATURE REFERENCES The following are the primary reference sources used in this decision logic. 1. Chemical Safety Data Sheets, Manufacturing Chemists Association, Wash., D.C. % 2. Sax, N.I., Dangerous' Properties of Industrial Materials, Third Edition, Van Nostrand Reinhold Company, New York, 1968. 3. Hygienic Guide Series, American Industrial Hygiene Association, Detroit, Michigan. 4. Chemical Company Guides: (A) Allied Chemical (B) Commercial Solvents Co. (C) Dow Chemical (D) Eastman Kodak 150 (E) Exxon (F) FMC (G) Monsanto (H) Olin Chemicals (I) Rohm & Haas (J) Shell (K) Union Carbide Company 5. American National Standard Acceptable Con centrations, American National Standards In stitute, Inc., New York. 6. Browning, E., Toxicity and Metabolism of In dustrial Solvents, Elsevier Publishing Company, New York, 1965. Browning, E., Toxicity of Industrial Metals, Butterworths, London, 1961. 7. Documentation of the Threshold Limit Values for Substances in Workroom Air, Third Edition, American Conference of Governmental Industrial Hygienists, Cincinnati, 1971. 8. Gleason, M. N\, Gosselin, R. E., Hodge. H.C., and Smith, R. P., Clinical Toxicology of Commer cial Products, Third Edition, The Williams and Walkins Co., Baltimore, 1969. 9- Thienes, C. H. and Haley, T. J., Clinical Tox icology, Fifth Edition, Lea and Febiger, 1972. 10. Spector, W. S. (Vol. I, II), Negherbon, W. O. (Vol. Ill), Grebe, R. M. (Vol. IV), and Dittmer, D. S. (Vol. V) (Editors), Handbook of Toxicology, Saun ders, Philadelphia, 1956-1959. 11. Paget, G. E. (Editor), Methods in Toxicology, Blackwell Scientific Publications, Oxford, 1970. 19. Stecher, P. G. (Editor), The Merck Index, Eighth Edition, Merck and Co., Inc., New Jersey, 1968. 20. International Labour Office, Encyclopaedia of Occupational Health and Safety, McGraw-Hill Book Co., New York, 1971. 21. Hygienic Information Guides, Commonwealth of Pennsylvania, Department of Environmental Resources, Bureau of Occupational Health. 22. Christensen, H. E. and Luginbyhl, T. L., (Editors), NIOSH Toxic Substance List, 1974 Edi tion, Hew Publication No. 74-134, 1974. 23. Survey of Compounds Which Have Been Tested for Carcinogenic Activity, U.S. Public Health Ser vice Publication No. 149, Original, Supplements 1 and 2, 1961-67, 1968-69, and 1970-71. 12. Stolman, A. (Editor), Progress in Chemical Toxicology, Vol. 2, and Vol. 4, Academic Press, New York, 1965 and 1969. 24. Spencer, E.Y., Guide to the Chemicals Used in Crop Protection, Sixth Edition (Publication 1093), Research Branch Agriculture, Canada, 1973. 13. Patty, F. A. (Editor), Industrial Hygiene and Toxicology, Vol. 2, Second Revised Edition, In terscience Publishers, New York, 1963. 14. Hunter, D., The Diseases of Occupations, Lit tle, Brown and Company, Boston, 1969. 15. Stauden, A. (Executive Editor), Kirk-Othmer Encyclopedia of Chemical Technology, 2nd Edition, Interscience Publishers, New York, 1972. 16. Glick, D. (Editor), Methods of Biochemical Analysis, Interscience Publishers, New York, 19541969. 17. Altman, P. L. and Dittmer, D. S. (Editors), Biology Data Book, Federation of American Societies for Experimental Biology, 1964. 18. Deichmann, W. B. and Gerarde, H. W., Tox icology of Drugs and Chemicals, Academic Press, New York. 1969. 25. National Safety Council Industrial Data Sheets, National Safety Council, Chicago, Illinois. 26. Baskin, A. D. (Editor), Handling Guide for Potentially Hazardous Commodities, Railway Systems and Management Association, Chicago, Il linois 1972. 27. Handbook of Organic Industrial Sovlents, Technical Guide No. 6, 4th Edition, American Mutual Insurance Alliance, Chicago, Illinois, 1972. 28. Committee on Hazardous Materials, Division of Chemistry and Chemical Technology, National Research Council, National Academy of Science, Fire Hazard Classification of Chemical Vapors Relative to Explosion-Proof Electrical Equipment, Report III, A Supplementary Report prepared by the Electrical Hazards Panel, Washington, D.C., May 1973. 151 29. National Fire Codes, Volume l, Flammable Li quids, NFPA 325, National Fire Protection Associa tion, Boston, 1969. 36. Doolittle, A. K., Lacquer Solvents in Commer cial Use, Industrial and Engineering Chemistry, Vol 27, 1169-1179, 1935. 30. National Fire Codes, Volume 7, Alarm and Special Extinguishing Systems, NFPA 69, National Fire Protection Association, Boston, 1973. 37. Grant, W. M., Toxicology of the Eye. Second Edition, Charles C. Thomas, Publisher, Illinois, 1974. 31. National Fire Codes, Manual of Hazardous Chemical Reactions, NFPA 491M, National Fire Protection Association, Boston, 1971. 32. National Fire Codes, Volume 3, Combustible Solids, Dusts and Explosives, NFPA 49, National Fire Protection Association, Boston, 1973. 38. API Toxicological Reviews, American Petroleum Institute, New York. 39. Gleason, M. N., Gosselin, R. E., Hodge, H. C., and Smith, R. P., Bulletin of Supplementary Material for Clinical Toxicology of Commercial Products, University of Rochester, 1969-1975. 33. Bahme, Charles W., NFPA Fire Officer's Guide to Emergency Action, Appendix A, National Fire Protection Association, Boston, 1974. 40. May, J., Odor Thresholds of Solvents for Assess ment of Solvent Odors in the Air, Staub, Vol. 26, 3438 (Sept. 1966) {English Trans.) 34. Factory Mutual Engineering Corporation, Handbook of Industrial Loss Prevention, Second Edition, McGraw-Hill Book Company, New York, 1967. 41. Summer, W., Odors Pollution of Air, CRC Press, Cleveland, 1971. 35. Armistead. G., Jr., Safety in Petroleum Refin ing and Related Industries (Appendix A), Second Edition, John C. Simmonds and Co., Inc,, New York, 1959. s 152 SAL 00005 "f APPENDIX G STANDARD OPERATING PROCEDURES Selection of the proper type of respirator is vital, but it is only part of the complete respirator program. Unless a standard operating procedure is set up, a correctly chosen respirator may be used in correctly. The OSHA regulations 1910.134b require written standard operating procedures whenever respirators are used. Examples are given below. at the start of each shift. He is also told that silica dust may be harmful to health some years after ex posure and that it is important that he use the respirators provided. It is further explained that it is impossible to install a ventilation system to take care of the dust problem in this area. STANDARD OPERATING PROCEDURES FOR USE OF RESPIRATORS IN THE MUL LER AREA Respirator Sanitation Program As the respirators are discarded after each day's use, there is no need for a sanitation program. The first respirator selection example in Chap. Six concerned a muller operator in a foundry. If we assume that this is a small foundry with only one operator, we can write a simple procedure as follows. Respirator Selection Respirator Use Surveillance It is the foreman's responsibility to see that safety devices provided are used. He checks the muller operator's use of the respirator daily. On the basis of the 5-mg/m3 dust concentration and a permissible exposure limit of 1.5 mg/cm of silica dust, we have chosen the brand X disposable respirator, approved for use in silica dust, to be worn whenever the muller is operated. Properly used, this respirator provides a protection factor of 5. Work Area Surveillance If operating conditions change, dust concentra tion in the muller area will be remeasured to ensure that the respiratory protection provided is still adequate. User Instructions in Training The muller operator who wears this respirator is trained in its use when hired and yearly thereafter. During training, he is taught to wear the respirator and a fit test using talc dust is performed to see whether the respirator leaks. If it does leak, another brand of disposable respirator is obtained. After the fit test, the employee continues to wear the respirator during the rest of the instruction and training class. He is told that he may have a new respirator whenever he wants and that he must use a new one whenever breathing becomes difficult and STANDARD OPERATING PROCEDURES FOR USE OF SELF-CONTAINED BREATHING APPARATUS DURING DEGREASER PIT MAINTENANCE In the fourth example in Chap. Six, maintenance personnel occasionally had to enter a degreaser pit while it was cool to clean it and perform necessary maintenance. The written operating procedure might be as follows. 153 ,,fsO0^ " Respirator Selection Extremely high trichlor concentrations may be encountered during degreaser cleaning. The pit is to be ventilated, but use of pressure demand suppliedair respirators with escape packs is required. User Instruction and Training Maintenance men required to wear this equip ment are trained in its use within 30 days of their employment. The training consists of wearing the equipment in fresh air and being taught how to regulate air flow and how to react in emergencies and if the main air supply fails. They are shown the alarm bell in the degreaser pit which rings if the air compressor fails. They are told that at that time they have 10 minutes air supply from their escape packs. The equipment is used in a training exercise four times a year and is cleaned approximately twice a year. The exercise consists of entering the pit after it has been ventilated and inspecting the equipment in the bottom of it. Escape bottles of compressed air that have been opened are replaced through an arrangement with the distributor. solutions. They are dried and stored in special cases in the maintenance department. Respirator Air Supply Air for normal use of these masks is supplied by an oilless portable compressor placed at the edge of the pit. Respirator Use Surveillance The Safety Director is responsible for seeing that training is carried out as specified and he must over see the training. Emergency Respirator Inspection The respirators are inspected monthly for deterioration and to see that the escape bottles are fully charged. This is the Safety Director's responsibility. Cleaning, Maintenance, and Storage After use, the respirators are cleaned by the main tenance staff using the manufacturer's sanitizing -s U.S. GOVERNMENT PRINTING OFFICE 1977--777-018/'32 154