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PLAINTIFF'S EXHIBIT B&R-lll ACCIDENT PREVENTION MANUAL for Industrial Operations EDITION NATIONAL SAFETY COUNCIL Chicago, Illinois 60<S1 1 COPYRIGHT 1964 NATIONAL SAFETY COUNCIL All Rights Reserved No portion of this book may be reproduced, by any pro cess without written permission of the National Safety Council, 425 North Michigan Avenue, Chicago, IU. 60611 Library of Congress Catalog Card Number: 64-24124 25M106463 Printed in U.S.A. Stock No. 121.35 !REFACE THE LIBRaK'i the university OF TEXAS The dominant theme of this Manual is safety; the pervading purpose is accident revention. Industrial accident prevention has as its primary objective the preven- "on of injuries to persons; an auxiliary goal is the prevention .of damage to equip- ent and other property. The favorable reception of the first four editions of this book by safety engineers d others who have the responsibility for accident prevention has provided the centive for this revised Fifth Edition. The object was to update the material and extend its scope while being more specific in both word and illustration to reduce the bulk of the book. For improved readability, a slightly larger and clearer typeface has been used. For easier refer ence, the index includes as many synonyms as possible, but it has been consider ably shortened by including only major references under each subject. If a subject discussed on successive pages, only the first page is referenced. Two new chapters have been developed: "Audio-Visual Aids" and "Industrial Noise." Many others have been completely revised. For more logical organization, some chapters have been retitled and material has often been regrouped. Some duplications will be found among the sections. The Editors think this facilitates the use of a section and avoids the necessity for frequent reference to other parts of the book. Where a significant amount of additional information is in another chapter, cross references are provided. The preparation of each chapter was directed by a National Safety Council staff specialist in the field. In some cases, new material was developed by recognized authorities who are identified by the footnote on the first page of each chapter. All worked with many collaborators. For all of these men, the most satisfying reward is the knowledge that they have contributed to the more effective per formance of the industrial safety men of today, and to the education of future safety men. To increase the effectiveness of those responsible for industrial accident pre vention, much detailed material had to be included, but it is not the purpose of this Manual to serve as a complete handbook of all design, fabrication, operation, inspection, and management principles. Rather, it attempts to set forth the important points to be considered when evaluating an industrial accident prevention program including the safe operation of equipment and processes. This Manual does not constitute an official code or standard, and it does not obviate prescribed regulations or minimum safe practices. When practices are described, it is not intended that they supplant other practices that have proven tisfactory, nor is their description intended to discourage innovation and original- in contributing to ever-more-effective industrial accident prevention. No one prescribed safety formula can be superimposed on all accident-prevention rograms. As a suggestive guide the Manual necessarily speaks in broad and gen eral terms; its contents must be adapted to the specific circumstances of the par- `cular operation. Ultimate responsibility, therefore, must rest in the selection of the ique or method for correcting any given condition or situation. Jam'h. ' Jr The Editobs INDUSTRIAL HYGIENE the larger particles are trapped by the hairs in the nose. Other dust particles are re moved from the air as it passes over the moist mucous membranes of the nose, throat, and other portions of the upper res piratory system. The bronchi and other respiratory passages are covered with a large number of tiny, hairlike cilia or mi croscopic whiplashes, which aid in the re moval of dust trapped on these moist sur faces. The cilia, all bending in one direc tion, make a fast stroke toward the mouth and a slower return stroke. This action tends to push mucous and deposited dust upward to the mouth so that the particles can be expectorated or swallowed. Retention of dust Many studies have been made in an effort to determine the amount of dust that is re tained in the lungs, but there is no simple answer to this question. It has been shown that the size of the dust particles, the rate of respiration, the density of the dust in the air, the efficiency of the dust-catching mech anism, and probably many other factors are involved. Sizes of particles inhaled Although an occasional dust particle of larger size will enter the lungs, particles less than 3 u in diameter are the most like ly to do so and thus have the greatest op portunity to cause a physiological reaction. In silicotic lungs, for example, dust parti cles under 3 u greatly outnumber larger ones, and many particles are less than 1 p. In the case of very fine fibrous asbestos dust, an exception occurs in the size of particles inhaled. Many fibers up to 100 u long have been found in the lungs of asbes tos workers at autopsy. A typical fibrosis caused by asbestos is produced by fibers that are 20 to 50 p in length, but only a few microns wide. Physiological Effects of Dusts, Fumes, and Mists The physiological reactions caused by the inhalation of airborne particulate matter will vary with different types of dusts, fumes, and mists. The reactions include: 1. The cardiopulmonary reaction which con. sists of the pneumoconioses, such as silicosis and asbestosis. In certain cases. specific types of lung pathology resul and the heart may be affected (cor pul monale) when the fibrosis is advanc In other cases, there is mainly just accumulation of a relatively inert dust the lungs. 2. The systemic reactions which are cau by toxic dusts of such elements as lead manganese, cadmium, and mercury, their compounds, and by certain organi compounds. 3. Metal fume fever which results from th inhalation of finely divided and freshly generated fume of zinc or possibly off magnesium or of their oxides. This is transient condition. 4. Allergic and sensitization reactions whichmay be caused by inhalation of, or skin contact with, such materials as organic dusts from Hour, grains, and some woods and dusts of a few organic and inorganic chemicals. There are also bacterial and fungal infections which occur from in halation of dusts containing active organisms, such as wool or fur dust containing. anthrax spores or wood bark or grain dust containing parasitic fungi. (See thesection "Biological Agents and Other Oc cupational Infections" later in this chap ter.) 5. Irritation of the nose and throat, which, is caused by acid, alkali, or other irritat ing dusts or mists. Some dusts such as. soluble chromate dusts may cause ulcera tion of the nasal passages or even lung, cancer. 6. Damage to internal tissues, which may result from inhaled radioactive mated such as radium and its daughter produe and from other radioisotopes that emi' highly ionizing radiation. (See Chapt 42, "Ionizing Radiation.") Pneumoconioses Pneumoconiosis comes from three Grc words that mean "lung," "dust," and normal condition." The present gene accepted meaning of the word is me "dusty lung." The kind of dust inhaled termines the type of condition or injurynumber of organic dusts are capable of ducing lung diseases, but not all theseeases are classified as pneumoconioses^ cause they are not all a "dusty condi" of the lung. 39-6 INDUSTRIAL HYGIENE particles, but by a combination of slight solubility with a physiochemical effect and an immunological effect--but no one is cer tain of the exact mechanism of the disease. Experimental work on the reasons for the development of silicosis is still going on in various parts of the world. If the precise mechanism of silicosis could be determined, better medical preventive measures might be developed and possibly a cure could be found. Amorphous free silica differs from cry stalline free silica in physical structure and in physiological effects. In the amorphous state, molecules of silica are randomly ori ented and may be naturally converted to opal and diatomaceous earth (kieselguhr) or artificially converted into such forms as silica gel, silica fume, and fused silica or quartz. If amorphous silica is heated to a high temperature, as in calcining, forms of cry stalline free silica called cristobalite and tridymite result, intermediate forms of amor phous silica are known as crvpto-crystalline (ultra-microcrystalline). Inhalation of these crystalline forms can readily cause diatomite pneumoconiosis. When diatomaceous earth is calcined, par ticularly in the presence of a trace of alka line flux, appreciable quantities are con verted to cristobalite. As a result of studies made by the U.S. Public Health Service, it has been recommended that the threshold limit value for crude or amorphous diatomite be placed at 20 mppcf (million particles per cubic foot), but that the atmospheric con centration for dust containing cristobalite W kept under 5 mppcf. Various commercial products containing particles of silica under 1 u in size are available. The physiological effects of these products have not been well defined. Until more experience with human beings is avail able, these products should be handled with care. "American Public Health Association. 1790 Broadway, New York City. "Report (Joint) of the Committee on Pneumoconi osis and the Committee on Standard Prac tices in Compensation of Occupational Dis. eases." Year Book, 1933. 39-7 INDUSTRIAL HYGIENE Free silica is uneombined silicon dioxide (SiO?). Silicates contain silicon and oxy gen combined with other elements in more complex molecules. The SiO> reported in chemical analyses for mineral and geological reports is the total of the silicon dioxide present, both the free silica (if present), and the silica combined in the mineral. Such analyses are not reliable indications of the silicosis potential of the material, because it is the uncombined or free silica that is most important in industrial dust exposure. So that an exposure can be properly evaluated, the percentage of uncombined silica must be determined by petrographic analysis using a polarizing microscope or, preferably, by X-ray diffraction analyses and special ana lytical chemical procedures. There has been some experimental evi dence that some dusts may tend to inhibit the action of silica on the body, but this in hibiting action is so slight and uncertain that it must be discounted in practice. In fact, there is also evidence that the nonsiliceous components of a dust mixture containing free silica may provoke a disabling condition more severe than that caused by the silica acting alone. With the exception of asbestos and some talcs, the silicate dusts do not ordinarily cause a serious disabling lung condition such as is produced by free silica. Much higher levels of silicate dusts than of free silica dust can be tolerated. In many industries, men have worked with silicate dusts that con tained no free silica without development of disability or of nodulation in the lungs. The X-ray may show shadows indicating dust deposits in the lungs, but the pneumoconiosis is essentially harmless. However, partially disabling pneumoconioses have been reported where men have worked for long periods of time in very high concentrations of certain silicate dusts. Disabling pneumoconioses from exposure to abnormally high concen trations of mica, tremolite talc, and kaolin dusts have been described in the literature. The clinical signs are not the same for these silicate dusts as for free silica, but the symp toms can be marked. The fine airborne fibers of asbestos can ] pass through the upper respiratory tract the lower parts of die lungs to cause irrita tion and to form "asbestos bodies" whe the fibers are encapsulated. This fibrosis probably begins as a "collar" about the terminal bronchioles. There is evidenc that other minerals having a fibrous charac ter (except glass fiber) can produce a tion similar to that of asbestos. Following a study by the U.S. Public^ Health Service of the asbestos textile indus-i try,* it was recommended that the dust con-1 centration be kept at less than 5 mppcf to prevent asbestosis. Evaluation of an expo-, sure to asbestos dust is based on the total amount of dust, since the concentration of injurious fibers will be kept within safe limits if the fine dust is kept below the suggested threshold limit. Miscellaneous pneumoconioses. Even though a dust is classified as harmless, amounts above the TLV can lead to trouble by causing a pneumoconiosis, mechanically irritating the walls of the respiratory system, or interfering with ordinary lung processes. Mica dust and kaolin dust are two good ex- ' amples of dusts that ordinarily are consid ered benign but amounts above the TLV can cause a troublesome pneumoconiosis. Mica pneumoconiosis has been observed in grind ing operations where mica dust, but no free silica was present. There were marked changes in the X-ray pictures of the lungs and some disability. The cases occurred where the dust exposures were massive over many years. Toxic dusts and fumes Systemic reactions are caused by toxic-1 dusts and fumes of various elements and ' their compounds and by certain organic com pounds. All metallic fumes are irritating, i pecially when freshly generated. Industrially important metals and their compounds that! can have a toxic effect when the dust ori fumes are inhaled include arsenic, antimonyj cadmium, chromium, lead, manganese, mer cury, selenium, tellurium, thallium, uranium^ and a few others. Asbestosis. Several minerals having a fibrous character are classed as "asbestos"-- hydrated silicates of magnesium with vari able amounts of iron, calcium, sodium, potas sium, and aluminum present as impurities. "U.S. Public health Service, Washington D.C. "A Study of Asbestosis in the Asbestod Textile Industry." Bulletin No. 241. 1938. 39-8 INDUSTRIAL HYGIENE Lead is a norma] constituent of plants and animals, and people ingest and excrete it daily even though they are not exposed to lead in their daily work. When intake rates exceed the normal excretion rates, however, lead builds up in the body. When the accu mulation reaches a sufficient level, symptoms of poisoning or intoxication appear. The concentration of airborne lead should there fore be kept below the threshold limit be cause of lead's high toxicity and its tendency to accumulate in the human system. Beryllium intoxication is a severe system ic disease that can result from the inhalation of the dust or fume of metallic beryllium, beryllium oxide, and soluble beryllium com pounds. (There is no evidence of intoxica tion from the ingestion of insoluble com pounds.) Only the inhalation of the beryl lium-bearing dusts or fumes produces sys temic disease. Accordingly, control of such dusts and fumes to keep them below the concentration specified by ACGIH (Ameri can Conference of Governmental Industrial Hygienists) threshold limit values is a basic protective measure. When the soluble salts of beryllium, espe cially beryllium flouride, contact cuts or abrasions on the skin, deep ulcers may be formed which heal very slowly, and com plete "surgical excision of the ulcer is some times required to effect healing. Metal fume fever is an acute condition caused by a brief high exposure to the fresh ly generated fumes of metals such as zinc, magnesium or their oxides. Symptoms ap pear from 4 to 12 hr after exposure and consist of fever and shaking chills. There is complete recovery usually within one day, and ordinarily the employee can return to the same job without recurrence. However, after a period in which there has been no contact with the fume, for example, after a layoff, resumption of exposure is likely to bring on an attack. Metal fume fever is caused by heavy con centrations of fumes. Zinc oxide fume is the most common source, but cases caused by the inhalation of fumes from magnesium oxide, copper oxide, and other metallic ox ides have also been reported. The condition does not occur from the handling of these oxides in powder form. Apparently, it re sults only from the inhalation of extremely fine particles freshly formed as fume (called a "nascent fume"). Cadmium, mercury, and other metals may also produce a fever fol lowed by the toxic effects of the element. Organic Solvents The widespread industrial use of organic solvents presents a major problem to the in dustrial hygienist, the safety engineer, and others charged withr the responsibility for maintaining a safe, healthful working en vironment. Getting the job done without hazard to employees or property is depend ent upon the proper selection, application, handling and control of solvents and an un derstanding of their properties. Labeling The labeling of solvents to indicate their properties and health and fire hazards is an extremely important method for recognizing and evaluating the hazards. In fact, if a sol vent is not properly labeled, it should not be used. The purchasing department can great ly help the safety department by notifying suppliers that only properly labeled solvents will be accepted in the plant. Uniformity in language and layout is de sirable to simplify understanding of solvent use. The MCA's Guide to Precautionary Labeling of Hazardous Chemicals, Manual L-l," recommends the following subject mat-* * Manufacturing Chemists Assn., 1825 Connecticut Ave. NW., Washington, D.C. 39-9 ELEMENTS OF INDUSTRIAL TOXICOLOGY in the handling of wet dross from a light metals plant, in the cleaning of tank cars which have held sulfuric and hydrochloric acids, in the cleaning of pipes with an acid contaminated with arsenic, in the precipita tion of cadmium with metallic zinc, and in other operations. Axsine rapidly destroys the red cells. After it has been inhaled, the first signs are those of lack of oxygen. After some time the body begins to excrete the damaged red cells, which appear as a dark or bloody urine. The kidneys may then become too clogged to operate at all. Arsine, in very small amounts, is also capable of producing a chronic type of poisoning, but it is more typically a source of acute episodes. The possibility of arsine formation should always be considered when there is freshly formed hydrogen around ores of the heavy metals, since arsenic is widely distributed in small amounts and only a trace of it is re quired to produce enough arsine to be trou blesome. One of the more common sources of arsine incidents in recent years has been the han dling of dross from the aluminum refining of metals. Probably the most significant ob servation about these cases, aside from the fact that the moisture in the atmosphere is enough to form arsine, is the fact that the people involved in them have not been aware of the garlic-like odor which is supposed to be a warning of the presence of arsine. See Hygienic Guide. Asbestos is a hydrated magnesium silicate found in the minerals chrysotile, amianthus, actinolite, and tremolite. Practically all the commercial asbestos is either chrysotile or amianthus, and about 90 per cent of that used in this country is chrysotile. It is used almost exclusively for heat insulation or for textiles which must resist high temperature, such as heat-resistant clothing and brake linings. Inhalation of excessive quantities of as bestos fiber can produce a fibrosis in the lungs similar to that found in silicosis but somewhat milder and usually not so rapidly progressive. Like silicosis, the condition de velops and advances slowly and is equally resistant to treatment. There is also good evidence that inhaled asbestos causes lung cancer. See Hygienic Guide. Barium, in the form of its soluble salts, is toxic on both ingestion and inhalation and highly caustic when applied to the skin. The carbonate and sulfide are sufficiently soluble to be toxic, although not very caustic. The sulfate, which is used as a contrast medium in X-ray work, is too insoluble to show any' toxicity, and soluble sulfates are specific antidotes for ingested barium salts. Since these salts produce violent stimula tion of all muscle, upon ingestion they pro duce severe disturbances of the digestive system. After absorption, the barium salts increase blood pressure by constriction of the arterial muscle, slow down heart beat by an action similar to that of digitalis, and first excite and then paralyze the central nervous system. In spite of the high inher ent toxicity, there are few cases of indus trial poisoning with barium. Barium is a heavy metal, and the dust of the insoluble salts will collect in the lungs and give rise to the condition known as baritosis. Its nodular appearance on X-ray film may be mistaken for that of silicosis. Men showing the sign of baritosis are ap parently not disabled or inconvenienced in any way. See Hygienic Guide. Benzene (benzol) is a colorless, flamma ble, volatile liquid with a rather pleasant aromatic odor. Its fire hazard is between ethyl alcohol and ethyl ether. The greatest hazard is that of chronic poisoning by in halation of comparatively small amounts over a long period of time. It is one of the two or three most dangerous organic sol vents in commercial use, and acts primarily on the blood-forming organs, producing se vere anemia, bleeding under the skin, and great reduction in the ability of the blood to clot. 40-18