Document zd9zabg4xB0YdNjXrRRgYVBbg

Petroleum Industries A total-ox 157 accidents and 29 deaths on grounded type vs none on double insulation. fillers Falls in 1960 became the American pioneer in double insulation, and that year manufactured its 1144 nylon drill with a two-prong plug, the first DI tool built in the United States. The Underwriters' Labora tories, with the company's help, wrote a temporary specification and approved this tool, and the double insulation movement was launched. It was understandable, in the light of the long struggle to gain acceptance throughout the United States for three pronged tools, that there was reluctance on the part of other manufacturers to imme diately endorse a change. This reluctance extended to the National Electrical Code, but in 1962 the NEC did act to approve the use of double-insulated tools in residential occupancies. Since that time, over half of the states have amended their codes to permit both, residential and industry use, and many manufacturers, other than Miller Falls, have started to manufacture and sell double in sulated tools. The National Code, however, is not easily changed. For a long time it was felt that field tests had not developed sufficiently to justify a change. The controversy centered in Electric Code Making Panel No. 5, a sub-conmrittee concerned with methods and specifications on grounding.-Among the strongest proponents for double insulation was the Underwriters' Laboratories. In the meantime, as state after state ap proved the industrial use of portable power tools, resistance lessened. Impetus was fur ther given in 1966 when New York State approved the industrial use of such tools. The final change came on December 9,1966 when the Correlating Committee of National Electrical Code endorsed Panel 5's interim change to the code approving use of ap proved double-insulated, two-pronged tools in industry. The 1968 Code lists the approval of the use erf approved doable insulated tools hx both residential and industrial applica tions. At the present time, Miller Falls has in troduced over 100 industrial and consumer DI shock-proof tools; other manufacturers, including Blade & Decker, Sldl, Rockwell (Porter-Cable), Stanley, Thor, Sears, Mont gomery Ward, and others have added doubleinsulated tools to their line. Some persons in industry, outside Miller Falls, have predicted that doable-insulation will become standard throughout the United States within ten years as more and more tool companies tarn to their manufacture. PRODUCT LIABILITY--PRECAUTIONARY LABELING OF PETROLEUM PRODUCTS By ALLAN E. DOOLEY , Supervisor, Industrial Hygiene and Toxicology, Texaco Lac, New York; N. Y. The safe use of petroleum products has been of prime interest to the oil industry for many years. It can be achiev d only if users know which products are hazardous and what measures should be taken to avoid illness or injury. Industry, including ours, and government have found that one effec tive aid is the use of precautionary labels for products which may be hazardous, whether they are encountered at work or in the home The policy of the American Petroleum Institute with respect to precautionary la beling reads, in part: "The petroleum in dustry recognizes the value of precautionary labels on containers of commercial products where their normal use and handling may constitute a significant health or accident hazard." ' This policy was formally adopted m the midT950's- But long before that tuSthe industry was using some precautionary labels. Probably the most familiar one is almost 45 years old. It is the sign on pomps that dispense leaded gasoline. It says in part, "For use as motor fuel only." This was a vol untary move taken after discussion between the manufacturers of anti-knock compounds, oil companies, and the Surgeon General of 7 1968 Nctional Safety Congress the Public Health Service. It is one of the best known and oldest examples of volun tary industry action in the field of consumer protection. In addition to voluntary industry action in precautionary labeling; there are many statutory requirements. Federal, state and municipal, that affect petroleum products. The principal Federal requirements sue the Interstate Commerce Commission regulations, the Federal Hazardous Substances Act, and the Federal Insecticide, Fungicide, and Rodentidde Act All of these require labeling of certain petroleum prodnds. The Los Angeles and New York City Fire Depart ment regulations aj^^te best-known munici pal regulations. Many states base laws in this area. Just recently, the six common-market countries fa Europe have begun to adopt labeling rules. Many variations exist in the labeling re quirements of the different juriidictiooi. This lack of uniformity presents a problem for companies who market nation-wide. It was especially true in the household products field until 1966. An amendment to the Fed eral Hazardous Substances Act, in that year, preempted this field to the Federal govern ment Now, any state or local law having requirements affecting household products is void if it differs from the Federal require ments. Industry's goal is complete uniform ity. Perhaps some day it will be reached. Despite the differences, certain common principles exist (Incidentally, they were first expressed by a trade association -- The Manufacturing Chemists' Association -- in 1945). These principles, as they apply to petroleum products are: 1. A label should be a true estimate of personal hazard, base! on experience, lab oratory testing (especially biological testing), and the inherent chemical and physical nature of the product ' , 2. Labels should not be used for relatively harmless products and should not contain unnecessary warnings because soch practices foster disregard of all labels and promote careless and improper handing. 3. Precautionary wording should be se lected by those who not cdy know die nature of die product but also have a broad ac quaintance with its field of use. 4. Precautionary labels are primarily in tended for use on containers. In the oil in dustry they are prepared for use on drums and smaller mffts-,Thns, quantity is impor tant when considering die wording relating to predominant use. A good precautionary label should satisfy these requirements: 1. Statements should be brief, accurate, and simple to understand. 2. It should call attention not only to hazards doe to die inhem*. nature of the substances, but also to bazanb anting out of die reasooably-atfiripated conditions of storage; handling; and roe. 3. It should represent the best available knowledge of the product and its behavior. If data are not adequate; die label should so state. ' These requirements apply equally to in dustrial and household products. They are the basis for vohmtary labeling programs and of requirements imposed by laws. To repeat, die objective of precautionary labeling k to prevent 21ncsr or injury among persons using or exposed to poten tially hazardous substance*. Industry has sccomp&shed much in protecting workers on the job from hxzankws substance* The Mg problem exists in die home; primarily be cause of the presence of small children. Annually, an estimated SMWOO children swallow product* left within reach. Petro leum product! are involved in probably about five per cent of these an.Mental ingestions. Most of the infliVnSr involve drugs and other medicines. 1 Fatalities from accidental ingestion also show die magnitude of the household prob lem. In a 13-year period (1952-1964) deaths from accidental poisoning among children under five years of age averaged 418 an nually. Deads due to swallowing of petro- knm products averaged 78 annually, or about 18 per cent of die total. Bat the deaths from petroleum prodnets dropped from an average of 105 in 1952 and 1953 to 46 in 1963 and 1964. Deads from all substances in these same years decreased from 444 (in 1952 and 1953) only to 421 (in 1963 and 1964). This favorable experience vrifli petrolenm products is not all because of precautionary labeling. A better knowledge by physicians on die proper treatment; we feel, is an important factor. (It is worthy to note here that die API contributed considerable money, to snp- 8 Petroleum Industries port research in the development of proper treatment for accidental ingestion of petro leum products by children.) * It is not the pttrpcce of this paper to teach in detail bow to write a precautionary label for a petroleum product. Ah excellent guide is API Bulletin 2511 on Precautionary Label ing. The second edition (1964) is undergoing revision, but the principles will be unchanged in the third edition, which should be avail able in 1969. The obvious first step in preparing a label is to determine if the substance is hazardous. A hazardous substance (or mixture of sub stances) b one wbich: is toxic; is corrosive to tissue; is an irritant; is a strong sensi tizer; is flammable; or generates pressure through decomposition, heat, or other means -- if such substance may cause substantial personal injury or illness during, or as a direct result of any customary or reasonablyanticipated handling or use. (The hazards of radioactive substances are a separate matter, outride the scope of this discussion of com mercial petroleum products.) This definition of a hazardous substance necessitates the determination of six differ ent properties: Toxicity. The inherent capacity of a sub stance to produce personal injury or iflness in man as a result of ingestion, inhalation, or absorption through any body surface. Corrosiveness. The property of a substance which, in contact with living tissue, causes destruction of the tissue by chemical action. It does not refer to action on inanimate surfaces. Irritation. The extent to which a substance, as a result of immediate, prolonged, or re peated contact with normal, living tissue, will induce a local inflammatory reaction. Most commonly, the tissues to be considered are the skin, eyes, and surfaces of the respira tory tract Sensifirntbrn. The property of a substance to prodncWn normal, living tissue, through an allergic or photodynamic process, a hy persensitivity which becomes evident in re application of the same substance. Flammability. The property of a substance, solid, or liquid, which enables it to burn. For a liquid, the degree of flammability de pends on its flash point Everyone seems to have his own definition 'of a flammable liquid. The ICC describes a flammable liquid as one with a flash point of 80F or below. The Federal Hazardous Substances Act uses this same cut-off point, but classes those with flash points of 20F or below as extremely flammable. The New .York City Fire De partment uses 100F as the tog limit for flammable liquids. There is a flash point temperature above which the hazard of flammability is not considered great enough to require a pre cautionary label. Between this temperature and the temperature presently used to class a substance as flammable, an area of un certainty exists. This is the area which many sincere authorities feel needs attention: the lowest class of flammability. The API Committee on Precautionary Labeling be lieves, currently, that petroleum products with flash points above 80F to 120F should be classed as "Combustible." This differs from the 150 top figure of the MCA and some other groups. The 80F and 120F range includes Stoddard solvent, a widelyused cleaning solvent, and most kerosenes. The volatility of materials in this range is such that care is needed in handling these petroleum products. This range does not in clude domestic heating crib both in view of its history as an article of commerce and in accordance with the true purpose of all pre cautionary labeling. Flammable solids are harder to define. Whatever definition or description is used, it would, at most, affect only a very few petroleum products. Pressure Generators. Examples are con tents of self-pressurized containers, those which can be exploded by an electrical spark or by percussion, and those which erupt from their opened containers at temperatures of 130*F or leas after being in the dosed con tainer at 130*F for two days. ' When information on these six properties has been developed and it indicates that the substance is hazardous, a precautionary label can be prepared. A proper label includes these'components arranged in this sequence: Name of the product. The chemical or commonly recognized generic name of the contents. Usually, a trade name is inadequate. In mixtures, the chemical or generic name of the hazardous components should be given. 9 1968 National Safety Congress Signal word. This word describes tie de contact Sensitization to petroleum products gree of hazard The words used are "dan is so infrequent that it is not considered a ger!" "wanting!" and caution!" in descend significant hazard An' occasional individual ing order of seriousness of risk. The word may develop a sensitization to a straight "poison" is not a signal word Its use on a petroleum distillate, but such cases are too land should be Suited to those products few to require their classification as strong which are poisons by a definite toxidty sensitizers. However, a few compounded lu standard or when required by law. bricants have caused episodes of skin sensiti Statement of Hazard. This is a brief, ac curate, affirmative statement of the major hazard or hazards. zation because of the presence of a sensitizing additive in tire product One that comes to mind is mercaptobenzothiazole, an antioxidant sometimes ttsed in cutting oils. It has been Precautionary Measures. Action to be fol used for many years in the rubber industry, lowed and to be avoided to prevent the injury with an apparently good experience among or illness stated m the preceding item. < workers handling it as a solid But when Emergency Adam and First Aid. Brief, simple ixistnxlions to be followed in the event injury has occurred If the substance is a poison, the prescribed antidote should he stated here: Container Storage and Handling. Only when indicated became of the nature of the contents, or when required by law. The state ment. "Keep oat of reach of children" is required on all boasehold containers of haz dissolved in mineral oils, it has caused sensi tization. Cases have been reported in Sweden. This is an example of a situation where pre cautionary labeling will not contro! the problem. Sims contact with cutting oils car. only be minimized; it cannot be completely eliminated Removal of the offending agent is the solstioo. There have been some cases of photo-sensitivity from some asphaltic products but again, their number does not appear significant. ardous substances. As turns pressure generation being a haz Name and Address of tke Manufacturer. ard, tins problem is minimal except for aero Good labeling practice and legal requirements sol and other pressurized containers. dictate that a precautionary label shall he prominent, conspicuous, legible, and in con trast to other prated natter on the container. Type size, color, and location of the label on the container are prescribed in many laws and regulations. Gammerrial petroleum products do present a potential irritation problem. The hazard of irritation to the respiratory tract surfaces because of vapor inhalation, in my opinion, is not significant Eye contact with liquid petrotemn products, especially the tight ones, How do commercial petroleum products , may cause some eye irritation. Generally, stand with respect to the six criteria of tins is mild and transitory. Flushing with hazards whether encountered at home or at water usually eliminates the discomfort Per work? For the purpose of this part of the manent eye damage as a result of contact is discussion, commerced petroleum products not expected. include tads, solvents, Inbricati greases, and asphaltic materials. Excluded are the marry petrochemicals and fertilizers produced by the col industry, antifreezes, and the great number and variety of automotive specialty products sold in service stations. Sian irritation is a hazard of commercial products, particularly in industry. Petroleum hydrocarbons are good fat sol vents. Prolonged or repeated skin contact with petroleum solvents and light oils will defat tire skin. It will become dry, fissured, The great bulk of these commercial prod and cracked. Dermatitis may develop. Infec ucts present no hazard in normal handling, tion nay set in from the bacteria normally storage^ and use. With many, flammability present on the skin and in the air. In the maybe die only risk, and the extent to which home, rids irritation from petroleum prod tins hazard is present is roughly indicated ucts is usually not a problem although der by tire predominant use. matitis does occur there. Hobby pursuits As regards corrosiveness, I know of no may involve skin contact Some household commercial product that causes tissue de cleaning agents contain petroleum solvents struction by chemical action as result of which may contribute to "housewife hands." 10 Petroleum Industries Paint thinners, brush cleaners also may con Deaths following ingestion of the very fight tain these solvents. But the relative infre petroleum distillates, such as gasoline, naph quency of their use in the home helps the tha, mineral spirits, Stoddard solvent, kero situation. * sene, and mineral seal oil, occur as a result The heavier products, greases and heavy industrial oils, can also cause dermatitis. They can cause plugging of the skin pores and result in an accumulation of fat, dan oils, bacteria, and dead cells in the pores. Pimples and local infections can develop. of aspiration of the material into the lungs. The familiar red-colored furniture polishes have caused many deaths of children. These polishes usually consist of mineral seal oil, small amounts of a dye, an odorant, anc sometimes a small amount of a wax. The solution of the problem is good personal Human experience indicates that petroleum cleanliness. Precautionary labeling is not con distillates with viscosities above that o: sidered necessary to advise people to keep mineral seal oil (about 43 SSU at 100?) clean. If it were, almost everything would do not possess this aspiration hazard to any have to be so labeled. significant degree. Animal experimentation The last hazard to consider is that of supports this conclusion. toxicity. Earlier, toxicity was defined as the This hazard of aspiration is the reason for inherent capacity of a substance to produce what may appear to be an unusual instruc personal injury or illness in man as a re tion on certain hazardous household products. sult of ingestion, inhalation, or absorption Most instructions on emergency treatment through any body surface. after swallowing a hazardous substance read, Petroleum products, as a class, have low toxidties. Absorption through the skin sel dom constitutes a hazard. When skin ab sorption is a problem it is generally due to the presence of an additive in the product Inhalation of vapors of volatile petroleum products may be hazardous under certain conditions. These vapors act as simple anes thetics. When inhaled in sufficient amounts, they can cause symptoms of inebriation, those of the so-called "gasoline jag." Higher concentrations can result in loss of con sciousness. "Gasoline sniffers" deliberately inhale the vapors to get a lift Recovery from gassing caused by such vapors is usu "Induce vomiting." But with these distillates, the statement is "If swallowed do not induce vomiting. Call physician immediately. A small amount of one of these distillates (the quantity usually taken by a small child) will not be harmful if left in the stomach. Most knowledgeable pediatricians say that it may be desirable to give the child a small amount of a salad or vegetable oil. . So far, in this presentation, nothing has been said about the first two words of the title of this paper, "Product Liability." This is a subject that should be discussed by a Lawyer, not an industrial hygienist. But a few comments are appropriate. ally without inddeut and withoat aftereffects, First is the matter of hazardous substances with one notable exception. If the product that are not labeled or are mislabeled. The contains benzene in a significant quantity, chances are that such omissions or errors are and the exposure is sufficiently prolonged or in violation of a law or regulation. Practi repeated, permanent health damage can re cally all of these laws prescribe penalties sult The effect is aplastic anemia due to thdf for these violations. For example, the Fed action of benzene on the blood-forming or eral Hazardous Substances Act contains these gans. Benzene is unique in this respecJ0No four provisions. ,, other hydrocarbon is known to cause this 1. FDA inspectors can inspect plants, effect warehouses and other establishments. They The oral toxidties of petroleum products are low. In industry, systemic poisoning as a result of oral ingestion of petroleum prod can (and do) inspect pertinent equipment, materials, labels, and obtain packaged and unpackaged products, subject to the Act ucts does not constitute a problem. However, 2. Shipments in violation of the require in the home, it is a definite hazard, especially ments can be seized. The owner or his agent among small children. Even here, it is not then has three choices: (a) he can deny the because of its oral toxiaty. An ounce of violation and the FDA may then contest the kerosene, for example, in a child's stomach, case in a federal court; (b) he can admit would not be expected to cause a fatality. the violation and ask the court for permis 11 968 National Safety Congress sion to post bond and relabel the product; (c) he can do nothing. Then the product will be condemned by default and destroyed or otherwise disposed of, as determined by the court 3. Criminal prosecution (whether the prod uct is seized or not)'can be instituted in Federal court A guilty plea or a finding of guilt can result in a fine of not more than $300 or imprisonment for not more than 90 days or both for each separate offense. If there is intent to defraud or mislead, or for second and subsequent offenses, the penalties are more severe -- a fine not over $3,000 or no more than one year in jail or both. 4. Injunctions can be sought to restrain a person from the commission of further violations. Failure to comply with the in junction may result in criminal contempt proceedings. The Food and Drug Administration has not been inactive in its enforcement work. During a reporting period from February 1967 to July 1968, judgments were completed in 64 cases involving 84 products. Destruction was ordered for 46 products and 36 were released for relabeling. Disposition of two products was not reported. (The multiple seizures of X-33 water repellant, Cracker 3all Caps, flammable rag dogs, and Magic Socks -- sodium silicate -- are not included in these figures). Hazardous petroleum dis tillates were involved in 22 of the 84 prod ucts on which judgments were ordered. During this same reporting period, 43 seiz ure actions involving 60 substances or prod ucts also occurred, final actions on which are still pending. In the states that require the labeling of hazardous substances used in industry, the Labor Department is generally the enforcing agent The penalties for non-compliance are, for the most part, the same, or similar to those for other violations of the state labor regulations. The second problem is that of liability because of injury or illness caused by a hazardous substance. Civil suits because of such injuries or illnesses are increasing in number. The dollar amounts of awards are also increasing. If a plaintiff can show that the hazardous substance was not labeled or was improperly labeled, a good case for negligence on the part of the manufacturer can usually be established and without too much difficulty. An adequate precautionary label on a haz ardous substance probably would negate a charge of negligence. It should not be con sidered as complete protection ajpinst damage suits or an award for damages. Witness this example: A small diild swallowed some red furni ture polish, aspirated it, and died The par ents filed suit against the manufacturer. The court found that the label wording was ade quate although it was printed in red on a brown background in rather small type. The type size was in reasonable proportion to other type on the labeL The mother said she knew how to use the polish and and ad mitted that because of this she did not read all of the precautionary wording. An award of $20,000 was made and affirmed by the appeals court However, all of the award was given to the father; the court said that the mother should not share in it because she contributed to the death of the child INTRINSIC SAFETY IN THE PETROLEUM INDUSTRY By S. P. AXE Senior Electrical Engineer, Atlantic Richfield Co, Philadelphia, Pa. Intrinsic safety 1-- what is it, where can it be used and what are the design require ments tor intrinsically safe equipment and circuitry? We will attempt to answer these questions without dwelling on the detailed technical aspects mainly because you, as safety directors and safety engineers, are not too involved in the details. In recent years, refinery people and equip ment manufacturers in the United States have been applying the concept of intrinsic safety without having any common ground 12 Petroleum Industries rules. It appeared everyone bad their own standards and was manufacturing and in stalling equipment as they saw fit. This condition became alarming to both the petro leum. end chemical industries, where flamma ble atmospheres are prevalent The purpose of this paper is to make you aware of the ster.cards that are being prepared which will be discussed later. The baric definition of intrinsically safe electrical equipment is: . .. "equipment and wiring which are incapable of releasing suf ficient electrical energy under normal or ab normal conditions to cause ignition of a specific hazardous atmospheric mixture." In other words, energy is limited at all times to levels which cannot possibly initiate an explosion. Lighting and power circuits, there fore, cannot adhere to the concept of intrinsic safety. However, instrumentation, remote control, and signal circuits can be well adapted because of the inherently low power. Approved intrinsically safe systems are recognized in Article 500 of the National Electrical Code and are considered safe for use In the specified hazardous atmospheres without special enclosures or physical pro tection tot would otherwise be needed. This equipment is appropriate for use in Division 1 ami Division 2 locations. Division 1 areas are those tot have a hazardous atmosphere mixture continuously under normal condi tions, while Division 2 areas are those tot have the potential of containing explosive atmospheres only under abnormal conditions, such as failure of equipment Although the National Electrical Code makes the above recognition, there is lacking, for the designer and for the inspector, a set of standards to provide information for the design and evaluation of equipment The Na tional Fire Protection Association became aware of this problem, and in 1963 they formed the Sectional Committee on Electrical Equipment in Chemical Atmospheres. One part of to scope of this committee is to make recommendations for the prevention of fires and explosions through the use of in trinsically safe, continuously purged, pres surized, explosion-proof, or dust ignitionproof; electrical equipment vwhen installed in chemical atmospheres. This committee immediately recognized its challenge and prepared NFPA publication No. 469 Purged Enclosures for Electrical A Equipment which provides information for to design of purged enclosures for the pur pose of eliminating or reducing the hazardous location classification. In addition, NFPA No. 493-T, Tentative Standard for Intrinsi cally Safe Process Control Equipment for Use in Hazardous Locations, was also com pleted. The object of this standard is to pro vide information for the design and evalua tion of equipment depending for safety cm limitation of energy to be used in Class I hazardous locations as defined in Article 500 of the National Electrical Code. It is not an instruction manual for untrained persons, but is intended to promote uniformity of practice among those skilled in the art I will briefly review to sir chapters of this publication. Chapter 1, "General Provi sions," covers to object and scope of, to standard which was mentioned previously and mentions the equipment covered, such as process control equipment, primary elements, converters, transducers, and valve operators, location of equipment; and definitions. Chapte- 2, "Fundamental Considerations,'* deals with the conditions that must be met to be intrinsically safe. There are two condi tions: (a) the energy available in the haz ardous area must be low enough under nor mal conditions so that it, is incapable of igniting the specified hazardous atmospheric mixture due to arcing or increased tempera ture; (b) the energy available In to haz ardous area must be low enough under ab normal conditions, Le., with assumed fault conditions, so tot it is incapable of igniting the specified hazardous atmospheric nurture due to arcing or increased temperature. This chapter goes on to explain tot in trinsically safe apparatus most be incapable of causing ignition with certain combinations of conditions, including numerous and varied types of faults. The number and types of faults are detailed. Chapter 3, "Evaluation," explains to three Steps of the evaluation procedure when ana lyzing a circuit to determine to effect of each possible fault and combination of faults. This evaluation may be dale either theoreti cally or empirically. In to theoretical ap proach, circuit analysis consists of assuming various fault conditions and calculating re sulting voltages and currents. In to em pirical approach, faults are actually created and to resulting voltages and currents are measured. 13 1968 National Safely Congress Chapter 4, "Test Apparatus and Proce dure," explains that the test consists of simulating: the effect of opening, dosing, and short circuiting that part of the wiring to be located in the hazardous area. To pro vide a margin of safety over actual field conditions, specialized apparatus with con tacts designed to have maximum effective ness is used, rather than contacts used in the field. The contacts are operated in a chamber filled with the most readily ignited mixture of a suitable test gas with air. Fault conditions are simulated during the test The chapter epatisnes to explain in detail the test apparatus, the test mixture of the gases to be used, and the auditions under which the tests shall be performed. Chapter 5 is "Comparison Procedure." Simple circuits, having energy levels under normal and abnormal conditions well below the known ignition Emits and conforming to fault criteria more stringent than for test ing, are considered intrinsically safe whhoat actual ignition test However, transients is complex circuits are not readily analyzed and therefore most be evaluated by actual test Chapter S highlights the ignition Emits and the maximum voltage and current levels. For redstance-indnctance circuits, graphs are included showing comMnatkns of inductance, voltage, and current which will not ignite the gases; for resistance-capacitance circuits the graphs show combinations of capacitance, voltage, and current which will not ignite the gases. ' Chapter 6 Is on "Construction Details." When eraboting intrinsic safety, it is as sumed that any component or structure can and will nL Safety depends on a mnltipBtity of dements and the improbability of shnnhaneoas toUnres, or it depends on such construction of one dement that the probaKEfy of faffme is negligible or that it can fail only in a safe direction. This chapiter discusses the elements as sumed not to fail or assumed highly im probable to hail when the fault analysis is made. It also indndes the testing required by manufacturers and the markings or labels that are to be installed on equipment and circuits indicating they are intrinsically safe. A coospicuoas wanting label shall also be indnded stating that any substitution of components may impair the intrinsic safety feature. In conclusion, I want to reiterate that this NFPA publication No. 493-T is a much needed tool so toe users, manufacturers, and inspectors have a common reference when the subject of intrinsic safety arises. I rec ommend very strongly that anyone interested in tins subject obtain a copy of this standard. HAZARDS OF ACID AND ALKALI CLEANING By padl d. hai.i.ky Manager, Safety Jt Industrial Hygiene, American Oil Cm, Chicago, HL The February 9,1968, issue of toe Casper, Wyoming; Star Tribune carried the story. One employee toed and one was given a complete exchange of blood to save his life. The first report was that the dead employee had suffered a total heart attack, but later reports indicated that arsine gas was in volved. The employee became skk to ins stomach, vomited, and then suddenly keeled over dead or toed shortly afterward. The report stated that an add inhibitor acciden tally came in contact with galvanized coating on a well pipe on which tire men were work ing. Although nothing further has come to our attention on this case, it. is reasonable to assume that the add inhibitor refereed to was an arsenic compound, that there wodd have been hydrochloric or muriatic add present; and that the add in contact with toe zinc released hydrogen which in torn reacted with toe arsenic in the inhibitor to produce arsine gas. The company involved is widely engaged in the chemical or add rlrutwng bnsmess and arsenic-type inhibitors are used, essentially in add cleaning in the oil fields, to prevent toe add from attacking the metal once toe rust and sludges have been cleaned away. Zinc or galvanized metal 14