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Gas and Electric Welding / WEDNESDAY MORNING SESSION October 28, 1942 Presiding:--R. H. FESGUSON.Mgr., Safety Dept, Republic Steel Corp., Cleveland Safe Practices in War. Time Application of Welding By HENRY A. MATIS Pullman-Standard Car Manufacturing Company, Pullman, Chicago, HL Conservation of our labor, welding labor, perature, but also because it does not ignite - is. advanced through the observance of sim /easily. Overalls, jackets, etc, should not be ple rules of safety: greasy or oily for .the same reason. As a protection from sparks, splatter, or slag, 1. Wearing of proper shoes and clothing. leather gloves, sleeves, aprons and jackets ' 2. Use of proper protective equipment for can be. wom. die glare of die arc or flame.- In our plants we are very insistent that 3. Use of adequate ventilation from fumes. proper clothing be worn. -Leather gloves, 4. Wearing of goggles at all times. sleeves', etc, are on sale at cost so that the welder can obtain them easily. Safety shoes 5. Removal of all combustible material are a "must" necessity. A welder, whether from. jot. he is in die aircraft division, tank division, or the shipbuilding division of our company, & Elimination of and care around loose; must wear safety shoes. By so doing Ids tools, equipment, cables, hoses, etc' work generally is'speeded up when the num 7. Awareness of one's position with re spect to himself and others and his sur roundings. r-' * ber of foot injuries are decreased. % ./ 't In the use of welding or cutting ft..b im portant that the eyes be protected from, the We have found through long years.of ex perience in car building and more recently on our work on government ordnance proj ects that these factors do promote safety, create more productive man hours and so conserve labor. * heat and the glare of the.'flame or the arc. In this same regard and as a further pro tection to the skin because of the . intensity of the ultra violet and infra red rays, weld ing helmets or shields should be worn in arc welding. Properly selected goggles are suffi cient for protection of the flame. In both Whenever working around an open flame, cases, the'colored, lens must be adequate for arc, etc., clothing of a proper nature should the job at hand. Valuable information for the be worn so that there is less danger of fires specifications for eye protection can be ob starting. Woolen clothing ;ls always better tained from the "National Safety Code for than cotton, not only from; changes of tem the Protection of the Heads and Eyes of In- 96 31st National Safety Congress dustrial Workers" issued by the National Bureau of Standards, Washington, D. C Welding should be performed in separate rooms or in locations where screening is possible in order to eliminate the danger of eye injuries from''reflected or direct rays of the arc to other workers or passers-by. Where many welders are working, as on a ship section, then care should be exercised by the welder in striking the arc as a con sideration of Ms fellow workmen. As a pre caution to protect their eyes, the workmen nearby, whenever the arc is. struck, should adequately shield their face and eyes. Ventilation is an important factor in weld ing. Health hazards result from the con tamination of the air from welding. In large open shops or in the outside atmosphere, fumes can dissipate themselves without re sulting injury, but, in smaller shops, schools, or unrestricted spaces, such as compartments or holds of a ship, ventilation must be used. In these places enough ventilation must be installed to insure good visibility and a com fortable working temperature. Usually one hundred cubic feet per minute per operator is sufficient ventilation'for most work. Port able ventilation systems are very useful in ship construction work for local exhaust. At a time when it is imperative to main tain full production and .to conserve labor, we are also conscious of the parts that sabo teurs and arsonists can play in hindering our effort -Without a great-deal of imagination we could be a tool in their hands to accom plish their purpose or we could uninten tionally achieve the same thing if we allow combustible materials near welding arcs or flames. When every small fire is a potential. Mg fire, definite rales must be set up to avoid a stoppage of production from this mmg,. * a. Do not perform cutting or welding in. or near rooms containing flammable vapors' or liquids or exposed loose combustible ma terial. b. Welding or cutting should not be set up near dipping or spraying rooms. Work performed in a hazardous location is not safe work. c. If cutting or welding must be done on a floor* that is combustible, tire floor should be kept clean and should be wetted down before starting work. Wooden floors should be covered with a metal or non-combustible material. In the welding of galvanized steel and its resulting zinc fumes, ventilation is almost mandatory. For occasional exposure due to lack of ventilation facilities, etc, a proper type of filter respirator .that fits under the d. For work performed near wooden structures or near combustible material that cannot ,be easily removed or protected, a small hose, chemical extinguishers, or fire pails should be conveniently placed. helmet will give adequate protection >`to the welder. ` fc. Where combustible material has been exposed to molten metal or hot slag, a watch- Goggles are worn by the welder at all . man should be kept in the vicinity for at times to protect hiseyes. They afe; valuable'' least half an hour after, completion of the protection when removing slag, from welds work to make sore that smoldering fires other before or after the welding process. are not started. *' Whether the slag will be removed by a slag hammer or not, on cooling it pops-up partides that may, enter the eye just as easily as during the cleaning process on the slag: Chips or partides froth grinding or chipping L - All hoses, cables, torches, electrode holders, and connections should be checked periodically to prevent overheating and to insure tight connection. may enter the unprotected eye of a near-by wdder. To minimize! eye injuries, we at Pullman demand the vfearing of goggles for the men's own protection. Whether on cars, ships, or tanks, even the welders wear, them continuously. They are worn tinder the hel Taking these factors into account, fires will be prevented. All-of us know too well the lesson that was brought so forcefully home to us in the disaster, to the ship Nor mandy. met for the added protection whenever the -Mary cases of stumbling or falling are hdmet is raised or off of the man's bead. doe. to loose tools, equipment, cables, or Eye injury with its resultant handicap is hoses lying around in disorder: Good house very rare in our plants. keeping, orderliness, and safety conscious ness wi wsys.'b allbek items.,! overbea ,, Am that u cumstr ccatini ban specuL the Tj Actual .0# 7 ''O^Y-' ' v' -: . "'' '".'--''"Y " */$S Gas and Electric Welding . 97 ness wfll dimmate thee hazards. Passage* wayvladders, openings, ditches, etc, should sdlbckept clear and free as possibleof these items. CkHes installed in ducte or suspended overhead wQl eliminate this hazard. A welder or a worker, on whatever job he may be doing, must be conscious not. only of his own salety but of the safety of others working near at hand. By his own safety efforts, his own work not only is made easier and safer, but. his fellow workers' opportunity for doing their jobs faster and safer is furthered. , These many factors--proper clothing, pro tective equipment, ventilation, goggles, fire prevention, elimination of tripping hazards, and the regard for others helps all of us in dividually and collectively to conserve our efforts so that each of our jobs can be done faster and better. Health Aspects ol Welding By A. G. CRANCH, M, D. Union Carbide Company, New York City, and B. L. VOSBURGH, M. D. General Electric Ca, Schenectady, N. Y. Tlw propose of tins paper, is to offer some have introduced any importanthealth hazards. {nactkal points for tfae better protection of As for the "mystery," most of these coat the health of welding operators. It is not ings have been patented. Not long ago the intended drain exhaustive research document Bureau of Mines issued an Information Cir - \ The health hazards of wddinginay be classed cular (1) giving mnch detailed information v : as ^teal ahd unreal".., The former should not on the composition of welding rod coatings be jgnroii& iw latter be allowed and fluxes. This was Cased cm patent in to tome undue alarm. Thereal hazards ate formation, purposes served' by. the -various pot mysterious; they should be easily under- ingredients and analyses of many typical stood l^ any reasonablywell trained operator coatings. Tins and other reports remove and . means for protection are available and the "mystery." . effective when used. A third and perhaps the most important A welding^ operator is usually exposed to reason for- the assumption that welding is a all.the. general, accident hazards.common .to the-industrial firid in wbidi.he is working. Structural iron workers, ship builders and the like . are. exposed to increased accident hazards. As a huge proportion of welding operations areincoonectioawhh sach work, this may be one reason for the common asscrtiontbat wriding is a dangerous and un healthy occupation. health hazard, are the dramatic deaths which have been reported in a relatively few in stances following massive exposures to weld ing fumes in strictly confined spaces without suitable protection for the-operators. That such incidents do not reflect a general hazard is well shown by the fact that in the past three years the number of welding operators has increased some 400% and in-the past ten years consumption of welding rods has in . Another posable source for the charge creased some 2800% with scarcely any in tint wdding is a health hazard is the cir crease in such fatalities. cumstance-that the formulas' of most rod coatings- are "trade secrets^. so stoat there Until quite recently the health problems of is'an-opportunity, to.indulge in all sorts/of .welding have been approached from a specutatioo'-as to- the danger to healtfa from speculative rather, than scientific view point. the"secret" ingredients in these coatings. Unfortunately in a number of instances even Actually very few coatings would appearto medical men, apparently with little attempt to 1 ... J.'i'W.-V. Srk: 31st National Safety Congress > check exposures dr weigh evidence available, have attributed.an amazing yariety of ills to welding exposures. These 'indude digestive disorders and malnutrition, liver diseases, respiratory affections even induding cancer but only glare from too intense light. The eyes must .be protectedjjy-^suitable colored lenses. In' electric art^wHding'tijere is not only the glare but enirag^t^tranolet radia tion to caff for a? dcepa-~|l&d^ofprotcctiya___1 of tire lung, circulatory, blood and glandular changes induding thyroid disease and Hodg kin's disease, various skin diseases, neurdlogical changes, sterility, and various other lens for the eyes, and also a face shidd ami. prgteSh^e dothing to cover all sldn areas' fWMch'inight. be' exposed. At present no \attemptwill bC tnade.to.go into details.as to complaints: A - careful analysis of. these win of protection,* as these; are easily reports generally shows little or'no' evidence available frtitn a nhmber of sources, especially of any connection with welding exposures. the American Standard Safety Code for the The agents usually blamed for these various Protection of Heads, Eyes, and Respiratory ailments would ordinarily be . present In Organs (7) (9). entirdy-negligible concentrations, if at all. Hazards .from radiation are not confined' Such substances as silica, asbestos, man to the welding operator alone; but also ganese, chromium, nickel, cobalt, various involve his helpers and others working in other metals and even iron have been given the immediate neighborhood, usually ^con as "potential hazards" in welding fumes. sidered to be within seventy-five to> one These have been charged with directly caus hundred feet id the case of arc welding. Any ing ill health or serving to activate other workman within this area should be protected conditions such as pneumonia, tuberculosis, either with suitable goggles or by the use etc. With tiie exceptions shortly to be men . of screens. If screens are used they should tioned, there seems to be no evidence to be so-designed as to interfere as little as indicate that they are present in a form or possible with ventilation. Shine types-of an amount which would constitute a health operation can be done in ventilated booths, hazard. Some have- stated that welding which' may serve to reduce the hazard to operators "are dying every day, and others others. Notonly must direct rays be kept, suffering permanent health impairment as the from theunprotected eye, but reflected, rays result of their work," and charge that no must be considered. ' This invariably caffs studies have been made to identify or control for the use 'of dnll non-reffective paint on the hazards. Anyone at all familiar with the areas which.-may otherwise 'serve as re research which has been done and is still flectors. i going on in this held will realize that such charges must be due to ignorance or prejudice. The very thorough study con ducted by. .Britton and Walsh (2) and the experimental work mid observations in this field by many other/ investigators (3) (4) (5) (6) fail to show any excess of ill health among welding operators, or any outstand ing type of illness among them. ' Excessive exposure of the eye to ultra violet 'radiation damages chiefly the outer structures of the eye, setting up conjunctivitis of varying degree. The damage is analogous to a blistering smHjuraof the skin and if ffie exposure is sfcvete very painful reactions will occur, with s^HneJtemporaiy visual dis turbances. Ultraviolet rays do not penetrate ihe lens or injure the deeper structures of the eye. Experimental cataracts have been pro r.~y The Real Welding Hazards The real hazards peculiar to welding are essentially from-: (1) radiation and (2) air contamination by gases and fumes. .,.,- duced in rabbits by prolonged exposure to' ultraviolet rays, but in actual welding ex perience lens changes do not occur and optic nerve injury is impossible from a physical standpoint Radiation presents the hazard of intense light, glare and of ultraviolet exposures. Probably all workers even casually ac quainted with welding operations are familiar with the need for eye protection in this work. In the case of gas welding there is little, if any, exposure to ultraviolet rays. Before leaving the subject of radiation it should be mentioned that in welding there is no exposure to short waves like the x-ray. Tins has been demonstrated repeatedly by having welding operators carry dental x-ray films in their pockets. - No systemic effects have been demonstrated as due to tire radia tion-m .ismenti been n original! and ses unfound support Amor welding may be die oxj welding reaction oxides'i of impi It is hi as used hazard, stitute email j from bi actively oxygen formed turns oi irritant ceases igators fined s] found It is e thing l Whil made cl defirier only so some < holds, some s 'sud lc "jgation '"was pr ations acetyle of oxy. weldini tmsatis deucy a level operate wddin conditi confine 5 Gas and Electric Welding' ('99 . tioh-in welding, least of all sterility. This depletion occurred. "Oxygen deficiency,'' .is mentioned because this charge has recently then can be put into the category of unreal been revived in some quarters. It was originally made during the last World War . and several investigations proved -it to be unfounded. There is no valid evidence to support such a theory. s.Gas Hazards hazard. ' /r-- One not infrequently sees references to the toxic effects of unburned acetylene or fc "impurities" present in acetylene gas. Acety lene is a ample asphyxiant-gas not in itself . a poisbn. It has had fairly wide use as. an anesthetic. A hazard would exist only when Among die much^discussed hazards of welding are those due/to gases. These gases may be essential to the type of welding as the oxygen and acetlylene in oxyacetylene welding or they may be produced through the reactions occurring in the welding process as oxides 'of nitrogen, ozone, or in some cases of. imperfect combustion carbon monoxide. It is hardly necessary to state that oxygen as used in welding does not produce a health, hazard. Misused, for instance, asa^Substitute for- compressed - air in ventilating small spaces, it'may. increase the hazard from buns, as any material .will bum more actively In die presence of an excess of, oxygen. . Ozone, a "peroxygen," may be . fonnedjsrthet'welding arc and in concentra tions of over ij^pan. may act as a pulmonary irritantVOmdeaving the arc; ozone rapidly the' gtiOs^^iresent in such concentration as to reduce the\oxygen in the air breathed so that not enough remained properly to supply the body. As the lower explosive limit of acetylene in airis about - 3% it is evident that in tiie presence of a flame an explosion would result long before the concentration woujd appreciably reduce the .available oxygen in the air. As for the alleged hazard from impurities--arsine; phosphine, hydrogen sulphide or ammonia--this purriy theoretical hazard is based chiefly, on .early analyses of acetylene made from materials of'foreign origin. Jo significant amounts are present in acetylene produced today from raw mate rials from North American sources. Re cently .tests were made for arsine in dissolved acetylene from four commercial producers and not even a~trace was detected. The - ceases to exist as such and many invest-:' igators have demonstrated that even in con fined spaces a. dangerous concentration is not found in the air breathed by an operator. It is extremely doubtful that ozone is any minute amounts 'of impurities .sometimes found in acetylene are, of course, destroyed in tiie flame. The health hazards' from acety lene and its "impurities" belong in tiie "unreal" class. thing but a theoretical hazard in welding. Gases formed in tiie flame or arc are the 'Wbiteipfe^lciag of oxygen, mention may be made o}Lthe>hazard said to be due to "oxygen defidenby'^from welding. This could occur only in very confined spaces, as in tanks or oxides of nitrogen, sometimes called "nitrous fumes." They are not nitrous mode, but are nitric oxide: and other higher oxides of nitrogen. In the concentration present in some of the small compartments in ship's connection with welding they are so diluted holds, and tiie like. There may have been as to be colorless. Under other conditions some accidents due to oxygen deficiency in of exposure these fumes may present other such locations but in all probability investi hazards but in welding the real hazard is as gation would show that this condition already a pulmonary irritant Except in small rtams Wwas present in the area before welding oper or in very confined spaces as in tanks, etc, ations were attempted. In the case of oxy no dangerous, concentration would be likely acetylene welding where a certain proportion to occur. Just what is a dangerous concen of oxygen is drawn from the atmosphere the tration has been undergoing considerable dis welding flame will usually become entirely cussion in the last two or three years. The unsatisfactory for its purpose and the defi classic figure of 39 p.pan. by vblume in air, ciency recognized before the oxygen readies admittedly was based on very limited obser a levd low enough to be dangerous to the vations but has proved a fairly satisfactory operator. Also the heat generated by tiie working standard. Just as much more ex welding operation under normal atmospheric tensive experiments were beginning to indi conditions would usually be unbearable in a cate that 70 p-pun. or even up to 100 p.pjn. confined space before dangerous oxygen might be a safe limit , for a day's work; 100 31st National. Safety Congress others on what basis is not dear, are advocat zinc fume; from welding on galvanized mate ing a "safe concentration" of only 10 p-pan. rial, or brass, or from using rods-with a Certainly a study of available evidence in high zinc content Zinc should not be con dicates that in welding operations concen sidered "highly toxic," however, as tins trations of 50 p.pjxL or less.bave not produced condition is an acute, > self-limiting reaction symptoms, and that probably under many of short duration and without known after conditions this amount may be''exceeded effects or complications. In a large number without harm. Protection will be discussed of those affected a considerable. degree of under fame protection.. immnmty is established so that subsequent attacksare very mild or lacking altogether. Carbon Dioxide and Carbon The permissible limit for zinc fame in the air has been suggested as 15 milligrams of Carbon dioxide is, produced by toe oxy- zinc' per cubic meter of air. If this concen acetylene flame and by the dectric^arc bat tration is not exceeded it is unlikely that never in concentrations of physiological im any cases of metal fume fever will occur. (6) portance. Carbonjmoooodde may be produced^through imperfect combustion as when start ) The. most serious condition likely to result ing welding or cutting of cold material or > from metal fume exposure is'probahly lead through the combustion of.organic matter poisoning. -Hus is not a hazard common to winch may be present cm tiie surface to be all. welding operations, but only in the rda- . welded, or in the coatings of rods used. tivriy few cases where welding or cutting There is considerable divergence of opinion is done on material previously covered with on the degree of hazard from carbon mon lead paint;' coated with metallic lead, or oxide, in welding. A careful comparison of where lead has. been introduced as an alloy the various reports seems to indicate that as in certain steels. In such. cases very tire danger of a significant concentration is definite protective measures will be required. very slight trader all ordinary conditions of welding. If standards of ventilation indicated by other features of the work are followed the hazard from carbon monoxide shotdd be non-existent. Next to lead ranks cadmium as a potential hazard. Lately cadmium has come into more general use as a rust-proof coating for steel 'in place of zinc. It enters into some alloys. The fume marjpt^ce^pidnxAary irrita Probably the most discussed health hazards tion and edemffsemMing'in many ways the of welding are those due to fumes. These are effects from whalingpxides of nitrogen. chiefly metallic, from -tire material bring A wide varietjToT other metals have been welded or used as a coating on that material or in the welding rod or its coating. The composition of welding fumes is so varied that this furnishes a wonderful Arid for the discovery of hypothetical and unreal hazards. These fumes also are the source of some very real hazards. If proper precautions are taken to avoid the real and recognizable hazards the same precautions should elim inate the theoretical hazards. Welding is now in such general use and the number of metals and their combinations involved is so great that there are probably but few metals which may not be handled by a welding operator. mentioned as injurious. Manganese; chro mium, cobalt; copper, tin, antimony, mag nesium, aluminum, tellurium, vanadium, titanium and many others. As encountered In welding fumes the amounts are tonally definitely less than those known to have toxic effects, and it is doubtful if any reports alleging injury from these metals in wdding can be substantiated. Manganese has been most frequently^ suspected, but a study of toe reports of alleged effects fail to show any conclusive evidence and the amounts involved are below those known to have produced effects. The charge that evensmall amounts of manganese predispose to pneu The most common complaint due to fume exposure is metal fume fever. This often monia is not borne ont by the known ex perience of welding operators. called "zinc chills," "brass founder's ague" Other materials than gases or metals may and the like, is really a non-specific reaction create fame hazards through air contami which ought come from any of a number of nation. These may be encountered especially metal fumes. The most common source is in repair work oh various tanks, vats, etc. Their ] Tber which inyrivii steels.; present rod co fluoric inhaled long p tionto edema. To s are no and pi effectn shotdd tograi 5.F and re Prot been t almost Varioi toesta ards it expres toe ga metalli as ha' air have tines 1 diffied Unfor qtndd; coocer comfit measu witost in api seven evolve tiden! 6* o Gas and Electric Welding Their presence calls for special ventilation. V Various studies of present day practice have been made winch Indicate -that welding There is one other source,of-real hazard;! out of doors or in large shops seldom results; which may be present in many operations.^ involving aluminum or some of the "stainless'' in any serious air contamination except in the case of lead. In spaces of less than 1000 steels, and alloy metals. This is from the co. ft and especially inside tanks, ship holds, presence of fluorides, in many of the fluxes or etc, special ventilation is necessary. Usually rod coatings , used for this work. Hydro the exhaust of contaminated air is much more fluoric-add may be formed and the fume if effective than an attempt to force fresh air. inhaled in appreciable concentrations or for into tiie space. In.stationary locations this long periods may cause considerable irrita cac-generally be done with properly located tion to tire nose and throat or even pulmonary exhaust fans or by themeof hoods and ducts edema. to withdraw fames as near as possible .to their ' Prevention source. Portable exhaust systems have been designed which are adapted to field needs. . To snm,up: The' real hazards of welding are not many, are generally easily identified and protective measures are available and effective when used. ' These real hazards shodd not Ite minimized or passed by. Briefly they are due to: In tire case of gases such as coridesof nitrogen, or the rareinstances of carbon monoxide^ if sufficient ventilation is .main tained from the beginning of the operation, and sufficient to insure good visibility anti to insure a comfortable temperature there should 1. Radiant energy--ultraviolet and .viable be no gas hazard even in confined, spaces. light - 2. Oxides of nitrogen. " 3. Metal fumes lead, cadmium and zinc If lead or cadmium fumes are present the only complete protection is by the use of stir supplied masks. These are of three types air supplied by 'special blower, air supplied 4. Fumes from organic residues or wastes. 5. Fumes from fluoride-containing fluxes and rod coatings. Protection from radiant energy has already been outlined. Protection from the rest is almost wholly a question of ventilation. Various means of approach have been-tried to establish standards for ventilation. Stand ards in terms of concentration of contaminant expressed in parts per million by volume for the gases or milligrams per cubic meter for metallic and other fumes have been suggested, as have standards expressed in number of air changes pet; time unit Both methods have value and studies made along these lines have done much.to solve some of the difficult points in ventilation requirements. Unfortunately, it is very difficult to obtain quickly and easily a determination of fume concentration on a given operation. Local conditions may also change the efficiency of measures based on rate of air change.. Not withstanding some of the practical difficulties in applying such standards in specific cases, several general rules on'ventilation have been evolved which have proved to be of siderable help. ~. from, compressed, air system, and masks with largo- hose without use of forced air supply.. If compressed sir is used from a general supply, special filters and presstme regulators are required. In the last named type with no forced air supply the length of hose on . seldom be over SO feet In. confined spaces one of the above devices 'shotdd be used. Out of doors or in large well Ventilated shops and for moderately short exposures one of the filter type respirators approved hr the Bureau of Mines for lead fumes may be satisfactory. In .any confined space at' least local exhaust ventilation is required when there is exposure to sine or fluoride fumes, or to fumes from heavy deposits of organic wastes and sludge. Air supplied respirators offer, of course^ the most, positive protection. Briefly, a minimum standard of ventilation is one flat will be sufficient to insure good visibility at the point of operator, and insure a temperature within a reasonably comfort able limit In confined spaces tins would call for exhaust ventilation. In case of lead or cadmium exposures air supplied masks are required. No serious hazard is apt to be present except hi confined spaces or when lead is involved. Special standards for veuti- V.V 102 31st National Safety Congress latioa in welding of leaded steel have been given by Halley (8) General requirements for ventilation are given in more detail in the reports of Tebbens and Drinker, (6) and in Special Bulletin No. 5 of the U. S. Depart ment of Labor, "Control of Welding Hazards in Defense Industries, (9) and by Hemeon. (10) 7. That the health hazards due to welding exposures are not great and can be well con trolled is evident from the enormous increase .in welding and* its applications without a corresponding increase in illness. A Bibtiograpby L il. S..Bureau of Mines, 'Materials Used Summary and Conclusions 1. Health hazards in' welding may be divided into "real" and "unreal." 2. Real hazards should not be ignored or minimized. They are usually easy to recog nize and effective preventive measures are available. -) ; - ' ' / "l 3. Unreal and hypothetical hazards are often alleged. If indicated precautions are taken to guard against'the real hazards, the unreal will disappear entirely. in .Welding," Ralston and vim Bernewitz, Information Circular 7121, June, 1940. 2. Britton and Walsh,: "Health Hazards oi Electric and Gas Wdding^L-J, Lid. Hy. and Tox, 22: 4, April, 19401 ' 3. Von Haam and Groom, "The Pathology. of Shielded Arc Welding," J. Lid. Hyg. and Tax, 23:2; Feb, 1941. 4. Harrold, Gordon C. "Welding Fumes froin Arc Welding," The Welding Jour. June, 1942. - 4. Hazards from radiation in welding are limited to eyes and skin. No systemic effects 5. Gardner and McCrum, "Effect of Daily have been demonstrated. Means of preven Exposures to Arc Welding. Fumes and Gases tion are well known and available. upon Normal and Tubercrilons Animals,". J. LxL Hyg. and Tax. SepT1942. 5. Hazards from, air contamination can usually be controlled by ventilation and in 6. Tebbens and Drinker, "Ventilation in some instances; by respiratory protective' Arc Welding with Coated Electrodes," J. equipment Hazard . from gas is. essentially LxL Hyg. and Tox. 23 :7, Sept 1941. limited to oxides of nitrogen. Ozone and carbon monoxide hazards are of minor im 7. "American Standard Safety Code for portance. Oxygen deficiency, ' if present, is . the Protection of Heads, Eyes and Respira {' usually not due to the welding operation but tory Organs," Nat Bureau of Standards, to other causes. Fume hazards for practical Handbook H 24. U.f S. Department of if purpos^ttrer^fimited to fumes from, lead, Commerce, 1938. ^.cadmium,; iinc oV fluorine, and rarely from * ' organic, wastes gl sludges. Fumes from'other 8. Halley, "Atmospheric Concentration of. ^~materiaIs,~w?Kh present are usually in non Lead Fume Associated with Forging; Weld toxic amounts, or would be removed bypro- ing, and Oxygen Cutting of Lead-Bearing tective measures indicated for the well recog Steel," J. Ind. Hyg. and Tox. 23:3, Mar. nized hazards just mentioned. . 1941. Tr 6. No reliable evidence has been presented to show that welding operators have any poorer health and accident records than other tradesmen working In the same environment or that they show any characteristic type of illness which could be associated with their world' 9. "Control of Welding. Hazards in De fense Industries,"' Special Bull. No. 5, Dhr. Labor Standards,-#. S. Dept of labor, 1941. 10. Hemeon, "Ventilation' for Control of Fumes In Wartime Welding Work/'/Heat- . mg, Piping and Air Conditioning, Jun& 1942. Go Presid Dep CHJ most s war efi factnre emploj young prodot contril ment s Prol atfd.tr trainir tional: Manpr ' the foi trainir safety under Centei versfo .. Unlve the L paiiy the n 1941. Dm was < media cation scale;these "to as : super bflity iuii , *. . , 1 . I I.