Document r6mBBKzgnxxyN7JVmQ79DvK50

Safe Practices Pamphlet No. 95 Compressed Gases Published by National Safety Council 425 North Michigan Avenue, Chicago 11' 1. tua pnuipmct xias oeen prepared primarily for the promotion of safe prac tices in the handling and storage of cyl inders containing compressed gases. 2. The Interstate Commerce Com mission, in its shipping regulations, de fines a compressed gas as "any material with a gage pressure exceeding 25 pounds per square inch at 70 F.; or any liquid flammable material having a This pamphlet is one of a series of more than 150 Safe Practices and Health Practices pamphlets. As a compilation of experience in accident prevention from many sources, it should not be assumed to include every acceptable procedure in the field covered. It must not be confused with federal, state or insurance require ments, or with American Standard safety codes. Additional copies of ibis pamphlet are available. Member price 40 cents each. Quantity and non-member prices on re quest. signed only for local use, all cylinders containing compressed gases should be constructed in compliance with the ap propriate LC.C- specifications and filled in accordance with the regulations. 7. In the following paragraphs, gen eral precautions applying to ail gas cyl inders are discussed. Gases commonly used in industry and the precautions applying to those particular gases are vapor pressure exceeding 40 pounds per square inch, absolute at 100 F., March to October, inclusive, or exceeding 45 pounds per square inch, absolute at 100 F,, November to February, inclu which may be procured from the Bureau of Explosives, 30 Vesey Street, New York City. Compressed gases may be classified as follows: then treated in alphabetical order. Precautions for All Gases Handling sive, as determined by the method de scribed in Appendix No. 1 of the I.C.C. Regulations." These regulations apply only to continental United States. 3. Many compressed gases are flam mable and when mixed in certain pro- porti^ns with air will explode if ienlted. . amphle: - .. 6---s commonly used in industry and. discusses the precautions that should be taken to prevent their uncontrolled burn a. Combustible cion-liquefied, gases. b. Combustible liquefied gases. c. Non-combustible non-liquefied gases. d. Non-combustible liquefied gases. 5. Flammable gases are sometimes termed "red label" gases because Inter state Commerce Commission regulations require any cylinder :"/''.:ning such a red label. Non-flamrr.aole gases are commonly termed "green label" gases for the same reason. 8. Do not abuse or mishandle gas cylinders. They should never be dropped, permitted to strike each other, or to strike any other object. A cylinder un der pressure is both delicate and ex plosive, and the records of many serious explosions indicate the seriousness of mishandling. Workmen, whose duty it is to handle cylinders under pressure, should be trained carefully and work only under expert supervision. ing or exploding. Problems confronting 6. Even though not intended to be 9. A lifting magnet should never be the gas manufacturer are not discussed. 4. If compressed gases are delivered to the consumer in cylinders, the cylinders should be manufactured and main tained in accordance with the specifica tions of the Inter state Commerce Commission and should be filled with gas and marked in accordance with these regulations. T'i shipped in interstate commerce and de used in handling cylinders, for if the electric power should fail, the cyl inders would drop and a rupture might result. Neither should a rope or chain sling be used, because of the possi bility of a cylinder slipping and falling. Where a crane is used to move cylin ders, a safe cradle or platform is most practical. The regulations, are 10. Empty cylin contained in the Bu ders should be seg reau of Explosives regated from full Pamphlet No. 9 Figure 1. A fire-resisting storage bouse for compressed gases. cylinders and, before (Copyright, 1950, National Safety Council. AU rights reserved. Printed in U.S.A.) RSV 0005973 Air. 2--S.P.P. 95 SAFE PRACTICES PAMPHLET NO. 95 COMPRESSED GAS CYLINDERS (Handling and Storing) L* jA* NmDelLt INjobd; c4'(Uil hoqfctd> ltAygKAmd**vi 4Vo tv^ory* doAgvfftwt. Ho'* or* ioa iwggtltiPAtf l. AUay i 9th <y'do< b M1 nd henoiii it octatd 1. If -*< gl* 1. bo >.urf tk*r* S| AO 0*1 0/ ' th*m >k><k n*gM <<* A with th* cyiid*r J. A-ald ift loodi!*? oftd yl* dfop th*i ' P*'(-.1 Ik.m lo tog*th*' hiovily. . wh,. eyl'Adm or* b inf >*rld bl*<i th.m curtly. i. LIU. r olh*r than illdo. oh cyii ndor Iron, o trv'h. oed !t*p th vo :*i"9 cop In V. Ui* q erodU or Holder vh* lilliAf oyllodon -IK q c'qa; novor wi* * mofnt. 7, flalltAg <yli*d*ri it doAgt'Ovif 4* <4rr*< h*A 'roAtpoMiAg tkom, I, oNn**lor r w<* ot*9m"giprKotv*yd mgo*t**cioyll.ii\d*f aa r4l- 9. $<' eylJ*d*r* tocv'ly. (hot Ihoy CPaao* loll ov*r, or b* itrvok by *>*hA<- col or olhor objoclt, o*d h*r* Ikoy *o< <0*0 lA OOAlofil with toil or tOrrojiro okomicolt or Imvooc. 10. Avoid capot!** it- ogor AplCoycVlo'tAgdothri**t>o kn#oootf flcmmobli motortola: " aploilon might ><ult. UFiTT INSTRUCTION CAIO No. 419 Figure 2. Reproduction of N.S.C. Safety Instruction Card. shipping, ali valves on cylinders should be closed and the protecting valve caps, if used, should be secured in place. This will prevent damage to the valve and threads. Cylinders containing combus tible or noxious gases, not provided with valve protection caps or not having their vaivea protected by being recessed into the cylinder, should be shipped crated. Empty cylinders should be re turned to the vendor promptly. Precautions During Use 11. It is advisable for every gas cyl inder to be equipped with a metal cap protecting its discharge valve against damage, unless the valve is protected by a recess in the head of the cylinder. When the cylinder is not connected for use, valve caps should be kept in place. Should an unprotected valve be knocked accidentally against an object, gas under high pressure might escape and consid erable damage result. 12. Various methods are used to keep caps for cylinders from becoming misplaced or lost. In one company, a ring and chain attachment is provided. In another plant, each oxygen cylinder is provided with a wire loop which holds the cap when it is not in its regular place. In another concern, the man to whom the oxygen cylinder is charged is held responsible for the return of the cap and is told that if the cap is lost, it will cost the company $1.50. 13. When cylinders are used in an upright position, precautions should be taken to prevent them from being acci dentally tipped over. In many instances the cylinders can be placed in clip racks. 14. No attempt should be made by the consumer under any circumstances to mix gases in a cylinder. Cylinders should be filled only by or with the con sent of the owner, and then only in strict accordance with the regulations of the Interstate Commerce Commis sion and any local governing bodies. 15. Alterations or repairs to cylin ders, or to valves, should be made by the gas supplier only. Users should never tamper with safety devices or with valve equipment. 16. The markings on cylinders should all be maintained clear and legible. Markings should not be changed with out authority of the Bureau of Explo sives, as provided in the Interstate Com merce Commission Regulations. Each cylinder should be marked by the gas supplier in letters at least one inch high and with the name of the gas the cylin der contains. 17. Make sure that the threads on regulators or other unions correspond to those on the cylinder valve cue.:.-;. .W.er force connections that do not fit. 18. Cylinder valves should be opened slowly. Cylinders, not provided with hand wheel valves, should have spindle keys on the valve spindles or stems while the cylinders are in service. Wrenches or other tools should not be used for opening cylinder valves, except where they have been provided or approved by the gas supplier. When empty cylinders are being returned, see that all valves are fully closed. 19. Cylinders of certain compressed gases should not be used without re ducing the pressure through a suitable regulator attached to the cylinder valve. An exception may be in cases where the consuming device is not equipped with shutoff valves. Manufacturers' recom mendations should be followed in all cases. Before a regulator is removed from a cylinder, close the cylinder valve and release all gas from the regulator. Combustible gas regulators, hose or other appliances, should never be inter- changed with similar equipment intended for use with other gases. 20. Before making connection to a cylinder valve outlet, open the valve for an instant to clear the opening of par ticles of dust or dirt. This is generally termed "cracking the valve." Always, however, point the valve opening away from the body but not toward anyone else. An exception to cracking the valve in this manner could, of course, be when the cylinder contains a highly toxic gas such as HCN. Also, never crack the valve of a cylinder containing a combus tible gas near a flame or other possible source of ignition. 21. After attaching the regulator, and before the cylinder valve is opened, see that the adjusting screw of the reg ulator is released (turned counter clock wise). Never permit the gas to enter the regulator suddenly. Open all valves slowly. Before removing the regulator from the cylinder close the cylinder valve and release all gas from the reg ulator. 22. Never try to stop a leak between a cylinder and the regulator by tighten ing the adjusting nut, unless the cylinder valve has first been closed. 23. Do not allow sparks, molten metal, electric current, excessive heat, or flames to come in contact with the cyl inder, hose or regulator. 24. Regulators or hose equipment should never be interchanged. For in- Figure 3. A cart for transporting welding equipment. RSV 000597^ COMPRESSED GASES S.P.P. 95--3 stance, where such equipment is used for one gas, it should be used for that gas only. Do not use oil or grease on attachments for oxygen cylinders. 25. When a large volume of acety lene, oxygen or other gases is to be used and more than one cylinder is required, manifolds should be used for coupling the cylinders together, but they should be of a design approved by insurance un derwriters and recommended by the gas supplier. It is advisable for users of manifolds to purchase them from reli able manufacturers, by whom they should also be installed. Storing Cylinders 26. Cylinders should be stored on end away from continuous dampness, on a concrete platform with a shed roof and side walls extending approximately half way down from the roof. Dividing walls should be installed also to furnish separate compartments for each kind of gas in storage. If valve protective hoods become frozen or filled with ice and snow, let them thaw out naturally in a warm room. Never use a steam hose to thaw them out, as fusible plugs may be melted and the entire contents of the cylinder released. 27. Cylinders containing compressed gas should never be Stored near highly flammable substances, such as oil and gasoline. Where a considerable number of cylinders are stored it is advisable to Figure 4. The interior of a fire-resisting store house for compressed gases. have storage spaces segregated! by fire resisting and heat resisting wails or par titions. This will facilitate removal in case of fire when gases under pressure not ordinarily hazardous may have the pressure considerably increased because of expansion due to the heat. 28. Do not store cylinders near ele vators or gangways, or in locations where moving objects may strike or fall upon them. To avoid confusion, always store full cylinders and empty cylinders in different groups and also store charged cylinders containing the same gas to gether. Cylinders containing com pressed gases should never be exposed to continuous dampness. Rusting will cause the caps to stick and will give other trouble. Store cylinders in a dry place and keep them away from corro sive chemicals or fumes. 29. When cylinders must be stored in the open, care should be taken to protect them against excessive varia tions of temperature. In winter, cylin ders should be protected against an ac cumulation of ice or snow. In summer, they should be protected from the con tinuous direct rays of the sun. General Precautions 30. Compressed gas cylinders should never be used for any purpose other than as containers for the particular GAS MASKS (N CASE ba*a 4* ut qi ' mttk la in am*rqA<T. T wJl kv la k*a* ka la M k biad al (4*ntar fa wia la raraat raw agauHt lk Wd a* git ar 999 pa a*da*gr*ag row' Vila, laak far Ubal Ik, pwaei a* a'aaii ^ar *>kck >k t*>**** ><-dd. if k lb*l k* ba>* 'b!.'rUd fa, <k, j,j,, Har ii ik <ada .1 tra'i *<*p*'*d wd' k Ikt S'*4i*d A..ac.<*. T pr9U Aid ............... Crba* maa.da -M'f Ae d a'qi**< Add arq*A;< *d Y*]|o- aitk any gf at fk b* g '/j lack black or k.ia caa*faiijg I k <rq*i*i ealart Maic,!ludkai 4cjKailla*r.r I.d No. 212Safety imstpuction caro Figure 5. Reproduction of N.S.C. Safety Instruction Card. SOME AMMONIA HAZARDS >\MUONlA ' ' * nvAt m v. aad ralaaj. A tmo\\ bracking I. Na*ar apaa a cvfl*4r ar rlata PAcbiag ** tka living ba* uHil lha V baa* aWw*al avtltda '? 2. Do ilaad eyKba*d *>>* pratta* S if* 4 \ WVaa TW*1 <a*. la g*t" fa. ya*w ?*t A. Sartv banzai *** *!, vka* baiag apa*ad bang >hvt, U**a al Ua la tap* tk, tU> n twraiag in iba pvcfclag (nl lha kaU a< ly/ning) * pa*S*q i*<k *W. S, If 9an 9* an*Mani wki<h ditckotgei / by. Uaad by (b ptcvitary la )*ia aga^a. If ibvld a dangar- aw* ea*aatf**aa ba built up and yaw m9w -at ba dbia la ratwra. 4. lavra ka^ la (Saa far bvri. C*d Na. J 4 J. ] 1. laara |ka pra" panw*a n*aVWad of 'w*ciloliaa. (Saa 5<aty lni<rwctiaa Cord Na. 145. | saFtrr instruction card No. 372 Figure 6. Reproduction of N.S.C. Safety Instruction Card. gas for which they were designed. They should never be used as rollers for mov ing heavy materials because of the pos sibility of weakening the cylinder. 31. Never use compressed gas to dust off clothing, as this may cause serious injury to the eyes or body. Se rious accidents have resulted from this use of gases. In one case an employee suffered a severe injury in attempting to blow dirt out of a wound when the gas entered under his skin and inflated his entire forearm. 32. Cylinders should always be con sidered as full and handled with corre sponding care. Accidents have resulted where the container was thought to be empty, but all of the pressure had not been released. The cylinder valve should always be tightly closed when the cylinder is not in use or when it is empty. 33. In transporting cylinders one should load or stow them so as to allow as little movement as possible. They should be secured to prevent the pos sibility of violent contacts. 34. Oxygen and anesthetic gases are sometimes sold in large cylinders. Hos pitals have purchased these gases la large cylinders, and then transferred the gas to the smaller cylinders used in the anesthesia machines. The practice of RSV 0005975 4--S.P.P. 95 SAFE PRACTICES PAMPHLET NO, 95 refilling small cylinders is attended with hazard and should be done only by competently trained persons. Many in dustrial plants also charge small cylin ders for use with protective masks, tak ing their supply from large tanks. The same is true in these cases. 35. Receiving charged cylinders or shipping empty cylinders should be in charge of an experienced man. Consid erable difficulty and confusion will be avoided if this suggestion is followed. Gases Used in Induscry 36. Table I lists the gases used in large quantities in industry, and several of their characteristics. 37. In the following paragraphs each of these gases will be discussed. While it is impracticable to give a com plete discussion of each, a few of their uses will be mentioned, together with their chemical and physical character istics and special remarks pertaining to particular hazards. For a discussion of health hazards of gases see Health Practices Pamphlet No. 9, "Gases and Vapors." Acetylene 33. The chemical formula for acety lene is C2H?. It is a colorless gas with a strong, unpleasant odor in the commer cial grade, highly flammable. It bums in air with a smoky flame except where a special burner is provided. It is used to considerable extent for illumination, but finds its principal industrial value when burned with oxygen. This com bination produces an extremely hot flame, widely used in cutting steel and for welding purposes. Under no cir cumstances should acetylene be brought into contact with unalloyed copper ex cept in a blowpipe or torch. Alloys containing less than 67 per cent copper may be used where needed. 39. Some reliable authorities (Le Chatelier) state that the gas forms flam mable mixtures with air in a wide range (from approximately 2.8 per cent to 65.0 per cent). Other authorities place this range at 2.5 per cent to 80 per cent, 40. Acetylene cylinders should be used and stored always in an upright position. Acetylene is dissolved in a solvent liquid, usually acetone, produc ing a porous mass which fills the cylin der. The acetone will thus be prevented from draining out into the valves and other fittings. 41. Acetylene cylinders as received are charged to a pressure of 2 50 pounds per square inch, based at a temperature of 70 F. Acetylene should never be utilized at a pressure exceeding 15 pounds per square inch (this means the working pressure in the lines or hose) be cause of the possibility of an explosion. 42. Always keep the cylinder valve spindle key or the wrench in place on the valve spindle when the cylinder is in use. (See paragraph 18.) When re turning empty cylinders, see that the valves are fully closed. 43. The pressure does not accurate ly indicate the amount of gas contained in the cylinder unless the temperature and acetone content are also taken into consideration. Gas 1. Acetylene -> Ammonia 3. Dutane* 4. Carbon dioxide 5. Chlorine 6. Ethylene 7. Ethyl chloride S. Helium 9. Hydrogen 10. Hydrogen cyanide 11. Methyl chloride 12. Nitrogen 13. Nitrous oxide 14. Oxygen 15. Propane* 16. Sulphur Dioxide TABLE I Physical State as Shipped Dissolved Liquid Liquid Liquid Liquid Liquid Liquitl Gas Gas Liquitl Liquid Gas Liquid Gas Liquid Liquid Effect When Breathed* Anaesthetic Irritant Anaesthetic None Irritant Anaesthetic Anaesclielic None None Toxic Anaesthetic None Anaesthetic None Anaesthetic Irritant Flammable * Yes Yes Yes No No Yes Yes No Yes Yes Yes No No No Yes No Flammable Range with Air (%) 2.5 to 80.0 16.0 to 26.0 1.6 to 6.5 None None 3.0 to 34.0 4.3 to 14.8 None 4.1 to 75.0 12.7 to 27. 8.3 to 19.7 None -None None 2.1 to 7.5 None Explanation of terms: 'An:lesthetic. These gases exert a druglike action when breathed, as they are absorbed into the blood. They mav cause death when breathed in considerable quantities. Irritant. These gases are not absorbed into the blood but injure the surface tissues of the breathing passages. Death may result from continuous exposure because of the contraction of the res piratory tract. Toxic. Poisonous. This gas exerts a a chemical action on body tissue and pre- vents it from absorbing oxygen from the blood. None. Tiiese gases arc harmless when breathed in small quantities, but death may result from suffocation when in haled in large quantities because they prevent oxygen from reaching the lungs. (This does not apply to oxygen.) Note: -- Oxygen, chlorine and nitrous oxide sometimes support combustion much more vigorously than does air. Many materials will burn in them that will not burn in air. This fact should not be disregarded in their handling and use. 'Classed under beading of Petroleum and Hydrocarbon gases In the discussion. 44. Never use an open flame to de tect combustible gas leaks. Use soapy water. During freezing weather, lin seed oil may be used. 45. In case acetylene should leak from the cylinder valve and cannot be shut off with the spindle, remove the cylinder to a safe location and tag it as having a "defective valve." Place a warning near the cylinder not to ap proach it with a lighted cigarette or other source of ignition. Then notify the supplier and follow his instructions as to its further handling and return. 46. Cylinders containing acetylene should be stored in a separate group, never with oxygen or chlorine cylinders. In shops or plants using both oxyacetylene and electric welding apparatus, care should be taken to avoid the han dling of these equipments in any man ner which may permit the compressed gas cylinders to come in contact with electric welding apparatus or electric circuits. Ammonia (Anhydrous) 47. The chemical formula for anhy drous ammonia is NH3. It is a color less gas with a pungent odor and is used widely as a refrigerating agent as well as in many chemical processes. It is ir- RSV 0005976 COMPRESSED GASES S.P.P. 95--5 ritating and corrosive and in concentra tions of two volumes in 1000 may pro duce dangerous irritation of the mucous membranes, permanently injuring res piratory passages and eyes. Heated to 1200 F., and mixed with a proper pro portion of air, it will burn or explode in contact with a source of ignition. Such explosions have frequently proved very serious. Gas masks with suitable canisters, hose masks, or self-contained oxygen breathing apparatus and eye pro tection should be worn in case of leaks. In strong concentrations, moreover, am monia may attack the skin and the breathing apparatus will not give full protection. Ammonia reacts with cop per and brass but does not ordinarily affect iron and steel. 48. Cylinders of ammonia should al ways be stored in a cool place. 49. A cylinder of ammonia should never be connected to an ammonia re frigerating system except when the sys tem is being charged or drained. Never withdraw ammonia from the system ex cept with the permission of the owner of the cylinder, and then the cylinder should be charged only to the amount recommended. 50. Should it become necessary to withdraw ammonia from a refrigerating system into cylinders, care should be taken to avoid overcharging of the cyl inders so used. Only empty ammonia cylinders should be used for this pur pose and in order to insure that they are empty, the valve should be opened and left open for five minutes prior to at Figure 7. a clamp to prevent cylinders from falling while b^ng used. taching to the system which is to be emptied. The cylinder should then be placed on a scale and its tare weight de termined. The tare weight should check closely with the tare weight furnished by the cylinder owner, and should there be a difference, the smaller of the two weights should be used. The cylinder can then be connected to the system but should also be weighed from time to time while filling and the amount charged should preferably be less than the weight given in Table 2. Table No. 2 CHARGING AMMONIA CYLINDERS (Maximum Amounts) Pounds of Ammonia Dimensions of Cylinder 150 7 ft. long by 12 in. diameter 150 58 in. long by 15 in. diameter 100 7 ft. long by 10 in. diameter 100 56 in. long by 12!/i in. diameter 50 46 in. long by 10 in. diameter SO 43 in. long by 10Vi in. diameter 40 42 in. long by 10 in. diameter 25 28 in. long by 10 in. diameter --Compressed Gas Manufacturers Assn., Inc. 51. When cylinders are used to re turn withdrawn ammonia, the customer should inform the manufacturer, giving the numbers of the cylinders so that such cylinders may be promptly weighed, examined, and cleansed before recharging with pure ammonia. Butane 52. Butane is one of the group of liquefied petroleum gases. Its chemical formula is C.H^, and it boils below 32 F. Fire and explosion hazards similar to those encountered with commercial gasoline are involved in handling butane and its varying mixtures. It is quite flammable and explosive when mixed with the proper amount of oxygen or air, and ignited. 5.3. Butane is a refrigerant, and care must be taken not to allow the liquid to come in contact with the flesh. Be cause of rapid evaporation a very small quantity may cause freezing with re sultant blisters similar to those caused by a burn. The eyes should be pro tected by goggles whenever there is ex posure. 54. The vapor is about twice as heavy as air. Leakage will, therefore, either the closed or open position. seek lower levels and will flow along like water. Since the vapor is color less and odorless, it may be taken into the lungs of an individual without his knowledge. Butane, when inhaled, acts to exclude the oxygen necessary to sup port life and the inhalation of large quantities may, therefore, cause serious trouble. 55. Containers for liquefied petrole um gases should be handled with the same precautions observed in the case of cylinders of other flammable gases. Installation should be only by compe tent and well trained men. Carbon Dioxide 56. This gas is shipped, liquefied un der pressure, in cylinders, and some times is known as carbonic acid gas. The chemical formula is C02. It is heavy, inert, colorless and odorless. The principal use of carbon dioxide is in the manufacture of soda water and other carbonated beverages. It is also used in refrigerating units. CO- dissolves in water, and is a weak acid which will attack copper, and such pipes or con tainers with which it may come in con tact should have a block tin lining. 57. An atmosphere of carbon dioxide will not support life. Breathing small amounts results only in respiratory stim ulation. Higher concentrations may pro duce physiological effects that are inde pendent of suffocation. A 10 per cent concentration may produce unconscious ness. The principal hazards in the handling and use of this gas, however, are in connection with its pressure. 53. Artificial heating of cylinders should be avoided whenever possible, but if it is necessary to prevent freez ing of the gas during discharge from the cylinder or to speed up the rate of i f RSV OO05977 t 6--S.P.P. 95 SAFE PRACTICES PAMPHLET NO. 95 DRY ICE Dry <<* {solid carbon diet'd*, l*mp. about -- MOJ eon eoas* frostbit* similar Io a tarot* burn. In q tight eontoinor, th* prmurc con couie on eiplaifon. 1. Wsar glove* when handling dry ice or melol lha( ha* been in contact with dry ice. 2, Never put dry ice in any drink; even a smoll piece will couse a painful frostbite. Never place dry ice in any tight container except one designed for the purpose. 4. When sawing dry ice, see that guards are in place. Use a wooden strip to push ice ogoimt the blade. 5. In a small enclosed space, gas from dry ice can cause suffocation. If warned by quickened breathing, diziiness or ringing in the ears, get into fresh air immediately. 4. Learn how to apply artificial reipirarion. Safety instruction Caro No. 417 N*liAJ !< Ha. Figure 9. Reproduction of N.S.C. Safety Instruction Card. discharge, the cylinder may be im mersed in a bath of lukewarm water. The use of a flame, or of an electric or other heater, should be strictly for bidden. The temperature of the heating medium should never exceed 120 F. 59. Carbon dioxide cylinders are sometimes brought into rooms of high temperature in order to recharge re frigerating systems. Exposure to higher temperatures may cause the gas to ex pand sufficiently to break the rupture disc. Instances have been known where fragments of the disc have struck work men, causing painful injuries. Persons in the vicinity should protect themselves against this hazard. 60. Care should always be exercised to avoid the backing up of water into the cylinder -- particularly in winter weather--because of the danger of freezing. Every effort should be made to prevent foreign matter from entering the cylinders or valves. 61. Carbon dioxide should never be used for carbonators in bottling plants or soda fountains, or for similar use, without reducing the pressure through a suitable regulator attached directly to the cylinder. This is an important precaution. 62. Before attaching the pressure regulator to the cylinder, open the cylin der valve a little and then close it. This will insure its easy operation, thereby avoiding damage to the regulator by an outrush of gas from a suddenly opened valve. 63. Cylinders should be weighed be fore any gas is withdrawn and again alter recharging the system, and the two weights recorded. The difference will be equal to the weight of the gas that has been withdrawn. This weighing and recording procedure should be followed every time gas is discharged from a cylinder so that the quantity of gas re maining may be ascertained at any time by referring to the record. In this way, partly full cylinders will not be con fused with empties. 64. In opening and closing valves al ways use the tools supplied by the gas manufacturer and avoid the dangerous practice of striking the valve wheel with a hammer or other such object. 65. Seltzer water is ordinary water saturated at a very high pressure with carbon dioxide. At a temperature of 40 F., a pressure of 100 pounds is necessary to carbonate the water suc cessfully. With higher temperatures, the charging pressure increases rapidly Figure 10. A truck for moving cylinders about the plant. Figure tl. A cradle or carrier for handling cylinders with a crane. and, in consequence, the danger of breakage of the container likewise mounts. 66. Carbon dioxide is sometimes shipped frozen into solid blocks (dry ice). Its principal hazard is that of severe "burn" or frost bite through bodily contact with the solid. Another possible hazard is the generation of car bon dioxide gas in quantities sufficient to cause suffocation. Carbon dioxide gas liquefies when compressed to about 1000 pounds per square inch at a tem perature of about 80 F. The liquid carbon dioxide is allowed to escape from cylinders into large tanks where "snow" is produced, which is then hydraulically compressed into hard blocks. This ice is commonly supplied to the trade in ten-inch cubes packed individually in brown wrapping paper and shipped in insulated containers. Dry ice does not melt but changes directly from the solid state into a dry non-flammable gas which is heavier than air. A pound of ice will produce at ordinary tempera tures about nine cubic feet of carbon dioxide gas. Dry ice should never be R$V 0005978 COMPRESSED CASES S.P.P. 95--7 placed in a closed container as the rapid either gas or liquid, presents a hazard, generation of gas may build up a dan and such containers must be handled gerous pressure. Gloves should be worn with extreme care. The Chlorine Insti whenever it is necessary to handle the ice tute has formulated a number of rules or metal objects with which it has been for handling chlorine containers and as in contact, unless some other protection these are extensive, reference is again has been afforded. made to Safe Practices Pamphlet No. 71. Chlorine 70. Liquid chlorine, under pressure, 67. The chemical formula for chlor- is transported in 100 and 150 pound rine is CI2. Commercially, chlorine is produced almost entirely by electrolysis of sodium chloride or potassium chloride. cylinders, in multi-unit tank cars hold ing 15 one-ton units; and also in single unit cars holding 32,000 pounds and It is shipped as a liquid under pressure 60,000 pounds respectively. in steel containers which must conform to I.C.C. regulations. It is an amber colored, oily fluid about V/2 times as heavy as water. At temperatures above --23.5 F. the liquid gasifies at at mospheric pressure, the gas being of - 71. It has sometimes been the prac tice when there was a chlorine leak of possible serious consequence, to spray water on the leaking liquid. The water was frozen by the chilling action of the greenish-yellow color with a character chlorine, and ice formed, sealing the leak istic suffocating odor. The gas is heavi for a sufficient period of time to allow er than air. Suitable gas masks with U. S. Bureau of Mines approval should always be available to workers exposed the container to be removed or until necessary repairs could be made. Based on its experience and upon tests, how to the gas. For further information on 1 ever, the Chlorine Institute does not chlorine, see Safe Practices Pamphlet , recommend the water treatment for a Mo. 7L, "Safe Handling of Chlorine." j leak of either liquid or gaseous chlorine. In the hands of an expert, this treat 68. Chlorine is used in the prepa-' ment might prove successful, subject tb ration of bleaching agents, fire extin-[ temperature conditions. There are, guishing fluids, solvents, antiseptics, j however, few experts, and outside wea anesthetics, fumigants, in the purifica ther conditions cannot be predicted. It tion of drinking water, and in connec- \ is, therefore, considered a dangerous pro tion with sewage and industrial waste i cedure for general use. disposal. 72. Chlorine leaks may be located 69. Every container holding chlorine, by using a doth wet with aqua-ammonia. Ammonia in the presence of chlorine will produce white fumes (ammonium chloride). If leaks in containers or tank cars cannot be brought under control speedily, telephone the shipper's plant for assistance. WkenOpeningValyes i/Jltji Gauge &Rgduciri$%(ve AWAY Jpom YOU Figure 12. Direct regulator and reducing valve away from you when opening valve. 73. Should it become necessary to warm a container, use great care because of the low fusion point (157 F.) of the safety plugs in the valves of the cylinders and in the heads of the ton containers. Valves should never be heated. The fusible plugs on chlorine cylinders and ton containers melt at ap proximately 170 F., and may soften at lower temperatures. Never permit live steam or hot water to flow on these fusi ble plugs. To warm up cylinders of 100 or 150 pound capacity, they should be placed in a warm water bath, not more than 12 inches in depth, but under no circumstances should open flames be used in contact with cylinders to warm them and increase the rate of discharge. The temperature of the water should never exceed 100 F. It is not practical to warm ton containers by this method. Dichlorodifluoromethane (Freon-12) 74. The main physiological effect of this gas seems to occur when the con centration in air is high enough to ex clude ogygen. It is practically non toxic. However, in the presence of a flame or hot surface, it is decomposed and products both irritating and dan gerous are formed. The products of de composition, however, are irritating and give adequate warning of their presence. 75. Extreme care should be taken should it be necessary to warm the cyl inder to promote more rapid discharge, and temperatures above 125 F. should not be used. Steam or an open flame should not be allowed in direct contact with the cylinder or valve. When a cyl inder is emptied of refrigerant, the valve should be dosed and the cylinder dis connected from the system. The brass protection cap should be placed on the outlet connection of the valve to pre vent dirt from entering the valve and also to prevent damage to the threads and to the valve connection. Cylinder hoods should be screwed in place be fore pladng the cylinder in stock or re turning it to the manufacturer. 76. Should it become necessary to withdraw dichlorodifluoromethane from a refrigerating system into cylinders, the same precautions should be taken as for other gases. The gas manufacturer should be advised of this procedure and given the serial number of the cylinder so that the particular cylinder, upon arrival at the filling plant, may be prop erly examined and cleaned before charg ing with pure gas. 77. Cylinders should be stored up right in a cool, dry place. They should be kept away from salt or other cor rosive chemicals or fumes, as rusting will cause damage to the cylinders and cause the cylinder hoods to stick. Proper protection should be afforded through the use of goggles to eliminate the possibility of the liquid's coming in contact with the eyes and causing possible injuries due to its freezing action. Ethylene 73. The chemical formula for ethy lene is CSH,,. It is 3 colorless, combusri- RSV 0005979 S--S.P.P. 95 SAFE PRACTICES PAMPHLET NO. 9S ble gas, the commercial grade having an unpleasant odor. It bums with a bright luminous dame, and when mixed with air and ignited may explode vi olently as do other flammable gases. It is one of the constituents of illuminating gas. It is now finding considerable use as an anesthetic by inhalation and is extensively employed in the synthetic chemical industry and for the coloring and ripening of fruits and vegetables. explosion may be caused. The products of combustion may be toxic. It has an anesthetic effect, a volume of 6 per cent for an exposure of thirty minutes being possibiy dangerous to life. While it has a distinctive odor, it may be tolerated long enough to be dangerous. 82. All cylinders should be carefully handled and when not in use protective caps should be kept in place. Care must be exercised in storing containers of ethyl chloride, and men handling them should be entirely familiar with the content. Helium S3. The chemical formula for helium is He. Next to hydrogen, helium is the lightest gas known and consequently has found considerable use in lighter-thanair-craft.-'Tts great advantage here lies in the fact that it is non-combustible. It is one of the most inert substances, for it has no known compounds. 84. Helium may be stored in small cylinders which are usually shipped in box cars and are of the standard hydro gen or oxygen type. Each cylinder has an actual space capacity of about 1 Y> cubic feet and is shipped under a pres sure of 1800 pounds per square inch. A cylinder holds an amount of gas which, when expanded to ordinary at mospheric conditions, occupies about 178 cubic feet. Cylinders are fitted with double seated valves instead of the sin gle seated variety usually employed in handling other gases. It requires be tween 1100 and 1200 of these cylinders to transport the same amount of helium as one tank car. The precautions in handling and maintaining these cylin ders are generally the same as for those of other gases. Hydrogen 85. The chemical formula for hydro gen is Hv. It is an extremely light gas, colorless, odorless and tasteless. It is highly flammable and explosive in mix tures with air. It is used in hardening oils and fats, particularly soap, edible and cooking fats. It is also sometimes used as a fuel gas in flame cutting and in such welding operations as do not require the higher oxy-acetylene flame temperatures. It has extensive use in Kghter-than-air-craft and is used as a cooling medium in many large gen erators. 86. Hydrogen, in mixture with air, has a wide explosive range (4.1 per cent to 74.0 per cent). Every effort should 79. Every precaution should be taken to prevent the possibility of igni tion. The minimum ignition tempera ture of--ethylene in air is 490 C. The precautions which apply to.other, g^ses compressed in cylinders likewise apply to this gas. For additional informa tion on this gas see "Recommended Safeguards for the Installation and Op eration of Anesthetical Apparatus Em ploying Combustible Anesthetics." This is a publication of the National Board of Fire Underwriters. Ethyl Chloride SO. The chemical formula for ethyl chloride is C;H-,C1. It is a colorless liquid with a pungent odor similar to ether. It is volatile and flammable, burning with a green edged flame. Ethyl chloride is employed as a local anes thetic. It finds considerable use indus trially as a refrigerant. 81. It is hazardous in certain mix tures with air, and if ignited, a fire or Figure 14. A device used for hoisting oxygen and acetylene cylinders aboard govern ment battleships. RSV 0005980 COMPRESSED GASES S.P.P. 95--9 be made to handle and use this gas properly. Always keep sparks and flames away from the cylinders, hose and regulators. 87. Connections to piping, regu lators, and other appliances should al ways be kept tight and an open flame should never be used to locate a leak. Always use soapy water. When cylin ders are not in use, keep all valves tight ly closed. 88. Never interchange gas regulator, hose, other appliances with equipment which ha* been used for other gases. This is particularly important in the case of hydrogen. 89. Cylinders containing hydrogen, should always be stored in well ven tilated places segregated from cylinders containing oxygen. Hydrogen Cyanide 90. Hydrogen cyanide is also known as hydrocyanic acid or, when dissolved in water, as prussic acid. It has the for mula HCN, boils at 79.7 F., and freezes at 53 F. Hydrocyanic acid is an ef fective fumigant for the control of in sects, vermin and other pests. The very characteristics, however, which make HCN effective as an insecticide make it dangerous for human life unless it is FUMIGATING With Cyonidtt Hydrocyofllc qos li th* mo\i poAMrvtinq and poiioflout oi all fui*Jgot. For tartly, follow 0 ikn pro<durt: 1. Ike-ewgk i.ort* YOURSELF *4 io `Hat ail p#'fo*t out #/ tho a'o la b# l*migot#d a*d ( ad|0<a*t '#oi iti\e which 2. S9latiOm*ight loot. at #4(h to th# P'^'l#t to p#v1 o*Mry #fthr vfcff# ih* >0'ck ; l* ' i(*<*#dio#iy o'tor It i.. Whtn cloi*g off a toon* or loetio*. foa th k#T <* th lock of on* fh# door-- in cot# It itifl T# eonCn# got to kb# aro il#*dd, tool all ttotKi. cr*ica and opening# ;* vaili. o*4 ftrv. 5. Fait voroiog iigni at oil cntranco*. Pul up bo"ia. 6. Em#r o ploet u*dor fumrgelioA o*!y h Ob#lut*ly *#t"tO<y. VVqr o got moib do* ><9'#d to protoct agaioit cyanrd*. 7. VVh#* working wilh a tr*w. too*, or <* pairs. lc*o yor wort without 'o*i*g to th oth#M wk#n Uovlrtg, od roport ogo>* vh#o f#t wr>ng. t, A*t#r fymigotio* hot bow atorfctd, orb in por* lor mutual p'otolian. Who gattiog U B**p!#tt, throw opoo ott doort and wi*doM. I* *o toil p#rm>< *< OpoMl to *!' uMlt 11 hourt oil#* oirina, chtld/## only aft#r 1$ kauri. fO. Xnoi wor*tg igo% o*4 botnftod**. SAFETY INSTtUJCTlOfl CAtO No. 217 National lo<#ty Coooil roorc* 10 v. Figure 15. Reproduction of N.S.C. Safety Instruction Card. Figure Id. Use only prop*., tools for opening cylinder valves. handled properly. Its vapors are poison ous, inhalation of a large quantity or continued inhalation of small quantities causing death. 91. Liquid HCN is shipped in sealed cylinders in two sizes, namely, 75 pounds and 30 pounds. The cylinders should be stored in cool well ventilated places, shaded from the sun. They should not be stored in occupied buildings or in poorly ventilated places. In extremely warm climates, cylinders should be submerged in water to keep them cool, or they should be placed in artificially cooled storerooms. They should be kept in an upright position. It Is a condition of sale of liquid HCN that cylinders must be returned to the point of origin within 90 days from date of shipment, whether the contents have been used or not. Suitable gas masks should be available and always worn when work ing with the gas. Either the gas or the liquid, however, may be absorbed through the skin, and masks in some cases may prove insufficient protection. Under no circumstances should a user attempt to remove a cylinder valve or make other repairs to cylinders. If op eration is not satisfactory, the cylinder should be set aside and contact made with the manufacturer. 92. The use of methyl-orange test papers is suggested as an aid in detect ing whether or not HCN is present. These are small strips of paper of ca nary yellow which, in the presence of an atmosphere containing HCN, turn pink or red and are very sensitive to relatively low concentrations of the gas. Authori ties have suggested that if methyl-orange test papers do not change color within two minutes after exposure the space is safe for human occupancy. For addi tional information, see Table 1. Methyl Chloride 93. The chemical formula for methyl chloride is CHjCl. It is a colorless gas which burns, when ignited in air, with a greenish flame liberating toxic fumes. Mixtures in certain proportions of air are explosive. It is used widely as a re frigerating agent. It is an anesthetic, and in concentrations of 2 per cent for ex posures of two hours may be dangerous to life. It does not give definite warn ing of its presence even in dangerous concentrations, although manufacturers of this gas generally are odorizing it to avoid this hazard. Approved respiratory protection- should be provided wherever the gas is present. 94. All cylinders should be carefully handled and when not in use protective caps should be kept in place. Care must be exercised in storing containers of methyl chloride, and men handling them should be entirely familiar with the con tents. NITROUS FUMES TWj furw#i r#/#rrd a* tbii <<d * tk# '#4 iumi fk*t *i# lomolimot pr#i*#t *>iro nitric St bi*q I*ar of &tm. Don't ui*d. or kntfld. if you r b.g #*d h#*lky. ih*l you t* tti# w.lb Fallow Ihii #dv<#r 1. Find out, b#fa# ifj'tinq work. tk b#i> w* to g#l out of tfcoia pl#e#i h#r funtat anqkl C(v', il lk*f do ltur, #wy from ihtm #i quicily ai BoitibJ. 2. *a #pp'vd if <f U for you *o work in N*r 4pt*d #" pitting k#ftdV#*eVii#i a* '#ipn#r vr yOu' r*ufk *d "Oi. ). Don't fkink lr on# nitvu ik* yau can q#t ui#d t# iho lu, 4. If you do ?> cauqkt # <umi you ko yo# bftk. > a doctor * You my fl protty good wk* you q#r y /'Bin lh# tu^t. but #ltar # 1i^#. #ry'ig fo*t # low ko#r lo j doy or l*o, you inay f#| funk#r J( *^#et$. (j^) sapett iNsr*uCTiON cao No. 2i9 Figure Reproduction of N.S.C. Safety Instruction Card. RSV 0005981 10--S.P.P. 95- SAFE PRACTICES PAMPHLET NO. 95 Figure 18. A carrier for transporting cylinders. Nitrogen 95. Nitrogen, the predominant ele ment of air, has the chemical formula of N,. It is a colorless, odorless, tasteless gas, and under pressure the usual pre cautions in handling such cylinders should be observed. It is not combus tible and does not support combustion. Nitrogen finds its greatest use commer cially in the manufacture of ammonia and nitric acid. It is also used widely in manufacturing chemicals and in met allurgical processes. Nitrous Oxide 96. The chemical formula of nitrous oxide is NjO. Under ordinary tempera ture and pressure, it is a gas with a sweet taste and a faint agreeable odor. It is shipped in cylinders under pres sure as a liquid. When inhaled it pro duces unconsciousness and insensibility to pain. Consequently, it is used widely as an anesthetic for short surgical opera tions. It is commonly called "laughing gas." 97. Nitrous oxide is non-flammable but will support combustion. The or dinary precautions applicable to other cylinders of compressed gases apply equally to those containing nitrous oxide. Oxygen 98. The chemical formula of oxygen is 0*. It is a colorless, odorless gas and is an excellent supporter of combustion. It is non-flammable. When used with combustible gases such as acetylene, it produces a very hot flame and is widely used in industry for cutting and welding metals. For additional information see Safe Practices Pamphlet No. 23, "Gas and Electric Welding." 99. The valve of an oxygen cylinder should always be opened slowly. 100. Oil, or other flammable ma terials should never be permitted to come in contact with the valves, regulators, gages or any fittings of oxygfen cylin ders. Oil and grease in the presence of oxygen under pressure may ignite vio lently. Such cylinders should never be handled with oily bands or gloves. Oxy gen is not flammable but supports com bustion. open flame. Always use soapy water. When cylinders are not in use, always keep valves tightly closed. 108. Cylinders should always be stored in a well ventilated location and as most of the gases are heavier than air particular attention should be given to venting the lower spaces of the room. They should be segregated from cylin ders containing oxygen. Sulphur Dioxide 101. Oxygen should never be used as a substitute for compressed air and should always be designated by its proper name. It should never be termed "air." 102. Oxygen cylinders, when full> are under a pressure of abau* i.tJCC pounds per square inch * 'll This pressure should be reduced through a suitable before use. Cylinders sticulu be handled with care and kept away from heat. The same precautions apply as to other gas cylinders, which because of their content should be stored and used in as nearly an upright position as possible. The cylinders should not be handled by cranes, except in approved containers, slings or cradles especially designed for the purpose. Magnets, wire or cables should not be used. 103. Oxygen cylinders should be seg regated from cylinders containing com bustible gases. Where there are a large number of oxygen cylinders to be stored inside, it is recommended that they be stored in a separate room. It is a good practice to fciore full and empty cylin ders in separate groups. 109. Sulphur dioxide is a color1-- non-flammable, suffocating gpc extremely irritating odor. 7'- unemical formula is SC,. 50o per million, by volume- s*v'e z sensation of suffoca tion: with the first breath. It is heavier than air and is shipped as a liquid. It is employed as a refrigerant and also in the textile industry. When working with cylinders of sulphur diox ide, gas masks with suitable canisters should always be available. Workmen continually handling sulphur dioxide should wear suitable goggles. 110. In some cases it is necessary to warm cylinders to promote more rapid discharge of the gas. Extreme care should be taken to prevent such tem perature from reaching more than 12S F. The fusible piugs in the cylinder melt at about 170 F., and may soften at even lower temperatures. Never use live steam or an open flame in heating a cylinder. OPENING TANK CAR DOME COVER Petroleum and Hydrocarbon Gases 104. Petroleum and hydrocarbon gases, such as propane, butane, etc., are grouped under one heading because of similar characteristics. All of these may be classed as fuel gases, and the same general precautions apply. 105. They are used for illuminating and heating purposes and industrially with oxygen for cutting. 106. The containers should never be exposed to excessive heat or to rough handling. Sparks and flames should al ways be kept away from cylinders. 107. Make sure that all connections to piping, regulators, and other appli ances are tight to prevent leakage. Should leaks develop, never test with an k < I lv. 9 d*a. M4 if.x vmcrwlng by ih<S *gv*vv pvshvi. */ i Avoid viinf mveh llroogth; o fail itroinod book might iv IL j, ff I* 4t cvr lv looso* It. 4. If 90s vscoooi from sldo o tl**k#**, ll get tv ikb bofaf* p'oaaodlng. 5. Aold striking moohvU * ogofait d*m> Ibis might ervt o pofk. h. I................*vr lying bvsid* doiit <>.> eh*;* it ottoohod. Othorvno. r<ov* tv Iwdroek piotform vh< it <o*ok fall. 7. If monboU coor Is of boltod typo, low*a *ck Ni tvro 1 O t*m*. pafmit 99a tv Opo, **. t. Qo not stfik# domo of go**f with vroMb; Ihlt might coviv o spofk. ?, l*oo a* tools lying th dom*. th eor, thv wvlfc plotfarm, Thay bsssma bod "falling bjaet" Soiofdi. (?5) saty instruction Caro No. 12 c Figure 19- Opening tank car dome cover. i A HSV 0005982 111. Small cylinders of sulphur di oxide should always be stored in an up right position. (The one-ton cylinders are shipped, handled and stored hori zontally.) Leaks in valves or piping con taining SO* can be detected by the use of aqua-ammonia applied with waste or a cloth. In the presence of SO*, white fumes will appear. Tank Cars 112. There are special precautions which should be observed in the han dling of compressed gases in tank cars: 1. Tank cars containing compressed S.P.P. 95--11 formed only by reliable persons and under strict supervision. 6. When a tank car is spotted on a sid ing for unloading purposes, brakes should be set and wheels blocked. Caution signs should be placed on the tracks so as to give necessary warning to persons approaching the car. Such warning signs must be left in place until the car is unloaded and disconnected. 7. When tank cars are located on a dead-end siding, the cars may be protected on a switch end by a de rail, or, if on an open siding, derails may be provided at both ends. gases should not be shipped unless they are charged by or with the con sent of the owner. 2. Tank cars should not be loaded with any gas that combines chemically with the gas carried previously, until the car interior has been cleaned thor oughly. 8. The shipping of a defective or leaky tank car is illegal. 9. Returning ton containers of one own ership on the underframe of another is illegal. 10. Changing numbers or marks stamped onto compressed gas tank cars with out written authority from the Bu reau of Explosives is illegal. 11. Never tamper with safety devices on tank car valves. 3. Cars should be unloaded only on a properly protected private track of the consumer and in accordance with Interstate Commerce Commission regulations. 4. Whenever possible, switch tracks on which the compressed gas tank cars are placed for unloading should be devoted solely to this purpose. A CKNOWLEDGMENT This pamphlet was prepared, by the Industrial Department, National Safety Council. It has been reviewed by the Safe Practices Conference Committee. The Council acknowledges its obligation also to various individual experts for their valuable assistance. 5. Unloading operations should be per- Rep. IM--1250--VHP RSV 0005983 f national safety council CHICAGO, ILLINOIS RSV 0005984 *w.. \ c