Document 6ww4ZpK39EvKoaLpY83x8RzVE

FILE NAME: General Electric (GE) DATE: 1942 DOC#: GE027 DOCUMENT DESCRIPTION: Transactions of the National Safety Council 1 y! w m -m m m >! ctxo n s \ V<.. f c j -'v 1 31st NATIONAL / ' SAFETY CONGRESS General Subject and Industrial Sessions CHICAGO October 27-29, 1942 National Safety Council, Inc. 20 North Wacker Drive, Chicago Copyright, 1942, National Safety Council, Inc. Printed in U.S.A. Foreword VOLUME I r 11H E Transactions of the 31st National Safety Congress and Exposition of the National Safety Council are pub lished in two volumes. Volume I contains the General Sub ject and Industrial Section sessions. Volume II contains the Public Safety, Child Education, Home Safety and Farm Safety sessions. Volume I is distributed to all members of the Council. Volume II is sent to those members who are believed to Ininterested chiefly in the sessions it contains, to other members on request. The Transactions are a record of the proceedings of the Congress, condensed and edited for reference purposes. They are therefore an abridged version of the papers and discussions. The original manuscripts, some of which have drawings and charts too expensive to reproduce here, are available in the files of the National Safety Council. The National Safety Council, at its Congresses, seeks to eliminate from discussion matters which arc not pertinent to the aims of the Congress, or which may be contrary to the Council's policies. However, it cannot accept responsibility for all views expressed, either in the discussions of the Congress itself or in this record of them. Extra copies of Volume I may be obtained by Council members at the following rates: 1 to 10 copies at $2.00 each; 11 or more copies at $1.75 each. Extra copies of Volume If are 75 cents each. THE NATIONAL SAFETY COUNCIL. INC. 20 North Wcrcker Drive Chicago, Illinois Contents volum e Council Officers ... Using the Transact The Council's Prog Annual Meeting of Congress Banquet Subject Sessions-- Aircraft Manu Air Raid Prec Dusts, Fumes, Fire Safety ant Fundamental > Gas and Electr Government S. Industrial Hea Industrial Nur: Occupational E Safety Enginet Safety in Fore War Safety Pr 1 War Safety Tr Industrial Section h Aeronautical S ASSE-Engineer Automotive ant Cement and Qi Chemical Sect! Construction St Food Section . Marine Section Meat Packing, Leather Indc Metals Section Mining Section Paper and Pul] Petroleum Sect Power Press Se Public Utilities Refrigeration S Rubber Section Steam Railroad Textile Section Wood Products Exposition Exhibits Index ......................... National Safety Council, Inc. Honorary Members A ssociation' of [run anij S teel E ngineers VV. II. C ameron Robert W . Campbell L ew R. P almeu Officers (1942-1943) Col.. J o h n S tilwei.l, President I. \V. M illar, Vice-President for Finance and Treasurer G. T. H ei.lmuth, Asst. Vice-President for Finance and Asst. Treasurer 15. Ji. McCci.i.ocii, Assistant Treasurer W alter S. P aine, Vice-President for Industrial Safety L ew R. P almer, Vice-President for Transportation A. V. Roiiweder, Vice-President for Home and Farm Safety J udge Lee L. S kef.l, Vice-President for Community Councils R. T. S olensten, Vice-President for Membership L eslie J. Sorenson, Vice-President for Public Safety Du. I.Ewrs A. W ilson, Vice-President for Education N ed II. D earborn, Executive Vice-President, Managing Director and Secretary ; R. L. Forney, Assistant Secretary Executive Committee (1942-1943) J. I. Ba n a sii, Past President W allace N. B arker, Pullman-Standard Car Manufacturing Company C. W. B ergquist, Past President Robert W . Campbell, Past President D. B. C iia nt, Ontario Pulp & Paper Makers' Safety Association R. G. Creviston, Crane Company A. J. R. C urtis, Portland Cement Association N ed H. D earborn, National Safety Council, Inc. L ewis A. D eB lois, Past President R. E. D onovan, Standard Oil Company of California M arcus A. Dow, Past President G. W. E i.ste, J r., Baltimore & Ohio Railroad Company H arold F. E ndows, The American National Red Cross D. D. F ennell, Past President R. H. F erguson, Metals Section Robert F. GilmouR, Utica Safety Council E. E. Grover, Columbus & Southern Ohio Electrical Company J ulies' IT. H arvey, Greatcr'New York Satety Council W . A. H azard, Construction Section D r. T. L yle H azlett, Westinghouse Electric & Manufacturing Com pany G. T. H ellmutii, Chicago Rapid Transit Company G. A. I I euser, Louisville Safety Council Carl E. H olmes, Marine Section W . A. J arvis, Chase Brass & Copper Company, Inc. W. D ean R eefer, Lumbermen's Mutual Casualty Company W alter G. K ing, Past President J oh n E. Long, Past Piesidcnt J. W illard Lord, Atlantic Refining Company T iios. H. M acD onald, U. S. Public Roads Administration Officers (contd.) W ills M aci.a ciian, H on. Carroll E. M e I. W . M illard, Indus H arold L. M iner, E P hilip M. M organ, Council Clarence J. M u tii, E liot N ess, U. S. Ol W alter S. P ain e, At L ew R. P ai.mer, l 'asl C. E. P etti honk. Past R. J. R kigelutii, New Col. H enry A. Ken is A. V. Roiiweder, Dull Carl J. R utland, Str H enry G. S ciiaffnkr J udge L ee E. S kkel, . C arl L. S m i t h , Greati T heodore F. S m it h , R. T . Solensten, Ellii L eslie J. S orenson, C Col J ohn S tilwkle, C M ajor R. C. S thatto C. P. T oi.m a n , Past P Bn. C. II. W atson, IV D r. L ewis A. W ilson, C. E. W oon ever, Autoi A rthur H. Y oung, Pa V. A. Zimmer, U. S. D Board of Truste W inthrop W . A ldhici National Bank, New S ewell L. A very, P ie Chicago, 111. M organ B. B kainard, Hartford, Conn. H oward Coonley, Cha Company, Now York B enjamin F. F airless. Pittsburgh, Penn. * W. S. F arisii, Presidei York City W alter Gifford, Presidi pany, New York City E. R. H arri m a n , Direc York City W illiam A. Irvin, Mem Corporation, New Yorl T homas I. P a rk in son , cicty of the U. S-, New * Deceased Officers (contd.) Robert C. S tanley, President, International Nickel Company of Can ada, Ltd., New York City Col. J oh n S tii.w h .l, Vice-President, Consolidated Edison Company of New York, New York City T homas J oh n W atson, President, International Business Machines Corporation. New York City C harles E. W ilson, President, General Electric Company, New York City Directors (1942-1943) H. J. A ldrich, Spencer Kellogg Jfc Sons, Inc. T. O. Armstrong, Springfield Safety Council ; Hampden County Safety Council W. C. B aker, Power Press Section J. I. B a n a s h , Past President W ai.i.ack N. B arker. Pullman-Standard Car Manufacturing Company Ernest W . B eck, United States Rubber Company C. W . B ergqulst, Past President M iss F rances B ethune, R.N., Textile Section W. F. B iggs, Peoria Safety Council H. R. B ixleh, Mutual Life Insurance Company of New York H. W. B oggess, Sinclair Prairie Oil Company F. A. Boguf, Steam Railroad Section E. G. Borsekine, Kansas City Safety Council C. B. Boulet, Wisconsin Public Service Corporation E merson A. B randt, Reirigeration Section E dward H. B rink, Grand Rapids Safety Council J oseph A. B ropiiy, Elizabeth Safety Council W. F. B rown, Commercial Vehicle Section S am W . B urciiikl, Automobile Club of Rhode Island, Safety Depart ment W. I ! . C ameron, Evanston, 111. Rodert W . Camphell, Past President R aymond A. Carey, Evanston Safety Council R ay C arr, Portland Traflic Safety Commission D. B. C h a n t , Ontario Pulp & Paper Makers' Safety Association C harles A. C happh.i., Safety Division, Syracuse Chamber of Ceni- merce 1.a m .mot iilP ont Copeland, Delaware Safety Council C. S. C kaigmh.e, Greater Chicago Safety Cotmcil R. C. Crkviston. Crane Company W. H. C r isman. Seattle Traflic & Safety Council J. E. C ulliney. Bethlehem Steel Company A. J. R. C urtis, Portland Cement Association John D ' A murosa. S r., Railway Safety Council N el> H. D eardorn, National Safety Council, Inc. W. N. D eatiierage, Long Beach Traflic Safety Council L ewis A. D eB i.ois, Past President C. W. D empsey, The Liquid Carbonic Corporation S. T. D idsdale, Wood Products Section M ilton W. D udrzensky, East Bay Safety Council R. E. Donovan, Standard Oil Company of California J ames B. D ouglas, The Philadelphia Gas W orks Company Marcus A. Dow, Past President D. C. D u n c a n , Public Utilities Section 6 Officers (contd.) G. VV. E lste, Jr., B; H arold F. K nlows, D. D. F ennell, Past R. H . F erguson, Me D r, H art E. Imsiieu, V ictor B. F itzpatuh H oward B. Fonda, 11 Ray G illktt, Meat I Roiiekt F. Ctl.MOUR, J o h n L. C rider, RiiIiI W. A. G riffin, Amor 11. J. Griffith, Jones E. F. Grover, Columh H arry C uii.iikrt, TIf A. J. H ager, Lansing D. 7'. H arrington. U F r an k H . H arrison, Jtn.iEN H . H arvey, C W. A. H azard. Const D r. T . L yle H azi.ett l>any C. T . H ellmuth, Chi C. A. H euser, t.ouisv H . W . H irsh klmer, C 4ahl E. H olmes, Mar: D r. R alph H. H ough S te ph en J. H urley, 1 W h F. J ames, Philadi E. A. J arvis, Chase Hr T homas P. K earns, I W. D ean K eefer, L uii W alter G. K ing, Past C. L. La Fountain k, C G eorge L a M air, Des \ Roy Lee, Contra Costa W allace O. Lee, Safel Jo h n E. Long, Past Pr C. H. L ongm an, C.hieai J. W illard Lord, Atlai R. A . McA rthur, Pub B. B. McC ulloch, Bur T n o s . H. M acD onald, W ills M ac L ach lan, r A lfred E. M affi.y, Be H. T . Markfe, Petrolev H on . C arroll E. M eai.i I. W . M illard, Iudustri H arold L. M iner, E. I. H. H . M oiilf:r, St. Jose P hilip M. M organ, Mr R. B. M ori.ey, Industrial C. I.. M urray, Mason C Clarence J. M uth, Saf merce E liot N ess, U. S. Office (contd.) F rank S. N ewell. Toledo Safety Council 1'. E dward O 'N eil, The Safety Council of Greater St.-Louis George C. A. O i t , The Detroit Edison Company W alter S. P aine. Aetna Life and Affiliated Companies Lew R. P ai.mi-.u, Past President D aviu A. P atton-, Newark Safety Council R. it. P erkky, South Bend Safety Council C. E. P etti one, Past President G. 11. P eeif, General Klectric Company D. W. P ontius, Greater Los Angeles Safety Council \V. M. P owell, Cement and Quarry Section A lhert S. Regula. General Time Instruments Corporation R. J. Reigelutii, New Haven Trap Rock Company Col. H enry A. R eninger, U . S. Office of Civilian Defense, 3rd Region J. W. R eynolds, United Pacific Insurance Company R oland W . R ichardson, Paper & Pulp Section Clifford T. R idley, Superior & Douglas County Safety Council M iss S adie R ogers, Employees' Publication Section A. V. R oiiweder, Duluth, Missabe & Iron Range Railway Company C arl J. R utland, Street & Highway Traffic Section H enry G. Sciiaffneu, Eric Safety Council F rank T. S heets, Portland Cement Association J ohn R. S herwood, Baltimore Safety Council Dn. L. A. S houdy, Bethlehem Steel Company J udge Lee E. S keel, Appellate Court, Cleveland Carl L. S m ith, Greater Cleveland Safety Council T heodore F. S mith, Oliver Iron & Steel Corporation . R. T. S olensten, Elliott Service Company L eslie J. S orenson, City Traffic Engineer, Chicago J oh n L. S pencer, Blackstonc Valiev Safety Council E. C. S tring, Philadelphia. Pa. E. B. S taiilman, Safety Dept., Nashville Chamber of Commerce Col. John Str .v'it.i, Consolidated Edison Company of New York, Inc. M ajor R. C. S tratton, C.W.S., Chemical Section II. B. T aylor, Food Section C. P. T olman, Past President J ohn T reweek, 'Mining Section R. A. T ucker, Western Pennsylvania Safety Council J. A. V incent, Madison County Safety Council Du. C. H. W atson, Past President M. F. M. W erth, Lehigh Valley Safety Council II. W. W iutcomr, Transit Section T. A nc.i.in W hite. Safety Div., Birmingham Chamber of Commerce A. W. W hitney, National Conservation Bureau C. E. W ilson, Detroit Industrial Safety Council D r. L ewis A. W ilson. The University of State of New York C. E. Wom.lKVKR, Automotive and Machine Shop Section R oy V. W right, Simmons-Mftardman Publishing Corporation M is s M ary M ay W y m a n , Child Education Section A rthur II. Y oung, Past President M. W . Y oung, Sacramento Safety Council W alter S. Y oung, Worcester Safety Council E. J. Zauft, Safety Bureau, Duluth Chamber of Commerce I rving R. Zerzan, Omaha Safety Council V. A. Zimmer, U. S. Department of Labor Each edition library of safet men and women portation, insu agencies--give t and background vention at the A This knowledt ing year after y gressive industri Plan Safety ideas, . as personalities i tv, can be foum Tabic of Conic" at the end of li. The Tabic rSessions, (b) .' problems comn. Industrial Seed- Subject Scs arc arranged a: the book the s. trial Section .a1 the daily time gram. The detailed easy to find s| . hundreds of i: jects discussed, shot.', third s: in tiic case of 1 are printed in tions, i. c., ( Marine, etc. '. are listed the gram. Dust, Fumes, Gases and Vapors WEDNESDAY MORNING SESSION October 28, 1942 Presiding:--S tuart F. M eek, M.D., Asst. Medical Dir., Chrysler Corp., Detroit Maintenance of Exhaust Systems An Important Safety Measure B y JO H N M. KANE Engineer, American Air Filter Company, Inc., Louisville, Kentucky In recent years the safety engineer's re sponsibilities have increased by leaps and bounds. Under his widening contrST logically comes the checking of exhaust systems for the control of hazardous dusts and fumes. This discussion will assume that such haz ards are evaluated by the industrial hygienist or safety engineer. Where exhaust ventila tion is required, the ventilation engineer makes recommendations for exhaust capaci ties, system and hood design to control the condition. It will be further assumed that this coordination results in an effective ex haust system removing the dust or fumes at the points of generation and preventing their dispersion to the workroom. Consequently, unless the process is changed, the hoods or enclosures altered, or the method of material handling revised, the hazard should remain controlled as long as the exhaust system func tions properly. The word "properly" can rightly be underscored because in many cases little attention is given to such an installation after the project has been completed. Yet mechanical exhaust equipment and dust col lectors require the same attention that ma chine tool and other plant equipment require and usually receive. If this precept is correct, a discussion of fundamentals may assist the safety engineer in quickly setting up a routine check on the performance of an exhaust system and catch ing any reduction in the system's effectiveness. The tools required under most cases are a manometer (U -G agc), and a short piece of rubber tubing. The engineer must also'have an understanding of static pressure losses and hood suction. While hood suction readings have rightfully fallen into a state of ill repute as a means of measuring air flow, they do offer a quick and accurate method of measuring relative air flow. If the hood suction is known while an exhaust system is functioning properly, its continued effectiveness can be assured as long as the hood suction docs not reduce from its original value. An expansion of this state ment, should indicate why this simple mea surement can be used as a ready check. The Exhaust System Exhaust ventilation is by far the most pre dominant means of controlling dust hazards. The fundamental elements and the design are not altered, whether the purpose of the ex haust system is to remove toxic or explosive particles, or simply to prevent dispersion for reduction in workman fatigue, improvement of visibility or general betterment of work ing conditions. In most cases the system will 5b 31st National Safety Congress ncliidc hoods or enclosures that surround and not a function of the hood suction except lust producing areas as completely as pos- that velocities in the branch must be sufficient ihle and as close to the source of dust gener- to convey the material without settling and lion as feasible and branch ducts that arc obstructing the air flow by such accumula inccted to the hood so an indraft of air can tions). maintained through the necessary hood An analogy and some illustrations may help penings--the velocity of the incoming air to clarify this fundamental concept of exhaust ufficiently high to prevent material flying system design: utward. These velocities vary from 50 to uO fpm for fumes and fine dusts, to 2000 fpm r large particles forcefully thrown toward cnings in the enclosure. An automobile requires more gas to accel erate from rest to 40 miles an hour than it does to travel the same distance at 40 miles per hour. Much of the power has been used The size of the duct connection is deter- to overcome inertia and give the auto a ve ined by the cubic feet of air to be exhausted locity pressure (energy not used in overcom ;d the velocity necessary to prevent settling ing friction but available to coast after the the ducts. Such velocities vary from 1000 engine is stopped or to be expended by brak :n for fumes to 50(10 fpm for heavy loads of ing if the car is stopped sooner). Similar arse material. energy is required to move air from relative rest in a workroom to the specified velocities Mote that velocities have been gaged by in an exhaust duct. An automobile requires -tallness of particles and method of gcncra- less gas to accomplish this acceleration on a j u . Dust and fume particles are too small smooth hard surfaced road than on a rough u have, too great surface area to be in- gravel or dirt road. :enced greatly by the specific gravity of the aterial. The same velocities are generally ed to confine or convey the same size pan ic of wood or steel. In like manner less energy (entrance loss) is required to move air through a flared hood which gradually changes its shape than through a hood with abrupt changes in shape \n exhauster is the usual air moving equip- or direction of air travel. . ent that maintains the flow of air through iod and branches. It must have sufficient pacity to maintain the indraft at the hoods, d develop enough pressure to move that Hmie, overcoming the resistance to flow of - from inertia, turbulence, duct resistance d collector loss. A dust collector removes e entrained material from the exhaust sysn. concentrating the material for disposal, 1 preventing its re-entry to the workroom. The actual static pressure reading (the hood suction) can vary widely dependent on the branch pipe velocities and hood entrance loss. However, once the hood design has been established and the branch pipe determined, any change from the original hood suction can only indicate a change in velocity in the branch and consequently a change in air volume removed from the hood. This relation will be true unless hood design has been Definition of Hood Suction changed which would effect the case of ex hausting the air volume (entrance loss), or obstructions or accumulations in hood or :n a branch duct dose to the hood, a static -sure reading is called the hood suction, is a measure of the pressure required to branch ahead of the point of hood suction reading. Restriction of the cross sectional area will reduce the air volume, although me air flow at the required velocity-in the hood suction may even increase, dependent ucli (velocity pressure) plus the pressure t in overcoming the resistance to air flow on location and degree of accumulation. 'red by the hood (entrance or acceleration ') Measurement of Hood Suction I lnnd suction therefore is a function of the At the time of exhaust system installation, i oeity of the air in the. branch duct and the a jV ' hole should he drilled in each branch e of getting that volume of air into the connection for static pressure (hood suction) 1. (Kfiective dust control however, is a readings. The hole should he perpendicular ii lion of the indraft velocity at the hood to the duct, in a straight section (4 to 6 dlam- % Dust, Fumes, Gases cters long if possible) at least one diameter fiom hood or connecting elbow. Such small holes will be in addition to larger pitot tube holes for actual measurement of air flow. A vertical U-Gagc is satisfactory for static pressure readings above 0.8". Use an inclined design for lower values. Both designs are inexpensive. The vertical type can be made with a scale divided into tenths of an inch and a hent glass tube approximately %" in-i11v diameter mounted on a support. The gage is leveled and zeroed and the length of rubber hose attached to the proper side (either side of the conventional U-G agc). Reading consists of measuring the distance in inches between the top of the water col umns in both legs of the U-Gagc. Most man ufactured gages use a special gage oil with scales calibrated for the specific gravity and with the reading indicated on only one leg of the gage. Re certain that the end of the rubber tubing is held tightly over the hole in the duet while the reading is taken. Folding over the end of the rubber hose assures a tighter fit. Check tubing for kinks or sharp bends that would close the passage. The easily obtained static pressure reading not only furnishes an accurate check on per formance, but the amount of change can be quickly calculated. It has been previously shown that hood suction is a static pressure equivalent to the velocity pressure in the branch plus the entrance loss which can be slated in terms of percentage of velocity pres sure. Velocity pressure, entrance loss and most pressure losses vary as the square of the u-locity of air flow. it CFM . = cubic feet of air per minute originally exhausted CFMi- -- cubic feet of air per minute ex hausted during test. SR hood suction originally noted. S i's ^ hood suction during test CF.Mi. = C F M . y - L 1-- V S]\ or if> Irrnis of conveying velocities in the branches-- -- feet per minute originally main tained F app ed : tior esti Uni abh abh be 1 umi rest voli 1 of ; for stai citi' is che ass: pitc rea cat: air. met unc of 1 cha vai veli to SYS red to C oft ing hai slit lai air 1 the hr: ve; va of material exhausted, or leakage losses caused by loose cleanout doors, broken joints, holes worn in duct (m ost frequent in elbows), poor connection to exhauster inlet. Losses in suction can also be charged to additional exhaust points added to the sys tem (sometimes systems are designed for future connections and more air than re quired is handled by present branches until future connections are made), change of set ting of blast gates in branch lines (blast gates adjust the air distribution between the va rious branches. Tampering with blast gates can seriously affect such distribution and therefore gates should be locked in place im mediately after system has been installed and its effectiveness checked). Increased pres sure loss through dust collector due to lack of maintenance, improper operation, wear, etc. vary with the collector design. Refer to op eration and maintenance instructions fur nished with the collector or consult the equipment manufacturer. Testing Toxic Atmospheres By N. R. BERNZ Chief Industrial H ygienist, The Fidelity & Casualty Co. of N . Y., N ew York, N ew York In manufacturing, many operations and processes of one industry are common to hose of another, although the two indusrics may be engaged in the production of ntirely different types of goods. For xamplc, welding is used very extensively hroughout the aviation, shipbuilding, auto mobile and steel industries; this applies also 0 spray painting, electroplating, buffing, Trinitrotoluene (dust and vapors) Ammonium Picralc (dust) * Mercury (vapors) Aniline | Radon Thoron b As will be seen by examination of the ? rinding, and many other operations. Simarly with raw materials, various kinds of 1ids, organic solvents, etc., are found in Imost any type of plant. For this reason j above list, some of these substances arc pres ent as raw materials; others are final prod ucts, while a third group occurs as by-prod ucts generated in the various operations. ere are certain industrial poisons which Typical of the first group arc the various pear much more frequently than others acids, organic solvents, chlorinated hydro : :! which may be found throughout the carbons, ammonia, and carbon disulfide. In :tire defense industry. Some of these are: the second class we have T N T and am monium picrate, while the remainder are 'usts Toluene commonly occurring dusts, fumes, gases and arbon Monoxide ydrogen Sulfide ydrogen Cyanide dfur Dioxide ides of Nitrogen Xylene T richlorocthylene Carbontctra chloride Carbon Disulfide Nitric Acid vapors of a toxic nature generated in various industrial processes. W hile the theoretical possibilities for exposure to toxic substances in the above industries are far too numer ] ous for tabulation, this list represents those most commonly encountered. mnonia Chromic Acid i iosgcn Hydrofluoric Acid D u sts ad dmium Hydrochloric Acid Sulfuric Acid Silica-bearing inorganic dusts arc prob ?. ably found in all of the above industries. For i ozene example, mining of the iron ore in the steel industry presents exposures to free silica i /thers which are more directly associated dust in considerable quantities. Buffing, i specific industries are: polishing, and grinding operations done very l extensively in a great many industries, o generate inorganic dusts, which for the most c part consist of aluminum oxide and silicon s: carbide, but also include free silica in amor tl phous and crystaline forms. w c< For the purpose of quantitative determina 1)1 tion, dusts may be divided roughly into three 0`| classes, as fo llo w s: c< 1. The inorganic type such as free silica tl and asbestos, which is collected and the num tl- ber of particles per unit volume of air deter c." mined microscopically. C( 2. Organic dusts of natural origin, the amount of which is usually determined by weight. Typical of these are tobacco and flour dusts. m 3. Synthetically manufactured organic di compounds which may occur in the form of in dusts, such as T N T and ammonium picrate. ef. These substances when present as air con pr taminants in low concentrations are generally as evaluated quantitatively by chemical means. up di: Besides above types, there arc also metallic th dusts such as lead, zinc, cadmium, manganese, sa etc., some of which will be discussed under of another heading. ha Inorganic Dusts pl< in The most common method for evaluation of of ibis type of dust is to collect air samples pk in liquid solutions by means of an impingcr do (I ) and to make the quantitative determina -A? tion microscopically. When calculating the dust concentration, usually- expressed in num ber of particles per cubic foot of air, the microscopic calibration factor, .the volume of the sampling liquid, and the size of the air iui sample arc taken into consideration. wa The sampling procedure, microscopic ar ra' rangement, and calculations are extremely on simple, but the actual counting is a tedious qu: job associated with severe eye strain and sul requires considerable experience before dust art counts can be relied upon. In recent years an: tlie micioprojection method (2) has been used poi for counting of impingcr samples. With this ha- method in which the microscopic field is pro dci jected on a translucent screen, the eye strain experienced in direct microscopic work, is ofJ eliminated. Fa Other methods for evaluation of this type 10 * c, u/i y/i. o-l impingcr. The chemical determination is based on the reduction of T N T to triaminotoluene, and finally, a colorimetric compari son with known standards. Ammonium picrate is highly soluble in water which therefore can be used as the collection medium in an impinger when sampling for this material in industrial at mospheres. The deep color whch results upon solution of ammonium picrate in water is also evident in extremely low concentrations and for this reason a direct colorimetric com parison of the sample with known standards can be made. With this method there is a possibility of interference from dinitropheuol, the extent of which has not been determined (6 ). Carbon M onoxide This is a very toxic gas encountered in various industrial activities. The toxic limit for this gas is generally acrcptcd as 100 p.p.m. for prolonged exposure. To the pub lic in general its presence is most commonly associated with automobile exhaust and gas burning appliances utilizing manufactured gas with a high percentage of carbon monoxide. As a result of incomplete combustion it may also be present when burning natural gas or other fuels. In industrial operations in volving baking ovens, drying kilns, coke ovens, blast furnaces, etc. carbon monoxide is frequently encountered. In industrial proc esses in general, and particularly where chemical reactions are involved, carbon monoxide may be generated as a dangerous by-product. In prism grinding, which is closely allied with the defense industry, a high quality iron oxide rouge is required. Occasionally this material is manufactured on the premises as an adjunct to the prism grinding work. This involves the use of oxalic acid for production of iron oxalate which is later decomposed by heat to yield iron oxide rouge. In this process carbon monoxide as well as other gases are gen erated. Several methods have been developed for the quantitative determination of carbon monoxide, but only the two most expedient procedures employed in industrial hygiene work will be discussed here. One of these is the carbon monoxide indicator based on the catalytic reaction of hopcalile which oxidizes carbon monoxide to carbon dioxide. The small electric current produced by the 1 beat of the reaction through a thermo- ^ couple is calibrated in terms of carbon mon- * oxide concentration which is read directly I cm the dial of a milliammeter. The source y of suction in this instrument is a small ccntri- :> fugal blower, the motor of which is operated t either from a built-in 6 volt battery or from } a 110 volt lighting circuit through a trails- f. former.. Another convenient method for estimation j of carbon monoxide though less sensitive and # not so accurate is the use of palladium | chloride ampoules. In this reaction the palla- 'J dium chloride is reduced to metallic pal- | Iadiuni thereby producing a stain, the in- j tensity of which is in direct proportion to ? the amount of carbon monoxide in the atmos- 1 phere under observation. The stain produced | is compared to known color standards for | evaluation of the carbon monoxide present. J This method is not specific for carbon mon- f oxide, however; three arc other reducing gases which also will produce a stain in the j presence of palladium chloride. Incidentally, I the standard method for carbon monoxide x evaluation, adopted by the British Depart- ^ incut of Industrial Research (7 ) consists of a 3 palladium chloride test paper through which I the air to be sanmied is drawn by means 5 of a handpump. Tne stain thus produced is compared with a standard color chart. '4 5 .T. Hydrogen Sulfide | % Hydrogen sulfide is a very toxic gas with J a disagreeable odor. It is found in many in- { dustrial operations where sulfur or sulfur J compounds are used, but primarily it is cn- i countered in the artificial silk, chemical and i petroleum industries. Safe limits varying be- .j tween 20 and 50 p.p.m. by volume have been 'i suggested by various State authorities in this country. ;i The most rapid method for determination ^ of hydrogen sulfide is undoubtedly the use g of a band operated instrument consisting essentially of an aspirator bulb ami a detector & tube through which the air sample is drawn. The detector tube contains a chemical sub- '3 stance which when in contact with hydrogen '5 sulfide produces a discoloration the length i* of which is in proportion to the amount of hydrogen sulfide present and can be mcasured on an atlachrd scale. It can also be ^ determined iodometrically, either by bubbling Dust, 1'umes, through a sodium hydroxide solution an pirating with iodine, or by bubbling throug P- `.assium iodide starch solution and a mcas ured amount of standard iodine in which re action the disappearance of the color indi eates the end point (8 ). Hydrogen Cyanide This gas for which the industrial hygieir bureaus of California, Connecticut and Mass arimsetts have established a safe limit of 2( p.p.m. by volume, is found in electroplating operations, heat treating, etc. A portable instrument of the type dis cussed in connection with hydrogen sulfide has been developed for hydrogen cyanide also. 1 have been informed, however, that the hydrogen cyanide detector in its original form proved less satisfactory and that it lias been withdrawn from the market temporarily pending further research. Chemical tests are available for detection of hydrogen cyanide, such as the Prussian blue and thiocyanate reactions, both of which are specific for this gas but allegedly not sensitive enough for concentrations encoun tered in industrial hygiene work. Other methods suitable for determination of this gas in small concentrations are the Congo red-silver nitrate and the benzidine--copper acetate test papers. These methods, which have been adopted as standard tests by the British Department of Industrial Research, are non-specific, however, so that the possible interference of other gases such as IICL, lla.N, SO and H jS should be taken into consideration. I11 a method suggested by the Air Hygiene Foundation (A .H .F .) the air sample is bubbled through 0.5 per cent potassium hydroxide after which the determination is made by titrating with silver nitrate (9 ) . Sulfur Dioxide fixposurcs to sulfur dioxide gas are com mon in the petroleum industry, rubber works, and sulfuric acid manufacturing. Sulfur dioxide is also encountered in bone and glue works, magnesium foundries, and other in dustries where sulfur compounds are used. It is an extremely irritating gas for which a threshold limit of 10 p.p.m. has been sugm -led.  'J flow over the wooden floor producing the brown nitrogen dioxide gas in great volumes. The operator not being familiar with the toxicity of this gas and experiencing no im mediate physiological warning, remained on the job attempting to clean the floor by mop ping up tlic acid, instead of leaving the work place ior fresh air. A s a result a consider able portion of this gas was probably inhaled. He became seriously ill a few hours later and died within 4S hours. Cases of men be coming side while doing electric welding in side tanks or in other confined spaces are often referred to in the literature. Many of these cases are undoubtedly due to oxides of nitrogen generated in the electric arc. ical industry. It is a strong respiratory irri-j tant for which safe limits ranging between S 50 and 85 p.p.m. have been recommended f (Russian investigators 15-59 p.p.m.; State i of Massachusetts 50 p.p.m.; I'ltiry and : Zernik 85 p.p.m.). i Ammonia vapors can be evaluated directly in the field by bubbling the air sample through a measured volume of 0.1 N hydro chloric acid in water solution using phcnol- phlhalein as an indicator; the appearance of a pink color indicates the end point. From the amount of acid used and the size of the air sample, the concentration of ammonia vapors can be calculated (8 ). While there arc several methods known tor the quantitative determination of oxides of nitrogen, testing for these air contaminants is not .so simple as that for some of the others discussed in this paper. Incidentally, in view of the cumbersome procedures in volved in testing tor these gases, the amount of ventilation required for their control aitcr blasting in mining and tunnel work is some times based on the amount of carbon mon oxide present, which can readily be deter mined. W ith explosives designed for a low oxygen balance resulting in a relatively high carbon monoxide concentration and corre spondingly low volumes of oxides of nitrogen, this is a safe and expedient procedure. For actual detection of nitrogen dioxide, the method employing starch-potassium iodide test paper is probably the best known. This paper when damp is colored blue in the presence of nitrogen dioxide. The method is non-specific, however, Other, specific meth ods for evaluation of nitrogen dioxide, and sensitive at low concentrations are the GriessIlosvay and the Bismarck Brown tests. With both methods, the air sample is bubbled through chemical solutions. after which the quantitative determinations are made in the laboratory by colorimetric analysis. Although physiological safe limits up to 40 p.p.m. have been proposed for these gases, atmos pheres which by odor or color indicate the presence of nitrous fumes should always be viewed with suspicion. Ammonia As stated elsewhere, ammonia is an im portant raw material throughout the chem Sulfuric acid can also be used with above method. In another method, recommended by the A .P.H .A ., the air sample is collected in sulfuric acid, but the final evaluation is made in the laboratory by standard analytical means. Lead Exposure to this metal occurs very exten sively in nearly all types of manufacturing. The most frequently encountered forms of lead are fumes, dust 3iid dispersed pigments.' These occur amurgj lead melting operations, soldering, welding of metals covered with lead-bearing paints, and in spray painting work. I Sampling of lead-contaminated atmos- 1 pheres is usually done either by means of ! the impinger or by the electrostatic predpita- ' tor. When the impiiiger is used, as is fre- | fluently the ease when investigating spray painting and many other types of work in- \ volving lead dispersion, the sampling liquid '{ may he either distilled water or dilute nitric ^ acid. | Regardless of the collection method used, \ the final evaluation of the amount of lead \ present is done in the laboratory by various | analytical methods, the description of which J is beyond the scope of this paper. It prob- t ably should he emphasized, however, that al- *| though some of these methods arc highly sensitive and the experienced analysts usual- * ly well-trained to handle minute quantities of lead in their work, it is preferable to take a large air samples wherever possible to facil- j itate the laboratory work. With the large j impiiiger and the electro-static precipitator J L J I< J > . i 1 with sampling rates of 1 and 3 cubic feet of air per minute respectively, this is not a problem. With the midget impinger, on the other hand, with a sampling rate of only 0.1 cubic fool per minute, this becomes a tiresome task, especially if the handcrankcd instru ment is used. Let us take, for example, a case in which the atmospheric lead dispersion is just about on (he border line of the safe limit, i. c. 1.5 mg. per 10 cubic meters of air. For a 30 .minute sample with the midget impiiiger, only 3 cubic feet of air have been handled. This represents only 0.013 mg. of lead in the air sample, which evidently re quires a fairly sensitive analytical method and careful handling for a successful com- pleiion of the test. Cadmium The United States Public Health Service ( L'.S.P.II.S.) (10) suggests as a safe limit with respect to toxicity of cadmium fumes a concentration of 1 mg. per 10 cubic meters of air. The metal is used extensively as a coat ing of iron and steel for rust prevention, as well as in structural steel to impart certain properties. Exposures to cadmium and cad mium fumes may, therefore, be encountered in such operations as electroplating, weld ing of cadmium-bearing iron and steel as well as many other processes where work in volves cadmium-plated articles. Some of you are probably familiar with the cases of cad mium intoxication in a plant in Ontario, Canada, a few years ago, when 14 persons were poisoned--two fatally--during anneal ing of cadmium plated rivets (17). As in the case of lead, sampling for cad mium fumes or dust may be done either w ill the impiiiger (with water as collcctior medium--A .P .H .A .) or by the clectrostatii precipitator and the samples evaluated in tin laboratory by gravimetric or colorimctrii analytical methods. At this point it probably should be brough out that for sampling of metal fumes, tin impinger lias a lower collecting cflicicnc; than the electrostatic precipitator, wliicl should he taken into consideration whci comparing results obtained on samples col lii-tcd with the two instruments (18). subject to other light intercepting media such as smoke and fog. tible gas indicator is far more expedient Most of these devices, used primarily for fire There are also other methods for determin prevention work, arc designed to read to ations of mercury, entailing condensation of within 1 9r>of the lower explosive limit oi the the vapors and subsequent electrolytic deposi gas or vapor under test. For above sub tion of the metal, chemical reaction methods, stances with lower explosive limits around etc. The first two mentioned above, however, 1% by volume, this means that concentrations are the most expedient and yield immediate down to 1(10 p.p.m. can he detected, which is results during the field investigations. approximately the accepted toxic limit for these solvents. For benzene with a safe limit Benzene (Benzol), Toluene and Xylene of 75 p.p.m. (19) a modified comhustihle gas indicator has been placed on the market, These three aromatic hydrocarbons are which measures concentrations ranging be widely used as industrial solvents and ingredi tween 0 and 1000 p.p.m. A spectroscopic ents in a number of chemical reactions. Tolu method for determination of benzene and ene. for example, is an important raw mate .toluene in air has been described bv Cole ria! in our ammunition manufacturing, espe ( 20). cially in the production of trinitrotoluene. With the increased demand for toluene and Chlorinated Hydrocarbons the corresponding scarcity of this material, benzene is rapidly taking its place as a sol vent in many industries. Xylene, which besides being an important solvent, also does enter as a raw material in certain chemical processes, at present associated with the defense industry and therefore used in great quantities. For instance, in a plant I visited recently xylene is used in the production of a certain type of resin, which in turn is employed in an article Of these, trichloroethylene and carbon tetrachloride are probably most frequently found. They arc used extensively as metal cleaning agents', the funner in regular de greasing machines on a production basis and the latter for work of a move occasional nature. These materials with their grease dissolving properties arc regarded by medical authorities as very injurious to the fatty tis sues of the human body. : manufactured for the United States Army. As in the case of other substances referred All these three materials are classified as to above, therefe are chemical methods for industrial poisons, although there appears to quantitative determination of vapors from he some confusion as to the relative toxicity these materials, but they are mostly too cum of each. Benzene is generally considered as bersome for routine sampling. Optical instru the worst offender, although this may' not be ments are available, however, for rapid evalu due to a greater toxicity of the material per ation of such vapors dispersed in the air. The se hut to the fact that it has a higher vapor best known of these is probably the portable pressure than the other two so that for a interferometer in which the difference be given temperature more of it will be found tween the refraction of air (the comparison in the air. However that may be,' the toxic substance) and that of the gas mixture to be j effect of all of them, once dispersed in the examined is measured. This difference is : air, is generally recognized and therefore in calibrated in terms of concentration of the dthiceayteasrcthuesedn.eed lor strict control wherever gas or gases under observation. Naturally the same readings will he obtained for all gas ; For the evaluation of these materials sonic mixtures resulting in the same refractive in- -j chemical as well as physical methods are dex, so the instrument is therefore not spe- j available. Most of these, however, arc com citic. With information, however, as to the plicated and cumbersome, involving such type of air contaminant concerned in a par operations as nitration by bubbling the air ticular problem it is an exceedingly useful through nitric acid with subsequent colorimet instrument applicable to the investigation of a ric determination, or condensation of the great variety of gases and vapors. vapors followed up by laboratory analytical procedures for the final evaluation. While Carbon Disulfide methods of this type may he satisfactory for scientific purposes, for routine sampling in control work in industrial plants, a combus This substance which at ordinary tempera- tures occurs as a liquid with a high vapor pressure, generates toxic vapors for which j' Dust, Dun relatively low safe limits have been sug; lw various authorities. Russian invcstii have recommended a threshold limit o .f p.p.m. for prolonged exposures, whi British Department of Scientific and 1 uial Research has suggested a value p.p.m. and our own State of Massacln 11 p.p.m. While there is a wide diver between these values, they all tend to in the potential dangers connected witl postires tu vapors of carbon disulfide. Although this solvent may he encom m a great many industrial operations, found primarily in the viscose--and r industries where it constitutes an impc raw material. For evaluation of these vapors, the Hygiene Foundation recommends dr:, the air through an alcoholic potassinn ill oxide solution to form potassium ethyl llialc which is determined iodumetrically. British Department of Scientific and I trial Research uses a colorimetric nr consisting of bubbling the air througl rthyl.aminc and copper acetate forming : nred compound the intensity of which is pared with standards. In view of the in inability of these vapors, a rapid metlic their evaluation in high concentrations v he by means of a combustible gas indie Unfortunately, however, the sensitivitii these instruments as built at present, an low enough to get within the physiolo safety range of this material. Acids In this group probably nitric, chr< hydrofluoric, hydrochloric and sulfuric ; are those most commonly encountered, these, nitric acid lias been discussed unde other heading. Exposures to chromic resulting in chrome ulcers and the perfot nasal septum are frequently found ar chi Minium plating tanks. A safe limit mg. per 10 cubic meters of air has been e lislird for chromic acid which in clectropl; work occurs as a mist over the plating b Ilyilmfluoric and hydrochloric acids alsc ist in gaseous form as hydrogen fluoride hydrogen chloride respectively. A safe of 5 p.p.m. has been suggested for the for while it has been set at 10 p.p.m. for latter. Sampling for nitric, chromic, and sul acids is usually done by bubbling throu, sodium hydroxide solution; hydrofluoric 06 31st National Safety Congress Contaminants, pp. 80-85, 1935-1936 Year Book, American Public Health-Association. 11. Fiddlier c.t al. Jo. Industrial & Engi neering Chemistry 11:519, 1919. 12. Evans, R, D. Apparatus for the Deter mination of Minute Quantities of Radium, Radon and Tlioron in Solids, Liquids and Gases. Review of Scientific Instruments, 5:99 --112 (1935). 13. Brown, S. C .; Elliott, L. G .; and Evans, R. D. Detection of Radon by Means of A Proportional Counter. Review of Scien tific Instruments 13: 147-- 151 (1942). 14. Evans, R. D. and Goodman, C. De termination of The Tlioron Content of Air and Its Bearing on Lung-Cancer Hazards in Industry. Jo. of Industrial Hygiene & Toxicology, 22, 3, pp. 89-99 March, 1940. 15. E\ans, K. D .; Nilsou, S. J.; Good man, C .; and Bernz, N. R. Industrial Ap plication of a Method for Determining the Tlioron Content of Air. Proceedings of the M ill International Congress on Occupational Diseases and Preventive Medicine, held at Frankfurt a. M. Germain-, September 26-30, , 1938. 16. United States Public Health Service, Division of Industrial Hygiene, National Institute of Health, Washington, D. C. Cad mium Poisoning. Public Health Reports 57, 17 April 24, 1942. - 17. Buhner, F. M. R.; Rothwcll, FI. E .; , and Frankish, E. R. Industrial Cadmium Poisoning. A report of fifteen cases, includ ing two deaths. Canadian Public Health Jo. 1938, V.29, 19-26. ; 18. Littlefield, J. B .; Fcicht, Florence, L. j and Sclirenk, II. II. Efficiency of Impingcrs for Collecting Lead Dusts and Fumes. R.I. ' 3401, U. S. Bureau of Mines, May, 1938. i 19. American Standard Association. Ben- ' zenc, allowable concentration. Z 37.4, 1941. ' 20. Cole, Peter A. Determination of the i Concentration of Benzene and Toluene in J Air by a Spectroscopic Method, lo. Optical -) Soc. Am. 32, 304-306, May, 1942. Selection, Use and Maintenance of. Respiratory Protective Devices* ^ Associate By H. H. SCHRENK Chief Chemist, Health D ivision, Bureau o f M ines and S. J. P E A R C E Chemist, Gas and D ust Section, Central Experim ent Bureau of Mines, Pittsburgh, Pa. Station, p u b lish e d l>v permission of the D irector, B ureau of M ines, U. S. D epartm ent of the Interior, Wash* inglon, D. C. ure or improper use of other control equip- A ment. 4? II. H. Schrenk, chief chemist, Health D i vision, Bureau of Mines and S. J. Pearce, associate chemist, Gas and Dust Section, Central Experiment Station, Bureau of Mines, Pittsburgh, Pa. There are several well-recognized pro cedures for controlling exposure to hazard ous atmospheres in industry. They include (a) substitution of less toxic material, (b) enclosure of processes, (c ) wet methods, (cl) local exhaust, (e ) general ventilation, and (f ) use of respiratory protective de vices. In addition to their employment as a control measure in occupational exposures, respit atory protective devices also are essen tia! in emergencies that may arise from fail Respiratory protective devices usually are rj employed to supplement other methods of control, as a temporary expedient, or when other methods are not readily applicable or fc practicable. It seems reasonable to assume, however, that where respirators arc used, consideration has been given to the factors t- involvcd, and that the devices can provide satisfactory protection if used properly. Their use should not be. arrived at simply by a ' process of elimination of other methods that ' arc more difficult to apply. Atmospheric contaminants include gases, vapors, dusts, fumes, mists, and fogs. Res- : piratory protection against these contamin ants may be required for concentrations that ; are immediately dangerous to health or life Dust, l'Ull after comparatively short exposures, o: may produce injury only after prolong repeated exposures. Also, it may he neci In use such devices against a single of contaminant, against a comhinatii various types, or in atmospheres defici' oxygen. To meet the conditions mentioned, v: types of respirators have been dove Two basic principles have been utiliz their development--purification of tb baled air by removal of the contaminant purifying respirators) and supplying a r able atmosphere to the wearer from a contaminated source (atmosphere--a: oxygen-supplying respirators). Air-Purifying Respirators Air-purifying respirators include ca gas masks and chemical cartridge respi ior removing gaseous contaminants an elianical-filter respirators for removing lieulate matter or dispersoids. Carlisle masks and chemical cartridge respirator he equipped with filters for removini persoids, thereby giving protection a both gaseous and particulate contami As these devices provide protection oi removing contaminants, it is obviou? sufficient oxygen must be present i atmosphere to support life. A canister gas mask usually consist full facepiece connected by a flexible b ins tube to a canister that may be c in a harness on the chest, under the o r on the back. The canister contaii materials for removing the contaminan purifying the air. These materials r Canister, type letter Contaminants proetei A B C D A E, etc. Acid gases ........................... Organic vapors .................. Ammonia ........................... Carbon monoxide .............. Dusts, fumes, mists, fogs, a nation with any of the al AB ABC N Acid gases and organic va Acid gases, organic vapor? All of the above atmosphei Canisters for a single gas or vapor o colored stripe around the c an iste r near the bi . . .xi.iyiiut \^uiiytcss Canister lias masks have been developed primarily for protection against atniospbcres immediately dangerous to life and are used mainly in emergencies. Therefore, first con sideration has been given to complete respira tory protection to prevent even momentary failure that might result fatally. These masks, however, are not designed for pro tection against extremely high concentra tions, and in Bureau of Mines Approval Schedule ME concentrations are limited to two per cent by volume, with the exception of ammonia, for which the limit is three per cent. The service life of the canister depends on the individual characteristics and the amount of absorptive material used. A l though these masks are designed primarily for emergency use, they will, of course, give good protection for non-emergency situa tions, and filters may be incorporated to remove particulate matter. Chemical cartridge respirators usually con sist of a small cartridge or canister attached directly to a half-mask facepiece. The mate rials for removing the contaminants arc the same or similar to those used in canister gas masks, and filters may be incorporated to remove particulate matter. These devices may be considered small gas masks and are designed for protection in atmospheres that could he breathed by workmen without pro tection, hut that might be irritating or dis agreeable or produce injury to health after prolonged or repeated daily exposures; hence, primary consideration has been given to light ness, compactness, and comfort. -Mcchanical-filler respirators usually con sist of a filter arrangement of some fibrous material such as felt or paper, in a holder connected directly to a half-mask facepiece. The filter consists of fine fibers criss-crossed to form a maze or intricate network of tortuous passages. The dust, fume, mist, and fog are removed by physical trapping when the air is drawn through this material. The filtering efficiency increases as the dust load oil the filler increases. The service life of the filter, therefore, does not depend on recogniz able leakage, as does that of the gas masks, but on increase in resistance of the filter to a point where resistance to inhalation be comes excessive or uncomfortable. Although the filters will remove ail types of particulate matter, the extent to which the material is removed depends on the characteristics of the particles, such as size and slate. Also. the amount of permissible leakage depends on the toxicological significance of the mate rial. Therefore, various types of filters are used; that is, a filter may be satisfactory for silica dust ami not satisfactory for a toxic dust such as lead or cadmium, owing to tlie greater toxicity of the latter. A filter that is satisfactory for dust (mechanically generated, as by grinding) may not be satis factory for fume produced by heating or burning, as in lead burning, owing to par ticle-size differences. On the oilier hand, a filler satisfactory for silica dust is considered satisfactory for all other fibrosis-producing dusts and nuisance dusts; and a filter con sidered satisfactory for lead dust is con sidered satisfactory for oilier toxic dusts, tile toxicity of which docs not exceed signif % icantly that of lead. -V, Mechanical-filter respirators have been de signed for protection against atmospheres 3* that arc not immediately harmful; there fore, primary consideration has been given to lightness, compactness, and comfort. Atmosphere-Supplying Respirators Respiratory protective equipment that sup plies a respirable atmosphere from a source independent of the wearer's immediate atmos pheric environment) is of two basic types--a hose type, in which air from an uncontaminated source is conveyed to the wearer through a hose or tube, and a self-contained type, in which a supply of oxygen is carried by the wearer. The air-supplying respirators commercially available may be divided into three types: Hose masks, air-line respirators, and abra *r> sive blasting helmets, hoods, or masks. Hose masks consist of a tight-fitting, full facepiece, breathing tube or tubes, a harness, a comparatively large-diameter, noncoilap- sililc hose line, and a hand-operated blower. The harness and hose are strong enough for retrieving the wearer in an emergency, and i'A the hose must not collapse under heavy weight and must not kink. The maximum I length of hose approved by the Bureau of Mines is 150 feet. The use of a hand-oper ated blower assures that a second person $ will be present in the event of difficulty. Also, the attachment of the hose to the f blower and the large diameter of the hose permit breathing without undue resistance, even though the blower is not operated. The S- Dust, Fume intake to the blower must be in un< laminated air. Iiusc masks arc sturdily constructed, they are designed to lie worn in atmospln immediately dangerous to life and to aff protection against all types of atmosplr rontaniinants and atmospheres deficient oxygen. Special-type hose masks without bioand generally used with about 25 feet liose also are available. Although the hi breathing lubes, and facepieces arc essenti; die same as those for hose masks witl blower, the harness is much lighter and device is designed for lightness, compactTM economy, and simplicity of operation. S' masks arc designed for non-emergency o r for use in atmospheres not irmnediat dangerous to life. Air-line respirators usually consist ol high-pressure air-supply system, a hose n latively small internal diameter, a deta able coupling, and either a full or h; mask facepiece, or even a helmet or a ho As the air for this type of respirator usua is supplied from a high-pressure compress air system, it must be checked to see t it does not contain objectionable or bar ini contaminants. Dust from dust, oil mi odors, and even carbon monoxide may present if the compressor becomes too h therefore, critical attention should be gi' to the air supplied to these devices. Although this respirator will give respi lory protection against all types of conta inants, it is designed for routine protect against concentrations of contaminants t are not immediately dangerous to life health. It is thus limited, owing to the p ability of leakage around the half-ni; facepiece and also to the fact that no p \isioii is made so that the wearer can brea ivspirahle air, should the air supply fail. Abrasive blasting respirators are essenti ly air-supplying respirators that have bi modified by the addition of a suitable cov ing tn protect the head and shoulders agai impact and abrasion by rebounding mater They are designed primarily for use in ab sivc blasting operations and not for use atmospheres that arc immediately dangcri to life. The most common devices for supply xygen to the wearer are self-contaii 70 31st National Safety Congress 1 e. the nature of the duties to be per with blowers and gas masks. Owing to i formed by the wearer of protective devices their weight and maintenance and training ns they relate particularly to restriction of requirements, oxygen breathing apparatus movements probably would not be used. The hose mask f. an understanding of the principles, de would be satisfactory and might be chosen asingdn, disscaodpveanotaf geusseo, f litmheitarteisopnisr,atoardyvapnrtaogteecs, tifoothgereenatc.umTbhreanmceosotf ptrhoebhabolsee lcihnoeicweerweounlodt A tive equipment available. be a gas mask, because of its light weight, case of maintenance, and the small amount of Virtually all applications of respiratory training required by the wearer. The appro prolcithc devices arc specific and require priate canister should, of course, be chosen. individual attention. Examples of typical conditions with indication of choice of appro priate respiratory protection are given. Eow concentrations are atmospheres that can be breathed without protection but that will produce discomfort and possible chronic Atmospheres deficient in oxygen may be injury after repeated exposure to them. Hose extremely hazardous and immediately dan masks and oxygen breathing apparatus would i gerous to life. Only oxygen breathing appar atus or a hose mask with blower should be chosen for protection under such conditions. give satisfactory protection, but they would be given little consideration for such a situa tion for the reasons already outlined. Gas Final choice between these two devices will masks, chemical cartridge respirators, or air depend on working conditions. line respirators would be satisfactory. Final For example, for rescue work in mines, the men must proceed for considerable dis choice would depend on actual conditions and freedom of movement required by (lie worker. tances from a source of fresh air. Obviously, For pneumoconiosis-producing and nuisance hose masks would not be satisfactory, as dust, air-line respirators and pneumoconiosis? wearers are limited to a distance of 150 feet; producing- and nuisance-dust respirators or therefore, oxygen breathing apparatus must all-dust respirators could be chosen. If the & be used. However, for use in entering con dust concentration is exceedingly high, air fined spaces, such as tanks and manholes, line respirators wfeuild be preferable. If the hose masks are generally preferred because conditions of work are such as to interfere they arc easier to maintain and relatively with the use of an air-line, mechanical-filter little training is required to use them. Air- respirators will serve satisfactorily, even purifving devices should never be worn in though they are awkward to wear for many atmospheres deficient in oxygen. kinds of work. By very high concentrations is meant those exceeding two or three per cent. Either oxygen breathing apparatus or hose masks with blowers are the logical choice, and again final selection will depend on working conditions. Although gas masks might afford some protection, they would not be a good choice, because very high concentrations in dicate a confined space with possibility of low oxygen; moreover, the absorbents would be used up rapidly. The marked discomfort produced by such irritating gases as am monia and sulfur dioxide and the danger of poisoning through the skin by absorption of hydrogen cyanide limit the concentrations that can be entered. Concentrations referred to here arc those not exceeding approximately two per cent but nevertheless immediately dangerous to life. Oxygen breathing apparatus would, of course, be applicable, as would hose masks For toxic dust, air-line respirators, toxicdust respirators, or all-dust respirators would be a logical choice. The final decision will de pend on local conditions of work and the ma terials being used. Knowledge of the concen trations likely to be encountered and of the safe or permissible concentration is necessary in evaluating the protection afforded. Fume is particulate matter formed by volatilization and condensation, as in lead burning. Fume is defined because it is a term used loosely to refer to gases, vapors, and particulate matter. Such usage is confusing and may lead to serious injury if a mechan ical-filter fume respirator is used for pro tection against some toxic gas or vapor against which it affords no protection. For fume as defined above, air-line respirators or mechanical-filler fume respirators would Ik- the logical choice, and final decision would depend on local working conditions. Dust, Fur Frequently protection must be af against a combination of gases and part matter (dust, fume, mist, and fog), atmosphere is not immediately danger life, air-linc respirators are gcncrall; ommended. However, gas masks cq with a suitable filter or cartridge-type rators equipped with a suitable filter n used. Final decision not only would < on the local conditions of work as relate to freedom of movement but a! thorough consideration to ascertain w gas masks or cartridge respirators give the desired protection. U se of Respirators Although choice of a suitable respir; important, other considerations are c so. Obviously, if a respirator is to do tl for which it is chosen, it must be properly and be kept in good condition qnontly persons do not know flow to a respirator, and if it is not clean it pleasant to wear. Better protection and cooperation doubtless would he ol) if the respiratory protective devices kept under the supervision of a respc person who would see to it that the \ is properly instructed in the use of the < that the device is cleaned and disir regularly, and that it is maintained in class condition. Xo instructions are necessary when bats or bard-toed shoes arc given to men, as they are used to wearing sm tides. Too frequently respirators are h out in a similar manner. Even the si: respirator is comparatively much more plicated than protective bats or shoes a device that most workers are not tomed to wearing. The principles on each device is based, its field of use, a limitations, as well as the essential should he explained to the wearer in lie can understand. Detailed instruction practice should he given to all person arc expected to wear such devices. Ft an explanation of the importance'of w the respirator should be helpful in obi more complete cooperation. For example, in the use of niccht filter respirators attention should be to the importance of a good facepii and pi "per but comfortable adjustment headband, and also to the fact that inc ,a*.J 72 31st National Safety Congress skin should be rinsed thoroughly with water, made, it should be stored properly. as some persons are highly sensitive to such materials. A good procedure is to have a central place of storage, possibly with sub-stations Cleaning and disinfecting afford an oppor at strategic points it the plant is large. Stor tunity for cleaning or replacing fillers, in age should he in essentially dustproof con specting valves, headbands, facepieces, and tainers away from sunlight and in a cool metal parts that might be distorted. place (not near radiators or steam pipes). Small devices, such as dust or chemical Maintenance and Storage cartridge respirators, can be kept in paper or cellophane bags. These devices may be A most important phase of any control numbered and assigned to some one person, procedure is maintenance. Choice of proper who returns them at the end of the shift equipment, and adequate instruction are com to the central station for cleaning and re pleted projects, but maintenance is a con placement of filter elements, and for repairs tinuous problem requiring constant atten if necessary. Thus, wearers are assured clean Pr tion. As such it should be supervised by devices in good working order for each day's someone thoroughly familiar with the appar use. This program may be facilitated by as atus being used. signing two respirators to each person, one being used while the other is being serviced. Washing and disinfecting the device af fords an opportunity to inspect it for minor Larger devices, such as gas masks and repairs. In addition, it should be inspected hose masks, usually come equipped with a thoroughly at monthly or longer intervals, sturdy- case or trunk that can serve as a depending on the apparatus, conditions of storage place. If they are stored at strategic use, and storage. Devices for emergency pur points for emergency use, they might be mi i r poses should be inspected after each use to placed in a case with a glass window that cal assure that they will he in good Condition requires breaking of a seal to assure that of and immediately available ii an emergency they have not been used or tampered with. rcc arises. After the equipment has been cleaned The seal should hear the date of the last wh and inspected and any necessary- repairs inspection. tio goi of e r< i ant tor opt Av off get Hi fey qRinz'ation represented -tly bigger today, five enty times bigger tlian ;co. The safety super..ot that many problems at many problems again, Itiply in greater proporpersonnel involved. tanning Job crvisors in general take :is point: that the bigger ts to be, the less their e, which is perfectly all -rganization. and vastly mng, training, coordinat or people who in turn cs to all levels of superioesn't it? And yet how .ily changed our thinking not only safety men but in a position of where ,:ing miracles every day, regular standards, and be balked by the little has hit a point here-- miraculous operation yet it little key spot there, granted. , take away the thought re, through all this dis- me, put it together, can 'aiming, of thinking, of little things in principle :u. if we cannot get away :hat so many personnel other people concerned i.'pects of industry arc inually, and that is of to beg for the little . big things that must be that we become enough se little details, which have not thought to go plan a program such as s talked about here in is Miss Norton has gone : h links the problem once '.ling the idea to manage.ces you a policy and a Steam Railroad Section Officers 1941-1942 General Chairman--O. E. Gnadinger, Elgin, Joliet St Eastern Railway Co., Joliet, 111. Vice-Chairman-- F. A. B ogue, Chicago, Rock Island & Pacific Railway Co., Chicago, 111. SVcrcfary and Netos Letter Editor--H . A. D aake, E rie Railroad Co., Cleveland, Ohio. Program Committee--F. A. Bogue, (Chairman), Chicago, Rock Island & Pacific Railway Co., Chicago, III. P. F. B uckle, Chicago, Burlington & Quincy Railroad Co., Chicago, III. G. W . E lste, J r., Baltimore & Ohio Railroad Co., Baltimore, Md. Membership Committee--R obert S cott (Chairman), Atlantic Coast Line Railroad Co., Wilmington, N . C. A. V. R oiiwedkr, Duluth, Missabc & Iron Range Railway Co., Duluth, Minn. Statistics Committee--T. H . Carrow ^Chairman), The Pennsylvania Railroad, Philadelphia, Pa, E. R. B radford, Boston & Maine Railroad, Boston, Mass. D. G. P hillips, Wabash Railway Co., St. Louis, Mo. Contest Committee-- C. E. H ill (Chairman), New York Central System, New York, L. C. B entley, The Chesapeake it Ohio Railway Co., Richmond, Va. L . R . P a l m e r (Sccrctar\), Equitable Life Assurance Society of .the U . S ., New N. Y. J. J. S navely, New York, New Haven & Hartford Railroad Co., New Haven, N. Y. York, Conn. Poster Committee-- W. R. I.ofgren (Chairman), Chicago, St. Paul, Minneapolis & Omaha Railway Co., St. Paul, Minn. C. M. D empsey, Chicago, Milwaukee, St. Paul & Pacific Railroad Co., Chicago, 111. 0 . A shwortii, The Alton Railroad Co., Bloomington, 111. Safe Practices Pamphlet Committee--W. J. F lannigan (Chairman), Northern Pacific Rail way Co., St. Paul, Minn. J. R. T enney, Western Maryland Railroad Co., Hagerstown, Md. R. C. H klwic, The Delaware & Hudson Corp., Oneonta, N. Y. . \ Nominations and Elections Committee--E. L. H enry (Chairman), Chicago St North I Western Railway Co., Chicago, 111. ; M. T. F ulton, Kansas City Southern Railway Co., Kansas City, Mo. j M. A. Lf.aiiy, Chicago, W est Pullman & Southern Railroad Co., Chicago, 111. ! Health Committee--D r. I. S. C utter (Chairman), Chicago St North Western Railway Co., i Chicago, III. i D r. H arvey B arti.f., The Pennsylvania Railroad, Philadelphia, Pa. ! .663 M _ 5:SV. iS iii k 664 31st National Safely Congress Officers 1942-1943f General Chair man-- F. A. B ogue, Chicago, Rock Island & Pacific Railway Co., Chicago, 111. I 'iccChairman--H. A. D aake, Erie Railroad Co., Cleveland, Ohio. Secretary--M. T. 1'ulton, Kansas City Southern Railway Co., Kansas City, Mo. A'civs Letter Editors--M. T. F ulton, Kansas City Southern Railway Co., Kansas City, Mb, II. G. T ownsend, Kansas City Southern Railway Co., Kansas City, Mo. Program Committee--J. R. T enney (Chairman), Western Maryland Railway Co., Hagers town, Md. P. F. B uckle, Chicago, Burlington & Quincy Railroad Co., Chicago, 111. H. A. D aake, Erie Railroad Co., Cleveland, Ohio. Membership Committee-- G. W . E i.ste, J r. (Chairman), Baltimore & Ohio Railroad Co., Baltimore, Md. J. E. Lonc, The Delaware & Hudson Railroad Corp., Albany, N. Y. Statistics Committee--T. H . C arrow (Chairman), The Pennsylvania Railroad, Philadelphia, Pa. F. R. B radford, Boston & Maine Railroad, Boston, Mass. D. G. Pim .i.ii's, Wabash Railway Co., St. Louis, Mo. j Contest Committee-- C. L. L a F ountaine, (Chairman), Great Northern Railway Co,, St. Paul, Minn. I O. F. Gnaiunger, Elgin, Joliet & Eastern Railway Co., Joliet, III. L. R. P almer (S e c r e ta r y ), Equitable Life Assurance Society of the U. S., New York, N. Y. Luster Committee-- E. L. I I enky (Chairman), Chicago & North Western Railway Co., Chicago, 111. G. M. D emtsey, Chicago, Milwaukee St. Paul & Pacific Railroad Co., Chicago, III. J. J. S navei.y, New York, New Haven & Hartford Railway Co., New Haven, Conn. Safe Practices Pamphlet Committee--W. J. Flan m o a n (Chairman), Northern Railway Co., St. Paul, Minn. S. C. F lagler, Atchison, Topeka & Santa Fc Railway Co., Topeka, Kansas. H. C. H elwig, The Delaware & Hudson Railroad Corp., Oneonta, N. Y. Pacific Summations and Elections Committee--AY. R. L ofc.ren (Chairman), Chicago S: North Western Railway Co., St. Paul, Minn. C. M. K imuall, Southern Railway System, Washington, D. C. L. B. H arper, Illinois Central System, Chicago, 111. Health Committee-- D r. I. S. C utter (Chairman), Chicago & North Western Railway Co., Chicago, 111. D r. H arvey B arite, The Pennsylvania Railroad, Philadelphia, Pa. * \j> i l t c t f d liy di'U'jiDtcs C n n g r e s s session. Steam 1 TUESDAY AF Octo Presiding:--0 . F. G nauinger, Supvr. o Joliet, 111. Greetings From By P. Supt. of Safety, Chicago, Burli It is, of course, an honor and a privi! to be able to bring to this meeting greet! from the Safety Section of the Associatioi American Railroads. There never has been a time when it so important that those of us .who arc gaged in accident prevention endeavor consolidate our positions, to do everyth within our power to promote harmoni relations between all safety agencies in interest of producing the maximum of cc crativc effort in this most worthwhile activities. Whatever may have taken place in the i that brought about disunity or lack of I mony between these two important agen should now he forgotten, and it should be duty of each and everyone of us to m these two organizations as effective as j siblc, above everything else, in the inte of winning this war, never forgetting humanitarian aspect of our responsibilii W e can only bring these things to pass subordinating our personal prejudices or sires for the common good. I hope I s always be able to do this and I need help of every one of my associates in bri ing this to pass. Whatever accomplish has come to the Safety Section during >-s- -: r- -w-r - -4 fe' ^toJ - Hi- attempted to govern solely i 60 days every one of his em- vorking at cross purposes-- out because no matter what s not satisfied. It was necese him of the headship of his i '-r to accomplish- the assigned delaying the work of other !lesirous of saving him for imi-c was made an assistant to a 'y old chief. His shortcomings d to him and he was smart 'll by his mistakes. Today he is dly. He has learned to know 'c of production. >. are justified in taking on is, if arrangements can be made re-examinations. In addition, ::y corrective procedures that -ted that will render one thor>ed to take a job for which would be rejected. Infections i cavity may be eliminated, and uarded with proper spectacles, t is no indication for nonlertheless the adjustment of ir to a badly depressed longuarsal arch may be followed qirovemcnt in general health, in for work instead of the ise abscessed tonsils may be . pre-employment hernia may we have what is known as the soldier. It would be a not- industry if we could revive interest in the school of the cry supervisor could be in.oportant physical deficiencies . a position to help preserve men. There are a few simple i ll his employees would take than any one else. Further-iild heed. He can emphasize ,;ty of excess weight, the iru- feet, of proper clothing, of :s food, of prompt attention me carefully controlled use of nnnot gainsay the fact that ment predisposes to accidents, used to excess. itary organizations grade from :e to the highest ranking gen- there are a number of corn ice at the same time teachers Steam Railroad Section 673 and leaders. In fact, it is a well recognized concept that the sergeants, from buck to mas ter, run the army. In like fashion, the fore men run the industry. They know their men. But they can become mentors not only in technical procedures but in all the factors which make for well being. They can learn and pass on simple first aid regulations which are safe as well as numerous precautions which will reduce hazards. A few hours of in struction to the members of this group (foremen) will be fertile seed sown upon rich soil. The output of many a plant can be gauged by the active integration of the organization coupled with the good health of the em ployees. But every task docs not require a Hercules. In fact, there arc many jobs that can be performed with dispatch by a man with one leg, one eye, etc. It becomes then the task of fitting the qualities, attributes, and skills ot the applicant to the duties to he accomplished. It is well known that handi capped men and women are among our most loyal, faithful, and conscientious workers. WEDNESDAY AFTERNOON SESSION October 2S, 1942 Presiding:--O. F. G nadinger, Supvr. of Safety, Elgin, Joliet and Eastern Railway Co., Joliet, 111. tr Safety and Labor Relations By H. J. H O G L U N D Chicago, Burlington & Quincy Railroad, Chicago Labor relationship has much to do with the attitude of mind of the worker, and upon this attitude of mind hinges the thinking before acting which is so fundamental to safety. Because of lack of control of action, be cause of thoughtlessness or because of mental laziness, needless accidents occur, and pre vention constitutes a real problem to perfect the attitude of mind. Good housekeeping, keeping tools and ma chinery in order eliminates much exposure to hazard, and its importance cannot be over emphasized, but despite these precautions ac cidents occur unless there is good labor re lationship. For years safety officers have been preach ing safety, and the results speak for them selves ; they are reflected in the record of the American railroads. You started way back in the early 20's talking about the three E's of safety--cardinal principles of great im- portance--yet consciously or otherwise, you added a fourth E which stands for the en thusiasm you have steadfastly maintained. Safety is the work of morale builders and morale cannot be built without the Nth de gree of enthusiasm. Our supervisors should keep this in mind. Primarily the supervisor is responsible for the saicty of his workers, and he should devote a great deal of effort to the art of handling or leading men. Generally speaking, this skill can he acquired only through lead ership training. The worker's attitude toward his job, his company, bis fellow workers and toward his supervisor is, to a greater extent than some realize, the essence of good labor relations. Everything possible should be done to avoid irritating workers. Irrespective of all other conditions surrounding a man's job, if be lias an irritating type of supervisor, he will not perform his work cheerfully, and he is not, under such conditions, likely to be as i i i m i.: ; I V ( <* production schedules in ucd delivery. Existing listed at 9 :2S A . M. . . . : parts will begin to be 1ight so they will arrive 0:15 A. M. N o loss oi no lapse oi time that the bullets out of Allied H laid plans, but, then a .uiders aimlessly through The fast freight loaded rials bears down on him, \rhaps that train is deIjecausc of that accident. : to be arranged to give 1 ?n light that will once the rails at lull speed, its destination at 11:08 two hours late, and the eded parts arrive at the 25 A . M., which is alhours of war production re 8,000 persons in that .- material to start down . That's a total of more man-hours lost because wandered into the path Sounds a little fantastic, right agent or someone rut of a railroad com be surprised to learn this ill too often. But, then if this nature would be lice officers of the railling because they come h the trespass problem, d 1,781,398 trespassers ad property, some oi cords. Railroad officers een of great assistance . persons who have no e railroad and will convely. Steam Railroad Section 677 THURSDAY AFTERNOON SESSION October 29, 1942 Presiding:--0 . F. Gnapinokh, Supervisor of Safety, Elgin, Joliet & Eastern Railway Co., Joliet, 111. Notes By W . R. LOFGREN A ss't. Supt. of Safety, Chicago & N orth W estern System , St. Paul, Minn. A highlight of the entire program was time and meets. Messrs. Hellweg (D & H ), that portion conducted by the inquisitive Mr. Phillips (Wabash) and Lofgren (CStPM NWo.rtJh.erFnlarP.naicgiafinc, RSuapilewrainyt,enwdehnot doefsiSreadfettyo, cStO) responded to questions. m know so many things. This type of program is outstanding aud reminds us very much of Train Accidents the lively "rump" sessions oi 1939 at A t The inquisitor called attention to the in lantic City and last year at Chicago. The crease in train accidents per million locomo delegates also requested a great deal of in tive miles run in 1941 over 1940, and in formation and the response was energetic. connection with checking speed restrictions, Mr. Flannigan's first interrogation ^kalt with the involvement of hand signals in a large number oi train accidents and the fact that failure in this respect could probably be charged to the new employee-- the rules providing that utmost care must be exer cised by train, engine and yardmen in order to prevent taking -ignals that may be in tended for other trains. 'The question in con observance of block signals, not permitting second or other sections of regular trains to proceed on yellow block, strict compliance with Rule 99 instead ot merely "decorating" and other means oi preventing collisions, Mr. Allison oi the Baltimore and Ohio was called upon and gave a very good description of plans employed to train and supervise em ployees to comply with the rules. nection with supervision oi older employees Mr. Washburn ot the Milwaukee Road and likewise the training of new employees made an excellent response to the question to see that proper signals arc always given of manner oi preventing hand brake accidents was answered by Mr. Cates oi the Seaboard by describing the CMStP&P hand brake in Air Line, who stated the practices in effect struction car which has been on the road on the SAL. since last February. (See News-Bulldin Number 3 c: Marci; 31st). Mr. Lowe like A number of delegates participated in an wise described the plan of the Southern swering the next item which covered the Pacific Company of having the different types U; causes accounting inr the largest group of of hand brakes mounted on a platform at two train accidents, i. e,, overrunning meeting locations--Klamath Fails and Dunsmuir-- point, disregard oi stop and caution signals, where train and yardmen arc hired and given > i> which would mostly be chargeable to the complete instruction in operating hand brakes ' older employees, and how they were being safely. In this connection, Mr. Collett oi prevented by la ) physical examination, (b) the Santa Fe suggested that a 16 mm. sound crhuelecskienxgamdiinsaptaitocnh,er(sc)ansduriiorpi.esreattoesrts afmori (adc) hfialmndbberapkreeps,areetdc.,onChthaeirmpraonpeGr noapdeirnagtcironadof t-;i curacy and compliance with the rules pro vising that preparations for a sound slide film viding for issuance of train orders. Other sub were being made by die Committee on Educa jects covered were higher speed, advance tion, Safety Section, AofAR. yard limit boards, proper respacing of auto matic block signals and checking oi brake- Question if constant checks were made men on assistance given to conductors and to make certain that proper elevation of engineers in watching train order signals, curves and other track maintenance stand- tT-: , /s1 -, , t-'4 *r V.*.!.