Document 2jbmbaQDazK44NdZbp7gDvLdg

FILE NAME: National Safety Council (NSC) DATE: 1942 Oct DOC#: NSC245 DOCUMENT DESCRIPTION: Excerpt from Transactions of the NSC - 31st National Safety Congress MW*.1!: Foreword TH E Transactions of the 31st National Safety Congress and Exposition of the National Snfe^r Coned! are pub lished in two volumes. Volume I contains the General Sub ject and Industrial Section sessions. Volume I I contains die Public Safety. Child Education, Home Safety and Farm Safety sessions. Volume I is distributed to alt members of the Council. Volume II is sent to those members who are believed to he interested 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 m atters which are 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. E xtra copies of Volume I may be obtained by Council members at the following rates: 1 to 1 0 copies at $2.00 each: 11 o r more copies at $1.75 each. E xtra copies of Volume II are 75 cents each. t h e h a h o n iil u n n o o m o L m e . National Safety Council, Inc. Honorary Mombors A ssociation op Iion and Steel E ngine * W . H . Camekon Robeit W . Campbell Lew R. P almex O ffices (IMS-1949) Col. J ohn Stilwell, President I. W. Millakd, Vice-President for Finance and Treasurer G. T. H ellmcth, A sst Vice-President for Finance and A set Treasurer B. B. McC ulloch, Assistant T reasurer W alts* S. P aine, Vice-President for Industrial Safety Lew R. P almex, Vice-President for Transportation A V. Rohwedek, Vice-President for Horae and Farm Safety J udge Lee E. S keel, Vice-President for Community Councils R. T. Solensten, Vice-President for Membership L eslie J. Sokenson, V ice-President for Public Safety Da. Lewis A. W ilson, Vice-President for Education N ed H. D eaiboin, Executive Vice-President, Managing D irector and Secretary R. L. Foxney, A ssistant Secretary Exocuthr CommittM (1942-1943) J. I. Banash, Past President W allace N. B akkeb, Pullm an-Standard Car M anufacturing Company C. W . Bebgquist, Past President Robebt W . Campbell, P ast President D. B. C hant, O ntario Pulp & Paper Makers* Safety Association R. G. Cbeviston, Crane Company A. J . R. C u m s, Portland Cement Association N ed H. Deaxxoxn, National Safety Council, Inc. Lewis A. D kB lois, P ast President R. E. Donovan, Standard Oil Company of California Mabcus A. Dow, Past President G. W . Elste, J i , Baltimore ft Ohio Railroad Company H aiou> F . E nlows, The American National Red Cross D. D. F ennell, Past President R. H . F ebcuson, M etals Section RoXekt F. G ilmoue, Utica Safety Council E. E. Gkovee, Columbus ft Southern O hio Electrical Company J u u e n H . H axvey, G reater New York Safety Council W . A. H azaxd, C onstruct* Sacthni Da. T . Lylx H azlett, WcstingbouM Electric ft Ifaaafacturiag Cum- pany G. T . H ellmuth, Chicago Rapid T ransit Company G. A. H susea, LomsriBe Safety Council Caxl E H olmes, M arine Seetfou W . A . J a n s , Chase B nua ft Copper Company, lac. W .D iu t K a m a . Lumbcnma* Mutual Casaaky Company W aL xn G. K ing, P ast Ptesidcnt Jew * E Long, P ast P rrridet J . W a u a s Lean, Atfanrie r ' By --' tfyrr. w er r and O fficers (con td .) W a u U acucvax, A SSE-I How. Cakuu. E, Meauey, New Y ork S tate Tift ComniMkm I. W . Molam i Industrial O o r a Company Ham** L. l ia n e , E. I. dn P ant de Nwwoww * Compear P b o ip I I . Mom* * , Mi raarhm ctti Safely Cownel; W orcester Safety ( j --yB Clabemcb J . M u n t, Safely D M sim , M iHiwdiie Aart of Buer Nim U. & OIBee ol Delwee HcaMi ft Wdfara S an k * Wachs S. P ai**, Aetna ! Lew R. Pauos, Ptet Pn..... C. JE, Pnm iw w ^ F h it Ihpccidmt R. h Resceuptw, New H aw T t y R o d k ^ ^ , .# C d , Hawn* A. Rjwiiujsb, II. S CMSce of Cjyftjan Defray*,.b ft.Reykra A* MDWSMWy ft^pWOlp I ^-it. , 4"AH' J . R tm ju m , Street ft Highway T tid c ; Hawnr & ScHAfvw**, Eric Safety Coancfl : ' J u k b La* E . S w an, AppeBMa Cowrt, Qevdawd '. ' ViABIi Jw*9K u B | W wpRi vtftMHRB Tnnom aa F. S im s , O S r b e * ft M Corporatioa R. T . SoMwa iw , ERiott Service Onapany T jttn t J . S o u * * * * , City T n ftk F a i i n f , O iiray o C cu Jm k S r a w iu , CniunHdWfd Edison Company of New Yack; Ine, Major R. C Smarco*, C M S, Quadrai Section C P . Tousak, P S* Prsident D i C R Watsoit, P u t President Da. Lewis A. W o so x , The University of Stale e f New Y ork C E W oousvca, Aotomo th c ft Machine Shop Section A xntu* H . You n<* P ast Presides* V. A. Ziuscer, U. S. D portaient of Labor Pu |.,|| U P U tlW I OK (1912-194 W imtrbof W . Aumoch, Chairman Board of D irector, T he C law Natrona! Bank, New Y ork C ity Sewill L A n a r, P rende* , Montgomery W ard f t Company, Inc, Chicago, III. Moba* B. Baaikaed, President, Aetna lif e Insurance Company, H artford, Com . Howaw C oenunr, Chairman of the Board of D bacton, W alwortb Company, New York O ty B urjA icnr F. Faibles*, President, United Slates S tili Corporation, riiu o iffp i re n i W .S . F abub, President, Standard O ft Company of New Jersey, New Yack City Waurb O n w g President American Telephaoe and Telegraph Com pany, Kew York City & K. ftv n tr a , Director, Unas M b Raftmad Company, New t h e k C ity Kmenthm Comndttaa:Unftsd Statn Steel UteAranraace So- il.I s (contd.) Robert C. Stanley, President. International Nickel Company of Can ada. Ltd.. New York City Col. J ohn Stilwell, Vice-President, Consolidated Edison Company of New York, New York City T homas J ohn W atson. President, International Business Machines Corporation, New York City C hasles E. W ilson. President, (encra) Electric Company, New York City Directors (1942-1943) H. J. Aldrich, Spencer Kellogg & Sons, Inc. T. O. A*mstrong, Springfield Safety Council ; Hampden County Safety Council W . C. Baker, Power Press Section J. I. Banash, Past President W allace N. B arker, Pullm an-Standard Car M anufacturing Company E rnest W . Beck, United States Rubber Company C. W. Bergqihst, Past President M iss Frances Bethune, R.N.. Textile Section W. F. B iggs. Peoria Safety Ccruncil H. R. B ixler, Mutual Life Insurance Company of New York H. W. Boggess, Sinclair P rairie Oil Company F, A. Bogue, Steam Railroad Section E. G. Borserine, Kansas City Safety Council C. B. Boulet, Wisconsin Public Service Corporation E merson A. Brandt, Refrigeration Section E dward H. Brink, Grand Rapids Safety Council Josefit A. Brophy, Elizabeth Safety Council W. F. Brown, Commercial Vehicle Section Sam W. Burchio, Automobile Club of Rhode Island, Safety Depart ment W. H, C ameron, Evanston, 111. Robert W . Campbell, Past President Raymond A. Carey, Evan,ton Safety Council Ray C arr, Portland Traffic Safety Cocmmssion D. B. C hant, O ntario Pulp ft Paper Makers* Safety Association C harles A. C happell, Safety Division, Syracuse Chamber of Cem- merce I.am mot dcPont CopELANti, Delaware Safety Council C. S. Craigmile. G reater Chicago Safety Council R. G. Cbeviston. Crane Company W. H. Crisma n, Seattle Traffic ft Safety Council J. E. Culli key, Bethlehem Steel Company A. J. R. C urtis, Portland Cement Association John D'Ambrosa, Sr, Rahway Safety Council Ned H. DtABBMN, National Safety Council, lac. W . N. Deatherage. Long Beach Traffic Safety Council L aw A. DeBlois. P ast President C. W . Dempsey. The 1jquid Carbonic Corpora tion S. T . D irsdale, Wood Products Section Milton W . Domzeksky, E ast Bay Safety Council R. E. Donovan, Standard O il Company of California J ames B. Douglas, The P hiladtlphia Ges W orks Gotnpaay Mabcus A. Dour, r a t P rriH m t D. C. Duncan. PNbfic U tiU tks S arti-- 6 Otiic e i fi f. 11 ) i i R. H l-H.I)r H art Yn Tor B How Aldi B Rat I in ,le Robert F. John I.. G W . A (rii H. J. G ain E. E. Gmn H arry G u A. J . H aw D. T. H ar Frank H. J ulien H. W. A. H a Da. T. Lv pony G. T . H el G. A. H ei H. W. Hn CarlE. H D r. Ralpi Stephen . W n F. J a E. A. J ari T homas I W. Dean W alter C C. !.. LaF George Lj Roy Ij.k W allace John E. 1 C. H. Lo J. WlLLAI R. A. Me B. B. Mrt T hos. H. W ills M Alfred E H. T. Ma Hon. Ca* I. W. Mt: H arold 1 H H. M< P h iu p .V R. 3. Moi C I- Me C larence m erer Eliot N e i ny oi hinc> York safety npwy lepart- a f Cem* Officers (contcL) G. W. Elste, Jk., Baltimore & Ohio Railroad Company H arold F. E klows, The American National Red Crow 1). D. Fennell, F ast P resident R. H. Ferguson, M etals Section Dr. Hast & Fishes, Chicago Rapid T ransit Company Vk i h B. F m rA taicK , Richmond Safety Council Howard B. Fonda, Burrough s W cllconw I C a (U . S. A .) Inc. Ray G u u n , M int Pecking; f amring ft Leather Industries Section Roaear F. Gilmour, Uffca Satiety Council J ohn L. G au n t, Robber Section W. A. Griffin, American Telephone ft T elegraph Company H .J. Griffith. Jones ft Langfaitn Seed Corporation E. E. Gaovaa, Columbus Safely Connril Habry Gm um nr, The PnUaaaa Cnmpany D. T. H arrington. U A ^ r a s d M ines Frank H . H abrison, Interactional H arvester Cnmpany Ji lien H. Habyey, G reater New Y ork Safety ConncR W. A. Hazard, Construction Section Da. T. Lyl* H azlbtt, W estmphome Electric ft M iaufactnriHg Coen* pnny G. T . H bixmoth, Chicago Rapid T ransit Cnmpany G. A. H elser. LonisvBle Safely Cmmril H. W. Hirsheimer, Chattanooga Safety Conned Carl E Holmes, M arine Section Da. Raltm H . H o o c m rn , Kenosha Safety Council Stefhen J. Hurley, Rochester Safety Cbandl W m F. James, Philadelphia Safety Council E A Jarvis. Chase Beam ft Copper Company. In c T homas P. Kearns, Industrial Commiinon of Ohio W. Dean Keefer, Lumbermen's M ntad Caaneky Company Walter G. King, Past President C. L. LaFouktaiwe, G reat Northern Railway Company George LaMair, D ei Moines Safety Conocfl Roy Lee. Contra Costa County Safety Council Wallace O. Lee, Safety Division, Indianapolis Chamber of i John E. Long, P ast President C H. Longman. Chicago ft N orth W estern Railway Company J. W illard Loan, A tlantic R tfain g Company R. A. McArthur, Public Service Coordinated T ransport B. B. McCulloch, Bnrean of Safety, In c T ao s. H. MacDonald, U. S. p d d c Roads Wills MacLacmlah, A SSE-Engm eeriag Section Alfred E. Maffly, Berkeley Traffic Safety ' H. T . Marker, Petr oleum Section Hon. Carroll E. Mealey, Near Y ork S tate T ax Cmneeiu ion I. W . Molar, Industrial Q ovm Company Harcld L. M una, E . L da Font de Nemours ft C m t any H i H . Momma. S t, Jeacnh Safety C ornell P g g t M. Mohcan, Mmeachaeette Safety CoaacS R.B.MORLKV, i C L M o m r, fNMtmMmngMwoemmnstm^ye MeatpnwrmssnLnp' sSu^a^f^^ewt^yjy HnamfsvwuintahMm^mm. Mdsmbbee A m adatioa owdf Cent* U S. Services , ilicers (contd.) F rank S. Newell, Toledo Safety Council F. E dward O'N eil, The Safety Council of G reater S t Louis George C. A. Opp, The Detroit Edison Company W alter S. P aine. Aetna Life and Affiliated Companies Lew R. P almer, Past President D avid A. P atton, Newark Safety Council R. E. P erkey, South Bend Safety Council C. E. P ettibone, Past President G. H. P feif, General Electric Company D. W. Pontius, Greater Los Angeles Safety Council W. M. Poweu, Cement and Q uarry Section A lbert S. Regula, General Time Instrum ents Corporation R. J. R eigelutii, New Haven T rap Rock Company Col. H enry A. Reninger, U. S. Office of G vilian Defense, 3rd Region J. W. Reynolds, United Pacific Insurance Company Roland W. R ichardson, Paper 4 Pulp Section C lifford T. R ipley, Superior 4 Douglas County Safety Council M iss S adie Rogers, Employees' Publication Section A. Y. Kohweder, Duluth, Missabe & Iron Range Railway Company Carl J. R utland, Street 4 Highway Traffic Section H enry G. Schaffner, E rie Safety Council F rank T. S heets, Portland Cement Association John R. S herwood, Baltimore Safety Council D r. L. A. S houdy, Bethlehem Steel Company J udge Lee E. S keel, Appellate Court, Cleveland Carl L. S u rra , G reater Cleveland Safety Council T heodore F. S m ith. Oliver Iron 4 Steel Corporation R. T. Solensten, Elliott Service Company Leslie J. Sorenson, City Traffic Engineer, Chicago J ohn L. Spencer. Blackstone Valley Safety Council E. C. S pring, Philadelphia, Pa. E. B. Stahlman, Safety D ept, Nashville Chamber of Commerce Col. J ohn Stilwell, Consolidated Edison Company of New York, Inc. Major R. C. Stratton, C.W .S., Chemical Section H. B. T aylor, Food Section C. P. T olman, P ast President J ohn T re week. Mining Section R. A. T ucker, W estern Pennsylvania Safety Council J. A. V incent, Madison County Safety Council Dr. C. H. W atson, P ast President M. F. M. W ekth, Lehigh Valley Safety Council H. W. W hitcomb, T ransit Section T . A nglin W hite, Safety Div., Birmingham Chamber of Commerce A. W. W hitney, National Conservation Bureau C. E. W ilson, Detroit. Industrial Safety Council D a L ewis A. W ilson. The University of State of New York C. E. W oouevu, Automotive and Machine Shop Section Roy V. W eight, Simmons-Boardman Publishing Corporation M iss Mary May W yman, Child Education Section Arthur H. Young, P ast President M. W . Young, Sacramento Safety Council Waltrr S, Young, W orcester Safety C oondl E. J. Zauft, Safety Bureau, D uluth Chandler of Irving R. Zrxah, Omaha Safety C o o n d V. A. Z a u n * U . S. D epartm m t of U h o r 8 Each edition library of safe men and woroei portation, insi agencies--give and background vention a t the Ani This knowledge mg year after yea g m siv e industrial P lan Safety ideas, as personalities in ty, can be found Table of Content, at the end of die The Table of Sessions, (b ) Su problems commo Industrial Sectioi Subject Sessio are arranged alj the book the sevi trial Section are the daily time s< gram . The detailed easy to find spe hundreds of iter jects discussed, i shoes, third shi in the ct sc of foi are primed in tions, i e., Ch Marine, etc. U. are listed the s gram . 58 31st Sat'wnal Safety Congress of material exhausted, or leakage losses caused by loose cleanout doors, broken joints, holes worn in duct (most frequent in elbows), poor connection to exhauster in let 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 brandies until future connections are m ade), change of set ting of blast gates in branch lines (blast gates adjust the air distribution between the rious branches. Tampering with blast gates can seriously affect such distribution ana 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 Atmoeplioras By N. R- BERNZ Chief In d u strial H ygienist, T he F idelity ft C asualty Co. of N . Y ,, New Y ork, N ew Y ork In manufacturing, many operations and processes of one industry are common to those of another, although the two indus tries may be engaged in the production of entirely different types of goods. For example, welding is used very extensively throughout the aviation, shipbuilding, auto mobile and steel industries; this applies also to spray painting, electroplating, buffing, grinding, and many other operations. Sim ilarly with raw m aterials, various kinds of acids, organic solvents, etc., are found in almost any type of plan t For this reason there are certain industrial poisons which appear much more frequently than others and which may be found throughout the entire defense industry. Some of these are: Dust* Carbon Monoxide Hydrogen Sulfide Hydrogen Cyanide Sulfur Dioxide Oxides of Nitrogen Pbosgen Lead Toluene Xylene Trichloroethylene Carbontetrachloride Carbon Disulfide N itric A dd Chromic A dd Hydrofluoric A dd Hydrochloric A dd Sulfuric A dd O thers which are more directly aaoocfetted w ith specific industries are: Trinitrotoluene (dust and Ammonium P k rate (dust) Mercury (vapors) Aniline Radon T h o ron vapors) As will be seen by examination of the above list, some of these substances are pres ent as raw m aterials; others are final prod ucts, while a third group occurs as by-prod ucts generated in the various operations. Typical of the first group are the various acids, organic solvents, chlorinated hydro carbons, ammonia, and carbon disulfide. In the second class we have T N T and am monium (aerate, while the remainder are commonly occurring dusts, fumes, gases and vapors of a toxic nature generated in various industrial processes. WhBe 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. Silica-bearing inorganic dusts are prob ably found in all of the above industries. For example, mining of A t iron ore in the atari industry presents exposures to free silica dost in considerable quantities. Buffing, polishing, and grinding operations done very UiwJtUiijitK! Dust, Fumes, Gases and Vapors ' t. 1: !Vc vang w>th blast gates . a-trUunon and locked in place in i' !*. installed and !>. Increased pres e le c to r dne to lack operation, wear, etc lcsign. Refer to Op* :e instructions furtor or consult the xtensively in a great many industries, generate inorganic dusts, which for the most ;iart consist of aluminum oxide and silicon carbide, but also include free silica in amor phous and crystallne forms. For the purpose of quantitative determina tion, dusts may be divided roughly into three classes, as follows: 1. The inorganic type such as free silica and asbestos, which is collected and the num ber ol particles per unit volume of air deter mined microscopically. of dust are by means of electrostatic pre cipitators (3) and various types of "grab" samplers. W ith the electrostatic precipitator, the dust is collected in a dry state and either weighed as is, or suspended in water and counted in a maimer sim ilar to that em ployed with the impinger method. Several of the grab samplers have microscopes in corporated with the sampling device and these are calibrated in such a manner that the number of particles per cubic foot of air can readily be obtained by almost instantan eous readings (4). !W Y ork, New Y ork tat and vapors) (d u st) 2. Organic dusts of natural origin, the amount of which is usually determined by weight Typical of these are tobacco and flour dusts. 1 Synthetically manufactured organic compounds which may occur in the form of dusts, such as T N T and ammonium picrate. These substances when present as air con taminants in low concentrations are generally evaluated quantitatively by chemical means. Besides above types, there are also metallic dusts such as lead, zinc, cadmium, manganese, etc, some of which will be discussed tender another heading. O rganic D ueta (N atu ral) This group as a rale is not classified by medical authorities as fibrosis producing dusts, and hardly warrants any discussion in titis paper. W hile claims do exist to the effect that some dusts in this class have produced respiratory irritation, bronchitis, asthma, etc, these dusts are generally looked upon as nuisances rather than occupational disease producers. No official physiological threshold limits have been established and sampling of this type of dust for the purpose of evaluating an occupational disease hazard has little o r no meaning. M ost of these dusts, however, are ex examination of the Inorganic D usts plosive when dispersed in certain proportions i substances are presithers are final prod in the air and require control from this point The most common method for evaluation of view. Considerable work to establish ex tp occurs as by-prod- of this type of dust is to collect air samples plosive limits for this type of dust has been ! `ft:, various operations, in liquid solutions by means of an impinger done by the United States Department of oup arc the various (1) and to make the quantitative determina Agriculture. ; , chlorinated hydro tion microscopically. W hen calculating the carbon disulfide. In dust concentration, usually expressed in num ber of particles per cubic foot of air, the Synthetic D usts save TN T and am- microscopic calibration factor, the volume of tbe remainder are sts, fumes, gases and the sampling liquid, and the size o: the air sample are taken into ooosidentioa. In the manufacture of TN T and ammon ium picrate, both of which represent basic generated in various war industries, we are confronted with toxic v'hile the theoretical The sampling procedure; microscopic a r raw m aterials as well as hygienically injuri e to toxic substances are far too numerlist represents those te n d . rangement, and calculations are extrem ely simple, but the actual counting is a tedious job associated with severe eye strain and requires considerable experience before dust counts can he rehei upon. In recent years ous final products. In this industry great quantities ol toluene, anhydrous ammonia, sulfuric and nitric adds are used, all of which are classified as industrial poisons. TN T and ammonium picrate are themselves systemic date dusts are probabove industries. F or iros ore fa ft* m i u n s to free atta quantities. them kroprajectianeietiiod (2 ) has been used for counting of hupedger samples. W ith tins method fa which the microscopic field ta pro jected on a tranalacrAt reTM--*, the eye strum eneeienced fa direct mCcmecttiic work, is fter for of ftfa type poisons as well as skin irritants known to have produced fatalities and severe cases of derm atitis. A method for sampling and determination of T N T was d eserted recently by Pinto and Fahy. (5 ) T his procedure calls for the use of 10 cx . of isopropyl alcohol in the midget >0 31st National Safety Congresi impinger. The chemical determination is based on the reduction of TN 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 m aterial in industrial at mospheres. The deep color whcfa results upon solution of ammonium p ien te in water is also evident in extrem ely low concentrations and for this reason a direct colorimetric com parison of the sample with known standards can be made. W ith tins method there is a possibility at interference from dmitr ophcaoi. the extent of which has not been determ ined (6 ). u t m sooom This is a very toxic gas encountered in various industrial activities. The toxic lim it for this gas is generally accepted as 100 p.p.m. for prolonged exposure. T o 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 bunting natural gas or other fuels. In industrial operations in volving baking ovens, drying kflns, cake 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 m dintry, a high quality iron oxide rouge is required. Occasionally this m aterial is manufactured on die premises as an adjunct to die prism grinding work. This involves th use of oxalic arid for production of iron cnralafr which is later decomposed by heat to yield iron oxide rouge. In .dns process carbon monoxide as w rit as other g ases.are gen erateli. dcvcru -fiu m i Nnv oven v n v n ^ i o r the quantitative determination of catbaa isodoxiqc, o n m f o k The small electric current produced by the heat of the reaction through a thermo couple is calibrated in term s of carbon mon oxide concentration which is read directly on the dial of a ariWammeter. The source of nwtinn in instrumen t is a small centri fugal blower, tbe m otor of winch is operated either from a built-in 6 volt battery o r from a 110 volt lighting circuit through a trans form er. Another convemcnt method for estimation of oo^bosi axmoriifc Icvo w ntifivo BBd not to accurate is die use of paHadhan chloride ampoofes. In *t< reaction die paOa- dmm ddoride is reduosd t o . m etallic pul-- latbam thwqfwf prodacm g' a ' staia, dm in- wBmuy m v n e s ip n ( v n t p ro p o n m n> dm aaapnst o f carbon monoxide in the utmau- pbere under ohservnttoiL The stain prodnoad is compared to known color t b a i m b h r cvaluatioa of die caihon monoxide preset T his rnftbrii is tvs i p n i f for carbon mon oxide, however; force are otbar redndnt gases w hidi If udH produce a stain h i the presence of paBadhan fUflti df Incidentally, die standard Htcdiril for m *" momwidr evaluation, adopted by the B ritish Depart ment o f Industrie! Research (7 ) constate of a pvtiwMum entonoe vcm psper w o o p i v m the a ir to be w q M is dra wn by. eamne at a bendpmap. The stain tfans prodneto is compared with a standard color h art H ydrog en M l h H ydrogen sulfide is a very toxic gas with a disagreeable odor. It is fatato in many in dustrial operations where salito o r stofwr compounds are used, but prim arily ft ia en countered in the artificial d b ; chendeto and petrolemn iadnetries. Safe lim its varying be tween 20 and 50 ppm - by votane bave b a n M0C19M o f fBnOUt SU R lO D w IiK t m u u t country. lo t w w ntpm mctnoo tor hum 11-- w of hydrogen s to id e is iiniiaiditnily I ta am li rn f e ijn f 7 n lu p trirT HiffT i r f - " Y - * " w ori^w H ("dbasm tel taro . O w a^fk aro is die earbsn amaatode Jndtadag ta n to til the r tdatofj^^w aclttai a i uruUKh a so--!. titrating with ),iUSSium lixltli' sUtr ! ure>i amount of standard action the disappearano rates the end point (Hi H ydrogen I This gas for which th bureaus of California, C< achusetts have establish* p pm. by volume, is fex operations, beat treating A portable instrtaner cussed in connection wi has been developed fo also. I have been inform hydrogen cyanide detei form proved leas satisfa been withdrawn from th pending further researri Chemiral testa arc a' of hydrogen cyanide, s blue and foiotyim ate rei are ip g d h fax th is % sensitive enough fa r a ten d m industrial h: methods scalable for gas in small concen trs red-silver nitrate and t acetate test papers. T have been adopted as British Departm ent of are noo-specific, howevi inter ference of other HN, SO* and H*S In a method suggest Foundation (A .H .F .) bdbbkto through 0 5 hydroxide after which made by titrating witl Stofwr : Exposures to sulfur nun in the pe rokum i and sulfuric arid dioxide is al ) encotin works, magir sium fo dustries wheie sulfur It is an extrrm ely ir a threshold U i t of 1 gened. > irrent produced by the through a thermo- ted in terms of carbon monon which is read directly i milliammeter. The source instrument is a sn ail centrii motor of which is operated alt-in 6 volt battery or from mg circuit through a trans i e n t method for estimation ide thoogh less sensitive and r is die use of palladium s. In this reaction the paQas reduced to metallic palprodaring a stain, the mi is in direct proportion to torn monoxide fat the atmoservatiou. The stain pr odneed known color standard for e carbon monoxide present, not specific for carbon mon* ; three are other redw ing > a ril produce a stain in the adman chloride. Incidentally, rm oQ to r caroon monomae tad by the B ritish Depart* ri Research (7 ) consists of a da test paper through whirh w apM is drawn by aacaas T he stain th a t prodnoed is i standard color ch a rt Ida is a m y toxic ga dor. It is ioand fas a a p t o aw where salfar o r atdhar a n d h at prim aray fat is ea a rtifa h l tSkp dm nicsl n d trisa Safa tfaate varying ha* 1p p m .fay roam e have haca S tate authorities fai (his Dust, Fumes, Gases and Vapors through a sodium hydroxide sedation and titrating with iodine, or by bubbling through iiotasstum iodide starch solution and a meas ured amount of standard iodine m which re action the disappearance of the od o r indi cates the end point <fi). For the testing of sulfur dioxide, the American Public Health Association (A.F. H .A .) (10) refers to an iodometric method (11) by means of which the air sample is passed through a gas wash bottle containing a measured amount of standard iodine in potassium iodide-starch solution. The disap pearance of the color indicates the end of the test, after which the amount of sulfur dioxide This gas fo r afajeh the industrial hygiene CStt (nSCSliCQSsicrfa bureaus of C ahfantia, Ccsawctkat and Mass achusetts have estoMUhed a alfa liad t of 20 p.pjm. by ualwns; fa found ia sdecfapopfatfaag operatic**, heat treating, <h& -- . of the type w itii fayd rogeu sulfide, has been developed fa r hydrogen cyanide also. I have been iafem wd, however, th at the hydrogen cyanide detector in ha original The B ritish Department o f Industrial Rei^^ansmm^ufuas esimlovwa aas w*v*waw*wr'whw^m*mm*sm--pi^w*^--^ro^>v h i W i p p um w gn wmen m e n r w iif is draw n fay aseans of a handpump. The sulfur tiie kvfiMT to iodine w ith the production o f a stem the degree of which ia to known color J -- 1-- ** O xides o f K hrogan form proved leas attiafaclocy and th at It has been withdrawn (rasa the m arket tem porarily pending farther research. Chemical tests are avaihfale for det ection of hydrogen cyanide, each as the Prussian bine and thsoqnm atc reactions, both of which arc specific fiw thw gas hot allegedly not sensitive <mmgh fo r concentrations entowttered tn m dw tiw l hygiene work. Other suitable fa r d*^Fin**iT*ftifi*n of tide gas in asnaB conm ntrations are (he Congo red-silver n itrate and the hm rirfiar ropprr acetate test papers. These methwh; whsefa H a s is a group of gases, some of ____ are extrem ely to x ic They are produced when nitric acid come ia contact with organic m aterials and certain m etals; during chemical nitration processes and bunting of nitrated m aterials; they are also present in small quantities daring electrical discharges fa> the air. Above gases may, therefore, be found in such induotnes and t , .. tioo w orld, photographic . - nitric acid plants, ekdregtating U pping), detonation of explosives, rieetnc welding, etc. have been adopted as standard tests by the British Department of Industrial Research, are non-specific; howeve r, so dad the poatiMe interference of other g u e s sw h ns H CL, HN,^ S O f and H *S thovid be tr im into consrferetion. dbOMSCB^ WftCfeKWl 1 above operations, a m ixture of oxides are formed. The haxardom nature of tins mimr, caBcd ``nitrous fames" is due to the nitrogen dioxide, a reddish w iicn r u c u wiiB w eicr to o upon In a asetbod suggested by the A ir Hygiene Fonadstion (A H JF .) the a ir sample fat OOWHU b h h B I VU9 BCw QH| VOSHPMWm uiw uuoc u v r w n o i me oeK nonnoB it t by titratin g witii silver nitrate (9 ). ------- forms nitric arid fat the lungs. re n ft is often pulmonary edema which proves fetid. The fact that the of thgse gases does not produce in spit of their ; .......... them doubly dangerous. A mmr he exposed to fumes and o rfy a th g h t respiratory irrita- wnw m wwdhtely following the exposure, * W e tim ew e may develop into a fatal con- tiMon 'by f-- day. I know of a case in a nitric b J ( t man was engaged fat arid into carboys in a depart- mnmt wfah a wooden Boor. One of the carorfdenmBy brake finalrg tiie acid to iiiil .- -,. ttflfcrrrf : - 62 31st National Safety Congress flow over the wooden floor producing the brown nitrogen dioxide g at in great volumes. The operator not being familiar with the toxicity oi this gas and experiencing no im mediate physiological warning, remained on the job attempting to dean the floor by mop ping up the acid, instead of leaving the work place for fresh air. As a result a consider able portion of this gas was probably inhaled. He became seriously ill a few hours later and died within 48 hours. Cases of men be coming sick while doing electric welding in side tanks or in other confined spaces are often referred to in the literature. Marty of these cases are undoubtedly due to oxides of nitrogen generated in the e le c tric arc. While there are several methods known for 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 for these gases, the amount of ventilation required for their control after 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 Hue in the presence of nitrogen dioxide. The method is non-specific, however. O ther, specific meth ods for evaluation of nitrogen dioxide, and sensitive a t low concentrations are die Griesstlosvay and the Bismarck Brown tests. W ith both methods, the a ir sample is bubbled through chemical solutions .after which die quantitative determ inations are made in the laboratory by colorim etric analysis. Although physiological safe lim its up to 40 p.pjn. have b e n proposed for these gases, atm os pheres which by odor o r color indicate the presence of nitrons fumes should always he viewed with suspicion. As stated elsewhere, ammonii i t an im portant raw material throughout the chem* cal industry. It is a strong respiratory irri tant for which safe limits ranging between 50 and 85 p.pjn. have been recommended (Russian investigators 13-59 p.p.m .; State of Massachusetts 50 p.p.m .; Flury and Zertuk 85 p.pjn.). Ammonia vapors can be evaluated directly in the field by babbling the air sample through a measured volume of 0.1 N hydro chloric ad d m w ater solution using phenol- phthalem as an indicator; the appearance of a pink color the end point. From the amount of ad d need and the s in of the a ir sample, the concentration of ammonia vapors ran be calculated (8 ). Sulfuric ad d can also be used with above method. In another method, recommended by the A.P.H .A ., the air sample is collected in sulfuric a d d but the final evaluation is made in the laboratory by standard analytical means. Lend Exposure to this metal occurs very exten sively in nearly all types of manufacturing. The most frequently encountered forms of lead are fumes, dust and dispersed pigments. These occur around lead melting operations, soldering, welding of metals covered with lead-bearing paints, and in spray painting work. Sampling of lead-contaminated atmos pheres is usually done either by means of the impinger or by die electrostatic precipita tor. W hen the impinger is need, as is fre quently the case when investigating spray painting and many other types of work in volving lead dispersion, the sampling liquid may be either distilled w ater o r dilate nitric add. Regardless of the collection method used, die final evaluation of die amount of lead present is done in the laboratory by various analytical methods, die description of which is beyond the scope of this paper. It prob ably should be emphasised, however, that altfaootfh some of these methods are highly sensitive and the experienced analysts usual ly wcS-trained to b o d e minute quantities of lead in their work, it Is preferable to take large a ir awnples wherever possible to facil itate the laboratory work. W ith the large fastinger and the atectro-statk precipitator ir per it : problem. W <: other hand, ^icubic foot J* r n ' task, especially ment is used. 1case in which tht is ju st about on limit, i. e. 1.5 r air. For a 30 mi impinger, only 3 handled. T his r> lead in die air quires a fairly and careful han ptetkm of the te The United 5 (U .S .P Ji-S .) < with respect to concentration of air. The metal is tng of iron and well as in stru properties. Exp mram fumes tn m such operat tug of cadflriu well as many o volves cadmiun are probably is tnium intoxica Canada, a few were poisoned ing of cadmiut As in the c miurn fumes oi the impinger medium--A .P . precipitator ar laboratory by analytical met At thi' poin out that for impinger has than th el should lc ts eompark g re lected w th d lattili# li!1! ;\rt*>ry irri*.- :..r-.ng betvsni Ktn recommended 3-.W pp.tr..; State p.p.tn. ; Flury and *: evaluated directly ng the air sample une of 0.1 N hydrolution using phenol; the appearance of he end point From and the sice of the tration of ammonia i (8). be used with above rthod, recommended r sample is collected e final evaluation is y standard analytical d tl occurs very extenes of manufacturing, ncomrtered forms of 1 dispersed pigments, d melting operations, metals co rn ed with d m spray painting -ontaminated atmoseither by means of dectrostatic precipita* r is used, as is frei investigating spray er types of work in, the sampling liquid w ater o r lu te nitric Uecthm method used. the amount of lead laboratory by various description of which th is paper. I t probBCQg HOwCrCT, DW methods are higfdy icttccd in ly s ti VMri* e mhmte quantities of is preferable to tabe ever possftie to farilw k . W ith the Iarde tro -su tic precipitator Dust, Fumes, Gases and Vapors with sampling rates of 1 and 3 cubic feet of air per minute respectively, this is not a problem. W ith the midget impinger, on the other hand, with a sampling rate of only 0.1 cubic foot per minute, this becomes a tiresome task, espedriiy if die haodcranked instru ment is used. Let as take, for example, a case hi which die atmospheric lead dispersion is ju st about on the border line of die safe limb, L e. LS mg. per 10 cubic m eters of air. For a 30 mmole sample with the midget impinger, only 3 cubic feet of air have been handled. This represents only 0.013 mg. of lead in the a ir sample, which evidently re quires a fairly sensitive analytical method and careful handling for a successful com pletion of the te st The United States Public H ealth Service (U .S .P JL S .) (16) suggests as a safe lim it with respect to toxicity of cadmium fumes a concentration nf 1 mg. per 10 cubic m eters of air. The metal is used extensively as a coat ing of iron and steel for rust prevention, as well as in structu ral steel to im part 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 sled as well as many other processes where work in volves cadmium-plated articles. Some of yon are probably fam iliar with the cases of cad mium intoxication in a plant in Ontario, Canada, a few years ago, when 14 persons were poisoned--two family--during anneal ing of cadmium plated rivets (17). A s in the c u e of lead, sampling for cad mium fumes o r dust may be done either with the impinger (w ith water as cdiectioa mwBnm- A PJH .A .' o r by the electrostatic precipitator and the samples evaluated in the laboratory by gcwdueetric or coforunetnc umlytkal --**--* At tWv point ft ptehoWy should Im brought out for sampling of metal fumes, the than the eteetroetatft1peurSpftotor, which shouM he M ercury The present emergency has greatly accel erated the use of mercury, not only in our ammunition works, but also in many other plants directly or indirectly connected with the defense industry. In some cases entirely new uses have been introduced for this metal. F or example, a recent development is an anti-fouling paint containing mercury, now used in our shipyards. Application of this mercury-bearing paint by means of spraying naturally introduces a serious exposure to mercury poisoning and calls for careful con tro l; this applies also to the manufacture of die paint Due to the great demand for mercury and the shutting off of foreign sup plies, many old mercury mines are now being reopened so that refining of this metal with accompanying occupational disease hazards has expanded considerably during the past year. The toxic properties of mercury as a respiratory hazard when present in the form of vapors o r in a finely divided m etallic state are probably fairly well-known to most men concerned with indii=tri;>i health. A safe limit, lexicologically, of about l mg. per 10 cubic meters of air appears to be generally accepted for inhalation exposures. Althouh the metal has a relatively low vapor pressure a t or dinary temperatures, investigations have shown that sufficient vapors are emitted to produce a mercury hazard m rooms where this material is used in metallic form. A number of methods are available for the evaluation of mercury vapors in air. One of die most expedient procedures is probably by means of the Nordhpoder apparatus utilizing a selenium sulfide test paper, the M o r of which darkens in the presence of mercury. The amount of mercury present is estimated by comparing the degree of darkening with a standard color chart. Another m ote recently developed method involves an optica! instrument based on the opacity of mercury vapors to ultra violet light of a certain wave length. In this instrument, therefore, when u ltra violet light of a specific w avelength is directed towards a phototube, interfering m ercury vapor will reduce the f t f t received by the phototube and consequently Mso its current flow, which in turn is (aiflwaled term s of mercury concentra tion. T h is instrument is not specific as it is 31st National Safety Congress subject to other light intercepting media such tible gas indicator is far more expedient as smoke and fog. M ott of these devices, used primarily for fire , varK-u* .o' There arc also other methods for determin ations of mercury, entailing condensation of the vapors and subsequent electrolytic deposi tion of the metal, chemical reaction methods, etc. The first two mentioned above; however, are the most expedient and yield immediate results during the Add investigations. prevention work, are designed to read to within 1% of the lower explosive limit of the gas o r vapor under to st For above sub stances with lower explosive limits around 1% by volume, this means that concentrations down to NO p-pua. can be detected, which is pH! lim it for these solvents. For benzene with a safe limit lavi- recoiiiiiii. !i .5 p.p.m. for |f>H British Def.artiin-rit ,rial Research has v p.p.m. and our own 20 p.p.m. While thei between these values, the potential dangc: of 7S r r m (19) a w iriffiffl gas Benzene (B enzol), Tohaana and Xyfeaa iwSira Mf hmf Ipfifm gg {He market, insures to vapors oi Although this solv These three aromatic hydrocarbons are which measures concentrations ranging be in a great many inc widely used as industrial solvents and ingredi tween 0 and 1000 p-psa. A spectroscopic daaMUMkiiiuS found prim arily in i ents in a number of chemical reactions. Tolu, BldllBW- JO BKRavJzMmMlOil OK OBBBK8B BnD industries where it < ene, for example, is an im portant raw mate toluene in a ir has been described fay Cole raw m sterial. rial in our ammunition manufacturing, espe ( ) . * For evaluation of cially in the production of trinitrotoluene. Chlorinated HpdracwbMg Hygiene Foundaticx W ith the increased demand for toluene and the corresponding scarcity of this m aterial, O f these, trichloroethylene and the a ir through an droxide solution to ft V, benzene is rapidly takpig its place as a sol tetrachloride are probably most i thato w bkb is detenr vent in many industries. Xylene; which besides found. They are used extensively as British Depniim ent being an important solvent, also does enter as cleaning agents; the former in regular de a raw material in certain chemical processes, greasing machines on a production bans and trial Bcacnrch uses consisting of bubtrii at present associated with the defense industry the latter for work of a more occasional ethyiamine and copp and therefore used in great quantities. For nature. These m aterials with their grease cured compound the i instance, in a plant I visited recently xylene dissolving properties are regarded by medical is used in the production of a certain type of authorities as m y injurious to die fatty tis pared with standard inability of these va resin, which in turn is employed in an article sues of the human body. their evaluation in h manufactured for the United S ates Army. As in the case of other subsances referred be by means of a c All these three m aterials are classified as to above, there are chemical methods for Unfortunately, how industrial poisons, although there appears to quantitative determination of vapors from these instruments as be some confusion as to the relative toxicity these m aterials, but they are mosdy too cum low enough to get of each. Benzene is generally considered as bersome for routine sampling. Optical instru- safety range of tins the worst offender, although this may not be irsnts are available, however, for rapid evalu due to a greater toxicity of the material per ation of such vapors dispersed in die air. The se but to the fact that it has a higher vapor pressure than the other two so that for a given temperature more of it will be found in the air. However that may be,' the toxic effect of all of them, once dispersed in the air, is generally recognized and therefore in dicates the need for strict control wherever they are used. Few the evaluation of these m aterials some chemical as well as physical methods are available. Most of these, however, are com plicated and cumbersome, involving m ch operations as nitration by bedridng the a ir through nitric arid with subsequent color imetric determination, o r condriwstinn of die best known of these is probably the portable interferom eter m which the difference be tween the refraction of air (th e comparison substance) and that of the gas m ixture to be examined (is measured. This difference is calibrated in term s of concentration of the gas o r gases under observation. Naturally the same readings will be obtained far all gas m ixtures resulting in the same refractive in dex, so the instrum ent is therefore not spe cific W ith information, however, as to the tVDg^^SS of wOnfi>T fvQmQwOnwtBnI^Hsisf^lBnsOmt OQflMSCfOOdl nuOn O |f^l^MwUpsT* problem it is an exceedingly useful t--tnwv--* t **9fa--ifSfgaffaff rJ f great1variety of gases mid' vapors. In this group f hydrofluoric, h y d ra are those most cm these, nitric arid hai other heading. Ex resulting in chrome nasal septum are chromium plating ' mg. per 10 cubic im lished for chromic a work occurs as a u Hydrofluoric and h ist in gaze mis form hydrogen blonde of 3 p.pjn. has beer vapors followed up by laboratory analytical procedures for the final evaluation. W hile methods of this tvue mav be satfaffaetonr for 'T his sahstsace which ail itfF n sry lea while it l as been latter. Sampling for nil K v n n e p v p o ta^ Mr r a m p m p > ^ in tares o e n re as a liquid vW i a U gh control work in indnrlriul ulunhL a eotobus- oxfc vapors for acids is trually do sodium h) Iroxidc yjt'isirttS'j Dust, Fumes, Gases and Vapors 65 < <iicnt. ; primarily for fire ignwi to read to plosive limit of the For above sub rive limits around that concentrations detected, which is sd toxic limit for c with a safe limit ed combustible gas d on the market, itiona ranging be* u A aoectroncooic i of bouene and described by Cote relatively low safe limits have been suggested tiy various authorities. Russian investigators have recommended a threshold limit of only j p.pjn. for prahmgad exposures, while the British D e p titsm t of Scifutiftc ond Indus* trial R em rd In s mu n U i a n h x at 10 nULrvS*.MnLSt naans nsnumt OwraVwRa Svrtaamlev of UumtotaMwrmCwukwwoS^^mCwttaSmg. Q pp4B* WBBO VSpf m m S m 'n fO fO w ff between these vahwa, diey a ltm d to iad k ate die potential danger coaarc ti d with taiposuras to vapors of carbon tBarifid t. through potassium hydroxide; and hydro chloric arid through glycerol-potassium car bonate-water solution For die final labora tory evaluation I refer to standard methods of the A P JH A . 1. Grcanburg. L. and Sm ith, G. W . A New Iiufrw atm fo r Sampling Aerial D o st R. L 2392, U. S. B araaa of Mines, 2 2 . Although dde ndvcnt mny ha us a gram n n p mopmrup apnanm m , *w. found prim arily la he irnuau up uuuw m . m s m i '. n ra-w--n^Uoa*nkH^iMnunmp!Ufl 11 F ar evaloation of these vapors, die A ir H jgtttrt W am btfm ^rtHli1 drawino ' the afr d m n ^b in alcohohc potasshnn hy- droxifr ^ ^ a n to fm ^ fM tt> iM m ie ^ mm- ; 3. Barnet. E. G and Penney, G. W . A a E lactn atatit Dnat Weight Sampler. Jc . In dustrial Hygiene It Toxicology, 20, 3, p. 259 M arch, 1938. m etal in regular derodnetion basis and a more occasional their grease by medical to the fatty tis- British Department of Scientific and Indus trial Research uses a colorimetric method consisting of h W iip the air through diCthytamme and coppr r acetate forming a col ored compound the tnesnmty of which is com pared with standards. In view of the infiam- mabfltty of theae vapor* a rapid aacriud of their evaloation In be by means of a L'nlommatety. however, the sensitivities of these inatnamm aa b a it at present, are ant low enough to f i t within the physiological 4. Berna, N. R. Dnat f*^ni<fnn^ii~ H eath. Piping, and A ir Con* ditioning, M arch, Jnae and October, 1942. 5. Pinto, S. Sherman and Fahy, John P. A New Colorimetric Method fa r the Deter mination of T .N .T . ( 2 ,4 ,6 Trinitrotoluene) in A ir. Jo. ladostriai 24, l ^ M Febrnary, 1942. MUBlp rV n K fm i w twEBIOCIi Avenue, New Yorh. N. Y. UnpabBahad data obtained through personal comamnication, A a p a t, 1912. O plkal instns- safety range of this i 7. Department of Scientific and Industrial ver, far rapid evaio- Research, London, England Methods fa r De rsed in die air. The tection o f Toxic Gases in Industry. abahly die portable dK diference be In g roup probpbiy nitric, L n le t No. 1--Hydrogen Sulfide a r (th e comparison hydrafiaoric. hydrochloric and salfnric grids Now Now , mdiifxfteurreenctoe bhe odth#efr, nbietnridciango.d hEasspobseaenredsiatcomaed under an NNoow. $--N itrous Fames S i No. 6 --tQwfaon Disulfide of die N aturally resritipff m > No. 7Y-Gmhon Monoxide for ail gas nasal sep ta^JnLsLamre A ;--*- fll_lg ,, i d Leader H a ff--Phoegen refractive in- ' faMn^l' W n n n nBI M Vi Leafiet No. 9--Arsine e not ape-, as to the J ie r tdneanie aria w hichiat Leaflet N a tt- O d o r u e m .a e rit acara aa p aria anar 1 Laaflet Haw H -A a ilia e I m l g No. 12--O rgaoic Compounds fl. Method rmployvri aft die H arvard PfV f rf PkHfc Berith: le t a* > p p a a 9. A lr B f g k u t Foundation of America, aria* Bulletin *t or#nary lampara* f on Methods Atmoaffreric 11< 31st National Safety Congress Contaminants, pp. 80-85, 1935-1936 Year Book, American Public Health -.Association. 11. Fictdner el al. Jo. Industrial & Engi neering Chemistry 11:519, 1919. 12. Evans, R. D. Apparatus (or the Deter mination of Minute Quantities of Radium, Radon and Thoron in Solids, Liquids and Gases. Review of Scientific Instruments, 4:99 -1 1 2 (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 Instrum ents 13: 147--151 (1942). 14. Evans, R. D. and Goodman, G De termination of The Thoron Content of A ir and Its Bearing on Long-Cancer H asards in Industry. Jo. of Industrial Hygiene ft Toxicology, 22, 3, pp. 89-99 March, 1940. 15. Evans, R. D .; Nilson, S. J .; Good man, C .; and Berm , N. R. Industrial Ap plication of a Method for Determining the Thoron Content of A ir. Proceedings of the VIII International Congress on Occupational Diseases and Preventive Medicine, held at Frankfurt a. M. Germany, September 26-30, 1938. 16. United States Public Health Service. Division of Industrial Hygiene, National Institute of H ealth, W ashington, D. G Cad mium Poisoning. Public H ealth Reports 37, 17 April M , 1942. 17. Buhner, F. M. R .; RothweU, H . E.; and Frankish, E. R. Industrial Cadmium Poisoning. A report of fifteen e n t a includ ing two deaths. Canadian P ublic H ealth Jo. 1938, V.29, 19-26. 18 Littlefield, J . B .; F rid tf, Florence, L. aHOdl XBiTvDKw si, XftvI BmSKfmmKW vft Tf^tJ^BBBHC^an for Collecting Lead D w a and Fumes. R.I. 3401, U. S. B u n s of Mme* M ay, 193ft 19. American Standard Association. Benacne; allowable concentration. Z 27A, 1941. 20. Cole, P eter A. Determ ination of the Concentration of Benzene and Toluene in A ir by a Spectroscopic Method. J a Optical Soc. Am. 3 2 ,304-306; May, 1942. Selection, Uee and Bfaintenance o fBeepbatory Protectfre By H. H. SCHRENK Chief Health Division, Bataan of Minas and ft J. PEARCE Aaaociate Chemist, Gas and Dust Section, Central Experiment Station, Bunan of Minas, Pittsburgh, Pa. *Publish'd hr perunsaion of the D in o a , B o rn e of M ines. U. S. D c f u te o t of the U teris*, Wash* itfi , 0. C. H . H. Schrenk, chief chcmiit. H ealth Di vision, Bureau of Mines and S. J. Pearce, associate chemist, Gas and Dust Section, Central Experim ent Station, Bureau of Mines, Pittsburgh, Pa. There are several w dl-raogaiaed pro cedures for controlling exposure to hazard ous atmospheres in industry. They elu de (a ) substitution of less toxic mattria l, (b ) enclosure of processes; (c ) wet methods; (d ) local exhaust, (e ) general veufflatina; and (f) ase of respiratory pr otective dev tc e s -In ure or improper use of other control equip m ent Respiratory protective devices usually are employed to supplement other methods of control, as a tem porary expedien t or when other methods a te not readily or practicable. It seems reasonable to assume, however, tfaaf where respirators arc used, consideration baa h*w gives to die factors involved, and d ttt the devices can provide satisfactory protection if need properiy. Their use sfaoaM " id be arrived a t daddy by a process M efim hudka of other dad are m ote d dm alt to apply. Abnospherie ooatandaants wf H f gates, vapors, dusts, foams, a n t* aad fogs. Bet- respiratory protective devices alas aro essen tial in emergencies d ad may arise from fad- are hnwadmOdy dangerous to health o r life 664 31st National Safety Congress Officers 1942-1943+ General Chairman--F. A. Bogus, Chicago, Rock Island ft Pacific Railway Co., Chicago, 111. I 'ice-Chairman--H. A. D aake, E rie Railroad C o, Cleveland, Ohio. Secretary--M. T. F ulton, Kansas City Southern Railway C o, Kansas City, Mo. Xettrs Letter Editors-- M. T . F ulton, Kansas City Southern Railway C o, Kansas City, Mo. if . G. T ownsend, Kansas City Southern Railway C o, Kansas City, Mo. Program Committee--}. R. T enney (Chairman), W estern M aryland Railway C o, H agers town, Md. P. F. B uckle, Chicago, Burlington ft Quincy Railroad C o, Chicago, 111. H. A. D aake, Erie Railroad C o, Cleveland, Ohio. Membership Committee--G. W . Elste, J b. (Chairman), Baltimore ft Ohio Railroad C o, Baltimore, Md. J. E. Long, The Delaware ft Hudson Railroad C orp, Albany, N. Y. Statistics Committee--T. H. Cakbow (Chairman), The Pennsylvania Railroad, Philadelphia, Pa F. R. Bbadfobd, Boston ft Maine Railroad, Boston, M asa D. G. P hillips, Wabash Railway C o, S t Louis, Mo. Contest Committee--C. L. LaF ountaine (Chairman), Great N orthern Paul, Minn. O. F. G nadingeb, Elgin, Joliet ft Eastern Railway C o, Joliet, III. L. R. P almed (Secretary), Equitable Life Assurance Society of York, N. Y. Railway C o, S t the U. S , New Poster Committee--E. L. H ekky (Chairman), Chicago ft N orth W estern Railway Co, Chicago, 111. G. M. D empsey, Chicago. Milwaukee S t Paid ft Pacific Railroad C o, Chicago, 111. J. J. S navely, New York, New Haven ft H artford Railway C o, New Haven, Conn. Safe Practices Pamphlet Committee--W. J. F lannigan (Chairman), Northern Railway C o, S t Paul, Minn. S. C. F laguck, Atchison, Topeka & Santa Fe Railway C o, Topeka, Kansas. H. C. H elwig. The Delaware ft Hudson Railroad C orp, Oneonta, N. Y. Pacific dominations and Elections Committee--W . R. Lopgben (Chairman), Chicago ft North W estern Railway C o, St. Paul, Minn. C. M. K imball, Southern Railway System, W ashington, D. C. L. B. H asped, Illinois Central System, Chicago, 111. Health Committee-- Da. I. S. C uttek (Chairman), Chicago ft N orth W estern Railway C o, Chicago, III. Da. H abvey B abtle, The Pennsylvania Railroad, Philadelphia, Pa. tA* dcctM by delegate* a C m r(n sm ioa.