Document daNDK8nY3kdEpew5evV97n6kQ

1935 TRANSACTIONS National Safety Council Incorporated TWENTY-FOURTH ANNUAL SAFETY CONGRESS Louisville, Kentucky October 14 to October 18, 1935 The Brown, Kentucky and^Scelbach Hotels Copyright, 1936, National Safety Council, Inc. Twenly-foiftth Annual Safety Congress--National Safely Council Carney, Chicago Safety Council. n:r I. Cati.in, Aetna Casually & Surely Company. ' . Ciiue, Evanston Safety Council. II. Coleman, Cement Section. IkiniriiT Corson, Safety Dept., Nashville Chamber of Commerce. nk Emery Con, Berkeley Traflie Safety Commission. Ctij. nkv, Bethlehem Steel Company. W. Da'.h, Metals Section. ii.iam G. Dkani.ii. Rochester Safety Council. us A. DeBlois, Consulting Engineer. E. Dec \Kti, Mason City Safely Council. W. Demfesv, EooiI Section. M. Diet/, Rubber Section. Mrs II. Douglas, The Philadelphia Gas Works Co. . Lons I. Duuu.v. Metropolitan Life Insurance Co. 1). Pennell, Consulting Engineer. \'Ai.it A. Fixkbeinkr. Toledo Safety Council. . ll.\uT E. Pi sun:, Chicago Rapid Transit Co. W. P kk, Jn., Marine Section. ms. Pr ^glr.vi.d, Western Pennsylvania Safety Council. vyaiiu I... Fonua, nurroughs, Wellcome & Co. (U. S. A.), Inc. !!. Foul.jin, Lehigh Valley Safety Council. F'osiru, Jr., Quarry Section, itn n. Giiison, Western Electric Company. A" M. Godwin, Public Utilities Section. I". Grant, Paper & Pulp Section. MiHV Gu'tt.nr.RT, The Pullman Company'. viaii Il.u r, The Atchison, Topcko & Santa Fe Ry. Co. ajor Roi.i.inc II. Handy, Richmond Safety Council. . T. Harrington, U. S. Rureau of Mines. J C. Haven, Vehicle Fleet Section. :. W. IIimss, Textile Section. I . T. ifu.f.Mcm, Chicago, North Shore A- Miluaul.ee R. R. Co. harms 1C. Ilii.i., New York Central .Lines. on. IIariu.d G. I Inn .max, GuviTimr nf New Jersey. i. ll/lit: J. HoLniNi:, Alliany Safely Council. invtN A. Kaysen, St. I.miis Safety Cnuucil. iiomas 1*. Kearns, Industrial OmmiiViuii nf Ohio. . T. Ki.li.k.R. Detroit Imlu.trial Safety Council. A V. Kki'.vlh, Pennsylvania Salt Mfg. Co. iii.hm C. Knoki.k, Street & Highway Trail!c Section. . 1.. LaFountaine, Great Northern Railway Co. . F. Larson, Missouri Pacific Railroad Company. MO.v Lazarus, Safely Council of Columbus (O.) Chamber of Commerce. It. Long, The Delaware Sc Hudson Railroad Corp. '. R. I.oyd, Safely Div. Birmingham Chamber of Commerce, nos. II. MacDonald, U. S. Department of Agriculture. T. McArthur, Peoria Safely Council. J. McCann, Meal Packing, Tanning & Leather Industries Section. Officers and Directors Miller MuCuntock, Harvard University. T. H. McKenney, Carncgic-Illinois Steel Corp. A. D. McWhorter, Safety Div., Memphis Chamber of Commerce. II. T. Martin, Fisk Rubber Company F. W. Matson, Minnesota Safety Council. James R. Mays, Elizabeth Safety Council. E. J. Mkiiukn, Portland Cement Association. I. W. Mii.i.ard, Industrial Gloves Corporation. James K. Miller, Grand Rapids Safety Council. Leslie W. Miller, Superior Safety Council. Harold L. Miner, E. I. du Pout de Nemours & Co. Lawrence M. Moore, Eastbay Safety Council. R. B. Mokley, Industrial Accident Prevention Assus. George C. A. OPi*. The Detroit Edison Company. George Oppen^eimer, Kansas City Safety Council. Lew R. Palmer/Equitable Life Assurance Society. David A. Patton, Newark Safety Council. Charles W. PfcVuoCK, Safety Div., Milwaukee Assn, of Commerce. C. E. Pettiuone, American Mutual Liability Insurance Co. Gen. George B. Pillsdury, United Slates Engineer Office. Arthur Potterton, Hudson County Safety Council. W. D. Price, Employees' Publication Section, j. A. Purdy, Wood Products Section. Aluert S. Recula, Industrial Relations Counselors, Inc. Lt. Col. Henry A. Renincer, Lehigh Portland Cement Co. Marinus Riter, Paterson Safety Council. R. B. Roaper, Petroleum Section. A. V. Roiiweder, Duluth, Missabc & Northern Uy. Co. George E. Sanford, General Electric Company. Henry G. Schaifner, Eric Safety Council. Rouert L. Schmitt, Louisville Safety Council. Karl G. Schokffler, Railway Safety Council. Harry A. Schultz, United States Steel Corp. Karl S. Siiartzkk, Utica Safety Council. Rav H. Sheets, Madison County Safety Council. Gen. John II. Shkkiiurne, Massachusetts Safely Council. Dr. L. A. Siiiiuiiy, llclldcliciii Steel Company. Ernest L. Si.monds, New Ilavrn Safely Council, Juih;e Lee E, Skkel, Cleveland Safety Council. C. W. Smith, Standard Oil Company (link). Edw in C. Smith, Blackstone Valley Safely Council. Walter Dent Smith, Delaware Safety Council. W. A. Snow, Construction Section R. T. Solknsten, Elliott Service Company. E. C. Spring, I.ansdale, Penna. George R. Stephens, Safety Bureau, BufTalo Chamber of Commerce. James M. Strike, St. Joseph Safety Council. Arthur M. Tode, Consulting Marine Engineer. Harold M. Toomds, Refrigeration Section. 8 T~vcvly-fourlh Aiuiunl Safety Congress--National Safely Council W. W. Trench, Schenectady Safety Council. W. D. Tukueville, San Antonio Safety Council. E. J. \Vali-mak. Power Press Section. Dr. C. H. Watson', American Telephone & Telegraph Co. Harry M. Webber, Illinois Bell Telephone Co. Albert C. White, Jr., Springfield Safety Council. S. F.. Whiting, Liberty Mutual Insurance Company. A. W. Whitney, National Bureau of "Casualty & Surety Underwriters. T. A. Willson, Accident Prevention Equipment Manufacturers' Section. W. II. Wina ns, Union Carbide & Carbon Corp. C. T. Winegar, Automotive K: Machine Shop Section. Harry Wise, Sr., Qiattanooga Safety Council. J. M. Woltr, The Youngstown Sheet & Tube Co. W. E. Worth. International Harvester Company. E. J. Zauft, Safety Bureau, Duluth Chamber of Commerce. Earl W. Zimmerman, Safety Div., Syracuse Chamber of Commerce. .Occnf'niioual Diseases Occupational Diseases FRIDAY MORNING SESSION October 18, 1935 The session *vas called to order by Mr. \V. Dean Keefer, director. Industrial Division. National Safety Council. Dr. C. H. Watson, newly-elcctcd President of The National Safety Council and Medical Director, American Telephone and Tele graph Company, New York City, presided. Present and Prospective Occupational Disease Legislation By F. ROBERTSON JONES General Manager, Association of Casualty and Surety Executives New York, N. Y. Shlcc me prevention of diseases is. to -some decree, a community problem, the state ought to do its part toward the prevention of occupational diseases, along with all others. The. public health authorities should study the causes oi such dis eases. their prevalence, virulence and the means for their prevention. They should advise as to such means of control, and. as a last resort, appeal to legislatures for power to order compliance with their rules. Statutory regulations for prevention, emanating irom other sources^ such as are common in "labor1' or "factory" laws, have too serious drawbacks to be efficient. They are apt to be indexible and quickly become "out of date": and they arc too apt to be perverted for the establishment of fictitious bases for wasteful and demoralizing damage-suit litigation. Scientific bureaus of occupational hygiene, under direction of public health authorities, are the best public instrumentality. Efficient bureaus of that character are now to be found in several states; but. generally, such public health organizations are inadequately manned ami equipped. Therefore tile primary need in occupational disease legislation is for measures to improve our public heaith services. Emphasis should be placed on prevention, not merely because `*an ounce of pre vention is worth a pound of cure." but because public measures for the assurance of relief to victims arc perilously susceptible of being so perverted that those affected will tend to rely upon and abuse the protection afforded as a substitute for, instead of as a supplement to . means for self-protection. Expert opinion now calls strongly for the entire elimination of employers' liability for "damages" for occupational injuries--by disease as -well as by accident--based upon negligence. That remedy is too uncertain in operation, litigious, demoralizing and wasteful; it furnishes relict to too few of the victims unless it he so liberalized as to he grosslv unjust and financially perilous to employers--and thereby harmful to industry and all dependent upon industry. Ixjsses front iil-bcalth among workmen arc primarily subjects for self-providence or for "social insurance"--for "sickness insurance" to licln out during brief illnesses, and for "invalidity." "old age" and "widows' and orphans' '' insurance where illnesses or infirmities result in long or permanent disability or untimely tlealth. The cost of these insurances against the common misfortunes of life cannot rightly or expediently be imposed wholly upon industry, hut needs to be distributed somewhat in proportion 1 IS Twenty-fourth .-tunual Safety Congress--National Safety Council to rc<i ui'iliiliii. Ami benefits, at a high scale of maximum earnings, as in workmen's compel ration, simply cannot be provided for all such workmen's misfortunes. In iiitalnl v. old-age and life insurance, at least, the benefits must be graded, more or lc<v in iropnrtiun tn the individual workmen's contributions to the requisite reserves; and (he right to hrnefit must lie conditioned upon some minimum number of contribulioiis. It is only for some relatively small proportion of the injuries and physical ills In which workmen arc subject that it is reasonable and practicable to impose the full icsp.Mi-ibility on industry. From its I,i "innings, the workmen's compensation law has covered all injuries to iic.iltli resulting from occupational accidents, Further it has now, in this country and ,ihro.nl. hern extended to cover many specified diseases, not resulting from accidents, classified as ` occupational.'' And in a few states in this country and Tallin America it has been extended indefinitely further to cover "all inclusively" all injuries to health "arising out of and in the course of the employment" or all "occupational diseases," undefined, "arising nut of the employment." In this country there is strong political pressure in favor of this "all inclusive" ioverage of injuries by disease based upon the contention that there is no difference in principle between "injuries by accident" and "injuries by disease"; therefore, indus try ought to he liable for both classes of injuries on the same terms and conditions. This contention is fallacious. The fundamental principles of the compensation law are that industry shall be held responsible and liable to compensate for the losses from thovi; injuries only which are caused by "trade risks", resulting from employment and which the employer can control; and that the liability for such risks shall lie stifficitnlly well defined, as to he insurable at practicable and equitable rates, fixed in adsanee. The standard compensation laws have been framed to carry out those prin ciples in application to injuries by accident. Rut the factual conditions relative to injuries hv disease are so different from those relative to injuries by accident as to necessitate different treatment. The crucial difference between accidents and diseases is the time factor. An accident i a Sudden event, happening at a definite time and place. Generally the cau-al ecl.'iliiMt between the employment and the accident and between the accident ami the resulting injury can he traced with reasonable certainly. Generally the impbiier is aulomalieallv identified. And there is a char-cut event from the date of wbirh time-ii.uils on notices, claims, etc., can he measured. In contrast, many diseases inttiibiilablc to occupational risks are of slow: contraction, and may he of equally slow progress to haimfiil results. In silicosis there may lie an interval of as much as Iwcnlv or thirty years between the first exposure and disability or death.. In the meantime. many causes for di'-ablcmcnt or death, other than the occupational disease mai hair operated. Often it is a mailer of extreme difficulty jo determine whether ! disability or, death really has resulted from an orcupnlinnnl disease or from other rnmes. Medical diagnosis of the mere existence of a particular disease is often linnwlai'ii; yet fur the proper oiieratinn of compensation (nr nrcupalioiial diseases it is essential in obtain true medical diagnoses, nut merely of the existence of the disease, lint alsii n( i|s causes and eiiiiseqursues. A fin liter difficulty is that, where the disease is of slow roiilraeliiin, it may he conliaetnl lie a workman under several different employers or insurance carriers. In sin h cases it is issinli.il for the prntretinn of the workman that some one existent riupbnir nr insurance carrier shall lie direellv liable fur the entire riuniHiisalinn. That ,:,s a hiphilv vicarious and harrh liability In impose upon an rniplnycr nr insurer whelier or not arrninpaiiii d hr a riphl to elaiin rnulriliulioii from earlier cmplnyrrs amt in.'itriTs and, in all fairness, slii.nld he subject to strict limitations. M'ueovir tin re is a ililhrtilli im ideiil.d to the provision of new insurance for ronip- n-atioii for such diseases of slow1 cniitr.'u linn as silicosis. Under such rnuditinns, tin li.il 'litr imposed upon the rniphnir im hides a liability for disability nr death in the filin' in fit her words, a liability, not merely for future risks hut a|sn for the cost of a loliiiue of physical iinpaii nuills already inclined llinugh the liability therefor is lint yet matured. In insurance parlance, these are termed "accrued liabilities." Such , arcimd liabilities, under it law newly imposing a liability to rniupcilsatc for silicosis, would, it is estimated, in a stale such as New York, aggregate many millions of dollars. This rust is additional, to losses (rum current risks; and bow to meet it and how to fix- reasonable charges fur insuring it is a complex financial problem. Occupational Diseases 110 - The situation, then, in my opinion, is this: The principle of compensation, re gardless of fault, inay weii be extended to cover those disabling diseases that are characteristic of and peculiar to and have their origin in the occupation or process in ' which a person is engaged. This would exclude the diseases of ordinary life, and would he applicable only to the specific hazards which arise nut of and because of industrial processes and occupations. The piorisions for such coverage should be separate and distinct from the provisions of law applicable to compensation for nrridcutnl injuries, and these distinctions should he constantly emphasized. TUc problem* of formulating such provisions is relatively .simple with reference to those recognized diseases set forth in the older occupational disease laws, since such diseases are reliably diagnnsnhlc, of quirk contraction and non-progressive. Rub it is difficult in respect to such progressive diseases of slow contraction as silicosis and asUslosis-- now generally regarded as being truly "occupational." Fortunately. howeVer, there .' arc promising models for our guidance in some of the foreign compensation laws, : whereas experience under indefinite, "all inclusive" coverage in Connecticut, Massa- ( cluisctts, Wisconsin and California is helpful with lessons ol faults to avoid. In niv opinion, a law fur the compensation of occupational diseases should contain , provisions (o the following effect: 1. Dresses to he made "compensable" should he distinctly specified--by listing .in a "schedule" or otherwise. They should include all those diseases, hut only those. to hf found in the stale, which, according to prevailing medical opinion, can be traced, in individual! cases, to origins in "trade-risks"--i. r.. risks, not of ordinary life, but created by special practices or processes in industrial occupations. 2. There should be a special regime for expert adjudication of medical questions in occupational disease eases. 3. There should be definite periods of exposure required as a condition to the right to compensation for various occupational diseases; the time within which, in order to he compensable, disability or death must follow exposure should be limited; and eases resulting from exposures prior to the effective date of the compensation coverage, or in industries wholly outside the particular state, should be excluded. 4. Prompt notice either of the first manifestation of the disca'C or of disablement --the time of Midi event In he determined as a medical question--should lie strictly required: and every presumption should be against the validity of a claim not made as promptly as practicable. 5. Tn case an occupational disease merely aggravates, prolongs or accelerates j disability or death due primarily or proximate!}- to a non-omipatiooal disease nr infirmity or. above all. to old age. the compensation should he reduced to lie propor tionate to the degree In which the occupational disease contributes to the disability or arrelcrales death. (>. The employer, as or the lime of the workman's last substantial exposure to hazards o( the disease, and the insurance carrier then on the risk should lie liable for the entire compensation--with or without right In eunirihiitinn front earlier employers and insurers. Rut all such liabilities, whether direellv. for compensation or for con tribution to the compensation payable by others, should he suhjrrl to brief time limitations. 7. In incurable diseases, especially silicosis, the obligatory medical benefits should he specially limited in time and kind. 8. In silicosis and other diseases of slow contraction, there should he special provisions for limited compensation to workmen laid off !-fnre artual disablement, with the alternative, tinder some conditions, of waiter of rompen-ation In- surli work men for aggravations resulting from being allowed to continue in the haz.inlouj occupation. 9. A law newly imposing liability to nniipriiialc for silicosis ami other diseases ol slow contraction should leave a substantial interval for preparation bet wren the date of its enactment and that when it shall take rlTcct; the compranalimi for such diseases should he specially reduced anil limited Inbitv what would otherwise In appropriate until the "accrued liabilities" are winked off. 10. Coinpeiisali-in for occupational diseases should he insurable Mparalcly front compensation for accidents; and. in the initial stage, at least, uf a regime of.coinpcnsaljnn (or such diseases as silicosis, the rating practices now imposed upon insur ance carriers need to lie radically modified..' .'0 Twcnly-faurlh .tniinalSafcly Conyrcss--National Safely Council Tlic iilioic program is sound and would l>c highly conducive to occupational aw prevention. Hut I am nut so confident that it would lie safe. The pressure is ng for "liberality" in compensation laws. Merely a few among a large manlier i n.liaUc slight diversions from what 1 suggest would convert compensation for palional diseases into indefinite health, old-age and life insurance'fur workmen in .) industries. The cost might ruin the industries, and, at least, would he so deniable as to make the risks `uninsuralde," except on the unlimited assessment at. ttiih all its financial perils and uncertainties. In regard to prevention, there are still some practices to he decided upon in '.cling a regime of compensation for occupational diseases about which there >ins much ilouhl. l-'or example: Such a regime will practically compel employers, riving employment, to discriminate against all the ailing or aging--against all pt the most healthy and rolnist. That seems to lie desirable in occupations when occupational disease hazards are great. Hut is it desirable otherwise? Again, an ideal'common In those of us who emphasize prevention is to require prompt 'removal from exposure of workmen manifesting the first symptoms of an ip.iliniinl disease. Hut for the cldcily or skilled workman the loss of lii.s trade-job . lie worse, in every respect, than the danger of continuing his exposure. How . should such rases he defined and trcalcd and how should the law he framed to .1 or iiultirc si eh treatment ? Political impatience is the chief obstacle to a just and equitable settlement of the ip.ilioital disease problem. If those thoroughly informed as to this complex suh- u bo have sincerely at heart the welfare of workers could he delegated the auity to devise a solution, some progress might he made. Hut when political igantla is injected into the situation there is little chance for an adjustment i.ielory to all concerned. The greatest need today is the divorcement of occnpad disease legislation from politics or political considerations. Some Practical Considerations in Dust Control By J. J. BLOOMFIELD vjitary Engineer, United States Public Health Service, Washington, D. C. The pi .vcutioii of ocrui>atioiial diseases due In the inhalation.of industrial dust i imarilv an engineering problem. Until recently, however, little attention had di-volei.'* to the control of dust, accounting for the paucity of fundamental data Mibji-t. The conwquenres of the neglect to furnish adequate protection from hazards ire now being fell, and the cost is becoming a serious drain on industry, mm- wi I established that exposure to certain kinds of dust, snclt as those conig considerable amounts of quartz, has increased the morbidity anil mortality from respiratory diseases; while metallic dusts, snclt as lead and its compounds, In-ell associated with general systemic poisoning of workers. It is obvious, lore, that any serious allnnpl to control the dust hazard should, in time, result iilv tii the improvement of the health of workers, hut also he of definite economic 'I In industry. I lie benefits of a preventive program. in the field of accidents arc well known, try is fast realizing the need of a similar picvcntivc program with respect to atinnal diseases. Evaluation of the Dust Hazard t lie first step in the evaluation of the dust hazard is the determination of the -itional exposure to the dust in question. A typical example of snclt a study serve to clarify the methodology involved. I aide 1 show s the various occupations in a granite quarry and the number of .rs employed in each occupation. Drillers arc the only persons using pneu- lools, known to. produce cmi'idcraldc quantities of dust. In other words, 38 ` "* " the quarry personnel arc shown to he cxposctl to a potentially dangerous i/aid. fhi. occupational analysis at once indicates that the dust investigation Occupational Diseases 121 Table 1--Occupational Classification of Granite Quarricr* Occupation Drillers: I.eyner ........................... Plug and jack hammer. Ulhcr quarry employees: Superintendent ............ Foremen ....................... Compressor engineer .. Hoisting engineers .... Locomotive engineer .. I.ocojiiolivc fireman ... Slcpm-shovel man ___ CAlttF operator ............ Derrick men ............... Muckers ....................... Iilhck smiths ................. Tool hoys ..................... Water boys ................. Machinists ................... Air-line repairers .... Pipe fillers................... Number in Each . Occupation 17 37 1 7 1 12 1 1 1 1 24 24 6 2 1 3 1 2 Total 142 Table 2--Occupational Dust Exposure of Granite Quarriers Occupation Number in each' uccupal ion 1 eyiu-r drillers..................................................................... Plug ami jack-hammer drillers (quarry-hole).............. Plug drillers (yard)............................................................ All other workers.......................................................f......... 17 37 88 Died counts in millions of panicles per cubic font of air. Weighted Average 144 4 112.1 3f>9 5.8 should especially concern itself with these workers. The next step involves the determination of the occupational dust exposure. Table 2 shows the results of such a study. ft is apparent in this table that the drillers arc exposed to high dust concentra tions, especially the I.eyner and jackhammer drillers working in the quarry hole. From a further analysis of the occupational dust exposure of drillers it is possible In determine which activities' are responsible for the dust. For example, experience has taught us that the various activities comprising the processes of most dusty occupations are usually associated with dissimilar dust vxposnrcs. For this re.,'.on it is essential to estimate the amount of lime spent in each activity in any one occu pation and to determine the dust exposure for cad). Table 3 shows the results of such a study in the ease of a I.eyner driller. It will he seen that a Leyncr driller has five different dust exposures. A differ ential analysis, as presented in Table 3. yields several valuable findings. First, it enables otic to obtain a true average (lust exposure for workers engaged in the occu pation of I.eyner drilling. (In this ease the weighted average is 144.4 a< contracted with 213.4 million particles per cubic font found during drilling operations only.) Second, it enables one to determine which activity, or activities, contribute most to the l Tn-cnly-f-nurlh Annual Safety Congress--National Safely Council . . fable 3^--Summary of Dust Exposure of Leyner Drillers in a Granite Quarry \< liv icy Average dust C-N|tf5urc in millions of Parlicle-hours Number of in millions particles jici cubic boors spent in per cuhic foot of air (a) each activity (b) foot (a X b) Itine:.............. myiiit* dri!J> .......... irhiii-j drills............ him: .......................... .............. u me *(( ............ .;........ fin I.HS5 0 4 853.fi 1 9.8 9 1 fid Ya 4.5 U 271.3 Total___ _; 8 1,155.2 55 3 paitirlc Ilnurs in millions per cubic font -------------------------- --------------------- - 144.4 tnillinn particles per cubic foot 8 liuurs ; t hazard. I (''is evident that the practice of blowing off boles by means of inserting nni|.ies?etl :>i. line into each hole is attended with a preat amount of dust; and null this activity lasts but 15 minutes of the S-hottr-working day, it is responsible 23 per cent of the total dust exposure. It is evident that 23 per cent of the Lcyner lirr's dust exposure may lie at once eliminated by prohibiting this practice. And ity. surii an analysis indicates the necessity for tievoting all one's efforts to the mini of dust during the drilling process, since this activity accounts for 74 per cent ilie t >l.iI dust exposure, nlthfitigh a l.cyncr driller spends but one-half of the I in-- day at his drill. .So iar in hate dealt with an industry in which the workers, as a rule. d< not ngc their occupation. Often workers have had several occupations, cither in the ik industry or in several different hinds of establishments. If the worker has been iibo'td iii various occupations in (lie industry, it is a simple matter to determine' t>-lal dii-t exposure in that industry. This is important from the viewpoint of nlaliug a worker's dust exposure and his clinical condition. A typical example is nn in Tahlc 4. Tabic *,--Total Occupational Dust Exposure of an Anthracite Coal Worker i' Oltfpminn le pii Kt r .................................... ft*T ............................................ Number ol years in c.'irli 4Vr!tp;ilimi 2 7 t I iImuc r ............................ irr............ '................................... lion fimn.nt .................... ........ Total.......................................... 3 -- Dost eoncentralion in millions of particles per citliir f/w>t 380 71 71 480 48(1 7 - Millions of particlevrars pci ruble font 700 142 213 1.4 m 7.2MO _35. 9.790 `^O millions of particle-years per cubic foot 30 years per cubic foot I-i lahle 4 the worker's occupations are arranged in the order of employment, las," one living his present occupation. It is obvious that had title considered this upation only, the dust exposure would not have yielded a true state of affairs, I j Ii r ! ) ' ' 1 Occupational Viscoses 123 nor would it have been possible to correlate this dust exposure with the man's clinical picture. In the above technic, correct weight is given to the number of y ears spent in each occupation and (lie dust exposure associated with each. Only by such an analysis is it possible to arrive at a fair estimate of a worker's dust exposure and Jiis proper designation. Sticii an analysis is justified by llic fact that results obtained with this technic yield excellent correlations with the dimco-roentgcnological studies conducted on anthracite coal iiiittcrs.' it is thus apparent that there is more tc> engineering dust surveys than the taking of dust samplcs-ttnd their analysis. Owing to the fact that the making of dust studies is rapidly being adopted in industry, it lias seemed necessary to emphasize the impor tant factors in such investigations. Although the making of dust counts, per sc, is not a difficult,, procedure, the collection of dust samples in industry amt their proper interpretation should be dune by a Iliunittglily trained investigator. The examples .just given slum' the value of Ibis tcclmic in the subsequent steps to be taken in the control of the industrial dust hazard. yjj,. General Dust Control Method; The selection of any method of dust suppression will depend primarily upon its effectiveness "tic reducing a given hazard ami its adaptability. A large percentage of reduction in dual docs not necessarily indicate that the method Used is efficient, unless titc reduction has actually been sufficient tu bring the exposure below die safe limit, and does not interfere with the industrial operations involved.. In general, there are four methods of dust control: (1) substitution of nondust-prudueing or harmless sub stances; (2) isolation of the dusty operation; (3) wetting tbc dust at its source; (4) local exhaust ventilation. These methods may be supplemented by personal respiratory protection. The first method has a limited application. One example is the use of a nonsilica parting compound for a silira compound in connection with the making ot foundry molds, 'fable 5 .'hows that although the use of parting compound, in lhi< particular study, only necessitated an exposure of 54 minutes of the 540 minutes of a moltler's work day (10 per centj, actually this activity accounted for approximately 5S per cent, of the mobler's total exposure. It is obvious that the employment of a parting compound, which is iml as harmful as one composed of free silica, will lessen the dust hazard in litis instance to a considerable extent. Table 5--Dust Exposure of Molders Activity Average Dust Exposure in Millions Time <d Expo of Particles sure in minutes per Cubic Toot (3) (b) Use of Parlinu Coinpnuuit.......... kemainiug tasks in molding........ IVmritijr ................................. UiimpiiiK timMs ("Minky-mil*').. 51 412 58 lfi fi.l R 44 31 32.5 Total...................................... ParticleMinutes in Millions (a X b) 3.445 1.813 18U 5-'(! 5,'5S 5958 million particle-minutes -------------------------------------------- 11.0 million particles (per cu. It.) 540 minutes lit the case of abrasive cleaning with steel instead of sand, we have the example ol tbc 'substitution of a substance involving a loser dust exposure as well as tbc use of a material not as toxic as sand.' Table 6 slums tbc improvement effected by Ibis t)pc of substitution. Mot only is tbc dust concentration reduced from an average ol %') to1155 million particles per cubic foot, but the potential exposure to quartz tht't is diminished from 42-99 to 3 per cent. \ I Twenty-fourth Annual Safely Congress--National Safety Council Me 6--Showing Reduction in Concentration and Quartz Content of Dust In Sandblast Rooms With the Substitution of Steel for Sand Abrasive c of rasiir .1 ... I ... Average dust concentration in millions of particles Percentage per cubic foot of Quartz 969 -12-98 IS5 3 i he siYi'ini method of dust control, isolating the dusty process, possesses many ibilitics, but tinfi-rtnnau-ly is not widely used. The theory underlying isolation- * concentrate the dust sources u> one locality or to a single closed space. In this , a ininiimun miiuhcr ol employees are exposed. At present, many foundries, durshal.e-oot expose workers who normally are engaged in occupations with low ! concentrations. 1 bus, molders in a foundry may he ex-posed to a dust coiiccii- iun of 3 million particles per cubic foot under normal occupational conditions, but u shat.e-out operations are carried on close lie, their exposure may be increased .lore than 50 niiljion. The same eondition exhts when annealing flasks containing nid slag arc emptied in malleable iron foundries, exposing grinders and tumbling cl alliudants at work close by. lYib.ips the - -.si example of isolation of a dusty process is the abrasive cleaning a. I bis completely encloses a liaaardons process ami exposes only the blaster who riierally eipiipprd with a protective helmet. The room is also exhausted, which her reduces the dust runccnirntion. Processes which arc isolated rcipiirc good ilalion. Oilier examples of isolation are the automatic turntable for abrasive ling, iipuhtiug barrels, and batch-mixing rooms found in some pottery cstahlish1s. ' riie third method, perhaps the oldest known, is the practice of wetting the dust s source. In Table 7 an example is depicted in connection with the drilling and mg of rock in anthracite coal mine operations.' It is apparent that a tremendous i lion in dust lias been effected by ibis method. However, as already pointed out, -s a pailirid.ir method is attendant with a reduction of the dust to a safe limit, oiioi be Vuip-rdrrcd successful. In the present instance, the workers engaged in mg are still exposed to unsafe concentrations of a highly dangerous dusUaud more positive method of controlling the dust in drilling operations by dust traps 'I be imliraled. For drilling anil loading operations involving an exposure to dusts toxic an those containing high amounts of free silica, as in the ease of coal or iji mb . the reduction shown by the use of wet methods may be considered live. Ic 7--Ci ntrasting "Wet" and "Dry" Methods of Rock Drilling and Loading "'s No. of Samples Average dust count in millions of particles per cubic fruit "Dry" "Wet" mg ............................................... me ............................................... 23 10 568 6.16 33 32 Flic fourth method--exhaust ventilation--is perhaps the most effective, and one the widest application. We cannot discuss here the details of the theory and u of li.eal exhaust systems, except to point out there is a real need for more -im-ninl studies of the tvuc conducted by DallaVallc with reference to the design r.d exhaust hoods, which he has presented in Public Health RuUctiii 217. Tli~ of Hatch and his colleagues" op the control of the silicosis hazard in the hard industries is another example of a scientific approach to the dust elimination :m. t Occupational Diseases 125 Table 8--Summary of Results Contrasting the Dust Exposure of Mine Workers Under Controlled and Uncontrolled Working Conditions . Operation Dust Cuticcnlralion in millions of particles per cubic foot of air Controlled Uncontrolled Remarks Firing charge ..............40 l.uading coal or rock.. 32 Loading coal ........ 3-26 Drilling........ .................33 Hauling coal in'-luiucs. 1.2 'reparation of coal... 24 834 636 291-1133* 568 17 ' 380 Unless at least 15 minutes elapsed after firing a charge, miners found to be exposed to high dust concentrations. l)v wetting the loaded material the dust count is reduced as shown. Mechanical loading decreases the dust cxpo-aue as indicated. Wet drilling is effective in reducing the dust concentration. Further reduction would necessitate exhaust ventilation. Welting coal and empty cars reduces dust in liaulagcways. Wet breakers reduce dust counts as shown. Hit timer icsutl ir as.MK.-i.ilcl w-iiti llie li.nul l.m.Iiiu: ol wet coal while ilic higher aveiagc i> mi die liaml lo.uliii^ ol dr> coal. It is apparent that there are no set rules for the mechanical protection of workers from the industrial dust hazard. Specific conditions in an industry, or a plant, will determine the type of protection to be employed. The present discussion has empha sized the importance of approaching the problem from the standpoint of the occupa tional exposure. Studies in representative plants of an industry often rcieal the various methods which may he employed in controlling the dust hazard. The follow ing two examples indicate the value of such investigations. . Table 8 indicates the various control measures which were found tn use in the anthracite coal mines investigated ill the study referred tn earlier. Although no single 'mine practiced till of the control measures shown in this table, by an occupational study in several representative mines it was possible to slum- that methods are nut known and practiced for the elimination of the dust hazard in this industry. Another example is indicated in the results of a study now in progress in connec tion with nitrcurialisin among workers in the hatters" fur cutting industry. Table 9 shows the exposure to mercury dust ami vapor oi some of the workers in this industry Table 9--Exposure of Hatters" Fur Workers to Mercury Dust and Vapor Under Controlled and Uncontrolled Conditions Occupation ** Drummers ................................. Total Mercury Exposure iu Milligrams per 10 cubic meters Uncontrolled Coni rolled 4.6 7.2 4.(1 18 3.8 1.7 3.1 1 2 2.5 06 1.5 07 Method o( Control Nunc practiced Local exhaust ventiMlation *' Segregation <1 ,1 126 Twenty-fourth Annual Safety Congress--National Safety Council under controlled and uncontrolled working conditions. It is apparent that where some measure ol control is practiced by such methods as segregation or local exhaust ventilation, a niateri.il reduction in the exposure to mercury has been effected. It Is onr licliil that in the ease of the blowers' exposure, a reduction may be effected by mechanical enclosure and local exhaust ventilation, anil that the shippers' exposure to mercury vapor may be lessened by a general system of ventilation sufficient to change the air in the store room fretpienily enough to bring the mercury concentratratioii to a lower level. Unfortunately, in the present investigation, it has been im possible to nntl a plant in which an attempt has been made to reduce the exposure for these two occupations. In some dusty occupations the methods of controlling dust have not been devel oped., In fact, operations such as removing the core? from very large foundry castings, sand-lysliug, handling of used storage battery plates, paint chipping, and cadmium oxide = lamif'iciure appear to offer no practical means of adequately controlling the dii-t piucr.Vcd. In such cases, it is therefore necessary to furnish the worker with persona respiratory protection devices to prevent his exposure to the harmful effects of the < lists present. These devices consist of various types of respirators, masks, and heir lets. It is important to hold in mind the limited use of personal protection devices. Because a worker cannot with comfort wear a mask or helmet continuously, such devices must be employed intermittently. Their use is generally extended to those operations where all other methods have failed or supplementary to them, as in storage battery repair where the exposure to small amounts of lead breathed is known to be detrimental to health. It should be pointed out that the U. S. Ilureau of Mines is equipped to conduct approval tests oi respirators used for protection against various dusts and fumes (Schedule 21). These tests arc conducted against the dust for which the device is to lie used and arc rated, not on an efficiency basis, but on the quantity of dust which actually passes the respirator. The results of a study of masks or helmets of the positive pressure type, made .during the sandblast investigation conducted several years -go by the Public Health Service in cooperation with the National Safety Coniii.il,' showed that the only practical safeguard to the worker inside the sand blast room was to provide him with a mask or helmet of the positive pressure type. In studying the efficiency of such devices it was found that a relationship existed between the amount of air supplied to the helmet and the concentration of dust in-idc the helmet during blasting. To determine the optimum air volume to be sup plied to such protective devices, it was necessary to obtain dust samples from inside the hclincl while varying the air volume, at the same time maintaining the dust conniirntii.n in llic sandblast room (outside the helmet) constant. The positive supply "f d en. ft. of dust-free air per minute will protect a worker under the operating 1'oinlilioitS' now in practice in sand-blast rooms. The ultimate criterion of protection, however, is the result of dust determinations of the air within the helmet, that is, the, air actually breathed by the worker and not the volume of air supplied. Too much emphasis cannot he stressed on the necessity of maintaining in good order the personal respiratory devices for the protection of the worker against various toxic dusts. Maintenance of exhaust ventilation systems, and other types of protectiic equipment, should be a rule in industry rather than ail exception. Too often the erm "good housekeeping" lias bi-cii interpreted as signifying only the periodic removal .f dust collected on doors, rafters, etc. Although such practice contributes to the general stale of cleanliness of a workroom and should always he in force, the time as siucly comer when serious attention should lie given to titc installation and rigid iiaiiitviiance of all types of dust coni ml devices. In every plant there should lie nine iciponsiblc individual charged with the periodic inspection of all workrooms ', sanitalioii. ventilation, and inainioinnrc of all dust removal and oilier protective cnees 1'irh.ips I lie bed criterion of I lie effectiveness of these devices is the iii,.-l,c J, i. hum iti,-n e.f the .In-1 i,mil in ,,i the air at the workets' Licatliing zone. i) I) 1..1.1.01 wciljuic and in .i|.pi rei. h lo ibc problem as ourlincJ in this paper . I. k I., note progrcis in Ibc ct...uol ol llic dust luiard in industry. ' 'b- i Oc I. ir 1.11 <f even * i.i.si eslinsnc progiain of dust control arc not ' i,,ol. u-hrol i Ins u ci|u11 illy true in dialing with fibrosis-producing dusts i plniii wlure some ol llic workmen base already inhaled sufficient quantities to Occupational Diseases 127 cause disability. However, in dealing with such dusts as lead, cadmium, and mercury compounds, control measures may produce salubrious results in a relatively brief period. It is difficult, because of lack of sufficient reliable data, to indicate here the economic benefits resulting from a preventive program of dust control. It has been estimated by Dean K. Itriimlagc. statistician of this office, that the minimum expectancy in savings to employer amt employee from an indicated reduction of the accident rale and of the time lost on account of illness (or an equivalent reduction in mentality), demonstrated ns attainable, is 520.000 per year per l.tlOO employees. And this estimate is lur plants whose accident rate is considerably Ik low the average, in which there arc no occupational health hazards. In plants where hazards are known lo exist the savings should be far in excess of this conservative estimate. When one realizes that in this country there arc approximately 15 millions oi workers engaged ill manu facturing, mechanical, and mineral industries, then it is evident that the magnitude of the problem has not been overemphasized. ,VJi Reference* 1. ntooiiifictir,' T. J. ami Drccsscn, \\\ C.: Kilicv^is ani'-iti; granite quart ic*. Public HcJib Reports, Vol. -{9. No. 23, June I, l`3l. 2.- AmhracVflKilicoMS anion/; hard coal miners. Public Health Hullelin No. 22), 1935. 3. IHuoutficId, J. J., and Greenbure, Lcon.ud: S.iml atnl metallic abrasive blaMtui; as an industrial health haiard. Jour. lml. llyg., vol. l\ no. 4, July, 1933. 4. Match, 'tllhxndnie, l)iinker, l'hilip, and Choate. Saiah l\: Control ol the J-ilicorU hazard ** the harj-rock ujtlnstiics. I. A. laboratory study id, the tlc-i^u ol du*t control 5\<tctnx lwr u-e utili pneumatic granite culling turds. Jour. 1 ml. )I\k-, vol. 12. no. 3, March, 1`UO. Hatch, Theodore, Keller, Gem ye S., and 1*cl.ncl. J. \V.: Control of the mIico*is haiatd in the haul-rock industries. Si. An investigation <d the Kelte) dust trap lor v^c with pneumatic rock rl ill j, of the *`Jack*li:imnerM type: Jour, fud, Hy/j,, vd. 14, m>. 2, l'rhruary, 1932. Hatch, Theodore, Warren, Henry,. and Kelley, I.c.-ikc S.: Cmittol of the silicosis hazard in the hard-rock industries. HJ. Design and opct.ttimi *d a dust-control system for u*e with pneumatic n*ek drills in open excavation. Jmjr. 1ml. lisp., vol. 14, no. 7, September, 1932. ^ v- Silicosis and Silico-Tuberculosis Medical Problems of an Important Industrial Disease By EDGAR MAYER, M.D. New York City A hidden element of the cost (if production is indtii-lri.il disease.- ImlnMry has rcnchcd a stage beyond the concern only oi wages and limirs. l*ar inure impnriant is conservation of man power by preventive medicine and ini;ii\,\a! engineering. Disease preventive measures are nut a co-t, but, in the Imig run, a great economic saving. Incidence. In the United Stales it has been computed that tin re are from 500.000 to a 1.00(1.0(10 people employed in occupation. where a silicosis hazard exists. In New York City there arc about fo.OiiO such employees. In a representative group of granite workers in Massachusetts silicosis alone was present in about 15 per Cent ami silicosis complicated witli tuberculosis in almost 8 per lent. Tuberculosis was the eau-c of death in over oue-lbird ol the granite wothers which is lour times the incidence fur males of 20 years and over in this country. In ioimdry nun studied in Massachusetts, silicosis was less frequent (alioiii ') per cent I and le<s advanced in degree than in granite workers, flic diualion oi espo-ure in foundry workers witli pneimioimconinsis lias averaged many more sears than that required to pioducc silicosis in ail industry such as gold mining. Tile lulivmilo-is hazard in foundries is nearly as great as dial reported for some of die other dusty liades. but the figures are much lower than those of miners oi gold, silver, copper and lead, among whom the mortality from tuberculosis is S to IS times the general expectancy. Death rates for all nun-tuberculous infections have been repoiied higher among workers in siliceous dusts than in llic general population. It is sugge-tnl that the winker in silica succumbs more often lo acute pnlinnunry infections rather than sure it in? die chronic fibrosis. . J \ S Twenty-fourth Annual Safely Congress--National Safely Council Silicosis is <liTmcd as a pathologic contlilioii of the'lungs dim to the inhalation ihVa, whither free or combined in such a state as to lie capable of setting tip its i.idcrislic pathogenic cllccts. The principal factors that determine the incidence ilicosis arc (1) the percentage of free silica in the inhaled dust; (2) the conration of silica particles less than 10 micra in diameter in the atmosphere; (3) duration of exposure to the dost, and <-I) the susceptibility of the individual used as modified by age. complicating infections, etc. The occupational disease dling from such inhalation has been defined as "morbid results of occupational , > ily traceable to specific causes or labor conditions and followed liv more or cxltndrd incapacity fur work." Wetubnlisin oj Silica. Significant amounts of silica are present in all body ie> and llnids. It enters the body through the digestive tract and the lungs, t of that entering; the stomach is eliminated in the stools, but a fairly large nnt is absorbed into the blood as shown hv the constant excretion of silica in urine. All vegetable foods contain silicon especially the hulls of grains, hay and iv. The low silica content of the liver, spleen and kidneys indicates the little ntion of the absorbed silica in the body. Silica content of the urine of animals he influenced at will by diet. The body possesses a very efficient mechanism the disposal of silica because of the low kidney thrcshhold. Silica entering lungs in particulate form is expectorated in part with its enveloping cells, but l ni it is carried into the pulmonary lymph channels. Many such particles reach lymph nodes and even the spleen by way of the blood. The finest particles ver, may be dissolved in alkaline body fluids and carried away in solution, to xcreted in the urine. There may be a constant drainage of" silica from the thruu-,'i the inhalation of extremely fine particles of silica in dusty atmospheres, mall that they are not seen under the microscope. Attempts to influence the absorption of silica from the lungs by administration dl.aii have been inconclusive. Elimination of silica by way of the sputum from cuts having deposits of silica (in their lungs appears to be higher than those ;ng no history of exposure to dust. Only small amounts of silica arc in the I and tins level is little different in normals than in silicotics. I'allwltigy.' 1 his disease is essentially a fibrosis of the lungs developing espey in such ir.-.i istrics as hard-rock metal mining, granite cutting, metal grinding sand-blasting. The pathological changes arc believed to result from two causes, ucking of the lung lymphatics by mononuclear cells laden with dust in addition he action of colloidal silica, the exact nature of which is in doubt. The small ides under 10 micra are the only ones capable of penetrating the lung tissue. Although silica plays the dominant role in the production of silicosis, the ad ore of other dusts lends to modify the pathological changes in the lungs so these resemble then those of other forms of dust inhalation, and the modification s some relation to the percentage of free silica in tile mixture. Silicates, as in -Ins. produce a definite change in the lung, as well as other dusts such as le. coal, etc. Such changes are represented by a fibrosis brought about because ivcly insoluble minute particles of minerals in sufficient concentration have brought by the activity of phagocytic cells into intimate contact with the enury connective tissue. This fibrosis is a diffuse cellular one that occurs in walls of the smaller bronchi and of all their finer divisions and extends to ve the supporting connective tissue of the adjacent blood vessels and to some t alst the walls of adjacent air spaces. However, when the great majority pf 'haled i.'irticles arc composed of or contain silica, there develops, in addition, a lie and-localized type of fibrosis called the silicotic nodule--an orderly whorlcd Helmut uf cells and fibres, and with sharp definition from the adjacent paren'.i. Ma. y dusts create a gcuerali/td fibrosis hut only one, namely one combined silicon lioxide produces the special fibrosis of silicosis. Scricile, known as - .mica, which is a hydrated silicate of aluminum and potassium, has not produced niiial experiments the silicotic nodule, but instead generalized fibrosis resulted, bisls must be ilifTcrcitliotcd into those which arc chemically active and those i are hint when inhaled into the respiratory tract. Silica is a chemically active uhiih must necessarily lie soluble to a degree in the body fluids and its activity "Is -mi its solubility. This activity which is manifested in (he areas where dust les arc carried along the lymph stream by phagocytes, causes lesions of two Occupational Diseases types, "toxic" and "selenitic" both of which have been reproduced experimentally. Toxic lesions depend upon local necrosis and slow death ami appear to favor the growth of tubercle bacilli; the sclerotic lesions produce the nodular fibrosis. 1 he inert ilusls arc insoluble in body fluids and cannot exert chemical action in the lung tissue, but if they accumulate to a marked extent their cflcct is mechanical which may lead to a certain amount of diffuse fibrosis armim! the dust deposits. Certain dusts, such as carbon, may have physical cllccts, they may adsorb toxic substances and it has been suggested that on this basis there is a relatively lower incidence of active clinical tuberculosis in silico-anlhracolics than in silicotic lungs. Other dusts may even protect, as in the case of certain clays, gypsum arid aluminum oxide. Pure pncnmonoconiosis may be only a laboratory disease, as the pulmonary fibrosis of workers in dusty trades probably results from the combined action of dust and infection, whether it be tuberculous or not. In silicosis it is not the mineral particles that arc breathed in during life that record the cause of disease, but the particles that have been dissolved, liisk to work, efficiency and health may be greatly accentuated through the inhalation of finely divided particles even of a chemically inactive dust when there has occurred a lymph stasis which is known to follow exposure to silica. This lymphatic blockage leads to retention and accumulation ol the inert dust. In suit coal miners who get what is called "miner's asthma" we have this accumulation of carbon. Such patients arc very liable to have a high incidence of bronchitis with mechanical anil physical changes due to retention of authracotic dust. Furthermore, uncipiivucal cases of silicosis, with or without tuberculosis, can no longer be doubted. Tuberculosis. Most apical tuberculosis is aciptircd before the age of 25 and so silicosis at the age of 30 makes a previous tuberculosis more serious. Most workers with tuberculosis going into the mines before the age of 30 die of tuberculosis by the age of da. The silicotic develops a sputum that contains tubercle bacilli late in life and the children who arc contacts with tubercular silicotics develop very little clinical tuberculosis. It is impossible to say definitely that tuberculosis engrafts itself upon the silicotic or vice versa, for we sec apical tuberculosis in silicosis that spreads downward, while other silicotics show only the tuberculosis in the lower lobes, it has been found that most silicotics die of tuberculosis. The diagnosis of silicosis is made primarily on two findings, the proper history of occupational exposure to siliceous dust and the presence of abnormal shadows on the pulmonary- X-ray. The physical examination and the patient's symptoms are of less value. There arc other diagnostic aids such as the finding oi large ipuntities of silica particles in the sputum, ipiunlitativc determinations of silica in urine, and at post mortem, chemical analyses of the lung ash supplemented by petrographic examination, roentgen-ray spectrum analysis and special incinerating studies of lung tissue. We must at times rely on the pathologist to determine the amount and distribution of fibrosis due to silica and from microscopic studies give an opinion on the importance of this fibrosis as the ultimate cause of disease and death. I .ting fibrosis may be present without any' silica. Silica may be present in lung tissue or the pulmonary lymph channels without associated fibrosis. 1-iucly divided siliceous particles from lung tissue may contain innocuous silicate which ronuut he distinguished from harmful silica particles. Hydrated silica which is not doubly refractive cannot he demonstrated with prisms. Therefore in the pathological section the presence oi siliceous fibrosis can be suspected hut cannot lie specifically identified with the siliceous material that it may contain. Accordingly the inicroincincrutinn method of Irwin with hydrochloric acid is now included in the microscopic examination of any lung as a means toward a surer diagnosis. 1 Jiaguoslic difficulties in clinical medicine may lie more obvious if we examine first the occupational history. Quartz grinders working under conditions oi massive exposure may develop silicosis in acute form oven in a period of months, whereas in other occupations it may lake 25 years. Workers in the same industry, indeed in the same room, experience different degrees of exposure dependent upon pci haps the dust-li|lcring capacity of the nose and functional condition of the lung as deter mined by constitutional characteristics and antecedent di.-ensc. The size and col loidal structure of the particles of silica, as well as the dosage and total amount of ilirn. wilt influence the rate of development of the disease. Apparently particles that oe larger than 1(1 micra are* not phagoryloscd in the lung. So a definite J ) Twenty-fourth Annual Safely Congress--National Safely Council '"T n( ospo-me must lie established :uul in general hospitals where patients are ratury, conditions under which they worked are very vaguely described ami ic arc not available data on dust counts and silica concentration, so that the history (leu misleading. As to symptoms, patients can perform strenuous lahor despite extensive disease I the symptoms .of dyspnea and cough are common to many diseases, l'evcr is lit unless infection occurs, hut most important is the great disproportion In-tween nilnt's complaints and what is seen on the X-ray, the latter showing extensive mini shadows in comparison with the symptoms. On physical examination, extensive disease may he present and few abnormal sical signs. The physical signs arc merely those of a general pulmonary fibrosis li emphysema, such as restriction of costal and disphragmatic movement, diitiinui of or intensified breath sounds and a hyperresonant note. Rales arc usually nt ui-'ess infection is present. As to the .V-niy, there are 3 essential types of shadow s described, linear strands. II disc etc shadows, and homogeneous shadows of varying sires; these Jorreul to the fibrous strands, silicotic nodules, and the conglomerate masses fibrosis The nodular shadows arc usually characteristically around the in, or < jnglinncratc nodular shadows of hat-wing appearance extend into both ir lung fields, or nodular shadows may he distributed in the upper two-lhird| lie lung fields, perhaps more pronounced on the right side, with the lower third f clear h_v emphysema. With infection present, the shadows are less sharp or linear strands interconnect or fuse. Large conglomerate shallows appearing (ruin the liilnm leaving the periphery of the liing clear throughout because of hyscnia. The distribution of some of these lesions may he determined by the lire assumed by the workers, and infection may likewise determine an ultimate deal distribution. Many variations from these patterns arc seen in the X-ray, ciallv under excessive exposure or when other dusts are inhaled, or in the line of infection. It is probable that the main source of the diagnostic diflics is caused by the emphysema which mufllcs the physical signs ami is responj emphysema, such as restriction of costal and diaphragmatic movement, diutinu- in great part for the absence of symptoms. It may blot out, even on X-ray, : ilicotic lesions of fine size. Examples of such difficulties in diagnosis as cncounI In- us are the foltow iug: ( njr I--Mr. T. A forty-five year old man entered the New York hospital ,.l.lining of mild cough and expectoration of four months' duration. He appeared ly ill. his fever was 103 degrees and respiration 2R. Rales were elicited over upper half of both sides of the chest. Examination of his eye grounds revealed Ural retinal tuhciclcs: his sputum Contained numerous acid-fast organisms. X-raj revealed fine mottled shadows distributed throughout li.ith lung fields p,a small cavity at the left apex. A diagnosis id miliary tuberculosis was made, rver. after one weeks' May in the hospital, hid temperature and pulse returned irm d and during the following iiiuiilli lie gained IS pounds. The signs ill his now liraine confined to the left apex. In view of his unusual progress the aois of miliary tuberculosis was doubled, llis ocnipatiunal history revealed up until three years before entrance to the hospital he had worked for 2(1 . poli-hiog leather on a sandpaper wheel. There were nmuerotis machines in work room and no precautions were observed to clear the very dusty air. 'sputum was examined through the kindness of l)r. Ilnrke of R.avhrook, N. Y. found it ladvn with numerous doubly retractile silica particles, lie expressed pinion that this was consistent with silicosis for he had found such mtinvruus ilvs only in eases of silicosis. The patient subsequently died of a tuberculous ugilis. Retinal tubercles were demonstrated on microscopic section. The logist's report was miliary tuhv-rculnsis. Ashing of the lung .showed increased . content, consistent with undue exposure to dost (more than 2 mgni. silica per t dried tissue). ntv II--,1/r. /?., aged 51, entered the New York hospital complaining of p;vses, .dyspm-a and chest pain. On physical examination there were rales dullness over the upper third of the right chest anteriorly. He ran a low fever but was robust and felt quite well. The chest X-ray disclosed enlarged i 'shadows, particularly on the right, and diffuse mottled discrete shadows Occupational Diseases 131 throughout both lung fields with a circumscribed density near the right apex. He gave a history of having worked for twenty-four years as a culler and sizer of asbestos-containing paper box hoards. The rooms were in a continuous cloud of dust. Examination of the dust revealed 5 per cent silica content. The hemoptysis, we felt, was to be explained on the basis of infection or neoplasm, but we did not know whether we were dealing with one of those processes alone or an associated silicosis or ashestosis. A small nodule in the neck was subsequently removed and showed carcinoma. We arc inclined to believe that this does not explain the whole process, as the man is still alive and certainly, from the X-ray standpoint, we cannot say that there is no silicosis. Case III--Mr. C. A dish-washer, aged 46. entered Ilcllcrtie hospital because of cough and expectoration, associated with dyspnea. There was some dullness and rales at the right base posteriorly. Chest X-ray revealed a homogeneous shallow at the right base. His sputum contained no tubercle bacilli and lipiodol study revealed no abnormalities, l'ronchoscopic examination disclosed a bleeding mass in right main bronchus. Symptoms and .disease progressed (hiring the following four years. Discrete mottled shadows first appeared in the tipper right lung field and the shadow at the right base cleared somewhat. Three years later extensive ab normal shadows were present throughout both lung fields, particularly on the right. Diagnosis of chronic pc'ituiuonia of unknown etiology was made. At no lime was a diagnosis of silicosis entertained, because as far as could he determinevi he had no history of exposure. Furthermore if there were silicosis it behaved very alypically having the lesion confined practically to the right base at the beginning and then spreading to the left lung. Autopsy however, revealed a typical silicosis associated with a small degree of tuberculosis. A picture of the lung showed how much morc_ extensive the silicotic process was in the rigid lung. There was stenosis of the right middle lobe bronchus with bronchiectasis in this lobe. Chronic infection in the lung field probably accounted for the unusual localization. This case illustrates how necessary it is to have the history of dust exposure fur without it here we arc unalde to even suggest a diagnosis. Case IV--iff. C., aged 45, complained of rough and dyspnea with slight expec toration and gave a history of having worked for many years repairing tires, using talc powder. It was difficult to obtain accurate details as to the possibility of silica exposure except that the rooms were filled with ctouvls of dust. Rales were present at Doth apices and a few tubercle bacilli were found in the sputum. Discrete and stringy shadows were disseminated throughout both lung fields. \Ye know from thp positive sputum that tuberculosis is present. The patient lias, however, been well fur a period of two years. The doubtful history of exposure' together with the numerous discrete nodular shadows in Ids lung, which are Con sistent with silicosis, makes this patient a problem. Is this tuberculosis alone or is this tuberculosis with silicosis? The patient is still living a scar later and working. Omrlusioit.' Cases such as these are exceptional. Imt their existence iniiM alvvavs he home in mind. It occupational history is inadequate and X-ray. clinical and ' lalior.itory studies prove misleading, the diagnosis may present great ililfiailty. However, a comprehensive Study n[ all possible data usuallr dears up the problem with reasonable certainty. ADJOURNMP.NT Safety litjuipnintl Safety Equipment WEDNESDAY AFTERNOON SESSION October 16, 1935 The session was called to order by Chairman, Irwin W. Millard, president, Industrial Gloves Corporation, Danville, III. Chairman Millard mentioned some ot the problems of providing adequate safety equipment for industry. Respiratory Protective Devices (An interpretation of the U. S. Bureau of Mines, Schedule 21) By CARLTON E. BROWN, Chemist, and WILLIAM P. YANT, Supervising Chemist Gas Section, Pittsburgh Experiment Station, Pittsburgh, Pa. The respiratory protective devices of industrial hygienic importance arc those designed to protect against the inhalation of harmful solid, gaseous, or liquid atmos pheric contaminants, or the inhalation of air dcficieut in oxygen. The devices in common use arc the mechanical filter respirator (commonly re ferred to as respirator) for protection against the inhalation of dusts, smokes, fumes, and mists or what may he referred to collectively as atmospheric particulate matter; gas masks for protection against the inhalation of gases and vapors: oxygen breath ing apparatus, hose masks, and air-line respirators for protection against the inhalation of any atmosphere provided it docs not contain harmful constituent which can he absorbed readily through the skin: and the abrasive blasting helmet or hood for pro tection against the inhalation of and the impact and abrasion from the atmospheric particulate matter generated in sand blasting or abrasive blasting with steel shot. These devices arc designed to furnish protection either by making the wearer's inspired air safe to breathe or by supplying the wearer with sate air from a supply which lie carries or from outside the contaminated zone. The wearer of the first or air-purifying type, on inspiration draws air from his immediate surroundings through the device which either removes the contaminant, usually by chemical or mechanical filtration, or converts it into a harmless substance. This type, of course, oilers no protection against atmospheres deficient in oxygcnt as it does not add oxygen to the air. There arc two types of respiratory protective devices of the second type designed to supply tile wearer with sale air. In one. the wearer receives his air supply from a cylinder of compressed oxygen, liquid oxygen, liquid air. or from a chemical which yields oxygen upon decomposition. This air supply is part of the self-contained unit, all of which is carried by the wearer. In the other type a hose, attached to a facepiece. is connected to a compressor or blower whose intake is located in safe air. Air is forced through the hose to the wearer. Xnte: Published by permission oi Director, IT. S. Itureau of Mines. (Not subject to copy, tislit.) 133 u-t v-jourlh Annual Safety Congress--National Safely Council \ There is some confusion in the use of the term "respirator," to designate devices for protection against the inhalation of atmospheric particulate matter. Such devices were titc first and for a lone; lime were tlic only respiratory protective devices! They were logically called respirators, and as long as they were the only deuces of this kind there was no confusion. The development of other devices of industrial hygienic importance anil the development of devices for maintaining artificial respiration over lout.' periods and for enabling men trapped in submerged submarines to reach the sur face safely, all called respirators, was responsible for the confusion. The Bureau of .Mines suggests that the term "respirator" be retained for all of these devices, hut that respiratory protective devices of industrial hygienic importance be called indus trial respirators ami that the different kinds of industrial respirators he assigned a name which will indicate their operating principle or field of use or both. Satisfac tory names in common use should be retained. On this basis, the Bureau of Mines suggests the following classification for respiratory protective devices of industrial hygienic importance: , Industrial Respirators 1. Supplied-Air Respirators a. Self-contained type (1) Oxygen breathing apparatus* b. Hose type fl) Hose mask (21 Air-line respirator* 13) Abrasive blasting respirator' 2. Air-Purifying Respirators a. Chemical filter respirator4 (1) Acid gas or type A' chemical filter respirator (2) Organic vapor or type R' chemical filler respirator f31 Ammonia or tvpc C."' chemical filler respirator V4) Cm b>i| iiioiinxide or type IV chemical filler respirator h. Mechanical filter respirator' fl) Dust or type A' mechanical filter respirator (21 Fume or type B* mechanical filter respirator (3) Mist or type C' mechanical filter respirator c. Chemical and mechanical filler respirator* Testing and Approving of Industrial Respirators by the U. S. Bureau of Mines Since its organization the U. S. Bureau of Mines lias been interested in industrial uspiralurs as a means of protecting workers in the mineral industry against liarmfiil atmospheric eoutamiivants. To this end the Bureau lias developed an appioval system, In* pmpo-es of vvliieh are: f II To nieonrnee and aid manufacturers in die drvclopoi.iil and iii.'iihrling of safe ami siiilahle equipment: ami f2) to em-ouiave the rollouter to use such cquipim-nt. to aid him in obtaining it and'In instruct him in its - .arc. These purposes are accomplished hv establishing a .schedule of the material ami .iifoimaiice lequiri-iiirols that a sale ami .suitable 'leeice should meet; by making |.|.local tests for conformance to such a schedule; ami by informing the public of the * Sometimes r;il)<`il mine tevitc l<t<\ulitH? nptMinttt*. * Sometime* I'.iiiH |n,iv irs|iit;ilr nr |H.*.iiivr jiii**mhc rc%|*ii:i|nr. * Sometimes riillctl samMitast helmet or hnml. 4 OuniiMitiljr r.'illdl js * l.citcts stsMKtc>! In cJnMrr\ of cIiciiimat filler ii'j'ii.tlois. Sec II. S- Ihitentt of Mine* Srlicd. ll|>, I*rnec<liiie for TcM'iuj* (*as Masks for l*ern>i^il>lit>*, 17 ||>.# 19.15, 1Ommmnly enllcil rr*|iiral*ir. Sometimes tefeitcil In nt iln<| rc5|>ir;ilor or tiinrhaiiical licr*lv|te le^nraior. , M.citef* assigned to merhnnir.Tl filler respirator filler*. See U. S. # Ihiieau of Mines Silted. 21, Ijr/Kfdiirc f**r Testing Filter.Type Ihisl, Fume, ami Mbt lfcspiratms (or < imissihihiy, h |*p.,` 19M. * The !*- irejs imw referred to as Tjpe N* or .Ml Set vice Ch* Mask '.md the ehcmiral MiMjc Tc-i'trjtor Ml under this heading. Safety Equifuteut 135 advantages in the use of devices bearing Rurraii of Mines appro)a}. If the device >3 found hv examination ami test to meet the riquirt-mcnis of the schedule the Bureau of Mines gives the manufacturer a certificate of approval* which he may display as evi dence ol the quality ol his product. The approved devices arc marked in a manner which clearly distinguishes them and indicates the purpose for which they arc ap proved and the limitations under which they may he toed. As an aid to the con sumer, the Bureau of Mines periodically issues a list of the devices which have met the rrijuircincnts. The submission of equipment is entirely voluntary on the part of the mamifac- irer. On making application for tests, the maimiacturrr rlrpnsits ;v fee whirl) vs trued into the miscellaneous receipts ofthe treasury of the United Stales; none of lillte; mmounme*y acvcvrues link by the tlcMrc tiovof' the th` e mBuarneuafuaco.t..u.f.r..e.M..r.s.i.n...et-os.....p...r..o.T..d.h.u..e.ceapapmriovmaal rks.vestte-gmooti.>sl motivated o..i.m. ..p..m....n..u. , ri.iti1>,,c.- interest of tire Durenu of Mines in having safe equipment available comiiMTCially, anu the dettiand of the consumer for such equipment is completed, the Bureau of Mines will have approval schedules for all types of respirators now in common use. The approval system undoubtedly is largely respon sible for the development of fundamentally safe and suitable devices, and the elimina tion of confusion in their selection and use. The general plan of the various schedules is similar. The requirements may he divided into 3 parts: (11 Pre-test requirements, or those with which the manufacturer must comply before examination and test of a device will he undertaken. For example, this respirator must he in a fully developed form ready for market and available for pur chase if approval is granted. Also. the.manufacturer must he prepared to test ami maintain control of the essential characteristics of his device by a method which mfcts the approval of this Bureau. ^ (2) Material, construction, and performance requirements which the vquipmoii must meet hv examination and test. (3) Post-test requirements, or those with which the manufacturer must comply after the device is approved. From the viewpoint of the consumer the most impnn.mt of these concern labeling and marking, provision of adequate instructions for proper me of the device, and maintenance of design and quality of the product marketed under the appioval. As a check on the latter, the Bureau of Mines obtains samples of the device on the open market and subjects them to tbc various inspections and tests of the appropriate schedule. The Bureau reserves the right to withdraw its appro' al of any device for cause. Interpretation of U. S. Bureau of Mines Approval Schedule 21, Procr-dur" for Testing Filter-Type Dust, Fume, and Mist Rexpiratois for Permissibility Aiming the reasons for tin* divilupnnnl of Selndoh- 21. I'toiidme h.r Testing l;ilter-Ty pe I Inst, l-'imir, and Mist k'cspiialnrs for I VrmisNihiiiiy, u:is tin- 11 ali/ali-.ii by the Bureau of Mines ami others that lliric was a definite need (or mevhanie.it tiller respirators l<* protect workers against lint infill aliii"spln-riv particulate matter in sitn.ilioiis where In-ller methods ol rollin') ol dns| prodm linn and removal weir either Hot available' or practical, the inefficiency of existing in.ileum.d titler re.piiat.us, amt 1 Marean c( Mine*. tV'cedmc (** KM.vhli-hiun a t.iM .( t'rnm-MMe Sell T*m iiitr.1 )lie;itlmi Jltn: Fees L'har.icier of Te-ls a ml 1`mlcr which Mine Keltic lliiMtlitHC AH'-h;i1u wilt lc Tested: Silted. V'A, .l.mihirv 21. 1**10. 1? 1*11. * lltiic-iii ( Mines J'roccdurc for Tcnijuk Pas M.rshs f.,j Pcmmsilnhi* : S htl lip, M.iv 9. V0>. \7 W`- * Ihinau uf Mine*, )'iK`c*lnre ("f Te^liuf 1lo-e f-r I*euni"*ihiliik : Sihcil. P. Ajml 2*. 1*07. 8 |'p 4 HufCiiti of Mine?, Fioeeduie f"r Fiher*T.pe Uu>t, Fume, :ul for rciniijkil)ilit> : Sdiol. 21, Aucu?t 20. 193*. 14 |*ji. .itntv runity-fourth Annual Safely Congress--National Safety Council -Is from manufacturers and consumers that this bureau test and approve Mich * 5. 'Z. -ilicdulc 2! follows the general plan of the other bureau approval schedules for . -tal respirators; the pre-test and post-test requirements arc quite similar, and , Micral principles of the test requirements arc the same. The primary purpose of*" taper is to explain the reasons for the various test requirements. Pre-Test Requirements I lie pre-test requirements of Schedule 21 require that the manufacturer submit nation, drawings, and samples of the device to he tested. The device must be* . letelv developed anil ready for release to the public, and the dev ice when tested he manufacturer or his agent must have passed tests of the nature described ihcdule 21. The reasons for the third requirement arc: (1) To assure the an that the manufacturer is prepared to control the filtering characteristics of cspiralnr; (21 to eliminate any question id competition with priiale consulting cits in developing respirators; f3) to furnish evidence that the respirator really ady for release to public market; and (4) to save the manufacturer's and the .au's lime. After the manufacturer has complied with all the above pre-test i.cmciils lie must submit a fee for the examination and lest of his device, fee is turned into the miscellaneous funds of the U. S. treasury and none of . nonev reverts to the Bureau of Mines. Test Requirements I lu developing the tests for mechanical filler respirators consideration was given : to the general requirements for a safe and suitable device. These requirements similar for all types of industrial respirators. The respirator must (I) give quale protection. (2) be reasonably comfortable and physically convenient to r. and (3) provide an acceptable service life. Adequate protection implies that the mechanical filler respirator when properly "ii.iiucd and worn must prevent the wearer from breathing enough particulate 'is r to cause a harmful physiological response miller the conditions of occupational ) Mire for which it is designed to he used. t'rmifort and physical convenience factors arc equal in importance to adequate P-clion. liven though aware of the ultimate serious effect which will he produced , r prolonged daily exposure, workmen are inclined to he diffident and unwilling iflcr nnirli daily inconvenience and discomfort from the respirator, rncmnlirancc and discomfort also increase fatigue, cause distraction, and in *al handicap the wearer's ability to take earc of himself, thus increasing the hility of accident. Important specific items include the weight of the respirator, arriage on the face or heed, effect on vision, heating of the area of the skin 1 r the facepiece, inability to expectorate, difficulty in talking, and resistance to idling. The iinpurtancc of comfort and physical convenience cannot be over iu.ilcd. , The servile life involves elements of practicability in the wearing and inainicnnucc he device, and indirectly die safely. This type of respirator is primal ilv not an igrnry device, hut a part of the workman's equipment for doing his regular job Iv. If die service life is short, die hollier of changing of filler etemeiils will u flected ill the workman's altitude toward ......I maiiileiianee and use. All iiieehanical filter respirators are subjected to certain inspections and tests lliey must fulfill certain rcquiriuimls. The general disign and cnin-li itrlinn. ocularly as to facial fit, frcrihun from iriHaling facial contacts, weight, effect vision and the wearing of goggles, and ease of changing filter elements, and' mined. The materials arc examined to determine if they arc obviously suited die purpose for which they arc designed. Rubber parts which conic in contact i die skin must not contain any skin-irritating constituent. Resistance to Air Flow Requirements . i ............ is h.r hsisi.m.i ti si llow aic die sonc (or all appro.cd mc- . .I lour i. | ,r aloi s At no Inoc ilm m; m ..Iter die filler tflicai) testing period i the .'i,nUiuc to air being diawu through the done at the rale of 85 liters Safety Equipment *" (3 cubic feet) per minute exceed 50 millimeters (1.97 inches) of water column height or the resistance to air being blown through the device at the sainc rate of flow* exceed 25 millimeters of water column height. An air flow of 8a liter per miiuilc is approximately equivalent to the respiratory rate of a man donii; brav, work. The amount of particulate matter pulled to the device during die jute, rlliracy tests is roughly equivalent to the amount that would be pulled to the litter by a worker wearing the mechanical filter respirator ill a moderately, concentrated suspension of the particulate matter during an R hour period, 1 bus resistance to air llow of an approved mechanical filler respirator should not become excessive when worn inr an 8-hour period in most suspensions of utmost heric particulate mailer en countered in industry. The manufacturer is rcniv-n! to eiio.instructions on cleaning or changing the filter dements when the ic-islm. ;ur iimv noticeably men uses. Direct Leakage and Man Test All mechanical filter respirators arc subjected to a direct leakage and man Ic-d tn determine facial fit. whether there is any diricl leakage of unfdicred air. and to obtain information on the comfort of the device. Three of the nicih.oiical filter respirators arc worn for 30 minutes by 3 men with dil'lcrvnt facial iv.iltncs in an atmosphere containing a heavy suspension of hitninin-ms-r.oil dust. At the end of the period the respirators arc removed and that part of the face covered by thd facepiece is examined for evidence of any leak under the idee of the facepiece. Sticks a millimeter thick were wedged under the edges of the faci pieces worn by subjects A and C to cause the leaks. The location and approximate magnitude of the leaks arc shown by the black streaks on that pari of the face covered by the edges .d the facepieces. The nasal passages and sputum of the subjects are also examined before and after the tests. Filtering-Efficacy Tests In the development of the filtering-efficacy tests, particular attention was giirn to the physical properties, especially particle size, ol the significant kinds of atmos pheric particulate matter encountered in indiMryg Previous studies of filtering materials had shown that, in general, filtering cflicary decreases with a decrease in particle size. It was derided that niosl of the significant iiulusti hilly generated atmospheric paniculate matter could lie classified into the following three groups in accordance with method of generation, physical state, and particle size: 1. Mechanically peucrated dusts resulting from the disintegration of a solid, surli as the dust clouds produced in the vaiious processes of mining, quarrying and tunneling and the grinding, crushing, and general processing of solid materials. This type of atmospheric particulate matter is referred to as Type A atmospheric particulate matter and mechanical filter respirators designed to (tiruMi prolection against these suspensions arc referred to as Type A mechanical filter respirators. 2. tonnes of various mcials (usually their chemical compounds, as oxides or carbonates) such as lead, mercury (except mercury vapor) manganese, magnesium, aluminum, aiiliinony. arsenic, copper, chromium, iron, cadmium, and zinc resulting from sublimation or the condcnsalion of their vapor, or from the rhemical riactions hclucin their vapor and gases. This type of atmosphci ic particulate matter is re- fi-rnd to as Type It atmospheric particulate matter and incrhaiiiral Idler rc-piiators designed to fiiiuish protection against these suspensions are referred to ax Type 11 mrihnuicnl filler respirators. 3. Mists as produced by spray-coating with paint ami vitreous cii.hihK chr.....ic acid mist as jirudnccd in chromium plating, and other mists of materials whose liquid vehicle docs not jirodticc harmful gases or vapors. This type of atum-phi rie paniculate matter is referred to as Type C atmospheric particulate inaltci ami qicclianical filter respirators designed tn furnish protection against these suspensions arc referred to as Type C mechanical filler respirators. The mechanically generated dusts and fumes consist of solid particles while the mists consist of liquid or liquid-coated solid particles. Tile particle size of me chanically generated dusts extends over a wide range, in some eases, from p.utkhi visible to the naked eye probably down to molecular dimensions. The range in .panicle size of fumes is much smaller. The upper limit is in the lower iiiicrosc-pic M8 Twenty-fourth Annual Safety Congress--National Safety Council nge (about O.S micron), while the lower limit probably approaches molecular nensinns. The. particles of some fumes, particularly zinc and magnesium. readily in and form large fiocklike clusters. The effect is least pronounced in the case lead. Mist particles arc spherical and probably more uniform in particle size than .sc of dusts and fumes. v Suspensions of carli of the types of industrially-generated atmospheric particle alter were selerted for use in the fillrring-cffirncy tests. These suspensions were iiosrn in the basis of their industrial hygienic' significance and their physical roperties. such as particle-size distribution and tendency to aggregate, which have appreciable effect on filtration. It was desired to test the mechanical filler piralors against the most common or widespread harmful suspensions of each .e: the test suspensions to have physical properties, such as particle size anil ercgatinii tendency, which would render them as difficult to remove by filtration any other suspension of the same type. The test sus|>ensiims selected arc: (a) hor testing Type A mechanical fdter respirators or those designed to Iiish protection against ineehanieally generated dusts a suspension generated from ry tine (')')+ per cent through .125 standard mesh sieve) silica dust consisting of *t I've cent free silica (SiO,) is used. 'Jhc suspension is generated in such a way nat all particles larger than about 3 microns arc removed before the suspension `Is rs the test chamber. J he par1 icIe-si/e distribution of the test suspension must ! exceed a geometric mean of 0.6 micron and a standard geometric deviation of ``0. The particle-size determination is made by collecting samples of the suspension the Owens jet dust counter and determining the particle size distribution by a icroprojrrlion method developed by the Ihireau of Mines* (h) hor testing Type II mechanical filter respirators nr those designed to nrnish protection against fumes, a lead oxide fume generated by the combustion ol ntural gas cnulainiug lead tetraethyl vapor is used. The particles of this fume arc Mrcmcly small mid have ulmut the least tendency to aggregate of any fume, lienee icy arc very difficult to remove from the air hv mechanical filtration. A suspension magnesium-oxide is also used to determine the effect of a fume, whose particles -lily aggregate ill large clusters, on the resistance to air flow of the filler of the vice. fc) For testing Type C mechanical filter respirators or those designed to :rnish protection against mists, three different suspensions arc used. Chromic id mist generated by electrolyzing an anurous solution of chromic acid, as is done industrial chromium plating: lead paint mist generated by spiay-eoating with lead nil; and a water mist carrying silica dust generated by spraying a 2 per cent nous suspension of silica dust are used. The water-mist carrying silica dust is d to simulate the mists generated in spray-coating with vitreous enamels, t I he i uiii eutratiou of the pailirulate mailer in the test suspensions was chosen represent more or less the higher coiirriilralions found in industry. Since the ineuliation of iiici'hanically generated dust found in industry varies over such de limits it was decided to test Type A uierhaiiiral filler respirators against two iceiitratiMiis: one to represent the more or less average dusty industrial eoinli-iis, anti the otlier to represent wry dusty conditions. The fimiplclc iiieehanieal filler, respirator is tested on a mechanical testing Paradis. The lest suspension is pulled through the device at the rate of 32 liters 1 13 cubic feet) per iiiiuule, coiitimious flow. The volume of air pulled through e mechanical filter respirator is 1(1 cubic meters in all rases except in some is against particular kinds of suspensions as mechanically generated lead dusts d in the high-silica dusl-concentratiou test and the magnesium oxide test whose rimary object is to determine the increase in resistance to air (low of the filler ith the amount of particulate matter retained. Ten cubic meters is approximately juivnlriit to the volume of air breathed by a worker in 8 hours. The samples of articulate matter for concentration determinations arc precipitated electrically in the air of the test suspension both before and after it has passed through mechanical filler respirator. The samples arc collected in containers which he weighed readily oil an analytical balance. For reasons of convenience, speed, 'l!.,..,ii. f" E joiJ Y.uil, \V. P. The - Mietfpntjcctor for Determining Particle Sire v iiil)iit>-*ii uini Number i'oticenlraiinu Aiim><.|-hcrir DiiMx. II. S. Jluieau of Mine* J(c|n>r| liivctturatioiis 3289, 1935. Safely Equipment 139 and accuracy the samples of silica dust are ipiantitatcd by weight rather than by count. Samples of the other particulate mailer arc ipiuntitatrd chemically. The rcipiircmcnls as to the amount of particulate matter that the iiirrhnuir.il filler respirators must remove from the air pulled through them is based on the first available information on the concentration of the particulate matter that is safe W breathe. These reipiiremcnts are subject to chance with the accumulation of k.mvvledge on the physiological clTccts of industrially generated atmospheric partisnl.iic matter. In other words, the filtering-efficacy requirement is that the air inhaled In' the wearer of such a device must lie safe to breathe, and not that the device have am' pailicular percentage filtering efficiency. Mechanical filter respirators arc not approved for any substance umre ban mil than the particulate matter in the test suspension against which they are tested. Thus Type A respirators are not approved for any snfistanco more harmful tliati free silica (SiO:) dust. However, Schedule 21 provides for testing and apprnvilip iiiiTlianical filter respirators against any kind of industrially giticrated atmo-phefic particulate matter. For example. Type A merhauiral filler respirators are not approved (or protection against poisoning hv breathing dusts whose main harmful constituents arc metals or their coniponmls. However, two mechanical filter respira tors have been submitted and approved (or protection against the inhalation id mechauieal generated lead dusts. Table I summarizes the details of the filtering-efiicary tests and lists the me chanical filter respirator* which have been approved to dale. (Pages 1 -10-Ml.) Post-Test Requirements The manufacturer of an approved mechanical filter respirator is required to mark his device with the name of his company, the name letter, or number by wliirli the type is designated for trade purposes, and the approval mmifier ns-it ml to the device hy the Ihireau of Mines; and the filter unit must In- marked with the approval mmifier and with the type or kind of atmospheric particulate matter for which it is approved. The mechanical filler respirator and rcplarrminl, filter units mu-t fie prnvidiil with substantial and durable ruulaincrs. Copies of the approval Infills issued to flu' manufacturer by the Ihireau of Mines must fie attached to these containers. The approval label gives the approval mmifier, shows to whom the approval is i: sued, stales what the device is anil is not approved (or. and cautions the wearer to I dime the manufacturer's instructions for the use and care of the device. The following is a sample of the required instructions, furnished by the iiuuiifarlurcr. These instructions are similar for all of the approval mechanical : her respirators. Instructions for Use of Mechanical Filter Respirator 1. Respirators will not prolert unless placed on the face piopcrly caili lime they are worn. Carelessness in face-lit means ifinigeious leakage. In general, a heller fit is olilaiued if the mask is vvom iml too high on the nose. 2. To fit the respirator to the face hold the ir-piratoi. eshau-.t valve poiiuiug downward, hv the metal srrcvv connection with either li.'imi. and hnfil the lu.idsti.ip with the other hand. I'lacc the facepiece against the face and liofil it in pl.we while pulling tile head-trap over the head and hclnvv the ears. Then adjust the facepiece until a firm snug fit is olilaiued. The head-trap may he adjusted while the respirator is ill place hy holding the metal slide between the thumb and forefinger of one hand and pulling on the proper strap with the other hand. .1. To instruct the wearer ill the proper adjustment of the head-traps mid position of the respirator on the face a cardboard disc is enclosed. To use this disc unscrew the filter hag. place the disc against the felt washer in the mct.d rnnnectinn on the felt hag, assemble the respirator, and put it on. '1 lie weaier should ' not lie able to breathe through the respirator or feel any inward leakige of air under the edges of the facepiece. The presence or absence of dust streaks on the face inside the line of fit of the facepiece after wearing the respirator in a dusty atmosphere can also be used to tell whether a proper fit was obtained. 4. The rcciinuueudcd procedure for cleaning the filler bag is to in-irt hmsilv ' the nuzzle of a high-pressure air hose into the bug opening anj to blow several HO nly-fourth Annual Safely Congress--National Safely Council TABLE 1. DETAILS OF FILTERING EFFICACY TESTS AND LIST Kind of mechanical nlter-ijpc loinHlor Industrially generated atmospheric particu* late mailer against which the device is designed to furnish protection Test suspensions used J>|*A Mechanically generated dusts resulting I'umipMly front the drsliutegiatron uf a .srthd, such ns the duft clouds produced m tntiuug. ifuairymg and tunneling, juul the industrial operations of grinding, crushing, and processing of minerals Air*suspended ground flint, which consists of 99+ percent free silica (Sit)-). Over V* percent of the dust passe* tfirough 323molt stamlnnl sieve J>pe U Tspe C Fumes of \uiiou* metals (usually their ihemical compounds, as oxides or carbon* ate*) such ns lead, mercury (except mer cury va|>or), manganese, copper, chromium, iron, cadmium, zinc, magnesium, alumi num. antimony, and arsenic resulting from sublimation or condensation of their vapor, .or limn chemical reactions In-twecn their \;t-*ir and ga*e* Mist* as produced hv spray-muting with paint and vmc*m*. en:nncl>, chromic and mr->t ns produced in rhicmium plating. and other mists of materials whose Ingrid ve hicle does not produce harmful gases or v|tors (a) l.ead oxide fume produced by the de composition and combustion of lead tetratthy! (b> Magnesium oxide funic, freshly pro duced by burning magnesium tild/ou (a) ('hinmic arid mist produced by electro lyzing an aipieous solution (200-500 grams of chromic acid per liter) ol chromic acid tally ted lead Mechanically generated du-t* whose main harmful constituent is had. Mich a had lusts generated in niamihutming storage batteries; iii.inu-ilng; |ottet> making; ilib ber compoiuidiug; sandpapering and chip ping painted surfaces; paintmaking; pte* paring litho-lransfcrs; and mining, milling and processing lead ores (h) l.ead paint mist produced by spraying a paint having the following composi tion? white lead (paste having approxi mately I'l percent white lead ami 9 peuent linseed oil by weight), 1(0 grams: linseed nil, 50 cubic centime ters* and steam-distilled turpentine, 25 . cubic centimeters (c) Mist produced by spraying a 2 percent aqueous suspension of giouml flint, air* floated 1*19+ peirrnl .llirongti .125 stand ard mesh sieve). The ground (lint con sists l 99+ percent free silica (SiO.d. Mixture u<ed in making negative plates "of had Murage bailrrics. Contains 72 percent litharge, J'bO; 25 percent red lead. rb.,(); and 3 percent lampblack One milligram = 0.0154 grain. 'One culm* meter rr 35,515 cubic feci. 'hate of sampling = 32 liters (l.l.l cubic feet) per minute. Mbit milhgram of this ribra dn4l contains appinximatrlv .VO million par titles as deter* ci| by the impingcr methoti as described by the* I*. S. Public Health Srrvicc. Ileucc. 1 'iiktaiti per cubic meter of this dust is approximately equivalent to 8.5 millions of panicles I ill IC foot. * previous listing of company for complete address. Safely nqiiihmcnl (a) '>o 10* (h) 5 2* 15 5 of Ic3(l 100 25 15 + S ol chromic acid 2U0-M10 of lead lit 54 of mIicu dust l i Snl lead 2.M 4 mg. for any I of .1 devucs, or an average of 3 mg. fur cath of the 3 devices ' 1.0* 9.98 . 12 mg. for any l of 3 devices, or an average of 10 mg. for each of the 3 1.0* 9.98 1.5 0.15 M.S A. C.nlo lfc|.iMtur. Al-|,\o. 2101, j>*ircil to Mine Sid*tv pliantes Co. W'iHsou Hag Respirator No. Approval No. 2102, issued to \ sou Prodm-ls, luc. Willson Hag Ue**pr: tvr No, Approved No. 2MJ, ueJ to \ -.* Products, Inc.4 rutmosau M-15 Pomh-Tjpe I Uespirator. Approval 2 . ?10t, sued to l'utmo>.m Safin Fqiiipu Corp. Mtever Respirator. Approi.il 2105. iMcl t* Slaiiihnl ,S.i IAfti j-ittcnt Co. < Willson Hag Rc'pirator.Xo. -4 ptoxal No. 2U>, r*Micd' b> Wit' I'loducls, luc * 2 9.9R 9.98 1.5 9.9S 5 2.M O.it 0-1 M.S.A. Cumin Uespirator. Aj.pn No. 2101. rsMud to Mine Sat Appliances (o.4 0.15 M.S.A. Ci'tiilu Respirator n*t proved for lead mm.lining imsjx n.5 M.S.A. Com!.* Rf'.piiaioi. Appro No. 2101. issued pi Mme S.ilclv Aj pliancc' Co.4 0.15 MSA. Coin In Respirator unit s n.il filters for |t.,,| dn*i. \t.pu.. No, 210/. issued pi Mine Safetv A pli.inccs Co.4 Willson 11.ig Rcspii.itnc \;. u. Approval No. ?urs. is^u-d p, \\.. sotr Product*. luc.4 I 142 T'oonly-fourth ,1 uiiiiiil Safely C oiu/rrss--National Safety Council short Masts of air into the bag. This procedure removes from the hue (lust and grit which clogs the pores of the filter ami makes breathing difticttlt. The proper time for cleaning the hat: is when the wearer experiences discomfort in hreathine:. When compressed air is not available some dust may he removed by tapping the bag lightly and brushing the outside of the hag. S. To prevent irritation of the skin and for genera! sanitary pnrposcs the respirator should he cleaned after' each day's use. The rubber and metal parts may bc_ cleaned with soap and water, and for general sterilization they may be dipped in a 3 per cent solution of carbolic acid, a 2 per cent solution of lysol. or a 70 per cent .solution of denatured alcohol, thru rinsed with water, assembled, and hung np by the loop in the felt bag to dry. The filter hag and hcadstrap always must be removed before the respirator is washed or sterilized. fi. While not in use the respirator should he kept in a dust-free place, prefer ably in the original container. The manufacturer is required to maintain the quality of his product and to see that each mechanical filter respirator in all its parts is constructed according to the drawings or records-that have been accepted by the r.urcait for this device and that are in the Bureau's files. Mechanical filter respirators that exhibit changes in de sign or include any parts that have not been approved are not permissible respirators and must not hear the Bureau's approval label. Schedule 21 provides for the manu facturer to apply for an extension of approval on any change in the mechanical filter respirator which does not affect the filtering characteristics of the filter. Changes in the filter require the application for a new approval. The Bureau obtains information on the maintenance of design and quality of approved mechanical filter respirators by testing samples of the devices obtained on ti'c open market. The Bureau reserves the right to rescind for cause any ap proval issued. A Safety Style Show By E. J. SMITH Safety and Health Director, Western Electric Company Hawthorne Works. Chicago For the purpose of assisting our foremen in the selection of the proper safety equipment we have standard specifications anti every foreman lias a copy. In it lie will find titc protective equipment required for any class of work. Holders, cupola tenders, furnace tenders and helpers in foundry and forge arc equipped with heavy duty metal or composition cup goggles with hardened lenses. Tlic lenses in tile furnace tender's goggles are of a forge and furnace shade. Electric furnace tenders, however, wear a welder's goggle, described later. When a goggle is equipped with clear lenses, it is used for such operations as breaking defec tive castings, cleaning castings with compressed air. grinding castings to remove gates or fins, pounding on castings to remove sand cores, pouring molten metal into molds with hand or hull ladies, removing gates or fins from castings with air chisels, or hand chisels and hammers, and working in vicinity of chipping hammers. Leggings are of the non-lacing, non-buckling and snap buttoning type held in place by hidden steel springs similar to the old bicycle pants guard. They will come oft instantly from a tug at any point. There arc no gadgets to confuse you or those who are trying to help you in an emergency. Just one simple tiling to remember-- grab anywhere and puli. Men wear safety hats when chipping slag out of cupolas. Our construction crews of masons, carpenters, millwrights, and so on. wear them whenever they are engaged in work where there is the slightest chance of objects falling from overhead. Our employees wear "Congress" safety shoes for their protection in addition to the leggings. We use a icatiier steel faced glove when charging a cujiola nr handling pig iron. Full leather palm gloves with hand top are used in chipping casting fins, load ing and unloading tumbling barrels, and removing castings from sand. For tiic protection of health, workers in die brass foundry arc provided witli overalls and undershirts with full length sleeves. This is in accordance with Illinois Safely Section, A A R--Strom Railroad Section, iV S C Safety Section, AAR-Steam Railroad Section, NSC Officers 1934-1935 General Chairman--T. H. Carrow, Pennsylvania Railroad. Philadelphia. First Vice Chairman--W. H. Failing, Central Railroad Company of New Jersey Reading Company, Philadelphia. Second Vice Chairman--C. F. Larson, Missouri Pacific Lines, St. Louis. Members of the Committee of Direction: Eastern Territory--H. R. Cole, Erie Railroad, Cleveland, Ohio; Charles E. Hill. New York Central Lines, New York City. Western Territory--L. F. SiiF.un, Chicago, Rock Island and Pacific Railway, Chicago. Southern Territory--D. H. Beatty, Southern Railway, Washington, D. C. Secretary--J. C. Caviston, Association of American Railroads, New York City. Officers Elected for 1935-1936 General Chairman--C. F. Larson, Missouri Pacific Lines, St. Louis, Mo. First Vice Chairman--E. A. Meyer, Qiicago, Milwaukee, St. Paul and Pacific Railroad, Chicago. Second Vice Chairman--K. G. Evans. Louisville and Nashville Railroad, Louisville. Members of Committee of Direction: Eastern Territory--A, O. Encic, Canadian National Railways, Montreal; H. A. Rowe, Lackawanna and Western Railroad, New York City. IFcstcrn Territory--F. W. Curtis, Denver ami Rio Grande Western Railroad, Denver. Southern Territory--L. G. Bentley, Chesapeake and Ohio Railway, Richmond. Va. _ Secretary--J. C. Caviston, Association of American Railroads, New York City. A complete report of these sessions is published by the American Railway Associ ation in it booklet entitled, "Froccedinns of the Fifteenth .Innual Medina of the Safety Section, Louisville, Ky,, Oct. IS to 17. 10.15." Copies of the booklet are available from the Association of American Railroads, M. Y. C. The follon/int/ is a condensed record. TUESDAY MORNING SESSION October IS, 1935 The opening session of the Safety Section, Association of American Railroads-- Steam Railroad Section, National Safety Council, was called to order by General Chairman T. H. Carrow, Supt. of Safety, Pennsylvania Railroad, who presided. - 459 Safety Section, A A li--Steam Railroad Section, iV S C 463 From the following it will !>e gleaned the situation on our railroads has im proved perceptibly with regard to the trespassing evil, particularly when considera tion is given to the fact that our population has increased and operation accelerated. Years Killed 1901 to 1910.:....................................50,025 1925 to 1934....................................... 24,951 Injured 53.427 30,200 Totals 103,452 55,151 Decrease................................ 23.074 ( 507o) 23,227 (43To) 43,301 (447) Seeking an answer to these decreases, the following comes as the result of investigations: (a)--Safety education in the schools, promoted to a great extent through activi ties of the railroad safety departments. (b)--Protective measures adopted by railroad police departments. (c)--Introduction of other modes of transportation brought about by improved highways and the practice of hitch-hiking. Persons entering upon property occupied by another, in the absence of any contraotural relationship between them, necessarily come under one of three distinct classifications or categories. (I) Invitees; (2) Licensees: (3) Trespassers; and the duty the occupier owes to any such person is graduated in strict accordance with the category to which such person belongs. Toward trespassers the occupier owes no duty. The trespasser goes on the premises at his own risk and the occupier is liable only for acts done with the deliberate intention of doing harm to the trespasser or with reckless disregard of the presence of the trespasser. The very nature of our business and the vast amount of territory covered by tracks, terminals, yards and stations renders the problem of trespassing unusually difficult. The impossibility of policing all these properties every hour of the day and night, is apparent. The best we can hope to do in that direction is to extend the services of our special officers, guards ami watchmen as far as they will go. and rely upon these men to inculcate the spirit of watchfulness into all otficcrs and employees so that trespassing will be held to a minimum. Trespassing by our better class of citizens who sometimes do it unwittingly is capable of being controlled by active interest on the part of our agents or representa tives. Trespassing by school children can be partially cured by appealing to parents and school authorities. This plan has been tried out on many railroads'-with success. As to what might be termed "general trespassing" on railroad premises, it is conceded that an appeal through the press, and hv continually reminding the public that hazards exist wherever there arc moving engines and cars, is by far the best method known for correcting this evil. The use of bulletins and posters should commend themselves to all railroads interested in breaking up the practice of trespassing. TUESDAY AFTERNOON SESSION October 15, 1935 Value of Accident Prevention By FRANK WENTER, JR. General Claims Agent, Chicago & North Western Railroad In the early days accident prevention activities on the American Railroads were confined to the safe delivery of the trains over the road, and these activities in lime were consolidated in our present Book of Rules. This apparently was the only safety 46.'; Twcnty-fonrlh AnnnnI Safety Congress--Xationnl Safety Council portent rules that arc not being enforced. and I want tn quote Mr. W, J. Patterson, director. Bureau of Safety, Interstate Commerce Commission, in what he said last year--"Alt operating ollicer assumes a firavc responsibility if. in his desire to ex pedite the movement of traffic, he permits violations ut rules to go uncorrcctcd.'' WEDNESDAY MORNING SESSION October 16, 1935v Address By JAMES J. DONOHUE Claims Attorney, Louisville & Nashville Railroad, Louisville, Ky. More than three decades ago. President Theo. Roosevelt. Gifford Pinchot. of Pennsylvania, his brother Amos, and others began to preach the preservation oi the natural resources oi our country, and since then we have heard much in regard to the conservation of coal, timber, iron, oil, copper, and the precious metals. But to me it has always seemed strange that it was not until 191V- that any organized, concerted effort was made to conserve the most precious things in -the world--the lives and limbs oi our men. women and children. In that year the National Safety Council was born, and there was then begun and intensively carried out a wellorganized campaign to instill into the minds and the hearts oi the people oi America the principles oi safety--safety not only on our railroads and in our manufacturing plants, but in the homes, on the streets, in our schools, and at other places where accidents involving personal injuries arc likely to happen. To my mind, the Na tional Safety Council, after the American Red Cross, is the greatest humanitarian agency in this country. In no other industry has the doctrine of "Conservation oi Men'' been more intensively and intelligently applied than in the railroad world. In the old days, casualties were considered inevitable: it was thought that they were all in a day's work and were bound to happen, no matter how well regulated or efficiently operated the particular railroad might lie. How utterly fallacious this theory was, you are able to demonstrate by pointing out the constructive work your organization has done in the past twcntv-iivc years. It is now well recognized that "railroading" is not extra-hazardous when con ducted by prudent, careful men. hut that when railroad operations arc in the hands of the rcciciess. the dare-devil, anti the chance-taker, it is hazardous in the extreme. Railroad managements, now more than ever before, exercise care to furnish em ployees with .tools that are safe and in good condition, and with a safe place in which to work, safeguarding that place in every way practicable. In addition. _ railroad supervisory officials, safety committees, antf employees acting in co-operation with such committees, are endeavoring, in season and out of season, to bring safety lessons home to the individual employee, through the written and the spoken word and through the medium of apt posters displayed in conspicuous places about shop and yard. The very nature of my calling makes me prefer to talk to you in dollars and cents. In 1927. fatal and uonfata! eases cost the Louisville 5: 'Nashville Railroad Company $1,001.51 l.Sfi, while in 1954 the cost was only $515,055.88. These figures tell their own story, looked at through the glasses oi a humanitarian or through those of an economist. They reflect a casualty* decrease of from 21.58 per millionman-hours worked in 1927 to 5.45 per million-man-hours worked in 1954. To Mr. Earl G. Evans, to our operating officials, and to the rank and file of our employees I take off my hat and felicitate both him and them with all my heart. Our experience Safety Section, A A R--Steam Railroad Section, N S C 477 Accident prevention is a problem that will be solved primarily by individual action. We will never have adequate protection lor human life until the manufacturer insists on safeguarding every machine before it is offered for sale; until the employer insists on safe equipment and safe methods of performing every jolt; until the worker makes safe practices a part of his sub-conscious habit; until the motor car driver becomes as courteous as he is in his home or office. Permit me to cite just one illustration. Not long ago in a large gas plant, an executive nf the company attempted to- enter the plant while smoking a dear. The gateman, not aware that this individual was the vice-president, flatly refused him admission until he had deposited his cigar in a metal refuse container provided for that purpose. This gateman fully understood his personal responsibility and lived up to the confidence reposed in him by his employer. But. you might ask. can we bring alwut such a change in the habits and customs of 130.000.000 people? Can we get cadi person voluntarily to assume his share of the responsibility for the prevention of accidents? The answer to these questions, in my mind, is unqualifiedly "yes." How? By continuing the same methods and procedures which have been em ployed so successfully during the past decade or more by our leading railroads and industrial 'organizations. In each location, in each industry, the work was started by one or two far-thinking individuals sometimes called safety men. WEDNESDAY AFTERNOON SESSION October 16, 1935 Transportation By Rail--Speed With'Comfort and Safety By ROY V. WRIGHT Managing Editor, "Railway Age" We arc in the midst of a speed age. Records of travel--in the air. and on the rail, highway ami water--arc being broken with such frequency that announcements of new records have lost much of their old force in challenging our attention. With the introduction of the private automobile on a large scale and the increas ing use of the motor bus and the airplane with high speeds, the railroads have steadily lost passenger business for many years, although the trend started to turn hack up ward slightly in 1934. Ill that year, however, it was less than 18 billion passenger-* miles, as compared to an average of 31 H billions for the five years 1930-1930. A further increase will be registered in 193S. Railroad managements realize that they face serious difficulties in attempting to build up their passenger business, and that only l>y unusual ami spectacular efforts, based on high standards of service, can they stage a comeback. The public demands fast transportation, both passenger and freight. The demand' for speed, as a matter of fact, has predominated over the demand for safety. Air traffic has continued to grow, and the sliced of higluvav traffic has increased tremenduously. However, the cost in human lives of this speed is startling. An increasing proportion of the public, it would appear, is going to demand safety in travel, along with speed, comfort and convenience, and reasonable price. What are the railways doing to meet this demand? The answer, in a broad way, is the provision of facilities over which modem and specially designed equipment can lie operated successfully* at high speeds with a maximum degree of safety. This may appear difficult, hut a study of developments indicates that the foundations have been wcil laid for a more intensive development of rail transportation at this time. The rapid extension of the railroads, in the effort to open tip ami develop the interior and far parts of the country, slowctl up hi the early part oi the present Safety Section, A A R--Steam Railroad Section, NSC 481 fatalities is concerned. However, there were 5,794 automobiles registered for each crossing injury, and this record is not so favorable. Your committee again recommends that individual railroads particularly stress the necessity of their train crews and others giving adequate and timely 'earning to the public of the approach of trains to a higlnvay crossing; that learning front engine shottld be continual until the crossing is definitely reached: that the standards oft protection established by the Joint Committee on Grade Crossing Protection he employed where necessary at crossings to facilitate uniformiy and public under standing of the signals; that crossings be periodically inspected and maintained in sound, travable condition with all obstructions to the view removed wherever prac ticable: that advantage be taken of the opportunity to address school children and students of colleges and universities on the subject of railroad-hichwav crossing safety, no opportunity being lost to present the subject at luncheon clubs, automobile clubs, and any places where automobile drivers may gather. THURSDAY MORNING SESSION October 17, 1935 Report of Committee on Non-Train Accidents By E. B. PERRY Assistant to General Manager, New York, New Haven & Hartford Railroad The reduction of over 4(5 per cent in non-train accidents to employees on duty, accomplished in the past three years, is gratifying. However, tile very fact that material reductions have been so readily made supports the belief that a large decrease from the 1928 figures is still easily possible. We have felt that no good purpose would lie served by a mere recital of statistics. That which has happened cannot be corrected but should be used as a basis for thought and action to prevent recurrence. Your committee arc agrcetl tiiat they should outline plans for the future rather than recite history. A review of the statistics indicates the major causes of non-train accidents fall into the following classes: Use of hand tools, apparatus, etc.; Collapse, fall, etc., of objects: Handling rails, ties, bridge timber, etc.; Handling freight and supplies; Falls of employees not in cludible in class (a) to (I). (Report had been distributed in advance to all delegates.) There has been a marked and steady decline in non-train accidents per million man hours worked--the 1933 figures 1icing the lowest on record. Use of Hand Tools and Apparatus By II. R. COLE Assistant to Vice President, Erie Itailroad All tools and machinery- should lie inspected at least monthly. Proper tools should be used tor different classes of work. Reclaimed tools such as claw-bars, cold chisels, etc., should be thoroughly tested before placing in service. New men should be instructed in the use of tools and how to keep them in proper condition. Tools should not lie left in dangerous places where employees may fall over them. Metal spurs should be used on ladders. The use of a rubber collar on cold or hand chisels to prevent pieces of material from flying is suggested. A 50 ton air jack can be used at wheel pits eliminating use of jacks with lever which might slip.