Document vVKjDevKL9Zx3B0MK93e9x42m

Safety litjtrifuii-iit Safety Equipment WEDNESDAY AFTERNOON SESSION October 16, 1935 The session was called to order by Giainuaii, Irwin W. Millard. president. Industrial Gloves Corporation, Dauville, III, Chairman-Millard mentioned 'wine o' 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 hvtrieuie importance are those designed to protect against the inhalation of harmful solid, gaseous, or Mpnd atmos* phene contaminants, or the inhalation of air deficivut in oxygen. Ihc devices in common use are the mechanical filter respirator (cuumtonly re* ferrul t<i as respirator) tor protection against the inhalation of duu. smukcl. fumes, and mists nr what may le referred to collectively as atmospheric tiarticuiatc matter: gas masks for protection against the inhalation of gases and vapors; oxygen breath* ing apparatus, hose masks, and air-line respirators (or protection against tiie inhalation of any atmosphere provided it does not contain harmful constituent which can he ahsnritcd readily through the skin: and the abrasive blasting helmet ><r iio.nl for pro tection aeaiuvt the inhalation < amt the impact and abrasion irnm the atmospheric particulate matter generated in sand Masting or abrasive Mailing with sn-t-l 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 safe air from a supply which lie carries or from outside the contaminated zone. The wearer of (lie first or nir-ptiriiving type, on inspiratMin draws air from his immediate surrnnnditigs through the device which cither removes the >..iit.iiniiuiit, usually hv chemical or mechanical filtration, nr converts it into a harmless uh>tancc. This type, of course, offers no protection against atmospheres deficient in usygent as it does not add oxygen to the air. There are two types of respiratory protective devices of the second type designed to supply the wearer with sate air. In one. the wearer receives his air supply Crum a cylinder oi compressed oxygen, liquid oxygen, liipiid air. or from a chemical which yields oxygen ii|Km 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 face piece. is connected to a compressor or blower whose intake is located in safe air. Air is forced through the hose to the wearer. Note: PnMitta) by r*ertm*in ol Director, It. S. ltnrsiu e< Mines. (Net uitiieet to copy- riffhi.) . 133 m, >> j- \-founit .-fuinm/ Safety Congress--Notional Safety Council Tlicrc is pn>c confusion in the use of ilic te\rm "respirator," to designate device* for protection acainst the inhalation of atmospheric particulate matter. Swell sJc'ift* were Hie fir*t ami (or a font; time Mere Hie only respiratory protective devices*. I hey were logically failed respirators. ami a* loo# at llicy were the only device* id this Lind there was no cunfusimt. Ttic development of oilier devices of industrial hygienic importance and Hie development of devices for maintaining artificial respiration over long periods and for enabling men trapped in submerged submarines to resell Ibe sur face safely, all called respirators, was responsible for the confusion. The Bureau of Mines suggests dial llic term 'respirator'1 be retained for all of these devices, but that respiratory prntefiht device* of industrial hygienic importance be called indus trial respirators and that die different kinds of industrial respirators be assigned a name which will indicate their operating principle or field of use or built. Satisfac tory names in common tor sltonld be retained. On this basis, the Bureau of Mints swqgvst* the following classification (or respiratory protective devices of industrial hygienic importance: 4 Industrial Respirators I. Supplied-Air Respirators a. Sell-contained type (I) Oxygen breathing apparatus4 b. Hose type fI) Hose mask fji Air-line respirator* ij) Abrasive blasting respirator4 2. Air-l'urilyutg Respirators a. Onmical filter respirator* (I) Acid gas or tjpe A* chemical filter respirator 12) Organic vapor or type II' chemical filter respirator (.1) Ammonia or hpc C* chemical filter respirator \t) 0*tUv wwoilc or type lY clnnncal fitter respirator li. Mechanical filter respirator* II) Dust or type A* mechanical filter respirator (?) Funic or type B* tnecltanic.il filter respirator (J) Mist or type C* mechanical filler respirator e. Chemical and mechanical filter respirator* Testing and Approving ot Industrial Respirators by the U. $. Bureau of Mines Since its organisation the U. S. flureati of Mines has hc inlttvMtd in mduMml respirators as a im-aiis of protecting workers in tin: mineral iiubi-lry against harmful alinospln ric 'oolantinanls. To this end the Ihiivau has ihvvloped an approval xsxtmi. In- pmp<* ,.f u Jin h me: (II in nimi.*- and aid monrfai Inn is in tin* d* vrlop ii'iil and m.iil-> ling >>l safe and siiif.iMe < >pi*pin< til; ami (2) In ihmnarc tin* ion- iiim r to use mhIi KpnpMh iil. to aid him in hlniuiug it aud io iiMruel him in it* IT. These purposes are ;n e*'iupli'hrd by e-lal>liliioi; a still dole of the maleiial and ifoi mam i- leipiiM ii nl* (bat a sale anil Miilable di tiee vlmidd nni-l; by ind.ini: I'lMuval lexis for rotiforiiiaui'e to so* b a sbi i|nle; and hv iuhumiiiK thv public of the '5aiirliinri mine n>i( tii. iil'idj* :>|'| i<iOt. I S"tnrliinri *-.*|l*-*t i-aii't ir-|.f**l-r r M'.ilitr |r<Mifl tr-S'ilil**r. Soiiirlhnts s-ullvd xs*>lbl:,* tirtim I ur * t><mii>'Milr r:il|ill ([;, mi i-Ii. * lailxix In puitirit i.t tlxiimat IiIki **te It S. Uiiif.vu i,t Stiiu-s 'it'mjl Elicit. Ii|>. I'mniliiK lr Tr-iii'e tt.n* Mk* lor 1 liila I? i-P 1 r*..... Malr tailed *f|.itvi..r. SuaiittiiuM Mlriitil l<> ax ili>l loi-ir-ilm nr iiaiilniainl Urt-lll** l'|>iral<>r. . * l.riltrs a*iriod In mr'liairir.xl filler r<W'i',xt<*r fall***. Ste tj. 5 ltiorail _ *4 Mauri iS'l'rttl S*tint. 71, I'rut'llIK ( '|>ltn|{ I'iMvlTsft llssxl, Ismt, w*t Mot Mi)>iijliiis to* . imoMtuli'r. M i p.,' I9H. .*ui-_l*<llir-si>l'itaimsos ' ultiidl unAct Itiis totira<aVsan'Jg.'jpc X or .Ml Sovin Mt wt tt* iWmiial Safety P.^iufttirnt v 135 advantage** in the use of devices liraring Ibirran of Mines approval. If the device is fonihl bv evaminaliirii .in*) lest to mvrt (lie rti|iiir nniil* ot the schedule llic purs.hi ol Mines gives tbc manufacturer ft certificate of approval1 wbich hr may display as evi dence of the quality of liis product 1 he approved devices arc marked in a inaniier winch clearly distinguishes them ami iodirates the pnrjmc for which they are ap proved anil ibe limitations under which liny may be toed. As an aid to the constuwer, the Bureau of Mines jiesiswjivany issues a list yf the devices which have nut llic rri|uircmciils. The submission of ripiipmcnl is entirely voluntary on tbc part nf the inannfacturcr. On making application for tests. Ibe m.iniiiacinrrr deposit* a W wliirli is lurnril intu the miscellaneous receipts ofthe treasury *( the United Stales; none nl llie mom) accrue* to the Bureau of Mines. I he approval syMcm is wn.tivatvd vvv tirely by llic ilrsire of llic manufacturers to produce and market good ei|Uipinvul. the interest of the Bureau of Mines in having safe iipiipituut available eomim rci.ill), ami the dvmattd nl live enmwmvr lor such e>|uipninil. Approval schedules have liceii issued for oxygen breadline apparatus.' chemical filler respirators nr gas masks,' liosc masks* ami mechanical filter respirators.' Ibe schedule covering hose ma*lc< is being revised (> include (lie oilier kinds uf supplied- air respirators, namely, air-line ami abrasive-blasting respirators. When this revision it completed, the Bureau of Mines will have approval xvhedwtes fur alt types nl respirators now in romumii me The approval system midi'iihtcdlv is largely respon sible for the development of fimil.iimntaMy safe and suitable devices, ami the elimina tion vd cnnfnshnv in their selection and me. Ibe general plan of the various schedules is similar. The rc>|uirriuents may he divided into .1 parts: (1) Pre-test reipiireineuts, or those with which the manufurturcr must rmnply In hue examination and test of a device ill lie undertaken. For rvample, dm respirator nnisl be til a fully deve)o|>ed form uadv lor market and available (nr pur- ibac if approval is granted. Also, the manufacturer mint be prepared to lest and maintain control of the essential characteristics of bis device by a method which imrts the approval of this Bureau. (2) Material. constrnrlSnn, and performance rnpiirrmcnts vvliicb the i ipiipuu nt must meet by examination and test. ' f.l) Post-test requirements, or those with which live manufacturer must comply after the device is approved. From the vievv|miul of the consumer the most imp-at mt of the sc concern labeling and maiking, pruvi-iou of adequate instructions for proper me of the device, and maintenance of design ami quality nf tbc product marie-ted umbr the approval, As a check on the latter, the Hutvavv <d Mines obtain* amplr* ol ibe devirv on tbc o|*rn market and subjects them to the various ins|H.cIam| tests of the appropriate schedule. The Bureau reserves tbc right to withdraw its appr>. al of any device for cause. Interpretation ol U. S. Bureau ul Mines Approval Siluiltilc ?l. I'romlm-* for Testing Filter-Type Dust, Prune, and Mist l(t-xpiralo s for I'l-rmixsibilit) Aitmni; |l*v n:ix*<n frr tin* d vi h-puu lit of Sibiilnb- 21. I'ndmr h.r l i'ling lillit-lv|H- Ibi'l, Iiiimc, am| Mi'l b'v'piialorx f>>i r iiii"ihi1ilv. v ix lb* ti.'lt/.ili-n by tlw I'.urv :wt >( Mim s and others ttv it tin t v n o a di tioilr m < d t.- o i bauir .d t 11 rr-pii a tor* 1<* pn>lc< I vvu l.i rs again* I bat mini all.......ph* r iv parti* nli,- m ill* i in *<1 m - lions where I* II* e in* tlnvls of roulrol <d *111*1 prodm Ii**tl ami nmoval w*re < 11 o * o- l available or piaetival. the in* fin i* n*v ol ixi-iing on > lino* at I 11 * r r. -pit i|.n v. ami li*iff* *( Mint*. P***cril*ne -i*iif s I .* - * - I l'*****--*i-it y>il oi,r.| n,,,n* tv> talt-* Al'l'mini; 1 ***, lluoiUr o| l*.|. o,,| I..,>Ioi..ii t **.t(* lint, Mm>c l( * or |ri* o|.ie A|-|-xill l l>*inl: S. I*nl. ll.V, I 71. MS. I? n* 1 I:iiii.hi *! Mmrv, l'i*Mt>linr lor Ir-on*; i;.* Mivg, f-,* I'oMiiiolnla* : 9. V'.tv. t? iv X, li,.| |l|l, g| . * piiu-:ii| *! Mint*, Pl-r-1m t'-r Ir'liog lino viol* li-r I'f.mi.Ml.il.i* *, l.f.l |S. ,Sj-*il 2*. p*I pp 'ItviOM wl Mint*, ViCKotuir If'line tillr*'l*e 1lurp 1u*nr, ;<i><| Mil Ilf-r.l.tla* f-*r Pcimtnibil'l* : Scl'ol. 71, Aic*i*l 74. HH, |l |-l' rurnly-fourth Jtnnta! Safety Congress--National Safety Council '* frt>"1 manufacturers and consumers lhat this bureau lest and approve such .l.cdulc 21 follows the cnieral plan of the oilier bureau apitrov.il schedule* for tal respirators; the pre-test ami poal-lesl requirements are quite similar, and tteral principles of the test re....... arc lire same. The primary purpose of'-' a|*er is to explain the reasons for the various test requirements. Pre-Test Requirements ' 1 he pre-test requirements of Schedule 21 require that the manufacturer submit i.ilion. drawings, and samples of. the device to lc Icsled. The device must he* . iclcfy developed ami ready for release to the public, ami the device when tested tc manufacturer or his asent must have passed tests of the nature described bolide 21. The reasons for the third requirement are: (I) To assure the .ii that the manufacturer is prepared to control lire filtering characteristic* ol .-pirator: (21 to diiniitalc any i|ueslS<>ii nl com|ntitif>ii wiih privale cctiisiiltinc; .iis ill developing respirators; (3) In furnish evidence lhat the respirator really adv for release In public market; ami (t) to j-avc the manufacturer's and the -Ill's lime. Aflcr the mamilaelurcr has complied willi all the above pretest iimiils he must submit a lee for the examination ami lest of hi* device, fee is turned into the miscellaneous fund* of the U. S. treasury and none of . Money reverts to the Bureau of Kline*. Test Requirements 1 In developin'; the test* for mechanical filler respirators consideration was given : to the general requirement* for a safe ami suitable device. These requirement* similar for all types of industrial ivspirator*. The respirator must (1) give quale prnlcctimi. (2) he reasonably comfortable and physically convcnicql to -r. ami (J) provide an acceptable service life. Adiquill.* protection implies that the inrdmnical filler respirator when properly >i.nued and worn must prevent the wearer from breathing enough particulate i r to came a harmful physiological ics|mnc umlcr (lie conditions ol occupational ' sine fur which it is designed to lie mol. t'nmfort and physical convi ounce laelors arc equal in ini|>orlancc In adequate ocliou. l-'vm though aware of the ulliniate serious effect whiih will Ik* produced r prolonged daily rx|nurc. workmen are imliind to Ik- difTulcul and unwilling ifile iniiili daily iiieonvcnicnec and discomfort from (lie respirator. rncuinhraiKT and discomfort also increase fatigue, cause distraction, and in *ul handicap the wearer's ability to take care of himself. Urns increasing the hilit) ol accident. Important specific items include the weight ol the respirator, arriage nil the face or herd, effect on vision, heating of the area of the skin ' the facepiece, inability to expectorate, difficulty in talking, and resistance to thing. The iin|n*rtancc of comfort and phvsicat convenience cannot he uver I lie sen .itc.lib.- involves dtnnitl* <>| prae.liml.il.ily .in the wealing and mai.ntenance `hr drvici. and indiroilv the sahty. This type of n .piialnr is primadlv iu>l an igmrv dt v he. but a pait of the workman'* npiipmi ut for doing his regular job Iv. H ihi- seniee life is shoil, the Ivolhrr of changing <( lilln ehnieuts will >i Heeled in the winkii'an's allilnde low aid gmit maiiili uaiua and use. Ml me' hanirat filter ri ^piialoi s are Mibjn led In certain impel li-ms ami tests I h* y must fulfill iirlain requirement*. 'I lu* [iini.il ilisign and coii'li nrlioii. `iidarly as lu facial fit, fuedotn from iriitaliug fa< ial innlatt*. wiiehl, iffiil vision and the wearing of goggles, and ease of changing Idler ilennnts, and mined. I lie nialrrial* arc examined to delcrmiuc ii (liey are obv iously Miilcd the purpose for which they arc designed. Rubber parts which come in conlact i the skin must not contain any skin-irritating constituent. t .Resistance to Air Flow Requirements I lie requirement* for resistance to air flow arc the same for all approved mesiir.il filler icspiralors. At no time during or after the filter efficacy testing period l the resistance to air being drawn through the device at the rate of 8.1 liters Safety Equipment 137 t.1 cubic feet) per minute exceed 50 millimeters (1.07 inches) of water column height or llie resistance to air being blown through the device at the same rate of Hmv exceed 25 millimeters of water column height. An air flow of 85 filer per minute il approximately equivalent to the* respiratory rale of a man doing hrav, work. The amount of particulate matter pulled to the device during the Idle, efficacy tests is roughly equivalent to the amount that would he pulled to the Idler by a worker wearing the mechanical filter respirator in a moderately, concentrated Mi-pcndun of the |irtienlale matter during an R honr pvri>d. Thus resistance In air Hove id an approved mechanical filler respirator should :mt become excessive wbrn worn ior an 8-hour period in most suspensions ol attm-q Iveric .particulate matter cmeniinlcfid in industry. The niamdacliiicr U rv-m ;`.<! tv give* imlruelmii* on.cleaning jr changing the filter elements when the rc-lom, ;.*r dnv nutivealdy imnar*. Direct Leakage and Man Test All iiM'chtuiical filler respirator* are Mib}eeted to a dirwl leakage and man lr`t to determine facial fit, whether tlu-re is any dirwl h.a!.age of unfili.ied air. and to obtain information on the comfort ol the device.. Ihire id themivhinical .fills r respiralnrs are worn for 30 minutes by 3 nun with dillereni facial ivalmes m an aliuusplierc containing a heavy suspension .1 bilmuhi'ais-rnal dii>t. At the md *( the period the respirators arc removed and that part id the lave covered by lbct laccpicec is examined for evidence td any leak under the idge of the facepieic. Slicks a niilliinelcr thick were wedged under the edges of the facipieve* worn by *nhjret* A and C In cause the leaks. The location ami approximate magnitude of llw- leaks arc slmwn by the black streak* oil that part ol the lave covered hv the edge* .d the latrpicccs. The nasal passages and sputum of the subject* an- also examined liefore and after the lesls. Filtering-Efficacy Tests lu the development of the fillrring-cfficary let*. pailiridar attention was given to the physical proiicrllcs. especially parlide sire, ol the significant kinds ol atmos pheric particulate matter encountered in imliMry. Previous studies of filloring in.i1tri.il* had shown that, ill general, filleting tfbeary ihcreroe* with a decrease in particle sire. .t It wa* decided that most nf the significant iodmlii.illy gviieialcd atm.-splm is parlirnlatc mailer could lie cki**ifhd into the bdlowmg.liner group* hi aiiordamc with iiicIIiimI ol general ion. physical stale, and particle sire: 1. .Vcf/miiifiiWy ftfMrrtittd itutlt rcsulling from the disinterialum of a s-did, Mich as the dtisl clomis nroduccd hi the vaiimi* prow^sC* ol mining. quarrying and limnding and the grinning, criishine. and general pr-iecs-ing of solid materials. I bis lv|*e of atmospheric |wtrlicnlalc matter i* refen cd to as lypc A aliiM-pberic particulate matter and mechanical filler respirators designed to lurnidt ptnliclion against these 5iiS|eiisioiis arc referred to as Type A imeh.inie.il filter rcpiralr*. 2. /-'time/ of various metals (usually their chemical compounds, as oxide* or r:uImitates) snrli as lead, mercury (except mercury vapor) manganese, maem sinm. aluminum, antimony, arsenic. copper. rlirominm. iron, tadoiiom. and due r suiting Ir.mi sublimation or the eoiulinvdi<m nl lliiir vapor, or from the rhrmieal M.olb-ii* hctwei n their vapor and ga*c*. 'Ihi* type of atmospluiic p.irtienl ill- nnllir is re bind to as Type II atmospheric particulate mailer and mcrli.mir.il fillet n-piialor di-iguid to furnish prolcclion against these snspmsions are rilcircd to as I ype It uiih.iiiie:il filler respirators. j. 3/irfx as produced by spray -mating with p.iiul and vitreom nniml. dir-miir acid iuis| a* pruditcnl in ihromium plating, and ilirr ini'lv id in iti rials wb-oe liqniil vehicle doc* not produce h.irmlul gases "r vapor*. Ibis typr id alMi'.-pb. m p.iilieulalc matter is referred to as Type C Utm-plufic jiitisnl.ilc mallei a"l mechanical filler respirators designed to lnruih pruluiion agaiml these siispuisiniis arc relerred to as Type C mechanical filter icipiralor*. The mechanically generated dusts and fomvt cou<il of solid pariirlcs while the misls consist of liquid or liqiibl-en.ilcd solid p.irliile* The paitirle *irc of me- chaincally generated du*|* extends over a wide ranee, in mine ea<*. frmn pni.ihv visible to the inked eye probably down to molecular dimnninn*. The range in .p.nlidc site of fumes is much smaller. 'I hr upper limit iy in the lower micro'c ;oc M8 Twenty-fourth Annual Safety Congress--National Safety Council -(? (about 0.5 micron), while the lower limit |ruhab1v approaches molecular nensinn*. The particles of some fume*, particularly zinc ami magnesium. rridily I ami form farce fhicklikc cluster*. The effect is least pronounced in the case lead. Mist particles arc spherical and probably more uniform in particle sire than se of dusts and fumes. ' 5n|Hnsir*ns of each of the types of industrially-generated alinotphciic particle alive were sclrcled fc*r use in the fihcrimt-rffieary tests. *1 he*c suspensions were iiiscn on the basis of their industrial hycienic significance and their physical f**pertiv*. such as p.ariiclc-si*c rlislrihniioii and tendency to aggregate, which have appreciable effect mi filtration. It was desired to test the mechanical filler pirators against lliv most comnion nr widespread harmful sn-peusious nf rach ,v: the lest suspensions In have |Jnsiral |irn|>erlii-s, such as particle sire and vrepalion tendency, which would render them as difficult to remove hy filtration any other siisjiensioii o( the same type. The lest sii<|H'iisi>His selected are: fa) lor tetimr Tyiw* A meehauical filter respirators nr those designed In' 'nidi protection *caiii--l imcli.aitivnlly gcncial.d dusts a *iis|N-i.don gincralcd Irom ry line (!/9+ per cent through 325 standard mesh sieve) silica dut consisting id *? P*t cuit frtc silica (SiOi) is used. 'J'hc suspension is gene rated in such a way at all particles larccr than almut J inknmv sire ttnmvril Indore the suspension hrs the lest chandler. *1 he p.-irlirlc-si/e disliilnilion nf the lest suspension must _ t cscicd a ccoinetric mean nf fl.6 micron ami a standard perimetric deviation of '*>. The parliclc-sire dclcrnhnation is made hv crilleclinc samples of the suspension the Owens jet dtis| counter and determining the particle size distribution hy a o-rnprnjirliini method developed hy the Uuieatt of Mines.' ' lh) lor testing Type II tticchanital filler respirators nr those designed to irnish pmUctinit against hums, a lead oxide fume generated hy the rnuilnistinn of tnral gas conlainnii; lead tetraethyl v:i|ior is used. The particles id this fume arc slrunely mii:iM ami have almnl l*c h-:is| tendency In aggregate of any finin', hence )' are -very difficult In remove from the air by mechanical filtration. A suspension inagncsiunr oxide is also used to determine the effret nf a fume, vvtinse particles dilj aggregate in large flusters, on the resistance In air flow of the filler ol the kr. fc) For testing Type C mechanical filler respirators or those desigmd to ruivli protection against mists, three different suspension* are used, (.'bromic id mist generated hy electrolysing an aitnenus solution of chromic acid, as is done industrial chromium plating: had paint mist pinnated hy spiay-cnaling witfi lead ml", and a water mist carrjinjj silica dust generated hy spraying a 2 |ier cent nous mis|hitsum of siliea ilrnt rire iim-vI. The water-mist earning silica dust is d to simulate tlie mists generated in spiay eoaling with vitreous tnamels. 1 I he imihnitration of |lu- pailSeulale mailer in the lest mis|husii>u< was ilxia-ii ivpri-Miil more or less the lih;lur coiicmti alioii* ...... id in iimIii-Iiv'. Sime the m i nli alion of mei hanieally pi neraled dust found in industry vaiies over u1i 'de limits it was decided In lest Type A uurhaiurat tiller respirator* against two <>ei nli .iinuis I one |o represent llie more or less :}Vr:n:r dlls|y indiisli i.il rondo ns, and the oilier In repriMiil very ditstv i udilioiis. Tin mpble imiliaideal fdtir respirator is tested nil a mechanical testing I'.iratus. The test suspension is pulhd ihrouudt the deviee at the rate of .12 liteis I l.t cubic (vet) per mmwle. contumnws flow. 'live vohmie ol air pulled through v inetbmical filter respirator is 10 rubic invlcis in all rases except in some t' agaiu<| particular kinds ol suspensions as mechanically generated lead dints "I in the high-silica diisl-eonreiiiralioii test ami the magnesium oxide lest vvtioe '"nary object is 1o determine I tic increase hi rrsistanre to air flow of the filler III the amonnl of parlicuhlc ni.illcr rttained. Ten cubic melers is approximately iLnalciit to the vnlunie of air breathed hy a worker in B lioiirs. Tire samples of rliculatc mailer for concentration determinations arc precipitated ehclrirally m the air of the test snspemom Imtlr hclnre anil after it has passed through - mechanical filter respirator. The samples are collected in containers which > lie weighed readily on an nnalytiral balance. For rcashus of convenience, speed, C. L anj Yanl, \V. I*. Tl>t Mieu-pr.je<igf for llrirriitSiiin* Partiflc Sir* . oilnii-.Ni ,m| Number I'onciulralion <4 Anmo|t>(iir |)u-|, It. S. tluiou ol Mints lli|il I'ottiiraiioui J.*!), 19)). . Sofety Equipment . 139 and accuracy the samples of silica dust are ipianlitaled by weight rattier than hy CfitNit. Samples of the other particulate neuter arc i|wantitatcd chemirally. The rcipiircmeiils as to the amount of particulate matter that the mcrhaniral filter respirators must remove from the air pulled through them is based on the bis| .nailable information on tlie concentration of tlie paniculate matter that is safe to breathe. These reipiircnieiUs are Mibjcct to change with the aicuinnlation of k.mwl- idee imi tlie physiologiral clTvcts of indu-lri.illy generated atmospheric partie'daic mailer. In oilier words, the lilh i ing-ellicacy miuircimnt is that lle air mh.dvd h>* the wearer ol Mich a device must be sale to hic.uhc. anil not that tlie device have any paitHular pereudage filtering efficiency. Mechauie.il filter respirators are not appioird for am substance more ban did than tlie particulate matter in the test suspension against wliivh they arc 1rs,rd. Thus Type A respirators are tint approved (or any substance more harmful than free silica (SI0s) dust. However, Sihedule 21 provides lor testing and approving ni-rlianiral filler respirator* against any kind o| industrially gviu-rakd almo-plnrie parlienlate matter. For exam|ik'. Type A im-ib.mual filter respirators are not approved for prut eel ion against poisoning hy breathing dusts whose main harmful ron-lit mitt* are metals or their compound-, |l>i(ui', two tncchaniral filler re-pita* tors have liven submitted and approved for proleriiiii against the inhalation id lueshanical generated lead dusts. __ Table I summarizes the details id the filieriiig enicarv tests ami lists the me* chauical filler respirators which have hern approved to date. (Papes Htl-MI.) Post-Test Rccpiircmcnts Ihc maiudaclurer rd an approved merhaniral filter respirator i rr>piirrd to mark his device with lire name ol his rompany. ihc name lelter, or uuiiilsr by vvliirh the tyjiC is designated for trade pnr|ises. and die appimal number :<"ii d to tlie dvvut ly tlC Hmcau id Mines; and the filter nnil nmsi l marked with the a(iprm.d inuulier and with the type or kind of alimopbrtic parlieulalc mailer for vvliieh it is approved. The meiliaiiical filler respirator ami replan nn nl Idler units mu*l ! providid with substantial and durable runl-iimrs. ('opies of tlie approval lalnk ismd to ihc inaiuifaiiurcr by the Ihtrcan of Mines must t>c atlarlrcd I" llnse loniaiiurs. 'Un approval latrcl gives the approval muul>rr, shows In whom the approval is i nid, stales what the device is and is not approved lor, and million* the wrartr to I Ibm die manufai tiirer's tusIriKlioits for llie ir-c and earc d the ilevirv. The following is a sanmlt* nf lire rei|iiind instruction*, furni-lud In the mumlavluriT. TIk'Sv insirnclions are similar lor all of the approwd un-fhaimal ; her respirator*. Insirnclions for Use of Mecliauical Filter Respirator 1. Ifespiiators will nut prolefl imh << plnv<l on the fate pi-|xrly iaili lime they are worn. Otrelessm-sS in laee-lit nii.nn dmeiious leakage. In gtmral. a lnlt>r fit is olii.iim-il it tin- mask is worn m.| |pi birli on the ii"'f 2. To fit the IV spir.ltor to ihe fail- hold ihc li-pilaloi. (\biul vali- |`"inl>iti: downward, hy (lie meial screw ri'imevfi--n wiili itlur liaml. and hold I be I . II ip wilh llie other hand. Flare the (arvpuvc ajiinM Ihe faw and IwM it in pine while pulling the hi ad-trap over the hi ad am) IkIow- the ear*. 'Hun adjust die fatepietC until a firm snug fit Is obtained. 1 be head-trap inav he adjusted vvlide llie respirator is in place by hobliuq the meial >lidi l>elwieu the thumb ami fotifioe<r of one loud and pulling on the Jiropcr strap with the other hand. .1. To imlrurl the wearer in the proper adjustment of the Inad-lraps and po-ilion of ihe respirator on the face a c ndli -ud di>c i* euebuol. In u<- ibiv disc unscrew the fitter bap. place tbc disc a-cainsl tbc tell wa-lur in tbr imi.il muneclion on the felt bag. assemble tbc rcpirali.r, and put it on. I be wcaier sin.old ' not lie aide to breathe through Ihe respirator or frcl any inward leal, tgr of air timkr the edges of llie facepiece. The presence or absence of dvist sneaks on live face inside the line of fit of ihe farcpiecc .after wearing t|(e rrspirator in a dmly atmosphere (.an also be ued to left whether a proper fit was obtained. I. The recnmnundcd procedure for rleaninp the filler hag is lo in-rt finisd* ' Ihe nuzzle ol * high-pressure air hose into the hag opening and lo blow Several 140 nty-fourth Annual Safety Congress--National Safety Council TABLE 1. DETAILS OF FILTERING EFFICACY TESTS AND LIST ------------------ --- -- ' . _______ _________ll____ _________ Kind of irclijniral loiinitr Indoitnatly ieneiated atmotjihetk panic ta lkie niatler which Hie <lc<i(( ii deritutd | IttcnUh piottition Tol UpCUtti>lt UMlI |rf*A Mrehaiiirally fcneraled Hull* irtullinff .allr liom tl.t diyttmeR.ati.m ul a n* !'* ,|u`l clooN produced io miimmir. ,,uic\mj and Innntlntc. Biot |hc ihiIm'IimI r|rnlii>ni p| Riinjiiiff, crulhinff, a iid iHWtillnc l ininti alt Air-tuspeiiilfd (round II in I, nhicli conxi'lt 0I pent..! lire nlica (SilM. Oier y percent of ilic lu<t pate iLourH 1:5inoh alamfard aieve , lilt U I .* p C * Kuniti uiiuii me*ala (nunHy |ht>i il>eniii'.il cotiipomidii, at oaiiltl of carbon ate*) audi a* It'd, tucrcucy met- eury \a|<or). muiihiiicic, coifci, clunmiinn. iron, cadmium, tine, mafineMuin, almwi- Hum. antimony, ami *rcnic ttuhing limn tiil.lnii.ilimi or riimlemtitait l tUer vanor, .or limn iliemie.il reaitimii Inliiecn ll>rir *:i|-r and a'*i Mult at prdinrd hi tpiav ralinff nilh paint ami viliemi- cii.hiuI*, a l*ir<raitc arid ini-l ai piodint<l in rhtontium pljlim;. and i.liter mini of Miaic'i-tll who** lirtuid v. Iiiilt iloet ini |idu<e hamilnl (ate* or tapon (a) l.rad oxide linne jifeduced by Ibe <lecomporjiion and comLmilion of lead tetraethyl (b) M-iffnc-inm oxide fume. (rcalilv pro duced by burning in.itriioluiii nldeto (a) t'lirnmic arid unit pti<diKed by tltrlro* t; ring an m|ncout notation I.V* SC0 arrant* nf clnimiic arid per liter) ol itirnmk acid >x Wy r-t lend Mcrliuiifeatt? ctncoinl tltnin >vhvr main hamilnl rutitiilutm i* Ii ad. Mith >i hail .ln*lt irriii'*tcil in nuiwlaiiwint ims* haliriicr; i ii.iiiii ling; imiteii m.ilnni; mli ber rMiijN.imtliinj; iiiul|n|xii<it; and chip, pine I'amied nnlicei; |>]iiitmalirif; pie* paring lillm-tramleri; and milting, milling and |ftcfMe lead 1'ir* (h) Lead painl min produced by spraiing I'lint having (lie Inllnn ill* ennipnii. linn: ntiile lead (paite having appioiitoatelf ft |tfifcnt nliiie lend ami V (rlceiil Iill>red nil In- Mfirl't). 110 (itmv, limrcd nil, W mint rnuinif lrr: and iir-ini-di'lilltil lurt-emine. Jt , enlwr etnlimeteia fe) til'll f'rndiHfil liy '|ii.iiie a 2 irnrni .vpieini *uttriiti> id irit-iiM.) flint, airfloated (*/) peirrui Itamiirli IJI >iandaid Mirth Mtve). 'f'he Kumid dint ron> itl* nl W+ |triren| fire tilira I SIM. Minute ued in ni.tl.inc WRitive iditti | Ii .id i>|ni.irrr It.illri in t`<-iit:ihii !' price,i| liili.irce. rut: 2t itnitii ini lead. l't>d>.; ami J |>rrrenl lanipldaeli fine niillirrcim 00151 grain. fclne i iilni* mtrrr ft ts.1l* inliir fnl. ' ll-ile nl `.ini|diiiB = *; liter* (l.l.l midi- Irelt |<r iniiinir. Bftnr iiiilliir.int id tlii* tilira dii<l Iimllint ai^noxim.iirtv VII ntillinn p.ntitt<r drier- f>rd liy the ii|tiii|:tr inctlnal at ilftriiItt'l liy llif I*. S. I'nMir (IraMh Srrvitr llrnrr. I 'iLtini ptr cnbir mrlrr of lhi rlii't it att-i.niin.ilrly r>|id*alul to flj niillit-n* of p.ntirlr* * 'll it fnol, * S< 1'irrioui litljng of tvn>pa>'r ter roinplclr addiet. Safety liquifnicnt OF APPROVED MECHANICAL FILTER-TYPE RESPIRATORS CdutcnUalioA of*tl tuipeiiiiMt, iinlliflianii* per cubic nieiet* ol air <a) H) * W4 -- (h) S 3* It 5 of lead Volume ot Maximum annmnl of |>ii|uulate le*l tu'ltntioi* in.iMer pcimiiird to ton .v,,m and mvinfirimee id tdle-l lUioujU the dt<>te ieal tiller tte ir-l'ii.H-ri am iluonch the ----. ------------------- -- indite. September 2, I'' device,cubic Mdlirom* mettra* MilliRitnit rril.te meter ol air . 3.W mg. Inr awv I *d ] rlevite*. r avnacc ol S *iii. M eatll of the 1 dcvicrl ' 10* MSA. r..... I.. Itt'linlur Ai Nn. 2101. i-'nod in Mine Sain pliaiMt* Co. Willti-n Ibe lleM-ir atm Ko Appioval So. M0J. it'nrd to Mm I'tiatiivlr. Ine. t.tt . IJ inff. fr any t l.iy* W itlviMi II.n; Me'pir: l->r Nr nf 1 device*, or AlH'cud An. 2t). i nrd to an average ol 10 mi I'r.iliirI*. Ine.* niff, lor each of the J I'uUuotln M l> I'mttlt- t'jpf Her-nair. Appi.ival .* i, 7t>' Miel to I'ttfni'i-An StliP F'tni* (*rp. fliever Uepii *r. .\|<tnxal 210*. Sljnd.iid ' r<n'it>nirut Ci. 9.M l.t 01* Milll'ii l!.ic Ur-piratwr^Vo. t pmial N.i. 2Ha>. i'-iird l<* " I'nrliicli, fne * 100 2S H^Jof i liionik acid StO-r/ntd lead 1t 1* t* III .. S* nf iTn a ditvl I * * nl lead 099 5 2M 0 It O.t M S A .......In lle'pir.ilnr. A| |' No. 2101. i>in.| In Mine S AM'I'.lMCri I n * fl.t* M S A V'-nil-i Itc't'irinr umi I.ltd Inr Ir.i'l mill lintnr *ni'l OS* 0 M.S A. (U-).iiMi. Aj.pi N. 2ltfl. ii-nc.l Mme N'ld) j-liaiHO Cl* M S A Coml.. Mr-l-i< '...Ii n.il filirn br I. -I ! i 'u- N'n. 2m;. i. - in.I i.. Mi,i, N.ili i pli incr I <i * tVilli.Mi l|,i; |lr.|iiil'.| N.i i ,\|i|inr.il An. `H*, 1..11. I l.i t ll I'lnlillM, Jne.v t ( 142 Trc ruty-fnitrtli .tuuuul Stiffly Cf/rr.t.t--Nutintwl Sofsty Council short blast* of air into the bag. Tim procedure removes frmn tltc bac dust and grit which clogs the pores of tire filler ami makes lirrathme UifiicuH. The proper time Uit cleaning the iiac is when the wearer experiences discomfort in breadline. When compressed air is not available some dust may tu removed by tapping the baj lightly and brushing the outside of the hag. 5. -To prevent irritation of the shin and for general sanitary pnrposc* the respirator should i>e cleaned after each day s use. The rubber ami metal parts may be cleaned with soap and water, and for general sterilisation thev may be dipped in a 3 per cent solution of earltolic acid, a 2 per cent solution oi lysol. or a "0 per cent solution of denatured alcohol, thru rincd with water, assembled, and lump up by the loop in the felt has to dry. The filter hap and headstrap always must be removed before the respirator is washed or sterilised. Ck 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 hy the Curran ir this device ;*nrt that are in the Bureaus files. Mechanical filler respirators tiiat exhibit chances m d<- .sign or include any parts that have not lcen approved are not permissible respirators and must not l*ar the Bureau's approval label. Schedule 21 provides tor the wsnu- facturer to apply for an extrusion of approval on any chance in the mechanical filter respirator which docs not affect the filtering characteristics of the filler. Clianees in the filter require the application (or a new approval. ' The Bureau obtains information on tltc maintenance of delicti and qualitv of approved mechanical filter respirators hy testing samples of the devices obtained ort the open market. The Bureau reserves tbe right to rescind for cause any ap proval issued. ' A Safety Style Show By E. J. SMITH Safety and Health Director, Western Eleetrie Company Hawthorne Works. Chicago For the purpose of assisting our foremen in the selection of the proper saicty equipment we have standard specifications and every foreman has a copy. In it he will find the protective equipment required for any class of work. Moldcrs. cupula tenders, furnace tenders and helpers in foundry and force are equipped with heavy duty metal or composition cup energies with hardened lenses. The lenses in the furnace tender's goggles are of a force and furnace shade. Electric furnace tenders, however, wear a welder's goggle. descnlwd later. When a goggle is equipped with clear lenses, it is used for sueh operations as breaking detec tive casttngs. cleaning castings with cnmprcneil air. grinding eastings to remove gates or fnu, potmmng on castings to remove sand cores, pouring molten metal mto molds with hand or hull ladles, removing gates or fins fnmi castings with air chisels, or hand chisels and hammers, ami working in vicinity of chipping hammer*. Leggings are of die non-lacing, non-buckling and snap buttoning type held in place by hidden steel springs similar to the uld iiicyclc pants guard. They will come oft' instantly from a tug at any point. There are no gadgets to confuse you or those who arc trying to help you in an emergency. Just one simple thing to remember-- grali anywhere ami pull. Men wear safety liais when chipping slag out of eutwdn*. Our construction crews nf masons, carpenters, millwrights, and so on. wear them whenever they are engaged in work where there is die slightest chance of objects falling from overhead. Our employees wear Congress" safetv shoe* lor their protection in addition to the leggings. \V'e use a leather steel faced glove when charging a ciqxda or Itatwlling pig iron. # FU leather palm gloves with hand top arc used in chipping casting fm*. load ing and unloading tumbling liarrels. and removing castings from sand. For the protection of health, workers in the brass foundry arc provided with overalls and undershirts with full length sleeves. This is in accordance with Illinois