Document MJoYp4K2NzJ3kXDz91r1BEJkk

w i'T.' 'a/.:, ir'criii '' j REPORT C? INDUSTRIAL HYGIZTS SJR7KI MILL I-CR /Pittsburgh Corning Corporation Port Allegory. Ps., September t S' .' I v Field *./orl: Ly: uicorr.bcry '..'ork V.y: <-**) ProneIs P. Koldun, ;T.aD., ."rius trial Hygienist /V.ir. o . Hyatt Industrial Hygienist 1, Icr.-bOj M.D., University of Pittsburgh L <niTr Ir.U'i3trial Hygiene foundation of Africa,..i By; John l7-. _ Ms Mahon f.,-. . Mnnagiivj Director . :;^i: yjurr Industrial Hygiene Suj-vcy nado Ter Pittsburgh Coming Corps,, Part Allegany, ?a*f Sapteaibor 26. 19lS TABLE Q? CCNTEtTS I SUhHAET........................ i - foa-gus puirr Hold rilling Operations...................... ...................... ............................ L Dust Concentration and Conposition from Hold Filling - Table 1 4. C Spray Booth..................................................................... ................... .................. .. Dust Concentration in the Air at Spray Booth - Table 2.. FOAMjIAS Lehrs............................................................................................................... h Dust Concentration at Tako-cfT End of FOAtftLAS Lehrs - Table 3 .. h Cutting aid Packing FOA.'-ELAS,*.................. ............................................... ... 5 ii Dust Concentration in Cutting and Pecking Room - Table k...... - MAIN PLAJIT - EATCH HOUSE...................................................................................... ..r - 5or* Dust Concentrations in Air of Scitoh House - Table 5.......... 6 Corooaition of Rcsoirable Dust in Air of Batch House - Table 6... MAIN FLtMJT - GLASS* TANK........................................................................................... 7 Dust Concentration in Air at the Glass Tank - Table 7.................. ... 7 APPENDIX A T^THCITg? INVESTIGATION.................................................................................. ....................... Duct Count Sanales........................................................... ................................................ Dust Counting....................................................................... .. Duat Composition Semples............................................................... The Separation oi Duct Sizaa. ........................... 6* 8 3 o. 1C appendix b HEALTH HAZARDS IH CONTAINER GLASS MANUFACTURE ' Sand......................................................................... Soda Ash.................................................................... Feldspar..................... ..................... Line and Lines tons*. ............................................ Salt Cake (Sodium SuiTote)............... Barytes (Eariun Sulfate) ................................. Ecrai............................................... .. Cullet................................. ......................................... Arsenic...................................................................... Selcniur....................... .. Sea Coal....................... ................... .......................... Iron Sulfide.............................. Ar.tir.cny............................................................... Silicosis.*..................................... .......................... Ketal Poisoning.,......... ......................................... Duatir.sss Inden of Sand.......'..*......... .. 13 22 II 11 12 12 13 13 13 31 11 15 15 15 AS 16 16 N /' ----------------------- ------------------------ industrial Hiar-:iri survey MADE FOR PITTSBURGH CCRN'IiS CORPORATION KLlT ALLEGANY, PA. SEPTEMBER 26, 19L6 ; .. 3 f * '' *j SU.W.RY Operations In the FOA KOLAS plant and tls? main glass plant at Pert Allegany, pa# vers studied on September 26, 9l:5 to identify tha working corw ditions that night be harmful to the health of workers# The results of our Investigation show that there i3 no silicosis hazard in either plant# We do however call attention to the gross dust ex~ pooure resulting at the spray booth in the FOA'-.uIAS plant whan the dust collec* ter is shaken# Cur data also add weight to the need for more scsi-automatic batch weighing equiprmt# ho ar.tirsony was detected in the air*-borno dust from the FCAXGLAS batch# However, a small amount of arsenic was present# General information on tho toxlcitics of batch ingredients and method cr.jloyed in this aurvoy aro presented in the appondico3# ' f c Industrial Hygier.o Surrey r.zc<s for Pittsburgh Ccrrdzrt Ccrpv, ?crz Allegany, fa., September 26. 19L5- ' * ' I - FCAMGLAS PLAIT ' rCAftDLAS i3 manufactured from powdered glass and carbon with a tre cf antirozy, All cf the silica is present cs silicate and henco there is no silicosis hazard* Theoretically, there is a possibility cf poisoning fren t: v-antinstry* This pesnibility wa3 appraised by chemical analysis of tha air-bo; dust collected fren the breathing zone of workmen* Throughout the plant Hast j ccrcrentrationa were measured by dust count* Theoo latter results are a aeasu cf the effectiveness of the plant ventilation equipment* ' fold Filling Operations '' *- '` \ \ * At tha tiro of this investigation, as a temporary procedure, FOAM2L batch for one lehr was being weighed and handled manually in a small hand scot Batch for two other lehr3, however, was vreighed by scmi-autoraatic equipment, w results from analysis of air samples arc presented in Table 1, T-'niz 1 - E'jsy co:i:i:;tratijm ,\r<p coryosincm FHOM MOLD KILLIKO Sample TIo* P.Ccl Date S/26 Tima 1:OjP 1:56: Location and Operations Mgs* of Arsenic Per Day Sample was collected bsoidc work- man weighing batch by hand, Much visible dust* This is r temporary operation* ' 0*7^^ _ Dust Coun k*p.c.f*- ii3 p,,c.io 9/26 2:L5? 2 :55P Sample was collected in the breath- -- in2 sons of workman operating the " semi-automatic mold filling machine* 6.3 o:t.h,C,F, equals Mill!,ona oi particles per cuulc foot of air0 a) *- Antimony was rot detected by Gutoeit test., Controls shoved characteristic e tr-ony reaction. Arsenic was found to bo present, however, in the amount irdi cated in the table, * \ cV Industrial Hygiene Surrey ratio for Pittsburgh Corning Ccr-., port Allegany, Pa*, September 25, 19L5. * It is of considerable interest that, whereas no antimony was detects in Sample P.C.3, arsenic was present to the extent of 0,7 milligrams per 10_cu meters of air, ?hi3 amount is slightly below the maximum allowable concent2*at vrecommended by the American Standards Association (1.0 mg. per 10 cubic meters Weighing of the FCAKSLAS batch by hard was nearly seven times as dus as was the seri-automatic equipment. The installation of the latter equipm/ ent all batch weighing is desirable* The dust exposure however is a nuisance rath? than 8 health hazard. 5Cray Booth .T i i The FOAKGLAS batch Is placed in metallic molds previously sprayed wit a clsy-vater dispersion to prevent sticking. The molds arc cleaned by an air J and then sprayed in a spray booth* The dust exposure of the spray operator is- .-.resented in Table 2. TA3LS 2 - DUST CCJCSKTRATION IN THE im?~Smr 1CUTH ' Sor.pie !Io. P.C.6 Dstc 9/26 Ti:e Ida? 1:51? 7,ocotiun and Oneraticna Sa:^lc was collected in tho breathing cone of vorkssan denning nold3 with air blast and applying clay by spraygun to clean molds. Dust collector ' wao shaken during part of this iostj ' hence no exhaust ventilation. Dust Count K-P.C.F. 260 i. y. xSJ-f.*-' \i Industrial Hygiene Survey race for Pittsburgh Corning Corp** fort Allegany, Pa*, September 26, 1915* . # During the sampling period the dent collector fer the spray booth v chakan vhich necessitated taming off th~- Tan and thus shutting off the spra^ ventilation, The resalting dust exposure curing the ten ruimta testing peidc ..was 260 M.PaC.To (niliiona of particles per cubic foot of air), Evan though free silica content of the clay ia low, such an exposure is excessive,, Wo recesnand that all spraying be stopped whenever the collector is shaken, 'Obsi vation indicated that spray removal in the booth is effective when, the ventil. #* synten ia operating, 'y F0AM1LAS Lehrs \ Air samples were collected by the midget irpinger at the feed and tz w- off ends of ths lehrs* Ths rocult3 appear in Table 3, I ?A3LE 3 - dust cc:r.E>rrHATior: at take -of? " l:;d c-f fOAmLAS uaihs Sample No* f.C.h Sate 9/26 Tirsa 1--13P 1:23? location and Ooerotions Sample war collected bssido workmen removing FOAKGLAS blocks from lehrs. Dust Coun K,PnC*P* 3,3 9/26 1:2?? 1;37P Sample was collected .beside workmen re moving FOA.'-GLAS from molds and placing it in lehrs* 2,5 The dust concentrations in the breathing zone of worlcnsn represent satisfactory working ccr-iitions* ., industrial Hygiene Survey rade for Pittsburgh Corning Ccrp,, Port Allegcny, Pa*, September 26, l?li5* Cutting and Pacirin? FOA>CL*S One air sample was collected beside workmen who operate the power as Table h contains the data* TABLE li - DUST COJCENTrlATION IN CUTTIIE AND PACXIKj FOAMSLAS i ' ` Sample No. ?*C*1 Date Ti-te 9/26 11:25a 11:35* Location and Operations Sample was collected in breathing cor of workmen operating saws Exhaust ventilation on saws is excellent* Some visible duct from hindling FOAs-DLAS blocks* * Duet Coun* ' MoP.O-F. 6.3 ` The ventilation prcvicod i'or tha power 3aws is excellent. Sena dust produced from handling tho FOAHGLAS blocks but, as shewn in Sample P.C.l, it is net eignificant* II - KAIN PLANT - BATCH HOUSE Tho principal dust hazard in glass batch houses is in sand handling* At Port Allegany ary S3nd is purchased in hopper cars which are unloaded into a hspner to on elevator. The sand is conveyed into an enclosed.bin without expose of workmen to dust* . f f. c Industrial Survey made for Pittsburgh Cor ring Corpv, Port Allegany, Pa., September 26, 1915. r I: The hatch house weighing operations arc totally enclosed with the 9 exception of the addition of minor batch' ingredients Materials feed from the bins into weigh hoppers and then are dropped onto a belt which conveys them to ''the mixer. Mixed batch is` loaded into a hopper car in small room which is separate from tha batch mixing room. - L A Two midget icpinger samples aiid one I-H-F conposition sasxple were collected in tbs main batch house. The rosults appear in Tables $ and 6. TAEI2 5 - BUST CONCENTRATIONS .IT? AIR OF BATCH HOUSE i 1 c vS* Sample Ko. P.C.7 Date Tins 9/26 2:02? 2:12P location and Operations Sample ves collected nhilc walking : around the batch house. The batch handling system is totally enclosed except for the addition of minor batch ingredients. ihist Count M.P.C.F. 5.3 PoC.S 9/26 2:11? 2:2hP Sample was collected while walking around the b3tch houso* The botch handling system is totally enclosed except for the addition of minor batch ingredients. ~ 3*3 L Tw s 'industrial Survey rnadc for Pittsburgh Corning Cerp- 3 Fort Allegany. Pc*, September 26, L?L5. TArI 5 - coiepcsiticn o? kzsptpjsiz tjst IN AIK Or HATCH HOUSE SoTa^le No. P.Cq2 fata Tits 9/26 12j50P 2i25P - Location and Operations Sacalc was collected from breathing sene near elevator to mixer* Free Sili in Reopira Dust (Pert f> iaicrcns less in Si n < The average duct concentration vas 16 MP,C*F., of which.only 7$ v. '\ found to be fres silica* The exposure to free silica 13 therefore about 0*3 t M.P.C.F* The naxinua allowable concentration of silica dust for continuous ex posure is 5 M*?.C.F.r the safety factor is therefore r.ore than 15 to one* c M \ u plan? - GU CC v w One air sample vac collected at the feed era of the glass tank* The result is given in Table 7. tabu: 7 - exist co?ss:;73atio;? in air at the glass tank ocaple No. P*C*9 Dato 9/26 Tito 2;30P 2:10? Location end Operations Sample was collected while walking around platform at' feed and of tank* latch fdwd is dust free* Duct Ccu MoP.C.? 1*0 The duct concentration in far baler.; anything significant to health* The batch feed setha rism is tho finest arrangement for controlling dust that* v have seen* w ' Ir.durtrial Hygicr.a Surrey made for Pittsbuxgh Corn!re Corp., Fort Allegany, Pa., Septerbsr 26, Z$h$* ** , APPENDIX A K5TH0D OF PJVE5TIGATI0:? / Dust Count Sanalc3 ' All of tha samples for counting purposes vero obtained with the raid ispinger. Vhsra workmen wore stationsd at one position the sample was collec in the breathing zone within a distance of a few inches of the worker's nose* many cases it was necessary to follow employees about a department i*n ordsr tc *" V obtain a ssnple representing their average exposure* This wad particularly tr \ in the batch houses vhilo appraising the exposure of botch Gatherers* Wars r. obvious source of dust was present a general air sample was collected to provi data on the exposure of groups of workman* This type of cample occurred in th wareroems and machine rooms* * : Ml of the cunt count camples vero collected in normal prcpyl alcohol with tho usual time period being 10 ruinutGs* Dust Counting All samples were counted in accord with accepted standard procedure. The dust suspension in tha impinger tubeo was deposited in a standard Sedgwick Rafter Cell, where it was allowed to settle for exactly 20 mimtog, then all particles at cr near the bottom, smaller than 5 microns, were counted at $ vidol spaced locations on the coll. This was repeated with another cell similarly pra pered and all 10 courts averaged, corrected for the bleak count, and the result computed on this corrected average count* The blank counts vero made at euitabl intervals* `Industrial Hygiene Surrey ;mde Tor Pittshurrh Coming Coro., Port AHogany, ?:*, September ?.C, Z9ii5> Dust Ccnscsiticn Samples Dust counting alone does not permit appraisal of the silicosis ham: since it indicates only the number of risible duct partition without regard tc their composition* That is, quarts duct which produces silico-is cannot bo di tinguished in the dust counting process from any harmless duct, and therefore j auxiliary dust samples of greater size cast be obtained for free silica cnalys In addition to samples for cast couniinr, therofora, separata air-bo * "* y ea:aple3 were obtained for determination of dvict cornositicr. for free silica* i These samples wore collected by means cf tho I-H-P Dust Sampler* This device encloys a portable exhaust fan with a capacity core than a hundred tinea that c the raid gut irpirger pump* Thu air is drawn tlirough a filter composed of a felt layer of salicylic acid crystals, about 0.2 inches in thickness* ; The filter hs an area cf approximately ore square foot* Dust collected by tho I-ri-F Dust Sampler is removed from ths salicyli acid by treatment with alcohol. Tho salicylic acid dissolves leaving ths dust particles* The solution is filtorod and the dust washed free from alcohol sold elements* Tcllcwarg separation by sedimentation uho fractions are analyzed by the X-ray diffraction method, Excericrso has shown that chemical methods for the determination of free silica in finely civ idol dust samples is unreliable* An alternative nethoc based on the petrc;>*ap!do microscope is also unsatisfactory because of tho impossibility of correct identification of different niruralo with the small pai-ticli-a size present. Vo, therefore, employed X-ray diffraction analysis Its/ Industrial Hygiene Survey made for Fitzobur; Fort Allegany, ?s, Septenta*- 26, on. for tnc dsterci;n cion of True silic; .. These: analyses wore serf orrzed for us b} the Saranac Labors bury , Saranac L:d;; . h'cw York, under the direction of Dr. L Gardner* The Sep.irfi.ticn of Dust Siren It is icnovn that only dust less than 5 ailerons in diameter is of significance with regard to silicosis* Therefore samples for composition .ansi which contain particles ns largo as iiO or 50 microns, should be treated to,res th2oe and other particles of non-rsspirabie sir.ee end this wo do by means of 'i uodinenzation* The separation is made at the 5 micron sire, and X-ray analyse. performed for the* finer fraction* Occasionally the larger r.on--respirable frsc* is analyzed. A proper snrplir.:: of glr.m fcr.tcu without attention to particle site would gr.cv about ~0% silica by viuight* it is hncvn, however, that the major portion of the silica is of large particle size ana frequent analyses of air~ tone dust from glass bates show only from o: to five percent free silica* The procedure far the separation is n3 follows: A sample is suspendc in alcohol to a depth of 5*3 cnntir.xtoiv ar.d whjen a unifora suspension has been obtained a settling period of bO rdnutos 13 allowed. The supernatant liquid, together with all particles in suspension, is then drawn off ond fresh alcohol added to the sediment sufficient to again ra-.hc the total depth 3.3 centiliters* The new suspension is agitated and again settled for i-0 minutes* This ia ropea 10 to 15 tirjis, until the supernatant liquid is observed to contain an insignif quantity cf fins particles* * . C^t'T5aTa(9^ C*v?!rw/V c Is* * R2ALTH HAZARDS IN CONTAINER CLASS KMUPACTUHS ' Container 6-sss made be rRufr.ctured froa the following ingredients* 'sand, soda a3h, dolondte, feldspar, slag, line or limestone, salt cake, end cu barytes, and borsx, Minor batch ingredients for decolorisatior. or for iha pro duction of color include arsenic, selenium, sea coal, iron sulfide and autircon; A discussion of the toxicity of the so ingredients follows: * Send \ *l i Glass sard consists principally of tluj chemical corzpound, silicon dioxide (SiO?), its nost cotton firm is crystalline quartz* Quarts, itself na be converted to trlriynito and cristobalito when heated to high temperaturos, Siliocsis is one of the two characteristic lung diseases resulting fr. exposure to dust. It is characterized anatomically by generalized fibrotic changes and increased susceptibility to tuberculosis* Silicosis is caused by free silica either in the fera of quartz, tridynite or criotobalite* It is gsn- erzlly recognized that combined silica (the silicates) with tho exception of asbestos, dona not produce disabling lung disoasoso Silicczia ttay arise from prolonged breathing of atmospheres containing finely divicca free silica. The fraa silica is only significant in the particle size ranges fre.u one to five microns or lees, and no lorn thought paya attention to ths presence cf these particles in the air which are lees than fivo nicronn l Studios of ths cilico3ic ha nrd in granite cutting, in the mining of c cnttir- te coal and other industries. have furnished the basis for establishing * Industrial HypicruJ Survey made for Pittsburgh Coming Corp., port Allegany. ?u*. September 26, ;y . ' a bench csrk in terns of dist counts for maximum continuous exposure to free silica. Authorities telicvs that disabling silicosis will very seldom if evt occur if the exposure is below 5 million particles of silica dust, less than 'microns in size, per cubic foot of air* Sods Ash j Excessive exposure to soda ash dust is irritating to the rpupirator. tract arai may produce dermatitis, this action being worse during warn weather. Studies of the health of workers in plants manufacturing this product have sh< that as much as 30 yearo contimous exposure has not resulted in any systemic disease* W Feldcoar * Feldspar -is a generic torn for a number oi conpiux aluminum silicate containing sodium, calcium, potassium, or barium* These minerals may contain free silica but in general the amount is loss than 5;So Materials containing 1 than free silica are considered s.c nuisance dust and it ic not bclioved tha exposure to thorn will result in disabling disease* ii.ue and Limestone Theca alkaline ingredients of glass batch aro also, nuisance dusts*. Excessive exposure to then during hot vjqthor frequently results in dermatitis but no general systemic effects occur* They do not produce eny characteristic lung disease* '' r<*r Salt Ccko fScdium Sulfato) _ Sodium sulfate dust is not..toxic* Excessive concentrations may caus^ ' nuisance. Industrial Hygiene Survey made for E'ittcburgh Corning Cor?,, Fort Allegany, P-., September 25, 191$ a B-irvtea (Barium Sulfate) - Barium sulfate is not known to couso any characteristic disease, Tho Italians described a lur.g disease which they call barytosis. pjidlolo gists, such as Pendergrass, attribute the effect described by the Ital to the fact that barium sulfato is rndiepaquo. They believe that the lnhalat i of finely divided barium sulfate will produce a characteristic roentgenogram that there will not be disability associated with this condition. In this re it is dollar to the lung condition described by Sander whers the lungs of V1 electric welders often exhibit an X-ray appearance practically identical with. .i silicosis. In general, therefore, we way conclude that barium sulfato will not cause occupational dissase but that it nay produco a characteristic X-ray fire c which could conceivably complicate th3 interpretation of the roentgenogram of workers also exposed to tree silica* The implications of this are especially important to glass plants and is the basis for our recommendation .to control t dust vhero it occurs* Bey OX . From the industrial viewpoint borax is not toxic* Schwarts reoorts that it is kno*.m to cause dermatitis and therefore oxposure to this compound should be kept within moderate limits, particularly in hot weather* 'oio' eN Cull;t Although glass consists principally of silica, that material is proas in a combined form as silicates* numerous X-ray diffraction, analyses of scrapie oi air borne glass dust have cho;m that tbsro io no free silica present. .wvj- > Industrial Hygior.s Survey maco for Pittsburgh Corn!1:3 Cor: Fort Allegany, ?a*j September 26, 19U5,, lL luring the early days cf the studies of industrial exposures to dust * it -me bolieved that lung damage was caused by the mechanical action of sharp dust particles. Chic v.*as thought to be true even in the case of free silica. -- investigation of vorbers ifho had breathed large quantities of carborundum and diamond dist, hcvever, disclosed that thcor lungs had not been damaged. It is m. knovn that fibrosis and irritation of lung tissue is a chemical action iadspandc: a from mechanical irritation vith tho possible exception of cerposure to asbestos. Arsenio I . -- - .V \ Historically, poisoning from arsenic and its compounds has been recog nised since ancient tinea. In arsenic poisoning tharo is r.n eoctrsno gastro-enter with particulnr dsnago to the nervous system, and fatty* degeneration of the cells in tho glands and muscles. There r-ay also bo direct paralysis of the hearto r. TS*^ The American Stancorco Association r.as recunrenfod that the xuccimm allc-able concentration to arsenic end its coropouncs should be 1-1/2 ruilligrans of arsenic per 10 cubic niewrs of air. Arsenic ray also causa perforation of the nasal sept*, as veil as severs dermatitis. ielcniun Soloniim and its compounds are cumulative poisons. Eonsoeivo exnosura ;sLl1 produce gaatrc-intastlml disturbances, nervousness, pallor and a garlic odoi in tho breath and perapimv-ion. Studios of tho acutn toxicity of selenium con- pounds chcv tiiat thy pevdsred r.ctnl is net very toxic vhen ingested. Csapek and V/cil, report that l. grnrs cf tho posdrrarl metal given to dogs by mouth produced f no toxic effects as the rioial \,U3 not absorbed. Cn tho contrary as littlo as h j . Industrial Hygiene surrey r.ado for Pittsburgh CorntiiC CersJp pert Allo^j'j Pa*. Sspcxibor 26s irU5* 15 > nltrran3 cf 30div.u sslorlto or 3-jlenatc per Iclonrs-.i of body roight is'uruoll; fatal vithin & f&v minutes, .`to authority has 3ug.~scted a rsixixtn allowable cor> esntratien for continuous exposure tc selenium and its compounds. It is dcubtft that s-aleniun is any r.cro toxic than lead* cadmiumy r.arcury and other cumulative i xaetallic poisons and ve therefore recemrsond that concentrations bs nulatalnad j belov ons nUligroa per 10 cubic neters of air., , -Sea Coa1 l . ` * Vi This material is finely divided bituminous coal. Since this materia^, contains saich less than If free silica its handling cannot cause a silicosis h&xj The coal dust itself doer not cause characteristic lung disclose* Iron 5u.1 fids This compound is relatively non-toxic ana its inhalation In noderate amounts is not considered harrafui* Antimony The action cf antimony in tho body resembles that of arsenic* differing cniefly in creator local irritation and rare difficult absorption* 2he natal is commonly associated uith lead or ersonic and no clear cut picture of industrial antimony poisoning is nvailablo* h'o rxxi.r:un allowable concentration has been established so it is cerrsn practice to r.ssur.u a limit similar to lead (1# mg3o ..ji* 10 tfubic meters cf alr)c Silicosis _# s mxsosuj*o to sili.es dust presents tho rosier and frequently the oily ' \ si (/nil-cant henltn nsssrd in ^Isso .manufacturo. fortunately tho problem is *>rr' Industrial Hygiene Survey mads for Pittsburgh Corning Corp,p Port, Allegany, Pa,, September 26, 19bS< 16. confined sal sly to tha handling of scuid as a raw material* V.hen it is combined with the other batch ingredionts the silicosis exposure is practically ail, . total Potscnia* Frequently it is necessary to add certain metals and their compounds 6 glass either to prevent undesired color or to produce color, Metals such as-lea j csy also be added when special glass characteristics aro needed* These minor- batch ingredients such os arsenic and uolenium are added in ssiall amounts and .* numerous investigations have shown that careful handling is common and does not i result in a health hacard. However, vo have encountered excessive dust vhon the; csstals are gathered and weighed because of careless handling by the particular workman. In these lattor instances cathode of control by exhaust ventilation arc iocemended on the basis that it is frequently Impractical to convert a careless workman into a caroiul ono. lead as a constituent of glass batch is generally a major batch ingre dient and when used normally requires exhaust ventilation of portIona of the proc Dustiness Index of land She cistiness index of glass sand is a r.easuro of the quantity of *\.epirabic dust contained in a unit weight and theroforc provides a basis for comparing various sands respecting their potentialities for producing atmospheric duet when handled, as by shoveling* . Tno unulyslu consists of sieving ICO grams of the material through a mcnh sercon, The amount passing through tho screen is weighed and a known * portion of it dispersed in alcohol and counted using the microscope. This data Industrial Hygiene Survey rrnco for Pittsburgu Corning Corp,, Port AUejany, Pa. September 26, I9h 17. provides an estimate of the oil,,liens of particles of respirable dust present in ICO grass of tho parent material. Variations in the dustiness index from 30 to 6C0 are common. It is obvious that a material vith a low dustiness indon ia desirable and that it3 use will assist materially in the prevention of 3ilicosis. Wo ero currently collect! data to provide a quantitative correlation botwesn dustiness indox and tho actual dust concentrations near certain specific operations, e.g,, freight car unloading by shovel and whoelbarrov* . "* 1 c l )