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TOXIC DUSTS PLAINTIFF'S EXHIBIT TPI-683 Their Origin and Sources in Various Industries By REUEL C. STRATTON THE TXAVEUXS DBOZANCE COUPANT HE SUBJECT assigned to me presupposes chat many in Tdustrial ^are produced through contact with or in halation of industrial dusts of a toxic nature. Personally, 1 do not believe chat the consideration of occupational disease Air-flushed drills distribute these particles over a wider area chan do water-flushed drills, but the offal from water-flushed drills dries and then becomes distributed in che air. When crushers are operated, either gyratory or jaw, dust is produced prevention should confine itself to dusts alone; it should in in an amount depending mainly upon the size of the unit clude all materials produced in such minner that they may be involved and upon che fineness of the material which is being inhaled by a worker. The question of whether a material processed. exists as a gas, a vapor, or a dust is but one of particle size and Sizing and screening operations also distribute dusc, although chemical make-up; but with materials whose source is in in they may not in themselves be producers. dustry, it does not seem fitting to stop with substances com monly known as dusts and thus fail to consider those which usually exist as vapors. It is a common fault to focus attention upon one object to such an extent that others of equal importance are thereby rele SBAirr StKEtNO, TUHNXUMO, KXCAVATTOH, AND DZMOUTION Drilling operations in all such activities afford opportunity for dust generation. Again, the exposure depends upon che type of rock encountered. Transportation of materials to and gated to obscurity. For the present, pueumonoconiosis, or more particularly silicosis, occupies the center of the stage and possibly for che purpose of this meeting such importance is from the face or working area also allows dust to be distributed. Steam-shovel work in excavations exposes workers to dust clouds. In demolition work, the pulling of walls, the dropping justified. However, the engineer interested in che control of of floors, the loading and unloading of debris causes the genera occupational by plant equipment and operation must not tion of much dust. Blasting operations when required not forget that there are many occupational diseases produced only generate dust through the action of the explosive itself, through exposure to industrial dusts other than silica-bearing but may precipitate ocher settled dusts by the shock transmitted ones and to vapors, and that the control of these industrial co the surrounding structures or areas. may be brought about through the application of che fundamental principles which will be propounded by other speakers today. At present and until new avenues of control RONS DMSSDtO AMS FlMlSnXMO When this activity is in conjunction with quarry operations, are discovered, explored, proved, and utilized, the problem in the same quarry items previously listed pertain. Stone dress ` many iww seems almostl acking a complete solution, but it ing and finishing is probably one of the most prolific sources of is unquestionably true that certain occupational or industrial dust known. At least the exposure is one of the most serious diseases need not occur. The engineering aspects of their con due to the intimate personal contact of employees to che area ' xrol ate to well known that in the hands of capable plant of in which the dust is generated. Stone dreasing promotes much ' finals there can be little excuse for their occurrence. In the .hand-tool labor. ^control of such diseases, industry today faces a problem, the Surfacing work, both hand and machine, produces quantities [solution of which rests in the hands of the scientist, che physi- of fine dust. Sawing, cutting, and channeling, as well as drill [dan, and the engineer. ing, are also prolific sources of contamination. Hand chisel While the generation of dust in various types of industries ing produces a certain amount of fine dust but in this work the i a more or less common mode of origin, namely, the produc- larger particle sizes usually predominate. Hand polishing pro of finely divided material, yet it does not seem fitting to duces some dust but only a very small quantity as compared to up industries together even though the operations producing a mechanical polishing mill or jack. Even when wet polishing [dust are somewhat similar. Therefore, in this paper, opera- is done, the quantity of dust is only slightly reduced. Sand will be discussed as individuaT to a general industry blasting operations, if not isolated, are dust producers. Such r than as individual unto themselves and assigned to many dust generation is cumulative, as the abrasive material is broken iustries. While rh may produce some repetition of ma and forms a dust in conjunction with the material which is be yor for the sake of those engineers who are especially ing blasted and eroded. interested in an individual industry, I feel che paper will have In addition to the operations indicated, worker* themselves 1 value. create a dust hazard by che blowing, by means of a compressed- QUAUT OnXATlOMS air nozzle, of dust which has accumulated around the tools or operations. L-Although the exposure in a quarry due to dust varies in ity baaed upon the chemical composition of the material ng quarried, most operations are similar. Drilling opera s, both well and small-bore, produce voluminous quantities fnall particles of the material in which the operations occur. ^Contributed by the Safety Committee sod presented at the Annual ' December 3 to 7, 1934, of Tin Axsarcair Soaarr or M. Emou atnxmvo cuAKoro The cleaning of buildings by hand or machine may be con sidered a dusty operation. This is particularly true when sand blasting either by air or steam is employed. The senousoess of the hazard somewhat depends upon the type of material being cleaned. Naturally, rht is additive with the dust from the sand used for blasting purposes. 95 - IV* w '" 96 MbCHANICAL ENOmSBUNQ vidual item* or as balk may produce dnat. Spoil heap* nniM salted down may generate dnat when the ordinary land breeze* blow over them. concutx raosocn and AixoncxAL-sroNB taNciicmim Mixing operations are dost producer* in this type of in dustrial activity. Finishing operation* if by sandblast or hand tools also produce dost. BB1CX lSANCTACTUllNO In the manufacture of brick as well as tile and terra cotta articles there are several sources of dust generation. The day-drying department, whether natural material is used or a mixed slip is used, produces dust when the dried materials are thrown into the air through handling. The dropping on the floors of small quantities of material allows it to become dry and then be dispersed in the air by workers walking or by transportation. Mixing opera tions give off dust. The operation of pug mill* and brick molders may generate dust through the drying of the waace material. Storage departments may be a source of dust oc casioned through the handling of material. CZMXMT AMD UK! MANT77ACTUUKO When operating in conjunction with a quarry or mine, previous sources of dust listed under such headings apply. In addition, all crushing operations produce dust. The charging operations to burners either hand or mechani cally done will create dust. The operations of the finish ing and packing department where bags and barrels are packed, dosed, crated,, and shipped are a source of dust generation. . BLIMXNATXKO DOST IN aOCX DKILUNO (The drill operates through a dust collector consisting of a "*i cap netted by a hose line to a suction tank and dost catcher.} HDdHO The more common forms of mining are coal, feldspar, glass, sand, metals, mica, refractory materials, and TMl<~ In any form of mining, dust is produced in the use of drills and exca vation machinery. This is true even in open-pit work. The exposure varies according to the rock encountered. As in other cases, the use of wet tools does not entirely eliminate the generation of dust. SAND AND OKAVSL DIOOINO--fUNT and'hrAX KZXXJNO These two operations are oftentimes associated. Underwater sand and gravel production is relatively noo-bazardoos but the sizing and screening operation, even though upon ma terial, may be a source of dust generation as the fine will collect on machines, ledges, and parts of the buildings and later be swept into the air. When flint and spar milling is carried on either in fflajaimtwi with sand and gravel digging or with any other source of taw stock, the hazard varies, ss has been previously stated, accord ing to the composition of the material being handled. Practi cally all operations are sources of duarmnramnwrion Primary crushers, either gyratory or jaw, produce dust; secondary crushers, screens,-jigs, air separators, conveyers, and ocher types of machinery generally produce dust in air to a greater or leu extent. Bagging, packaging, and shipping either si indi- The exposure to dust in foundry operations varies only slightly seconding to the type of foundry. A non-ferrous foundry may be little if any different on an overall exposure from a ferrous foundry. Sand-condition ing operation* produce dust. The use of sand cutters or blenders, screens, riddles, slingen, grab backets, and ocher conditioning machinery or operations may create dust. In molding processes the general work an the molding floor or the use of sand throwing and blowing may produce a hazard. The application of parting compounds to the mold may create a dust. This situation is naturally more serious when the parting material used is of high free-silica content. Shake-out procedure, rattling sod tumbling with or without air, sand-blasting, grinding, and snagging are dust-producing operations. Scratch-brushing work may generate dust. As previously mentioned, sand-blasting generates dust under any urging operations in loading a cupola or any other type of ftmuce may generate dust nrtbe immediate vicinity and later contaminate the remainder of the premises. The storage of raw stock, such as Ihnrswwe, coal, sand, and pig stock, may through handling generate additional date. In addition to the eipotniet cmimmtrd undv mining and ore production, dure exist in the refining operation dusty ex posures. Furnace operations, inch es:%heipng and drawing, generate dust. This it particularly true ashen all or portions of the charging material consist of soap, snch as storage-bat tery plates. Trucking of such may strew the fine material on the ground or floors where it mey be picked up and thrown into the air by walking or by the wind. Skimming, rehearing, and FsnrAftY, 1935 sampling operation* produce dost. The handling of the material in bag honaea, floea, or Cottrell pre cipitators may create a dotty expotorc which ia particu larly aerioaa daring the cleaning operation* necessary to keep Cottrell precipitator* or bag house* operating at proper efficiency. The transportation of materials in leaky container*, con-enclosed mechanical conveyer*, or oncovered can creates a hazard. Hand (hoveling may pro duce dost in lerioo* quantities. MZBCOIY, rate, ams cam* unNnto The items enumerated under lead refining apply here also. In the production of zinc, one added exposure ap pears which is the dost produced in the blowing oat of re tort condenaen, either by barring down or by "shooting" the condenser with a slog of water. BAimr MAMUFACTOUMO--STOBAOB AMD niMUT In the manufacture of storage batteries an exposure to dost exists in the preparation department. The handling, weighing, and mixing of the lead oxides either by hand or machine generates dost. In the pasting operations, either hand or machine, the material may be spilled upon the m.rtiiny or the floor, become dried, and later be thrown into the air in the form of dost. The brushing of pasted grids will generate dust in a like manner. On the assem bly line even when only hand operations are in progress, dost may be generated. In the manufacture of primary batteries not only may dost be generated by metal-casting operation!, hot also ' hi mixing, filling, and sealing. cnaacAt UAMOsAcroaiMO It would be impractical to attempt to list all the opera- i in chemical manufacturing which may be dost pro . Here again the seriousness of the exposure de- opon the material handled and the amount of ferial that is thrown into the air. Chemical dusts, rly some dye and dye intermediates, are posi- : sources of dermatitis where the dust generated lodges the skin of employees. It is sufficient to say chat mocr mm. mounts* om Tartan amd iqtnttsD wttb stua warn. TUB BLDdMATlOM Ot SOJCA DOST (The. bottles shown on the tripod measure the amount ai silks which would be *> by the drill operator.) ; are generated in the chemical industry and each in itial operation requires study by itself. or machine, the packaging of the insecticides into hags, cartons, ln chromic-acid manufacturing the sintering of ore is s dust- barrels, either by hand or mechanically, and the transportation sg job. The handling and transportation of the ore of materials from point to point in the plant generate dust in to the sintering either in furnace or kiln produces dust, varying degree. quenching of the sintered material may generate dust a* ' the crushing of the sintered stock. SADR AM COLO! MAXCTACTPBIMO Aiaasru* and asmros-ooods mamoyactuvno The handling of bulk raw materials, as well as the grinding of filter-press cakes, will generate dost. Mixing and blending ' mining operation* and quarry operations are exposures, operations either wet or dry produce dust. This exposure ia ' oaly discussed. In the manufacture of asbestos goods, inherent in the handling of dry materials, but the spillage of --xly dusty atmospheres are created in the break-out, water-wet materials may dry our and later be thrown into the r, and picking operations. The crashing and grinding air. Batch weighing when the handling ia by hand produces i fiber, as well as all spinning and weaving operations, dusty exposures. i tendency to throw asbestos fiber into the air and create ~e of dost conraminarion. Crashing and grinding ashes- ducts generates dust. The most dusty' areas is gfaaafcanufacniring are tuOTnonno louattd in the raw mafsrhh receiving department and the batch-mixing department., The unloading of glass sand, soda : toxicity of any dust generated in inarcriridr manufactur- ash, spar, flint, and ocher manriab from bos can or tracks into ' i according to the material being processed. There is storage bins produces dust. - 8wa when (hem material* are ity of operations in most insecticide manufacturing. mechanically handled, duet ia gencrased. Beech mixing where ation department, where the raw materials sremanu- -the varioue ingredlrnta aredrawo from storage bias and , involves dusty proceases. The grinding of cakes from weighed preparatory to being transported to tbe furnaces also f presses, the mixing of different ingredients, either by hand produces dust. ' _>* fcr- 98 Mechanical Engineering POTTMT MANUFACTUUNO What has bees listed /or glass manufacturing also applies to pottery manufacturing. This is true even when a slip system is used. In addition, the grinding and kiln-firing operations are important sources of dust contamination. ZNAMSLXSO AND SNASOL-WAJU MANU7ACTUXINO In the preparation of enameling material by mixing, grind ing, in either bar or ball mill, blending, and solution-making dust is generated. Spray coating or dipping objects may cre ate a dusty atmosphere through the dispersion of the fine drop lets in air and drying out at the suspended material. The rim ming of articles to produce stripes is a dust producer of high severity. Loading kilns for firing including the operation of continuous tunnel kilns may produce dust in large quantities. In such manufacturing as well as in many others, the transport ing, storage, and handling of raw materials may be sources of dust. TKXTILBS This caption also includes paper, linoleum, felt, hair, and other similar types of manufacturing operations. Such dusts are not generally considered as being toxic, but yet a sufficient number of instances have arisen to make it.appear warranted to include them within the scope of this paper. Picking, opening, mixing, blojving, carding, willowing, spinning, and other similar operations produce dust. In linoleum manufacturing the receiving of the raw filler material, such as soapstone, talc, and mica, as well as the storage of these materials and their handling during process work, may produce dust. Both in hair and in hair-goods manufacturing, the dust may also in clude the spores of anthrax and the origin of such contamina tion may be particularly prevalent in the blowing and curling operations. MBTAXX1C-FOWSB* MANUSACTUXINO Where a cupola is operated in connection with such opera tions, certain exposures previously listed may be found. In stamping the metal, dust may originate.. In coating operations dust also occurs. Where an air-float method is used for the separation of fine particles from large, dust may be ex hausted into the atmosphere of the place of work in copious quantities. MisrmJAimoDS xxvostrus There are certain exposures where a material may exist in the form of a dust, a vapor, or possibly a spray of fine droplets. The correction of any exposure of this type requires recognition on the part of the engineer of the material to which workers may be exposed and a determination of the point of origin of such material. A few miscellaneous exposures are discussed in the following paragraphs. Exposure to Mercury. Exposures to mercury may occur in the mining of the ore, the reduction of the ore, and in the amalga mation of gold ores. Exposure is also found in the manufac ture of thermometers, vermillion, and other dyes, the felt-hat industry, the treating and handling of furs; incandescenrlamp, radio-tube, and other electrical-apparatus manufacture; explosives manufacture; and laboratory work, including photo graphic and research laboratories. The exposure may be from the dust of the salts of mercury, the generation of fine droplets of mercury together with dusts of other nature, and the vapor of mercury which is generated at high temperature as well as small amounts which may be given off at ordinary room temperature. Eseposurt to Chromium. The exposure to chromium is usually found in the generation of the dust of the salts of chromium. There are certain processes in the manufacture of chromic acid and chromium salts from chromium ores which produce dust. The manufacture of paint pigments containing chromium, yam dyeing and calico printing, the use of bichromates in dye prepa ration, the chrome process of leather tanning may also have dusty operations. In electroplating with chromium many fine droplets of chromic acid may be thrown into the air by the bubbles of hydrogen disengaging at the surface of the liquid in the electroplating tank. Exposure tt Benzol. Exposure in the case of benaol is usu ally due to the vapor of the material. The operations of its production, its use in artificial-leather manufacture, in de greasing operations, and in others may result in an exposure. Information may be found in the report on benzol which was published several years ago by the National Safety Council. Exposure to Lead. As lead is used in widely varied operations and in widely varied forms, it would be relatively impossible to list all of the operatioas which might include an exposure. The exposure usually exists in the form of dust of the material itself or its compounds or in the form of fumes which may be generated at points where the material is handled at tempera tures above its melting point. Dusty operations may occur in lead mining, lead refining, lead smelting and sintering, the manufacture of plumbers' supplies, foundries, battery manufacture, both storage and dry, pottery operations, glass manufacture, certain printing trades, rubber-tire manufacture, and paint manufacture. In addition, dusty exposures may occur in the chemical-manufacturing trades which involve the manufacture or use of lead or its compounds. Exposure to Arsenic. Exposure to this material may often be found in the dusty operations surrounding the refining of copper ores and the manufacture of insecticides containing arsenic, either in the form of the oxide or other salts. Exposure to Rodium and Radioactive Substances The exposure to this material while not by any means general has been recog nized in isolated sections and attained for itself relative promi nence. The exposure may exist in the inhalation of dust from radium-bearing materials or the exposure to and the inhalation of emanations from radium. In general, this exposure is pro duced in the mining and handling of radium ore, the refining of the ore, the collection of radium emanation, and the use of the material in producing luminous dials for watches, clocks, and instruments. CONCLUSION One should not necessarily conclude that every operation listed in this paper is an absolutely dangerous source or point of origin of a toxic dust. It should not be a foregone conclu sion that the operations listed in this paper include all of the possible sources of toxic dusts. The operations discussed, however, are typical of those where known cases of exposure have occurred. To the engineer unfamiliar with sources of air pollution, even in the so-called non-hazardous industries, the listing may yrm far-fetched and ambiguous. It should not be assumed that an exposure listed in this paper is prima facie evi dence chat trouble is inevitable, but to an engineer interested in protection against the more important sources of air con tamination by dust generation from ordinary industrial pro cedure, the listing will provide a basis upon which he may work. All in all, it is best for any engineer to proceed upon the basis that any dust of any type in any concentra tion creates an industrial exposure and to suppress the dust at its origin.