Document ExVEnK15rdqjyVdNyVV6zdo3g

FILE NAME: BF Goodrich (BFG) DATE: 1937 Apr DOC#: BFG059 DOCUMENT DESCRIPTION: Trade Journal Article - Talc Dust in the Rubber Industry TALC DUST IN THE RUBBER INDUSTRY COMMERCIAL talcs are highly variable in com position since they generally contain not only the mineral talc (hydrous magnesium silicate), but, in addition, natural mineral impurities such as dolo mite (hme-magnesium carbonate) and serpentine (hydrous magnesium silicate). These variations in composition are relatively unimportant to manu facturers because of the fact that the uses of talc depend more on physical characteristics than on chemical composition. In the rubber industry the chief use of powdered talc is as a dusting agent !o prevent pieces of unvulcanized rubber from sticning together. Possible Health Injury When so used, talc is disseminated into the air in large quantities and the question has often been raised as to the possibility of permanent lung damage resulting from the continued inhalation of such dust. There has been very little work done in connection with this problem. In two published studies of the effects of exposure to dust in talc mines and mills in Georgia and Vermont (one by Dreessen,1 the other by Dreessen and DallaValle 2 of the U. S. Public Health Service) the writers con cluded that talc does not produce disabling pneu moconiosis, although Dreessen found some evidence in his Vermont study (l,p.98) that the dust (70% talc) produces a "fine diffuse bilateral fibrosis of the lungs which is definitely demonstrable in the x ray.'' In order to determine the possible dust exposure involved in the use of talc, the w riter undertook a-survey of plants engaged in the manufacture of rubber tubing, insulated wire, rubber thread, l Dri^taacn. W. C.~*" Effect* of C ertain Silicate DubU on the Luti*s," Jour, industrial Hygiene, Yol. XV, No 2. Mar 1933 pp fi6-78 i D roosseu, w C , and D a lla V a lle , J UM ---- 'Tbe EEffects of Expoeare to l>ust m Two Oeoryla TMc Mills and Mines " U S Public H ealth Report. Pol 50. No 5. pp. 131-143 b y CHARLES R. WILLIAMS Petrographen Engineering Department, Liberty Mutual Insurance Company and other rubber goods. It is the purpose of this report to outline the findings of this survey. Method The data on which this paper is based were gath ered in a representative group of plants in the rub ber industry, which use talc as a dusting agent. Table 1 shows the products manufactured at each of these plants. TABLE 1 P lan t A \\ C D E F G il 1 Product Insulated Wire Rubber Goods (all kinds) Rubber Hose A Tubing A utom otive Cable Insulated Wire insulated Wire Webbing Rubber Thread Rubber Thread In each plant data were gathered as to sources of dust; number and types of machines; nature of ventilation, if any; number of employees; length of service in dusty operations and nature of work. Air samples were taken with a Greenburg-Smith impinger and counted standard light field tech nique within a few hours of the time they were taken. There was probably some solution of car bonate particles, but a comparison of tables 3 and 4 will show that the bulk of the carbonates were not dissolved. Samples of the raw materials and the air samples were anaiyzed"-by the petrographic method for mineral content. In every possible case data are put into tabular form to facilitate comparisons between conditions at various plants. .......... .......... . i SAFETY ENGINEERING Eminent Industrial Physicians Are Recommending Sodium Chloride Experience with Last Summer's Intense W eather Increased A ttention to H eat Sickness The installation of Fairway Dispens ers at drinking fountains together with a supply of Fairway Sodium Chloride Tablets represents an ex penditure that is so slight it is nearly negligible. uswr Kauoppa I,waits asshow ttRIrnSKHWf but Kroon WtOtt*AuW I )ftt& .SANI au anaagagas** * * *saig * Industrial Physicians are pretty well in agreement that heat sickness, regardless of its manifestation, finds its cause in a deficiency in sodium chloride in the system. This deficiency can readily be compensated for by swallowing Fairway Sodium Chloride Tablets as thirsf is quenched at the drinking fountain. The preventive value of Fairway Sodium Chloride Tablets has been tested and proved again and again. A very marked de crease and many total eliminations of heat sickness are re ported from mills, shops, and factories where Fairway Sodium Chloride Tablets are used. Write for "Prevenfion of Heat Sickness." FAIRWAY LABORATORIES, Inc. 2626 W . Main Street Belleville, III. Dust Concentration Table 2 gives a summary of the number of ma chines generating dust, ventilation, men exposed and dust concentrations in the various departments of these plants. P lan t A R C D E G H i Machines 12 3 3 4 7 4 3 6 3 1 1 9 1 1 1 2 1 . 1 . V en ti D epartm ent lation Insulating W Depanmng (large wire) WF D epanm ng (sm all w ire)1 W tv Depanm ng w T u b in g Vulcanizing (depanrung) ) w Mill Room w w Tubing & V ulcanizing Mill Room (cellar) w Molded Hose w D e p a n n in g w In su latin g w D epanning Punning Depanmng Spool Winding , , Mill Room tv T hread D epartm ent Thread Department w tv Mitl Room tv Spool W inding Concentration m illio n s cu. ft. 64 2 169.0 71.6 14 3 46.0 22.6 14.0 .. 5.3 11.7 280 13.3 81.0 13.8 144 0 7.8 23 8 10.6 7 1 10.7 26 4 7.9 49.4 Em ployees exposed 26 14 26 7 9 92 $11 3 4 9 41 4 4 2 0 11 18 4 2 W--Windows. F--Fan In Wall. 300 A t plant B samples w ere taken under two groups of conditions. W ith both tubing and vulcanizing departm ents, which are not phys ically separated, operating, the dust concentration m the vulcanizing departm ent was 194 m illion and in th e tu b in g departm ent 46 million When the vulcanizing departm ent was not operating the concentration In th e tubing departm ent dropped to 22.6 m illion. T his is an excellent eianiDle of contam ination of workroom air which could be avoided by segregating dugty from non-duaty operations. It may be seen from this table that in three of the seven depanning operations (removal of vul canized rubber from its bed of talc) dust concentra tions are over 140 million and only one below 20 million. The concentrations in the extrusion (in sulating, panning) departments ranged from 8 to 64 million--the two highest 46(B) and 64(A) be ing in the same plants having the most dust in their depanning departments. In both of these cases there was no physical separation of the extrusion and depanning departments and much of the dust in the extrusion departments originated in depan mng operations. Three of the four mill rooms studied had concen trations below 10 million and the fourth, which was located in a basement with little ventilation, had a concentration of 28.0 million. In the processing of rubber thread, the dust con centrations were found to vary from about 10 mil lion to 50 million. Composition of the Dust The wide variation in composition of talcs used in the rubber industry may be seen in Tables 3 and 4. P lan t A B C D E F G H I TABLE 3 Petrographic Analyses oi Raw Material (Bv count--less th a n 10 m icron^ % % less soluble th a n 10 Ser- Car- by welgt microns 41.73 95 T aflac pentlne - bonate Quartz 5 86 7.95 90 32 49 9 tr. 35,50 90 12 35 45 tr. 28.18 95 18 15 62 tr. 45.53 95 21 33 82 tr. 25 27 90 6 S 82 22.94 90 16 26 47 tr. 5.08 80 27 57 9 tr. 3.50 75 38 50 8 Others 3 10 8 3 14 4 11 7 4 c P laut A B D E F G H I TABLE 4 P etrographic Analyses oi G reenburg-Sm itb Samples (By count--less th a n 10 microns) % less than 10 m icrons Talc S erpentine C arbonate Q uarts SO 15 12 75 50 35 42 8 t2r. 90 17 12 02 tr. 95 45 32 14 tr. 95 19 12 61 tr. 90 12 34 04 tr. nr> 10 21 58 tr. 05 34 49 5 tr. 60 53 36 6 Others 29 IS 9 9 8 10 5 12 5 Table 3 shows that the mineralogical composition of the talcs being used (raw materials) and Table 4 the composition of talc dust taken from the air. The differences are slight and so it may be assumed for all practical purposes that the dust has essen tially the same composition as the raw material used. Little is known as to the toxicity of the silicate minerals present. Some authorities believe the carbonates are practically harmless, so it would seem reasonable to believe that the higher the car bonate content the less harmful the talc. The important factor to be noted in the above tables is the extremely small amount of quartz present in either raw materials or dusts. The paucity of quartz which may produce silicosis takes these dusts out of the class of dusts considered dan gerous such as granite dust or dust from other material with a high free silica content. Employees In the nine plants studied there are 300 em ployees, who have been exposed to various concen trations of dust for different periods of time. Table 5 gives the proportions of employees exposed to FOR APRIL, 1937 various concentrations of talc dust. Approximately one-fifth of the men involved are exposed to over 50 million particles per cubic foot of air. TABLE 5 Employees Exposed to Various Dust Concentrations Concentration at particles per cubic foot Emploiees of air) exposed % Over &0 04 21.3 25TM.Xi 28 9.3 10--25 103 350 Less tlian 10 105 35.4 300 100 0 It may be noted from Table 6 that approximately 35% of all employees have been exposed to talc dust for 10 years or more. In the "over 30 year" group one man has been exposed for 44 years, one 45 years and one 55 years. Of those employees exposed to over 50 million particles of dust per cubic foot of air 50% have been working under dusty conditions for 10 years or more. Over 30 years 25--30 20--25 15--20 30--15 0--10 Less tlian 5 TABLE 6 Lengtli of Service All employees 5 7 14 19 59 $2 114 J00 Employees exposed to over 50 m illion 2 1 7 21 16 17 6-1 Summary Studies including dust counts and petrographic analyses were made in nine plants which use talc as a dusting agent. In these plants, 300 employees are exposed to concentrations of talc dust varying from 7 to 194 million particles (less than 10 microns in size) per cubic foot of air. The highest concentra tions were found in the tubing and vulcanizing de partments of rubber tubing manufacturers (50 to 200 million) and the depanning departments of in sulated wire manufacturers (generally over 100 million). In the mill rooms which, in these plants, were isolated from depanmng or other dusty opera tions, the dust concentrations were generally found to be less than 10 million particles per cubic foot of air. In the manufacture and use of rubber thread, the concentrations ranged from 10 to 50 million. Of all (300) of the employees exposed, 195 or 65% were working in concentrations greater than 10 million and 64 or 21.3% in concentrations greater than 50 million. The talcs encountered in this study covered a wide range of materials. The contents of silicate minerals ranged from 14 to 92%, while the car bonate contents varied from 8 to 86%, by particle count in the respirable sizes. Recommendations 1. Handling of materials. It was noted in sev eral plants that considerable unnecessary dust was generated by careless handling of the talc. Control of this factor may minimize some exposures. 2. Isolation of dusty operations. Such operations as depanning which are sources of high concentra tions of dust should be located so that other parts of the plant may be kept free from such dust. 3. Raw material. Wherever possible the talc used should have a high carbonate content. 4. Insulated wire depanning. In the cases of smaller sizes of wire it is practical to cover the pan with a cone so that the wire comes out through an opening in the apex. This procedure is effective in minimizing the exposure. 5. Panning operations. Talc should be intro duced automatically, obviating the necessity of hav ing a man throw the talc in with a scoop or shovel. 6. Respirators. The use of respirators is recom mended for short exposures to high concentrations. POWERS RAPID X-RAY FOR THE X-RAY EXAMINATION OF GHQUPS OF INDUSTRIAL EMPLOYEES SURVEY SEE VIC REDUCES THE COST OF CHEST RADIOGRAPHS TO WITHIN ECONOMICAL LIMITS Powers' Service is limited to the making and processing oi chest x-rays on paper film at low cost, rapidly and satisfactorily, for and under the direction oi, physicians. POW ERS X-RAY PRODUCTS, Inc. GLEN COVE NEW YORK