Document DG858Qp663B0gz20eGwZEX5ra

FILE NAME Talc TALC DATE 1979 DOC TALC020 DOCUMENT DESCRIPTION Conference Presentation from Dusts & Disease Conference - Fibrous Mineral Content of Consumer Talc- Containing Products 392 ET WAGNER AL Timbrell V. Skidmore J.W. Hyett A.W. Wagner J.C Exposure chambers for inhalation experiments reference samples of asbestos of the International Union agaaignastinst Cancer UICC J. aerosol Sci 215-233 1970 Wagner talc WJa.Cl.ton by the Berry G. Cooke T.J. Hill R.J. Pooley F.D. Skidmore J.W Animal experiments with W.H. ed Inhaled particles IV Proceedings of an International Symposium organized British Occupational Hygiene Society Edinburgh 22-26 SepSeptembter ember 1975 PPaartrt 2 647-652647-652647-652 Oxford Pergamon 1977 of Wagner Berry , J.C. , inhalation G. Skidmore J.W. G. Timbrell V The effects of the J.W. V in Brit inhalationaasbesstos bestos Brit J. Cancer 29 252-269 1974 Wagner J.C. , Berry inoculation with G. , Timbrell V V Mesotheliomata in rats after inoculationinoculation with asbestaossbestos and other materials Berry materials Brit J.Cancer 28 173-185 1973 FIBROUS MINERAL CONTENT OF CONSUMER CONTAINING PRODUCTS A. N. Rohl and A. M. Langer Environmental Sciences Laboratory Mount Sinai School of Medicine City University of New York New York New York 10029 INTRODUCTION Approximately 800,000 tons of raw talc are produced annually in the United States Talc is used in a number of industries for a variety of purposes e.g. the manufacture of ceramics paints paper rubber roofing insecticides stucco plastics textiles and soaps Wells 1978 Pulverized talc is also used on much smaller tonnage basis as an ingredient in such consumer products as cosmetic talcums paper mache and modeling compounds in spackling patching compounds and putties in automotive and boat body repair fillers and caulking compounds The uses of talc in food products include rice coating peanut polishing candy molding a and salami dusting It is also used as filler and excipient for pharmaceutical pills and for dusting contraceptive diaphragms Undoubtedly there are other uses of talc in consumer products which are not generally known Each product carries with a distinct and individual inhalation and ingestion potential of the mineral components The present report will deal with our studies of four types of these products specifically talcum powders spackling and patching compounds coated rice and modeling materials We have studied talc in other types of consumer products but these four categories represent the varietal range of applications It was our purpose to examine these materials to determine the presence or absence of minerals with known or suspected disease potential specifically the fibrous am- phiboles quartz and the asbestos of mineral chrysotile GEOLOGICAL OCCURRENCE OF TALC Talc rocks occur fairly commonly in nature and are formed as the result of two important geological processes i.e. the hydrothermal alteration of ultramafic rocks and the low grade thermal metamorphism of silica dolomite CaMg These metamorphic processes frequently result in the formation of an assemblage of existing minerals principally hydrous magnesium silicates but also hydrous magnesium silicates Some of these are the magnesium and calcium amphibole minerals which include anthophyllite and tremolite and the serpentine minerals including chrysotile asbestos Depending on the nature of the parent rock varying amounts of mica minerals e.g. chlorite quartz and carbonates may also be found Table ) Although pure talc deposits exist very frequently the mineralogically complex deposits are used to provide talc for both industrial and consumer products The mineral talc is a layer sheet silicate with the empirical chemical The authors wish to acknowledge support in part by grant ES 00928 from The National Institute of 394 ROHL AND LANGER TABLE 1. Minerals which are commonly found in talc deposits Carbonates Minera Calcite Dolomite Dolomite Magnesite Ideal formula CaCO03 CaMg MgCO3 Amphiboles Tremolite Anthophylite Anthophyllite Ca Ca Mg5Si022 Mg5Si022 Ca Mg5Si02 2 Si8022 Serpentine Others Antigorite Chrysotile Chrysotile uncommon Lizardite uncommon Quartz Mica Phlogopite Phlogopite Mica e.g. Chlorite e.g. Penninite Mg3SMg3iSi2052054 Mg3Si205 OH MgSi 04 5 SiO2 SiO2 K SA2020 OH Mg 8020 OH 16 formula Si 0,0However aluminum Al or titanium Ti may substitute for silicon Si and iron Fe manganese Mn nickel Ni chromium Cr cobalt Co etc. substitute for magnesium Trace metal contamination is common One talc may deposit in the eastern United States containing up to 0.2 Ni and substantial amounts of Cr and Co has been used as a source of consumer talcums for many The years layers of talc are very weakly bound to one another and this accounts for which the ease with it breaks into sheets or platy fragments This excellent cleavage combined with high surface area softness and light color make talc important as industrial both an and consumer material The geology and mineralogy of talc have been extensively reviewed elsewhere Rohl and Langer 1974 Rohl et al 1976 IDENTIFICATION ANALYTICAL TECHNIQUES FOR IDENTIFICATION CATION OF FIBROUS MINERALS IN TALC IDENTIFICATION AND QUANTIFI-QUANTIFI- which Techniques have been successfully used for the analysis of mineral fifbeirsbers in talc products include optical microscopy ray diffractometry and electron beam instrumentation The use of polarized light optics has long been a standard for technique the indices the of minerals By using immersion oils of known refractive dentification example the optical properties of unknown crystalline particles can be determined However there are a number of conditions which limit the usefulness of optical microscopy The accurate determination of refractive indices is extremely difficult when applied to particles less than 1 ...min diameter The optical properties of flibrousminerals frequently obviates full characterization of their optical constants In consumer talc products most of which are finely pulverized powders the particle 395 ASBESTIFORM CONTENT OF TALC identification very difficult if not impossible Large numbers of fibers may go undetected when this technique is used exclusively Stanley and Norwood 1973 However it may be useful in some cases at least as a screening or preliminary technique ray powder diffraction has been used in both the continuous scan and scan modes of operation for the identification and quantitation of fibrous minerals in talc Rohl and Langer 1974 Rohl et al 1976 Stanley and Norwood 1973 This can be achieved by comparison of dilutions of known minerals in a talc matrix with unknowns Quantitative analysis using this technique requires 1 a talc standard or matrix completely free of contaminating minerals and pure standards of fibrous minerals for preparing fiber dilution standards 2 a prepara- tion method which is both sensitive and reproducible and 3 selection of diagnostic ray reflections for quantitative analysis of specific minerals ray diffraction in the scan mode is used for quantitative determination of tremolite chrysotile and weight anthophyllite in talc at levels as low as 0.1 0.25 and 2.0 by respec- tively Rohl and Langer 1974 Rohl et al 1976 These minerals are often found as grained and intimate components of talc rock and they are of particular concern as constituents of consumer talc products because of their biological potential Daymon 1946 Dreessen 1933 Dreessen and Dalla Valle 1935 Kleinfeld and Messite 1960 Kleinfeld et al 1955 1967 1973 Mclaughlin et al 1949 Millman 1947 Noro 1946 Porro and Levine 1946 Porro et al 1942 Reichman 1944 Schepers 1965 Siegal et al 1943 The major limitation of ray diffraction analysis is its inability to distinguish between different morphological habits of the same mineral For example short tremolite fragments and long fibers of asbestiform tremolite give virtually identical ray patterns To distinguish between different habits or shapes of the same mineral including asbestos minerals requires microscopic techniques Transmission electron microscopy used in conjunction with selected area electron diffraction SAED provides the resolution capability to visualize all particles and in many cases to identify them For example at magnifications of about 25,000x or greater chrysotile fibers may be identified on the basis of their unique morphology In some instances the morphological similarities between fibrous talc and amphibole fibers may be close enough to preclude the unequivocal identifica- tion of the latter on the basis of such characteristics as cleavage diffraction contrast figures and aspect ratios However talc fibers can be easily distinguished from amphibole fibers on the basis of SAED patterns CONSUMER PRODUCTS STUDIES Consumer Talcums and Powders In a paper published in 1976 we reported a mineral and chemical chacterization of 20 consumer talcums and powders obtained in New York city during the period 1971-1975 Rohl et al 1976 Where known all were formulated prior to 1973. Of the twenty products 10 contained either tremolite or anthophyllite or both The proportions determined by scan ray diffraction ranged from 0.1 to over 14 by weight No attempt was made to distinguish proportions of fibrous and fibrous morphological phases although every sample contained fiber Two contained detectable amounts of chrysotile The presence of these lime a 1 396 ROHL AND LANGER ASBESTIFORM CONTENT OF TALC 397 FIGURE 1. Electron photomicrograph of amphibole fibers in cosmetic talcum powder x25.000 FIGURE 2. Electron photomicrograph of amphibole fibers in cosmetic talcum powder x52,000 398 ROHL AND LANGER Quartz was found in eight samples with seven ranging from 2 to % and one as high as 35 Chemical determinations including bulk chemistry and trace metals were also made on the twenty samples Four samples showed systematically high levels of nickel chromium and cobalt with average values in parts per million of 890 518 and 57 respectively The mean concentrations of nickel chromium and cobalt in the other 16 samples were 18 29 and less than 3 respectively A study by this laboratory of cosmetic talcums purchased during the period 1975-1978 is in progress Preliminary results suggest that fewer products contain fibrous minerals Spackling and Patching Compounds Spackling and patching compounds consist of grained powders or pre- mixed pastes The ingredients usually are plaster of paris limestone talc clays micas or some other type of pulverized rock filler Chrysotile is added to some products to provide reinforcement and to control shrinkage and cracking as it cures Fibrous amphibole minerals are found in some products because they occur naturally in talc carbonates and other raw materials In paper published in 1975 the mineral content of 15 consumer spackling compounds purchased during the period 1972 to early 1974 was reported Rohl et al 1975 Two products contained talc as major components and one of these also contained about 4 to % by weight of tremolite Chrysotile was found in three products ranging from 5 to 10 by weight Another product consisted principally of anthophyllite 10-12 and quartz Quartz was found in nine products in proportions ranging from 5 to 70 by weight Optical and electron microscopic analyses showed that the asbestos and other mineral fibers ranged in length from 0.25 to 8.0...mFigure 3 Almost all were shorter than 5 ...min length which is of respirable size yet they were not detected by optical microscopy The paper also reported the results of mineral analyses of 10 industrial taping compounds used in drywall building construction Nine of ten contained chrysotile in about the same proportions 5-12 as the consumer products Air measurements made during mixing sanding and clean of drywall taping showed airborne concentrations of two fibers per milliliter of air or more were common Electron microscopic analyses of the air samples showed that for every fiber visible by light microscopy x400 magnification from 200 to 1,000 fibers could be seen at magnifications of x 25,000 In the follow to this study during different consumer 1975 five spackling compounds were obtained and analyzed Of the five four had talc present as a major phase and also contained tremolite or anthophyllite ranging from 2 to 12 by weight Chrysotile was also found in three of the five products in proportions ranging from 5 to 15 . The latter concentrations reflect chrysotile as an additive not as a talc contaminant Talc - Coated Rice The practice coating short grain and medium grain rice has been common in the United States for over 50 years Several explanations for this practice have been advanced The principal reason given for coating rice is to give an appealing smooth and shiny luster to the product Puerto Rican Oriental and Hawaiian consumers reportedly show a decided preference for coated rice It has also been claimed that coated rice better withstands insect and fungal infestation and maintains moisture stabilization The U.S. Department of Agriculture statistics indicate that about 300 million ASBESTIFORM CONTENT OF TALC FIGURE mocnifcation Electron fibers photomicrograph of consumer in fibers chrysotile FIGURE photmicrograph Electron photomicrograph of chrysotile fibers in consumer spackling compound x52,000 are than 5...min length Other particles are plaster Paris talc and mica 400 ROHL AND LANGER ASBESTIFORM CONTENT OF TALC 401 that an additional 470 million pounds were distributed to the Territories and the State of Hawaii that year Federal Register 1977 The total of 700 million pounds of coated rice represents about third of the rice sold in the United States and its Territories annually Approximately one pound of talc is used for coating 100 pounds of milled rice Two samples of talc powder which are used for the coating of rice that is raw powders were obtained from rice dealers Five samples of coated rice were purchased from local grocery stores Three duplicate purchases were made Standard weights of rice samples were washed twice in known volumes of water Prior to rinsing the water used for washing the rice was passed through an absolute filter to remove any adventitous mineral contamination After each rinse the wash water was passed through a 0.4 mmembrane filter to remove insoluble material The material retained was dried weighed and ashed in nascent oxygen to remove organic substances then reweighed These residues and the two raw talc powders were prepared and scanned for diagnostic asbestos reflections by ray diffraction according to procedures described by Rohl et al 1976 In addition polarizing optical microscopy transmission electron microscopy and micro- probe techniques were used to verify and further the characterize minerals present Quantitative analysis of talc coating showed that one of the two samples of talc powder contained tremolite on the order of % by weight Three of the eight rice coating residues were also found to contain tremolite and anthophyllite up to % by weight and averaging about % Another rice residue contained about 20 of a fibrous amphibole mineral with a chemical composition similar to glaucophane In four samples amphiboles were not detected by ray diffraction However analyses by transmission electron microscopy and microprobe showed that three contained trace amounts of asbestiform amphibole minerals Chrysotile was not detected in any samples Eleven samples of short rice were purchased by colleagues in various cities in the United Kingdom where much of the rice is imported from Australia and Italy The washings of these samples of rice were found to contain no talc One sample coating was found to be calcium carbonate containing Modeling Materials Arts and crafts or modeling materials consist of dry powders often mixtures of plaster of paris or gypsum or calcium carbonate or talc with fibrous minerals including chrysotile tremolite and anthophyllite These powders are mixed with water and then cast or shaped into figures In the school year 1971-1972 The New York City Board of Education had purchased 50,000 packages of paper mache- type material each package contain- ing five pounds The product upon analysis was found to contain about 50 chrysotile As a result use of the product was discontinued in New York City schools The material which was subsequently submitted for it consisted of a mixture of plaster and talc including 15 to 20 tremolite and anthophyllite Thereafter this material was discontinued as well Six other commerical samples of arts and crafts materials some marketed specifically for school children were analyzed for their mineral content Of the six three contained talc and also tremolite and chrysotile The asbestos and FIGURE 4. Electron Photomicrograph of asbestiform amphiboles in dry type modeling compound CONCLUSIONS which contain products Some of the studied consumer contain varying which contain talc have been amounts havebeen varying of natural mineral contaminants some of which contain demonstrated to be biologically active in humans These minerals include chrysotile anthophyllite tremolite and quartz In addition a number of trace metals were detected in essentially unknown It is therefore recommended that sigfnoirfmiscance evaluated 1. The of these materials in consumer products be on a systematic clinical or epidemiological basis Heavy intermittent or habitual use of these products with high levels of fibrous mineral fibers : may produce disease For example recognition of this possibility has led to | efforts by the cosmetic talcum industry to reduce or eliminate contaminated products by changing their sources of raw materials home repair work 2. Air measurements taken during drywall construction suggest using consumer spackling and patching compounds during could expose members of entire households to high concentrations of dust An assessment of the risk to consumers was made by the Consumer Safety Product Commission in proposing rules to regulate patching com- pounds Blejer and Arlon 1973 It was calculated that for a conservative exposure of four hour days the increased risk of death from aybelaerlryespiratory cancer from even such a modest exposure.would be unaccept- 3. While some investigators have proposed that the ingestion increased neoplastic contaminated talc products may pose a hazard of Henderson especially of the intestinal tract Hammond et al 1965 1975 al Matsudo et al 1974 Merewether 1930 Selikoff et al frequently this disease potential is presently unknown coated rice fiber- 1967 constitutes a staple of the diet of many Americans and one kilogram per week of talc could be consumed by some individuals Since several of the talc analyzed contained up to % and % amphibole minerals coatings these some individuals could ingest about 600 milligrams per week of mineral tmhienesraamlescotnitmaemiTnhaentcosating eliminatingelimnating it or Approximately 9.4 grams of talc would be ingested at of rice with talc should be reviewed with the aim substituting coatings contain substituting coatings that do not contain these suspect 4. The presence of unbound asbestos fibrous and quartz minerals of respirable size in arts and crafts materials especially those used by children with their long life expectancy represents in our view an unaccept- exposure able These should be eliminated from such products immed- Artists artisans and hobbyists may also be exposed to these mate- iately rials as well as to similar dusts generated during sculpting of talc or steatite rock These individuals should be made aware of hazards associated with such exposures and should protect themselves accordingly REFERENCES BlejerBlejer H.P. and Arlon R Talc A possible occupational and environmental carcinogen Jour Occup Med 92-97 1973 H Latent silicosis and tuberculosis Amer Rev. Tuberculosis 554-559 1946 Daymon W.C Effects of certain silicate dusts in the lungs J. Indust Hyg 66.78 1933 Dreessen W.C. and Dalia Valle J.M The effects of exposure to dust in two Georgia talc mills and mines Dreessen Publ Health Rpts 1405-1415 1935 Federal Register Proposal to Revise Standard for Enriched Rice by U.S. Food and Drug Administration V 42 no 136 July 15 1977 HamondHammond E.C. Selikoff I.J. and Churg .: Neoplasia among insulation workers in the United States with special reference to abdominal neoplasia Annai N.Y. Acad Sci 519-525 1965 Henderson W.J. Evans D.M.D. Davies J.D. and Griffiths .: Analysis of particles in stomach tumours from Japanese males Envir Research 240-249 1975 Kleinfeld M. and Messite .: Problem areas in pneumoconiosis Arch Environ Health 428-437 1960 Kleinfeld M. Messite J. Kooyman O. and Zaki M.H Mortality among talc miners and millers in New York State Arch Env Health 663-667 1967 Kleinfeld M. Messite J. and Langer A.M A study of workers exposed to asbestiform minerals in commercial talc manufacture Environ Res 132-143 1973 Kleinfeld M. Messite J. and Tabershaw I.R Talc pneumoconiosis Arch Indust Health 66-72 1955 Matsudo H. Hodgkin N.M. and Tanaka .: Japanese gastric cancer Potentially carcinogenic silicates talc from rice Arch Path 366-368 1974 pneumoconiosis Mclaughlin A. Rogers E. and Dunham K.C Talc 184-194 1949 Merewether E.R.A The occurrence of pulmonary fibrosis and other pulmonary affections in asbestos workers Ind Hyg 198-222 239-257 1930 Millman .: Pneumoconiosis due to talc in the cosmetic industry Occup Med 391-394 1947 Noro .: On the history of asbestosis Acta Path et microb Scandinavia 53-59 1946 Porro F.W. and Levine N.M Pathology of talc pneumoconiosis with report of an autopsy North N.Y. State Med J. 23-25 1946 Porro F.W. Patton J.R. and Hobbs A.A Pneumoconiosis in the talc industry Am J. Roentgenol 507-524 1942 Reichman .: Uber talkumstaublunge Arch . Gewerbepath and Gewerbehyg 319-322 1944 Rohl A.N. and Langer A.M Identification and quantitation of asbestos in talc Environ Health Persp 95-109,1974 Rohl A.N. et al Consumer talcums and powders MineralMineral and chemical characterization J. Toxicology and Envir Health 255-284 1976 Rohl A.N. Langer A.M. Selikoff I.J. and Nicholson W.J Exposure to asbestos in the use of consumer spackling patching and taping compounds Science 551-553 1975 Schepers G.W.H Discussion of Newhouse M.L. and Thompson H Epidemiology of mesothelial tumors in the London area Annals of N.Y. Acad of Sci 579-602 1965 Selikoff I.J. et al Asbestosis and neoplasia Amer Jour Med 487-496 1967 Siegal W. Smith A.R. and Greenburg .: The dust hazard in tremolite taic mining including roent- genological findings in talc workers Amer J. Roentgenolog 11-29 1943 Stanley H.D. H.D. and Norwood R.E The detection and identification of asbestos and asbestiform materials talc Report Pfizer Inc. 1973 Wells J.R Talc and pyrophyllite in 1976. Mineral facts and problems U.S. Bureau of Mines Washing- ton D.C. U.S. Government Printing Office 1978