Amphibole content of cosmetic and pharmaceutical talcs

Our plain-English summary of Amphibole content of cosmetic and pharmaceutical talcs, by A.M. Blount (Environmental Health Perspectives, 1991).

The study

• Author: A.M. Blount
• Journal: Environmental Health Perspectives
• Published: 1991;94:225-30
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Pharmaceutical and cosmetic-grade talcs were examined for asbestiform amphibole content using a new density-optical method. Talcs under the Food and Drug Administration are not regulated as to asbestos content; however, all talcs were well below the level mandated by the Occupational Safety and Health Administration for industrial talcs. Only one was found to contain an amphibole particle size distribution typical of asbestos.

In plain English

This laboratory study measured amphibole minerals in high-grade cosmetic and pharmaceutical talc powders sold in the United States. The author noted that talcs under the Food and Drug Administration were not regulated for asbestos content. The samples were talc products from five deposits in Montana, three in Vermont, and one each in North Carolina and Alabama, plus four talcs from outside the U.S. sold on the U.S. market. They were analyzed with a centrifuge/optical method the author had developed. It separates the denser amphibole particles from talc before counting them under a microscope. Counts of regulatory particles (length more than three times width) ranged from 0 to 341 particles per milligram, and several samples had none detected. All talcs were reported to be well below the level OSHA mandated for industrial talcs. In one sample, labeled I, the tremolite had a shape distribution similar to tremolite asbestos. In another, labeled M, the tremolite resembled the nonfibrous type. The author concluded that high-grade talc powders were uniformly low in amphibole content.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory analysis of talc products using a centrifuge (density) and optical microscopy method developed by the author
• Who was studied: High-grade cosmetic and pharmaceutical talc products from five deposits in Montana, three in Vermont, and one each in North Carolina and Alabama, plus four talcs from outside the U.S. available on the U.S. market. Table 1 lists samples A to O. Lower-grade talcs from other U.S. districts were examined but not included in the report.
• Exposure: Amphibole mineral particles, including tremolite, in talc powders. Particles with an aspect ratio greater than 3:1 were counted as regulatory fibers and were classed by shape as cleavages and prismatic pieces, needles, or fibers.
• Main results:
  • Across the high-grade talc powders, counts ranged from 0 to 341 amphibole particles per milligram.
  • All talcs were reported to be well below the level mandated by OSHA for industrial talcs. The FDA had equated 0.1% with 1000 particles per milligram.
  • Talc from some districts appeared to be completely free of amphibole minerals. Several samples (B, C, E, F, G, O) had none detected.
  • Talcs that contained amphibole showed two distinct types: cleavage type and asbestos type.
  • In sample I, the tremolite particles were composed of fibrils, and their aspect ratio distribution was similar to tremolite asbestos. Sample I had a higher particle count than the samples showing cleavage fragments.
  • In sample M, the aspect ratio distribution indicated that the tremolite was of the nonfibrous type.
• The authors' conclusion: The author concluded that the high-grade talc powders were uniformly low in amphibole content. The author also concluded that the centrifuge method was useful both for counting particles and for describing their shapes.
• Limitations the authors state:
  • Standard deviations were high for the centrifuge method because very few particles were counted. Larger counts were generally not made.
  • The 0.1% figure is percent by particle count, not by weight or volume.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Talc and vermiculite.

Medical terms in this study, explained in our Lexicon: Amphibole Group, Talc, Asbestiform, Industrial Talc.

Related studies

• Identification of chlorite and serpentine in cosmetic or pharmaceutical talc — A.M. Blount, A.H. Vassiliou (1983)
• Evaluation by electron microscopy techniques of asbestos contamination in industrial, cosmetic, and pharmaceutical talcs — L. Paoletti, S. Caiazza, et al. (1984)
• Fibrous and mineral content of cosmetic talcum products — L.J. Cralley, M.M. Key, et al. (1968)
• Serous Ovarian Cancer Caused by Exposure to Asbestos and Fibrous Talc in Cosmetic Talc Powders-A Case Series — J.E. Steffen, T. Tran, et al. (2020)
• Cosmetic talc and ovarian cancer — D.L. Longo, R.C. Young (1979)
• Mesothelioma Associated With the Use of Cosmetic Talc — J. Moline, K. Bevilacqua, et al. (2020)

Browse more research in Environmental Health Perspectives, or return to medical research.