J-M Research Center Report 414-3 on the FDA Fiber Count Method and Chrysotile and Tremolite in Talc Samples (1973)

A confidential report (No. 414-3, revised October 29, 1973) of the Johns-Manville Research and Engineering Center on a method proposed by the U.S. Food and Drug Administration for counting chrysotile and tremolite fibers in talc, and on fibers found in J-M and competitors' talcs. The FDA was expected to limit talc for food, drug and food-contact uses (including paper) to 100 chrysotile or 1,000 tremolite fibers per milligram. J-M had Hazen Research of Golden, Colorado, try the FDA method on 35 samples; Hazen's petrographers worked two weeks and could not complete a count, and their attached report calls the method unworkable for chrysotile. J-M's own petrographer counted fibers by another procedure, and all samples were checked for fibers by transmission electron microscopy.

What it shows

The report found chrysotile "in a substantial number of products previously thought to be, and sold as chrysotile free." Every one of eleven customer samples of United Sierra's Mistron Vapor contained it, and "Both J&J Baby Powder purchased on the market and J&J Green Mountain Standard have chrysotile present," though the tables mark the Johnson & Johnson results as traces that "could be attributed to contamination." J-M's own Cyclo-Sorb and Cyclo-Fil talcs from California were counted at 12,000 and 35,000 tremolitic fibers per milligram, and Nytal 300 of the R.T. Vanderbilt Company and Asbestine 5X of International Talc at 17,000 to 22,000 fibers per milligram of each kind. Only Pfizer's Montana talc (and perhaps Engelhard's) appeared chrysotile-free. The report recommended telling the FDA that its method "will not work" and that the proposed limits were arbitrary and "so low as to be indefensible." In 1974 J-M's labeling of its talcs drew an objection from Vanderbilt (Kotin on Vanderbilt's objection).