Asbestos Textile Institute Air Hygiene and Manufacturing Committee Minutes on Dust Sampling and the 5 Million Particle Limit (1959)

Three pages of undated minutes of the Asbestos Textile Institute's Air Hygiene and Manufacturing Committee, signed by A. E. May of Keasbey and Mattison as chairman, with Maurice LaChance of the Thetford Industrial Clinic as a guest. H. M. Jackson reported on Johns-Manville's tests comparing the standard and midget dust impingers, and on continuous dust sampling with the U.S. Public Health Service. He also explained the 5 million particle limit: "The 5 million p.p.c.f. is a carry over from the quartz industry and seems to be confirmed by clinical experience." Members also discussed dust collectors, wet weaving, and trading hood designs with Britain's Asbestosis Research Council.

What it shows

The minutes record how the industry's own committee understood the asbestos dust limit then in use (the Threshold Limit Value (TLV) of 5 million particles per cubic foot): borrowed from the quartz industry and, as Jackson put it, seeming to be confirmed by experience. Jackson also said a 10 micron particle size cutoff had been set at Saranac Laboratory and that many authorities believed particles over 10 microns were not harmful; someone later wrote "under" beside "over" on the copy. The minutes also note that rock dust was "not considered harmful" and could not be told apart from asbestos under the microscope.

In Johns-Manville's index

Johns-Manville's legal department indexed the Motley 1,000 in 1984. Its index describes this document as follows:

ATI Meeting Minutes, illegible date - Air Hygiene Committee. Methods of dust sampling and current asbestos TLV are discussed.

About this copy

This is document 58 of the Motley 1,000, from the set the Manville Personal Injury Settlement Trust's records facility certified as true copies, pages CRMC-Motley1000-Subj-000584 to CRMC-Motley1000-Subj-000586.