Johns-Manville Executive Bulletin 33-26 on Dust and Fume Abatement Project Evaluation (1955)

Johns-Manville Executive Bulletin 33-26 of June 13, 1955, "Dust and Fume Abatement Project Evaluation." To protect employees' health "through control of industrial health hazards," it makes it J-M practice to evaluate every dust and fume abatement project by a "task team": a methods engineer, the plant's safety engineer, a production supervisor and a plant engineer, appointed by the plant manager. The second page is a sheet from J-M's Manual of Standard Practices (Safety, Appendix II), signed by H. M. Jackson, adopting the American Conference of Governmental Industrial Hygienists' threshold limits as J-M's standard with one exception: for asbestos, "Our tentative standard" was 1 million fibers per cubic foot.

What it shows

Jackson's sheet explains the exception: Saranac's animal research indicated "that the fibers 10 - 15 microns and longer are the fibrosis producing agents--not the dust," British publications had confirmed it, and although the information had gone to the conference, it had not yet changed its limit of five million particles per cubic foot. J-M had begun reporting its counts in fibers in April 1954 (Jackson to R. C. Smith). Two years later the company's president had this bulletin revised to cover all industrial wastes and their legal and public relations side (President's Bulletin of April 1957).

In Johns-Manville's chronology

Johns-Manville's own chronology of what the company knew describes this document as follows:

Executive Bulletin 33-26, dated 6/13/55, becomes part of Standard Practices Manual, IH-96, Dust and Fume Abatement Project Evaluation. J-M will use the task team method to obtain data on conditions that may cause unhygienic exposure. Task team will prepare thorough analysis and evaluation of individual projects. Outlines manner in which task teams should proceed with assignments.

Editor's note: J-M's description summarizes the task-team procedure in Standard Practices subject IH-96. The bulletin says IH-96 is attached, but the attached page in this file is a different one, Safety Appendix II on threshold limit values.