Johns-Manville Executive Bulletin 312-3 on Environmental Control Standards, Revised (1969)

Copies of Johns-Manville's Executive Bulletin 312-3 on "Environmental Control Standards": a draft revision of September 16, 1969, and the bulletin issued "to be made effective immediately" on October 7, 1969, cancelling the version of April 28, 1968. Signed by W. L. VanDerbeek, J-M's vice president for production and engineering, it set company-wide rules for handling asbestos fiber: vacuums instead of brooms and shovels wherever sweeping raised dust above J-M's Threshold Limit Values, hooded bag-opening stations, sealed or buried empty fiber bags, covered containers, and respirators for workers unloading broken bags. New or rebuilt dust control systems had to be engineered to keep dust below the J-M limit, given "for example" as "2 F/cc for asbestos fiber dusts."

What it shows

The bulletin was reviewed by J-M's Environmental Control Subcommittee and the general managers in September 1969 (Fenner's report of the subcommittee meeting). Its 2 fibers/cc design figure was far below the levels J-M was then measuring in its own plants: the same year, many stations in the Manville textile plant were above 12 fibers/cc (Jackson's June 1969 survey), and Sheckler was recorded saying counts "must be under 12/cc" (September 1969). The bulletin covers new and rebuilt systems; it does not say when existing ones had to meet the limit.

In Johns-Manville's chronology

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

Executive Bulletin 312-3 requires respirator to be provided wherever exposures exceed TLV; new systems must be designed for 2 f/cc; existing systems to meet current TLV as soon as possible. Executive Bulletin 312-3 Revised dated 10/7/1969.

Editor's note: J-M's description says the bulletin requires respirators wherever exposures exceed the TLV and requires existing systems to meet the current TLV as soon as possible. Neither appears in these pages; the only respirator rule is for workers unloading broken bags.