T. S. Patterson to D. J. Allison on Abrasive Disc Saws, with J-M Canada's Open Letter to Pipe-Laying Contractors (1979)

A one-page memo of July 26, 1979, from T. S. Patterson to D. J. Allison, with the open letter Johns-Manville Canada Inc. was sending to pipe-laying contractors and a certificate for warehouse managers to sign. "Because of the inherent danger from the dust generated when these saws are used to cut asbestos-cement pipe," Patterson writes, "it is absolutely essential that we do everything we can to prevent their use for this purpose." He adds, "I belive it is important that we have on file evidence of those things we have done to prevent our employees and customers from being needlessly exposed to airborne asbestos fibre."

What it shows

The open letter told contractors that asbestos-cement pipe such as Transite "is perfectly safe for a municipality to use to transport water" and that, with the recommended work practices, "no special precautions or procedures are required." Its one warning was against abrasive saws, which "when cutting dry, create a cloud of dust that contains asbestos fibre particles that could be hazardous if inhaled," set out in capitals: "DO NOT CUT IT DRY WITH AN ABRASIVE SAW!" The file also holds two certificates signed by warehouse managers, one at Winnipeg, promising not to let anyone use an abrasive disc saw on asbestos-cement pipe.

In Johns-Manville's chronology

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

T.S. Patterson (J-M) writes to D.J. Allison (J-M), 7/26/79, that "[b]ecause of the inherent danger from the dust generated when abrasive disc saws] are used to cut asbestos-cement pipe, it is absolutely essential that we do everything we can to prevent their use for this purpose." Patterson attaches a copy of a letter J-M will be sending to all of its pipe contractors encouraging them to do the same. Patterson also states that J-M needs to take strong steps to guarantee that its employees also adhere to this policy. As a suggestion, Patterson attaches a draft form to be sent to each warehouse manager to sign. "I believe it is important that we have on file evidence of those things we have done to prevent our employees and customers from being needlessly exposed to airborne asbestos fibre."