B. C. Machin to E. Stevens on Stations Listed as "Did Not Operate" in the Toronto Plant Survey (1976)

A one-page confidential memo of January 7, 1976, from B. C. Machin at J-M's Toronto plant to E. Stevens at Jeffrey, on G. Swallow's report of the September 1975 hygiene survey of the plant. Machin wrote that the plant was "very encouraged by the results," but that critics kept "talking up" the large number of stations listed as "did not operate." The long list raised, "even to myself," questions such as "just how much of the plant was checked?" and "I wonder if they purposely shut some high station areas down during the survey?" He gave examples of stations next to sampled machines, and of trucks and a sweeper that ran "virtually steadily on a non-stop basis," that had been marked as not operating.

What it shows

Machin concluded that either a machine had been shut down when the sampler came to it, or the sampler did not take, or did not plan to take, a sample there, and he asked for a reporting format that would tell the two apart ("no sample taken" rather than "did not operate"). His concern was how the surveys looked to critics. Later in 1976 J-M made it policy that surveys reflect the maximum exposure levels of normal operations (Executive Bulletin No. 776-2).

In Johns-Manville's chronology

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

Machin (Toronto plant) writes to E. Stevens, 1/7/76, regarding the September 1975 Toronto plant hygiene survey. Machin notes that an unusually high number of stations were listed as "did not operate." Machin is very surprised at this because the machines associated with these stations are usually in continuous operation. Machin wonders if some of these operations were just shut down to avoid a sampling.