Arthur L. Fisk Jr. and Glenn A. Coughlan of Idaho on a Rock Wool Lung Fibrosis Claim (1952)

Two letters. On June 23, 1952, Arthur L. Fisk Jr. of Johns-Manville replied to Glenn A. Coughlan, an assistant attorney general of Idaho handling a claim against the State Insurance Fund for total disability "allegedly arising from fibrosis of the lungs due to breathing rock wool dust." Fisk enclosed a 1935 article by Dr. Lawrence T. Fairhall, "Rock Wool in Relation to Health," and described a Metropolitan Life Insurance Company survey of nearly 400 workers at a J-M rock wool plant that found no silicosis or abnormal lung fibrosis. He added that J-M had never "heard of a single instance where a workman contracted silicosis as a result of exposure to our rock wool." On July 1 Coughlan asked for a copy of the study and for a qualified witness he could depose on the effects of rock wool on the lungs.

What it shows

Coughlan was defending the claim, and he wrote that a finding of liability "would have far-reaching effects," which J-M would likely be "very interested in." Fisk's answer relied on the absence of free silica in rock wool and on the Metropolitan Life survey. J-M had in fact heard of earlier claims: in 1933 an insurer told it of two claims of alleged silicosis by men who installed home insulation made with J-M material, and in 1948 Dr. Kenneth W. Smith had written to the Toronto plant about asbestos and silica hazards. Earlier in 1952 Fisk had answered another claim over rock wool home insulation in similar terms.

In Johns-Manville's chronology

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

Correspondence between J-M and Glenn A. Coughlan, Attorney for the State Insurance Fund of the State of Idaho, re workers claim for permanent disability arising from fibrosis of the lungs due to breathing rock wool dust. Arthur L. Fisk, Jr. replies in letter of 6/23/52 with information on study by Metropolitan Life Insurance Company and states that J-M has never heard of a single instance where a workman contracted silicosis as a result of exposure to our rock wool.

Related documents

• Maryland Casualty Company to Johns-Manville on Home Insulation Silicosis Claims (1933)
• Dr. Kenneth W. Smith to W. A. Young on Asbestos and Silica Hazards at the Toronto Plant (1948)