Arthur J. Vorwald to Owens-Illinois on Kaylo Causing Asbestosis in Animals (1948)

A three-page letter of November 16, 1948, from Dr. Arthur J. Vorwald, director of the Saranac Laboratory, to U. E. Bowes of the Owens-Illinois Glass Company, enclosing an interim report dated October 30, 1948, on animal experiments with Kaylo, an Owens-Illinois insulation made with asbestos. A year earlier Saranac had tentatively concluded that Kaylo "fails to produce significant pulmonary damage." After 30 to 36 months of exposure, Vorwald writes, "unmistakable evidence of asbestosis has developed" in every animal, and the report concludes that Kaylo "is capable of producing asbestosis and should be handled as a hazardous industrial dust."

What it shows

To help Owens-Illinois plan a safety program, the report also drew on Saranac's unpublished asbestos experiments, which it said had been reported "to certain other supporting companies, but not as yet published" (the industry-funded study begun by Leroy Gardner). Vorwald asked that this part be kept confidential. He closed that it was "better to discover it now in animals rather than later in industrial workers," so the company could protect its employees and "its own interests." A month later Owens-Illinois asked the Industrial Hygiene Foundation to study Kaylo dust in its own and its customers' plants (W. G. Hazard's letter of December 14, 1948).

In Johns-Manville's chronology

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

On 11/16/48, Vorwald (Saranac) concluded Kaylo, an Owens-Illinois product (which contains silica and asbestos) causes asbestosis. Kaylo is composed of hydrous calcium silicate like J-M's Thermobestos. 10/22/1948 is Saranac Interim Report on Kaylo Dust

Editor's note: J-M's description dates the Saranac interim report October 22, 1948; the report is dated October 30, 1948. The comparison with J-M's Thermobestos is not in the document, which does not mention J-M.