H. M. Jackson to Brush Beryllium Company on Cerafelt (1958)

A one-page letter of March 1958 from H. M. Jackson, manager of Johns-Manville's industrial health program, to the Brush Beryllium Company of Cleveland, which had asked whether J-M's Cerafelt was toxic. Jackson replied that the mineral fibers in Cerafelt caused no toxic reaction but could cause a skin irritation and discomfort in some people, especially the fair-skinned. He said the irritation usually passed, that barrier creams on the hands, wrists and neck would help, and that in rare cases a worker had to be removed from contact with the material. The letter does not discuss breathing the dust.

In Johns-Manville's chronology

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

Letter from H.M. Jackson dated 3/13/58 to Brush Beryllium Co. Advised that there is no toxic reaction involved in exposure to Cerafelt but a chemical irritation could cause discomfort to certain individuals, i.e. skin problems.