Arthur L. Fisk Jr. to the Chesapeake and Ohio Railway on Skin Irritation from Stonefelt Rock Wool (1952)

A two-page letter of April 1, 1952, from Arthur L. Fisk Jr. of Johns-Manville's Legal Department to E. M. Hudgins, general claim agent of the Chesapeake and Ohio Railway Company in Richmond, Virginia, about complaints of rashes from J-M's Type A Stonefelt insulation, which Fisk describes as made mainly of rock wool. Fisk writes that the irritation is mechanical, not chemical, that workers usually develop "an immunity" within a week or two, and that Harvard School of Public Health experiments for J-M had found its rock wool contained "nothing of a toxic or poisonous character." He suggests goggles, long sleeves, collars buttoned, trouser legs tied and a shower after work.

What it shows

The letter is one of many J-M answers in these years to questions about skin irritation from its mineral wool products, going back to the 1940s inquiries about Stonefelt from aircraft makers (for example Vandiver Brown's 1944 letter to Continental Can). It addresses only the skin and says nothing about breathing the fibers.

In Johns-Manville's chronology

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

Arthur L. Fisk, Jr. responds to inquiry of Chesapeake and Ohio Railway Co. in letter dated 4/1/52. Advises that rock wool contains nothing of a toxic nature, and workers should wear long sleeves and tie their trousers to reduce any skin irritation.