Vandiver Brown to E. P. Burlew of Continental Can on Skin Irritation from Stonefelt (1944)

A two-page letter of January 28, 1944, from Vandiver Brown of Johns-Manville to E. P. Burlew, factory manager of the Continental Can Company in Stockton, California, answering a complaint about "difficulties encountered by your workmen in handling Stonefelt," a J-M insulation made of rock wool fibers. Brown wrote that J-M was "familiar with the type of complaint," that the skin irritation was physical rather than chemical, and that "an immunity speedily develops" within a week or two. He added that experiments by the Harvard School of Public Health "conclusively determined that our rock wool contained nothing of a toxic or poisonous character," and suggested goggles, long sleeves, snug collars, overalls and a shower at the end of the day.

What it shows

The letter deals only with skin irritation; it does not discuss breathing the fibers. Other customers had asked J-M whether Stonefelt was safe, among them the Edward G. Budd Manufacturing Company in 1939 and Douglas Aircraft in 1941.

In Johns-Manville's chronology

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

Letter from Vandiver Brown dated 1/28/44 responding to Continental Can Company, Inc. inquiry re irritation from exposure to Stonefelt. Brown stated that Harvard's School of Public Health concluded "our rock wool contained nothing of a toxic or poisonous character".

Related documents

• Vandiver Brown to George Trautvetter of the Edward G. Budd Manufacturing Company on Stonefelt Insulation (1939)
• C. E. Bryant and Vandiver Brown on Answering Douglas Aircraft About Stonefelt (1941)
• Elliot Fairback and Vandiver Brown on Answering North American Aviation About Stonefelt (1940)