Dr. David T. DuBow and Dr. Kenneth W. Smith on Warning Fibrocel Installers About Perlite (1954)

Two short letters. On August 3, 1954, Dr. David T. DuBow of the Manville plant's medical department told Dr. Kenneth W. Smith that once J-M's expanded perlite product went into production it would be applied "by either our own or other applicators," and that it had been suggested the general sales force "be alerted with respect to the potential health hazards in the use of expanded Perlite." Smith replied on August 16 that his July 28 precautions were for J-M's operating personnel, since the information on toxicity concerned expanded perlite and not "our J-M product," Fibrocel. He did not recommend examinations or other precautions for installers, but if the finished product's dust proved toxic, "then we shall consider" periodic examinations for them "as well as caution labels on the packages."

What it shows

The exchange followed Smith's July 28 memo on the confidential warning about perlite. Smith said Hugh Jackson had made several inquiries and that further study of the finished product was likely to be recommended.

In Johns-Manville's chronology

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

Dr. DuBow (Manville) letter to Dr. K.W. Smith, 8/3/54, re expanded perlite. Dr. DuBow states that J-M Research informed him that once J-Ms expanded perlite (Fibrocel) product "is put into production, the finished material will generally be applied to various installations by either our own or other applicators." Dr. DuBow tells Dr. Smith that it has been suggested that "the general sales force be alerted with respect to the potential health hazards in the use of expanded perlite." Dr. Smith responds (8/16/54) that at the present time there is no information that J-M's finished perlite product is toxic to installation personnel. Hugh Jackson has made inquiries on this subject, and if the dust is found to be toxic, "then we shall consider the recommendations of periodic examinations for the installation personnel as well as caution labels on the packages."

Related documents

• Dr. Kenneth W. Smith to N. J. O'Brien on Health Hazards of Expanded Perlite (1954)