Leroy U. Gardner to U. E. Bowes on Animal Tests of Hydrous Calcium Silicate (1944)

A one-page letter of May 31, 1944, from Dr. Leroy U. Gardner, director of the Saranac Laboratory, to U. E. Bowes of the Owens-Illinois Glass Company, reporting on injection tests of the product "Hydrous Calcium Silicate." Ground fine, it "proved to be quite toxic" in guinea pigs, and the tissue reaction "had none of the appearances of a silicosis but did resemble asbestosis." Gardner judged the dust "potentially dangerous if in processing the material the particle size is reduced considerably below that in the samples submitted."

What it shows

Gardner left it to Owens-Illinois to judge whether the samples matched the dust in the air of its plant, since the company was "in a better position than we to know." The letter is the first animal result on Kaylo, and it pointed to an asbestosis-like disease. Later in 1944 the company asked for a full study (Bowes, November 21, 1944).

In Johns-Manville's index

Johns-Manville's legal department indexed the Motley 1,000 in 1984. Its index describes this document as follows:

Dr. L.U. Gardner letter to U.E. Bowes, 5/31/44, reporting on the results of his animal experiments on the physiological effects of Bowes' product, hydrous calcium silicate. Dr. Gardner states that if the dust of this material were ground sufficiently fine to be inhaled in appreciable quantities it would probably produce a pulmonary disease simulating asbestosis. However, the "appended" data indicates that in the samples submitted, the particle size of the components is such that inhalation of most of the components would be difficult. Dr. Gardner indicates that Bowes is in a better position than he is to know whether the samples are representative of the airborne dust in Bowes' plant. In Dr. Gardner's opinion, the dust of this hydrous calcium silicate is potentially dangerous if in processing the material the particle size is reduced considerably below that in the sample submitted.

About this copy

This is document 237 of the Motley 1,000, from the set the Manville Personal Injury Settlement Trust's records facility certified as true copies, pages CRMC-Motley1000-Subj-001386 to CRMC-Motley1000-Subj-001386.