C. J. O'Neill to All Salesmen on Answering Customers About Diatomaceous Earth Hazards (1952)

A Celite Division bulletin of October 1, 1952, from C. J. O'Neill to all Johns-Manville salesmen (Supplement to Bulletin 384), giving information on diatomaceous earth hazards to use in answering customers' questions. It instructs: "Under no circumstances should anyone be told that these materials are innocuous or that no claims have ever been made against us for alleged disability resulting from exposure to diatomaceous earth dust." It lists facts salesmen could pass on: calcined Celite contains crystalline silica; J-M had supported research by the Saranac Laboratory and Metropolitan Life Insurance Company; the U.S. Public Health Service was surveying the industry; and the program was under J-M's medical director, Dr. K. W. Smith.

What it shows

The bulletin ends with the same advice J-M gave Union Oil in July: "we know enough to warrant our advising customers, a) to minimize so far as possible the dust created by the use of the material and, b) if the nature of the use will not permit the reduction of the dust concentration to safe levels, to require the use of protective devices." An attached form letter answers customers who asked about the new caution labels, which followed Jackson's May 1952 memo. It says "it is rather generally accepted that the inhalation of crystalline silica over extended periods of time is harmful."

In Johns-Manville's chronology

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

C.J. O'Neill memorandum to all salesmen, 10/1/52, regarding information on diatomaceous earth hazards which J-M salesmen may pass on to customers. This document is to be used a basis for answering questions raised by customers. O'Neill states that at the present time J-M knows enough to warrant it advising customers to minimize as much as possible the dust created by the use of the material, and if dust cannot be reduced to safe levels, then a respirator should be used.