H. M. Jackson to William J. Reeves of R. J. Reynolds Tobacco Company on Marinite (1960)

A one-page letter of July 8, 1960, from H. M. Jackson, manager of J-M's Industrial Health Program, to William J. Reeves of the engineering department of the R. J. Reynolds Tobacco Company in Winston-Salem, North Carolina, answering his question about Marinite board. Jackson writes that there is no silicosis hazard in the dust from cutting and machining Marinite 36, but that the Marinite products contain 25% to 50% asbestos fiber and "it is a recognized fact that continued inhalation of asbestos fiber in sufficient quantities over a long period of time may cause some pulmonary damage." He encloses the American Industrial Hygiene Association's Hygienic Guide for asbestos, cites the 5 million particles per cubic foot limit, and recommends good housekeeping, ventilation at the source and, where dust cannot be controlled, approved respirators.

What it shows

This is the form answer J-M gave customers who asked about Marinite in 1959 and 1960, close in wording to Dr. Kenneth Smith's reply to Michigan's health department (Smith to Van Farowe, 1959) and to Jackson's letter to Los Angeles three days later (Jackson to Terry, July 1960). A customer who asked got a plain statement that the board's asbestos could damage the lungs. The boards themselves still carried no caution label, a step J-M had considered and rejected (the 1958 Marinite label memos).

In Johns-Manville's chronology

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

Letter from Jackson dated 7/8/60, responding to R.J. Reynolds Tobacco Co. inquiry re Marinite products. Jackson advises that there is no silicosis hazard from the dust created when cutting and machining Marinite-36. However, he also advises that the Marinite products contain 25% to 50% asbestos fiber and that it is a recognized fact that continued inhalation of asbestos fiber in sufficient quantities over a long period of time may cause some pulmonary damage. Jackson recites the ACGIH 5 mppcf standard, and encloses the Hygienic Guide for Asbestos published by the American Industrial Hygiene Association. Jackson also states that adequate ventilation at the dust source will remove any health hazard that might exist, and that, if engineering control of the dust is not possible, respirators approved for pneumoconiosis producing dusts should be used.

Related documents

• Johns-Manville Correspondence on Describing Marinite to the American Medical Association (1948)
• Johns-Manville Memos on a Caution Label for Marinite (1958)
• Dr. Kenneth W. Smith to D. E. Van Farowe of the Michigan Department of Health on Marinite (1959)
• J-M Industrial Insulations to the National Sanitation Foundation Testing Laboratory on Marinite 36 (1957)