Standard Interpretations - Table of Contents
• Standard Number: 1910.1001(c); 1926.1101(c)

July 23, 1999

William L. Dyson, Ph.D., CIH
Workplace Hygiene
P.O. Box 49176
Greensboro, NC 27419-9176

Dear Dr. Dyson:

This is in response to your June 16, 1999, letter to Mary Carol Lewis, Associate Assistant Secretary for the Occupational Safety and Health Administration (OSHA), regarding OSHA's permissible exposure limits (PEL) for asbestos. In your letter, you request that OSHA clarify its May 13, 1999, interpretation of the asbestos PEL and respond to several questions that you have posed.

This response is based on OSHA's published views of these issues, which are, in turn, based on the evidence in the record of the asbestos rulemaking. We cannot comment, however, on the Federal government's definitions of Environmental Differential Pay or Hazardous Duty Pay. Your questions and our responses are presented below in the order in which they appear in your letter.

Question 1. Why did OSHA not choose to set a PEL below which significant risk does not occur?

Response: In OSHA's latest revision to its asbestos standards, the Agency acted under a remand order from the District of Columbia Circuit that required it to eliminate significant risk to workers to the extent feasible. Building & Constr. Trades Dep't. v. Brock, 838 F.2d 1258 (D.C. Cir. 1988). In responding to the remand order, OSHA found that significant risk remained at a PEL of 0.1 fiber/cc and that lower levels could be feasibly achieved. It did not set a lower PEL, however, because lower levels of asbestos cannot be reliably m