Mean Testing: I. Advantages and Disadvantages

Abstract

Abstract The idea that the American Conference of Governmental Industrial Hygienists (ACGIH) time-weighted average (TWA) threshold limit values (TLVs) and the Occupational Safety and Health Administration (OSHA) TWA permissible exposure limits (PELs) were and are intended to be used as upper control limits for each worker's long-term mean exposure (and not as upper control limits for single-shift TWA exposures) continues to be advanced in the industrial hygiene literature. The corollary concept that compliance with a TWA TLV or TWA PEL is best determined using mean testing is also advanced. The objective of this article is to examine two questions: (1) Do long-term occupational exposure limits (LTA OELs) exist? and (2) What issues should be considered when designing an exposure monitoring program for a true LTA OEL? These issues will be examined from the viewpoints of the employer, inspector, and employees. Assuming that a valid LTA OEL exists, there are numerous issues to be addressed. These include dete...