Panel discussion: Role of high risk groups in standard derivation.

The recognition of high risk groups in the setting of occupational standards in the United States really appears to date from the establishment of OSHA of 1970 and the concomitant mandate for the development of criteria for Federal occupational exposure standards. Although the ACGIH recommended threshold limit values (TLV's) had been available as guidelines in increasing numbers since shortly after World War II, and these TLV's received legal endorsement by several individual states, the declared intent of the TLV's has always been to protect ""nearly all workers" from adverse health effects. Explicit recognition is given to the Preface to the ACGIH TLV booklet each year, to the fact that "'a small percentage of workers may experience discomfort from some substances at concentrations at or below the threshold limit; a smaller percentage may be affected more seriously by aggravation of a pre-existing condition or by development of an occupational illness." The preface goes on to point out that hypersusceptibility to certain industrial chemicals (respiratory irritants, hemolytic chemicals, organic isocyanates and carbon disulfide are cited as examples) can be detected by readily available simple tests, and that such tests '.... may be used to screen out by appropriate job placement the hyperreactive worker.. In contrast, the philosophy behind the OSHA Standards is to protect "all workers" from adverse health effects over a working lifetime. Recognition of the existence of hypersusceptible or high risk groups with respect to certain chemical exposures (and possibly physical agents also) must therefore impact upon the development of standards which are intended to protect all workers. Refuge in the practice of screening out of hypersusceptibles from