Abstract
This article reviews research relevant to the American Conference of Governmental Industrial Hygienists' (ACGIH's) suggested wet bulb globe temperature (WBGT) adjustment to threshold limit values (TLV®s) for workers in vapor barrier encapsulative protective clothing. This adjustment was recommended to be 10°C according to the 1990 ACGIH guidelines but was not included in the 1991 guidelines. Six studies were reviewed comparing heart rate and rectal temperature increase over time. The studies were matched based on the ambient WBGT and the workload performed by the subjects. Results show that a TLV adjustment of 5°C is not large enough, and 14°C appears to be too much. The findings of this research review support the suggested WBGT TLV adjustment of 10°C when wearing encapsulating protective clothing.