Report No: DOT/FAA/AM-90/16

Title and Subtitle: Inhalation Toxicology: XI. The Effect of Elevated Temperature on Carbon Monoxide Toxicity

Report Date: December 1990

Authors: Sanders, D.C. and Endecott, B.R.

Abstract: Laboratory rats were exposed (a) to experimental concentrations of carbon monoxide in air at ambient temperature, (b) to elevated temperature atmospheres from 40° C to 60° C, and (c) to selected carbon monoxide (CO) concentrations at the elevated temperatures in (b). The incapacitating potency of each of the environments was evaluated by measurement of time-to-incapacitation (ti) as a function of CO concentration and/or temperature; incapacitation was defined operationally as loss of ability to walk inside a motor-driven, rotating cage enclosed in an exposure chamber. Comparison of data from the combined (CO + elevated temperature) exposures and exposures to CO and elevated temperatures alone indicated that incapacitation occurred earlier when CO inhalation was combined with a whole-body, elevated temperature environment than was observed for the same exposure parameters applied individually. No evidence for a synergistic effect was noted. An empirical equation was derived that allows the calculation of a predicted ti for combinations of CO and temperature within the ranges utilized in the experimental exposures.

Key Words: Combustion toxicology, Carbon monoxide, Heat, Thermal effects, Time-toincapacitation

No. of Pages: 18