Donald C. Sanders

The Effect of Elevated Temperature on Carbon Monoxide-Induced Incapacitation

Laboratory rats were exposed to experimental concentrations of carbon monoxide in air at ambient temperature, to elevated temperature at mospheres from 40°C to 60°C, and to selected CO concentrations in 40-60°C whole-body environments. Incapacitating potency was evaluated by measuring time-to-incapacitation as a function of CO concentration and/or temperature. Incapacitation occurred earlier when CO inhalation was combined with elevated temperature than when the same parameters were applied individ ually ; a fractionally additive effect was noted. An empirical equation was derived for predicting time-to-incapacitation from CO concentration and tem perature data.

Incapacitation in the Laboratory Rat Induced by Inhalation of Carbon Monoxide-Acrolein Mixtures

Laboratory rats were exposed to experimental atmospheres of (a) carbon monoxide (CO), (b) acrolein, and (c) to mixtures of carbon monoxide and acrolein. The toxic potency of each environment was evaluated by measure ment of time-to-incapacitation (t,) as a function of toxic gas concentrations. Regression equations were derived relating observed t,s to concentrations of in dividual gases. Comparison of individual gas exposure data with results obtained from com bined gas exposures indicated no evidence of synergistic action. Evidence did exist for an inhibitory effect of undefined mechanism when acrolein (in the mix ture) was at a concentration of lesser potency than the CO. An empirical equation was derived that allowed calculation of a predicted t, for exposure to CO-acrolein mixtures at concentrations within the experimen tal exposure ranges.