Effects of irritant gases on avoidance/escape performance and respiratory response of the baboon

The major toxicants in smoke are generally categorized as asphyxiants (hypoxia-producing agents) and irritants. Although the rodent appears to be an adequate model for evaluating the toxic effects of asphyxiant gases in man, the suitability of the rodent for evaluating the effects of irritant gases has not been established. In a study of the effects of irritant gases on escape performance of the baboon, exceedingly high concentrations of neither acrolein nor hydrogen chloride (HCl) prevented performance of the behavioral task; however, severe irritant effects were evident, even at lower concentrations. In a subsequent study of the respiratory response of the baboon to HCl, 15-min exposures to 5000 and 10,000 ppm (nominal concentrations) produced severe hypoxemia with a concentration-related increase in respiratory rate and minute volume. The difference between the rodent and the nonhuman primate in response to irritant gases suggests that the rodent may be an inadequate model for evaluating the toxicity of irritant gases to man and, therefore, the use of results of laboratory combust combustion tests to predict the toxicity of smoke in humans may lead to erroneous conclusions.