Effects of Combustion Gases On Escape Performance of the Baboon and the Rat

In postcrash aircraft fires, only a few minutes are often available for egress. To assess the potential of selected combustion gases (CO, acrolein and HCl) to impair human escape, a signalled avoidance task was developed for use with the juvenile African Savannah baboon. After a 5-minute exposure, the animal was required to select and depress the correct lever to open an escape door and then to exit into the adjacent compartment of a shuttlebox. With CO, the EC ₅₀ for escape failure was 6850 ppm. Acrolein (12 to 2780 ppm) neither prevented escape nor affected escape times, despite irritant effects at all concentrations. Similar results were obtained with HCI (190 to 17,200 ppm) in that, despite severe irritant effects, all animals successfully performed the escape task. With a comparable shuttlebox and escape paradigm for rats, the EC ₅₀ of CO was 6780 ppm. Five-minute exposures to HCI (11,800 to 76,730 ppm) did not prevent escape but severe post-exposure respiratory effects and lethality occurred at 15,000 ppm and higher. In both species, escape time was not affected by HCI but a concentration-related increase in intertrial responses was evident. The data suggest that laboratory test methods for measurement of incapacitation of rodents may be useful in evaluating potential effects of atmospheres containing CO or irritant gases on human escape capability.