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.

Studies of rodent lethality due to exposure to HCl, as well as to mixtures of HCl and CO, have shown different apparent toxicological effects at low and at high concentrations of HCl. At low concentrations of HCl, sensory irritation causes a decrease in respiratory minute volume, with somewhat slower loading of CO and a delay in incapacitation. This effect is observable only at low con centrations of CO. At much higher HCl concentrations, pulmonary irritant ef fects are observed leading to postexposure lethality. An empirical analysis of the data for mixtures of HCl and CO suggests that exposure doses leading to lethality may be additive. The lethal toxic potency (LC50) of PVC smoke may be largely, but not entirely, accounted for by the HCl produced. However, PVC smoke exhibits a greater in cidence of early postexposure deaths. The early deaths, which may be partially attributable to a combined effect of CO and HCl, may also be linked to the pattern of respiratory penetration by the smoke. There is evidence that com ponents other than HCl are present which cause PVC smoke to be more irri tating than HCl alone.

performed well; but shorter columns, 4-foot and less, gave rise to poorer yields. As the column is shortened, water solutions are adversely affected to a greater degree than alcohol solutions.Column Temperature. Low initial temperatures and programmed temperature analysis produced the best results for polyols. The fatty acids and dicarboxylic acids were not as sensitive to column temperature changes. Silylation Reagent. SILYL • 8 is composed of three powerful TMS agents which are claimed to have a synergistic effect on silylatable materials. It was developed as a column conditioner for improving column efficiency, reducing tailing, and removing silylatable residues from columns. Silylanizing agents that release HC1 into the system are absent. Some

Fully furnished and finished 3.7 by 5.5-m (12 by 18-ft) rooms, designed to simulate a typical hotel/motel arrangement, were ignited in identical scenarios and allowed to proceed past flashover. The test facility consisted of the burn room attached perpendicular to the end of a 13.7-m (45-ft) corridor with another room off the corridor 4.9 m (16 ft) from the test room. The second room contained animals for an assessment of both preflashover and flashover toxic effects. The rooms and corridor were fully instrumented with thermocouples, heat flux radiometers, smoke meters, gas sampling trains, and, in the burn room only, smoke detectors and sprinkler heads. In the few minutes prior to visual flashover, the toxic hazard of this fire scenario increased dramatically. At the 1.7-m (5 1/2-ft) level in the burn room, temperature rose to 650°C (1200°F), carbon monoxide (CO) concentration reached 70 000 ppm, oxygen concentration dropped to zero, and the hydrogen cyanide level exceeded 1000 ppm. In the remote room, the animals died from carbon monoxide poisoning around 12 min after the dramatic change in conditions (approximately 10 min after visual flashover occurred). Other factors besides CO contributed to the incapacitation of the animals.

The acute inhalation toxicity of smoke produced by five halogenated polymers used as electrical wire coatings was investigated in this study. The polymers in cluded two chlorofluoropolymers (Halar 500® and Halar 555®) and three fluoro polymers (Teflon 100® , Tefzel 200® and Kynar® ). The toxicity of each material was evaluated under flaming and nonflaming combustion using the NBS developmental protocol supplemented with measurement of incapacitation and analyses of the combustion atmospheres for HF, HCl and COF2.