Assessment of toxic hazards of smoke: Toxicological potency and intoxication rate thresholds

Abstract

AbstractSmoke toxicity test methods which determine only lethal toxicological potency under ‘worst case’ conditions do not satisfactorily address the critical issue of relative hazard, including time‐to‐escape and tenability limits resulting from the fire performance of materials under comparable conditions. Since threats to escape from a fire are largely time‐dependent, toxic insults produced by burning materials should also be considered as rate processes. Assessment of time thresholds exhibited by burning materials under test conditions to effect performance impairment (incapacitation) of an animal model would appear to be more relevant than lethal toxicological potencies in estimating probability of successful escape from fires. A model is advanced in which intoxication rate thresholds for materials are obtained using a rodent exposure test method. Concentration‐time curves, obtained from experimentally derived concentration‐time‐response surfaces, are the basis for estimating rate thresholds which are distinctively different for each material and which vary as a function of test conditions. it is this performance impairment response surface which is potentially a key to the modeling of toxic hazards of smoke in perspective with other hazards presented by fire.