AbstractA review of literature was undertaken to ascertain the current knowledge of the nature of the thermal decomposition products generated from ABS and the toxicity of these evolved products in toto. The literature review encompasses English language publications available through June 1984. This literature surveyed showed that the principal ABS thermooxidative degradation products of toxicologic importance are carbon monoxide and hydrogen cyanide. The experimental generation of these and other volatile products is principally dependent upon the combustion conditions and the formulation of the plastic. The toxicity of ABS thermal degradation products has been evaluated by fire methods. The LC50 (30 min exposure + 14 day post‐exposure period) values for flaming combustion ranged from 15.0 mgl−1 to 28.5 mgl−1. In the non‐flaming mode of combustion, the LC50 values ranged from 19.3 Mgl−1 to 64.0 mgl−1. Therefore, no apparent toxicological difference exists between the flaming mode and the non‐flaming mode. The toxicity of ABS degradation products was found to be comparable with the toxicity of the thermal decomposition products of other common polymeric materials.