COMPUTER SOFTWARE ARE FOR RISK ASSESSMENT

LHASA UK Ltd. is well established in the field of expert computer syst ems for chemists and toxicologists. A rule-based expert system approac h is currently being used successfully in industry for the prediction of toxicological hazard. Each rule contained in the rule-base describe s the relationship between a structural feature or ''toxicophore'' and its associated toxic effect, These rules are derived by an evaluation of toxicological, mechanistic, and physico-chemical data. New compute r software for the risk assessment of chemical toxicity is now being d eveloped as a collaborative project which includes a qualitative asses sment of risk for each predicted hazard. This is achieved by an argume ntation-based approach using general toxicological and physico-chemica l concepts. The results of the assessment are presented to the user in a clear and standardized format. This novel approach improves the ass essment of risk under uncertainty and aims to make the nature and pote ntial impact of risks easier to understand.