The toxicity dose-response relationship is a critical data requirement for a quantitative risk analysis of a chemical processing facility. This paper will review: The use of toxicity dose-response relationships in a quantitative risk analysis The development of dose-response relationships for use in a quantitative risk analysis from toxicity data Examples of variation in published dose-response relationships for some common chemicals The impact of differences in dose-response relationships on the results of a quantitative risk analysis Finally, we propose the development of a standard protocol for development of toxicity dose-response relationships for use in quantitative risk analysis, with emphasis on the benefits to the chemical industry of a standardized methodology.