The objective of the proposed investigation is to develop and validate a predictive quantitative structure/activity relationship (QSAR) model for the biological activity (toxicity) of halocarbon type materials. Another objective is to compile the available data for the halocarbon compounds presently known, and to identify the additional data needed to be generated and compound to be synthesized for validation of the developed QSAR model. The ultimate objective is the utilization of the model thus developed to provide predictive capability, both for biological and chemical activity, and to permit the design and synthesis of nonflammable, biologically inert materials tailored for specific air force or industrial applications.