The major United States producers of ethyl acrylate, Celanese Corporation, Dow Badische Company, Rohm and Haas Company, and Union Carbide Corporation, are sponsoring safety evaluation studies on ethyl acrylate. The Toxicity Research Laboratory of the Dow Chemical Company, under contract to Rohm and Haas on behalf of the ethyl acrylate producers, is conducting in Fishcer 344 rats and B6C3F1 mice subchronic and chronic inhalation toxicity studies. In the subchronic groups, rats have been evaluated after three and six months and mice after six months, exposure to 0, 25, 75, or 225ppm of ethyl acrylate vapors six hours per day, five days per week. The continuing chronic/oncogenic groups of rats and mice are in the ninth month of exposure to 0, 25, or 75ppm ethyl acrylate vapors six hours per day, five days per week. The 225ppm chronic/oncogenic exposure was terminated after six months because this level was judged to be far in excess of a maximum tolerated dose and to provide chambers for initiation of a new exposure level. The animals exposed to 225ppm for six months are being retained for continuing observation.