Prepn: F. Swarts, Bull. Sci. Acad. R. Belg. 8, 343 (1922); by oxidation of fluorine olefins: A. L. Henne, US 2371757 (1945 to du Pont); A. L. Henne et al., J. Am. Chem. Soc. 67, 918 (1945). Improved prepn: A. L. Henne, P. Trott, ibid. 69, 1820 (1947). Photochemical prepn: R. N. Hazeldine, F. Nyman, J. Chem. Soc. 1959, 387; eidem, ibid. 420. Toxicity and metabolism: M. M. Airaksinen, T. Tammisto, Ann. Med. Exp. Biol. Fenn. 46, 242 (1968). Review: J. B. Milne in Chem. Non-Aqueous Solvents vol. 5B, J. J. Lagowski, Ed. (Academic Press, New York, 1978) pp 1-52.