Comment submitted by J. L. Adcock

The expected reactivity of the two principal components of Novec 774 with water, alcohols and amines to produce derivatives of in one case perfluorobutanoic acid into the environment, and on inhalation into the bloodstream of individuals via reaction with water at the lung blood-air interface poses significant potential risk to individuals using these materials or breathing the vapors in an incident. The metabolites and environmental residues need to be thoroughly examined prior to any widespread use of these agents. The initial reaction of either of these perfluoro ketones with water is to form a perfluorinated "gem-diol" of low volatility, moderate acidity and significant surface active behavior, and in a sensitive environment such as the lung blood-air interface, could cause significant long-term debilitating effects, thus impairing proper oxygenation of the blood or lung edema. Such a risk must be thoroughly investigated before such agents are allowed on the commercial market. This negative indication is based on the known chemistry of perfluoroketones cf., Gambaryan, N.P., et. al., Angew, Chemie Intern. Ed., 5(11), 947 (1966) ; Lovelace, A.M., et. al., Aliphatic Fluorine Compounds, ACS Monograph Series, 1958, p. 180.