Environmental risk assessment of hydrofluoropolyethers (HFPEs).

Hydrofluoropolyethers (HFPEs), a new family of linear oligomeric fluorinated fluids, are being used as potential replacements for halon, hydrochlorofluorocarbons (HCFCs) and perfluorocarbons (PFCs) that have been listed as ozone depleting substances and/or greenhouse gases. Because of their physicochemical properties, these substances may be industrially used as cleaning solvents in the electronic components, fire suppression agents in the fire protection, and heat transfer fluids in the heat exchangers. From the environmental, ecological, and healthy points of view, it is urgent to understand their environmental risks of these HFPEs. This article aimed at introducing these HFPEs in physiochemical properties and potential uses, and evaluating their environmental risks (i.e., global warming, photochemical potential, and environmental partition). Further, the updated data on their toxicological profiles and potential exposure hazards from their degradation products were also addressed in this paper. It is indicated that HFPEs still pose some significant hazards, especially global warming and photochemical potentials, to the atmosphere. Regarding the estimation of partition properties (i.e., vapor pressure, octanol-water partition coefficient and bioconcentration) of HFPEs, the predicted values of logKow for several HFPEs were found to be below zero, suggesting that they should possess very low potential for bioaccumulation in the environment.