Evaluation of PFO formation from the biodegradation of a fluorotelomer-based urethane polymer product in aerobic soils

This study is the first to evaluate the rate of formation of perfluorooctanoate (PFO) from the aerobic biodegradation of a fluorotelomer-based urethane polymer and to use this information to assess the global environmental significance of this source. A fluorotelomer-based urethane polymer product test substance was studied in four aerobic soils over two years to determine the rate at which the fluorotelomer side-chains covalently bonded to the polymer backbone were cleaved and subsequently transformed to form the anions of perfluorocarboxylic acids including PFO. Over the two year duration of the experimental study, a polymer biodegradation half-life of 102 years (range: 28-241) was calculated for the urethane polymer based on regression analysis of the rate of PFO formation in four test soils. When this half-life was applied to the estimated total historic production, use and disposal of fluorotelomer-based urethane polymer, the annual potential global generation of PFO was estimated to be less than one tonne per year.