Perfluorooctanesulfonic acid

Perfluorooctanesulfonic acid (conjugate base perfluorooctanesulfonate) (PFOS) is an anthropogenic fluorosurfactant and global pollutant. PFOS was the key ingredient in Scotchgard, a fabric protector made by 3M, and numerous stain repellents. It was added to Annex B of the Stockholm Convention on Persistent Organic Pollutants in May 2009. PFOS can be synthesized in industrial production or result from the degradation of precursors. PFOS levels that have been detected in wildlife are considered high enough to affect health parameters, and recently higher serum levels of PFOS were found to be associated with increased risk of chronic kidney disease in the general US population. 'This association was independent of confounders such as age, sex, race/ethnicity, body mass index, diabetes, hypertension, and serum cholesterol level.' Perfluorooctanesulfonic acid (conjugate base perfluorooctanesulfonate) (PFOS) is an anthropogenic fluorosurfactant and global pollutant. PFOS was the key ingredient in Scotchgard, a fabric protector made by 3M, and numerous stain repellents. It was added to Annex B of the Stockholm Convention on Persistent Organic Pollutants in May 2009. PFOS can be synthesized in industrial production or result from the degradation of precursors. PFOS levels that have been detected in wildlife are considered high enough to affect health parameters, and recently higher serum levels of PFOS were found to be associated with increased risk of chronic kidney disease in the general US population. 'This association was independent of confounders such as age, sex, race/ethnicity, body mass index, diabetes, hypertension, and serum cholesterol level.' In 1949, 3M began producing PFOS-based compounds by electrochemical fluorination resulting in the synthetic precursor perfluorooctanesulfonyl fluoride. In 1968, organofluorine content was detected in the blood serum of consumers, and in 1976 it was suggested to be PFOA or a related compound such as PFOS. In 1997, 3M detected PFOS in blood from global blood banks, although the company's internal documents indicate knowledge of this decades earlier, dating from the 1970s. In 1999, the U.S. Environmental Protection Agency began investigating perfluorinated compounds after receiving data on the global distribution and toxicity of PFOS, the key ingredient in Scotchgard. For these reasons, and USEPA pressure, the primary American producer of PFOS, 3M, announced, in May 2000, the phaseout of the production of PFOS, PFOA, and PFOS-related products. PFOS and PFOS-related chemicals are currently produced in China. Advances in analytical chemistry in recent years have allowed the routine detection of low- and sub-ppb levels of PFOS in food, wildlife, and humans. Two primary methods are used for the industrial scale production of PFOS: electrophilic (or electrochemical) fluorination (ECF) and telomerization. ECF is an electrolysis production method where a precursor of perfluorooctanesulfonyl fluoride is dispersed in a solution of hydrofluoric acid and electrified. This production method, whilst economic and mainly results in PFOS, also results in shorter chain perfluoroalkyl substances being formed. PFOS predominates in the resultant mixture, however, if the reaction is allowed to continue this begins to favor the production of shorter chain PFAS. A distinct isomer ratio has been observed in PFOS produced by ECF, in the order of 70% linear PFOS, 25% branched and 5% terminal; this is not a function of the production process but rather that the precursor also exhibits this isomer ratio. ECF was the means by which 3M produced PFOS up until May 2000 when the company announced a phaseout of production along with other PFOS related products.