Formation of C₇F₁₅COOH (PFOA) and Other Perfluorocarboxylic Acids during the Atmospheric Oxidation of 8:2 Fluorotelomer Alcohol

Abstract

Calculations using a three-dimensional global atmospheric chemistry model (IMPACT) indicate that n-C8F17CH2CH2OH (widely used in industrial and consumer products) degrades in the atmosphere to give perfluorooctanoic acid (PFOA) and other perfluorocarboxylic acids (PFCAs). PFOA is persistent, bioaccumulative, and potentially toxic. Molar yields of PFOA depend on location and season, are in the range of 1-10%, and are of the correct order of magnitude to explain the observed levels in Arctic fauna. Fluorotelomer alcohols such as n-C8F17CH2CH2OH appear to be a significant global source of persistent bioaccumulative perfluorocarboxylic acid pollution. This is the first modeling study of the atmospheric chemistry of a fluorotelomer alcohol.

Methodology for studying biotransformation of polyfluoroalkyl precursors in the environment

“…Wang et al [3] calculated the mass flux of PFCAs in the global transport processes and suggested that historical direct emissions from manufacture and consumer usages were the major contributors of PFCAs detected in the environment. However, the indirect contributions via the biodegradation and biotransformation of polyfluoroalkyl precursors and atmospheric oxidation have also been confirmed by model prediction [9], laboratory experiments [10,11] and environmental monitoring [12]. Laboratory systems utilizing microbialconsortium and animal models to study polyfluoroalkyl-precursor biotransformation provided insight to understand the extent of contributions of such precursors to PFCAs and PFSAs detected in the environment and biota.…”

Perfluoroalkyl and polyfluoroalkyl substances in the lower atmosphere and surface waters of the Chinese Bohai Sea, Yellow Sea, and Yangtze River estuary

“…Additionally, Wallington et al (2006) calculated a 8:2 FTOH concentration of around 4 × 10 5 molecule/m 3 at 50 m above the sea level in July, which corresponded to a concentration of about 308 pg/m 3 , in the air of Bohai and Yellow Sea by modeling. The concentrations were in the range of the monitoring data in this study.…”

Perfluorinated Compounds in the Asian Atmosphere

“…2 In addition to their presence in various perfluorinated products, PFOS and PFOA are also stable degradation products/metabolites of neutral PFCs. These precursor compounds are more volatile, 5 and therefore more likely to undergo LRAT, with sufficient atmospheric lifetimes to reach remote locations, 6 where they can break down. Possible precursor compounds for other chain-length perfluorocarboxylates (PFCAs) and PFOS are fluorotelomer alcohols (FTOHs) 2 and fluorooctane sulfonamides/ethanols (FOSAs/FOSEs), 7,8 respectively.…”