Decades-Scale Degradation of Commercial, Side-Chain, Fluorotelomer-Based Polymers in Soils and Water

Abstract

Fluorotelomer-based polymers (FTPs) are the primary product of the fluorotelomer industry. Here we report on a 376-day study of the degradability of two commercial acrylate-linked FTPs in four saturated soils and in water. Using an exhaustive serial extraction, we report GC/MS and LC/MS/MS results for 50 species including fluorotelomer alcohols and acids, and perfluorocarboxylates. Modeling of seven sampling rounds, each consisting of ≥5 replicate microcosm treatments, for one commercial FTP in one soil yielded half-life estimates of 65–112 years and, when the other commercial FTP and soils were evaluated, the estimated half-lives ranged from 33 to 112 years. Experimental controls, consisting of commercial FTP in water, degraded roughly at the same rate as in soil. A follow-up experiment, with commercial FTP in pH 10 water, degraded roughly 10-fold faster than the circum-neutral control suggesting that commercial FTPs can undergo OH–-mediated hydrolysis. 8:2Fluorotelomer alcohol generated from FTP degradation in soil was more stable than without FTP present suggesting a clathrate guest–host association with the FTP. To our knowledge, these are the only degradability-test results for commercial FTPs that have been generated using exhaustive extraction procedures. They unambiguously show that commercial FTPs, the primary product of the fluorotelomer industry, are a source of fluorotelomer and perfluorinated compounds to the environment.

Occurrence, Distribution, and Risk Assessment of Perfluoroalkyl Acids (PFAAs) in Muscle and Liver of Cattle in Xinjiang, China

“…In addition, animal feeds may contain some perfluorinated chemicals [ 24 ]. Moreover, PFAAs can bioaccumulate and biomagnify in terrestrial and aquatic food chains, thus more contaminants will accumulate in animals of upper trophic levels [ 29 , 46 , 47 ]. The occurrence of PFAAs in water has been reported frequently, and tap water is even regarded as a major route of exposure to PFOA for adults in Korea [ 21 , 40 , 46 ].…”

“…Moreover, PFAAs can bioaccumulate and biomagnify in terrestrial and aquatic food chains, thus more contaminants will accumulate in animals of upper trophic levels [ 29 , 46 , 47 ]. The occurrence of PFAAs in water has been reported frequently, and tap water is even regarded as a major route of exposure to PFOA for adults in Korea [ 21 , 40 , 46 ]. Air sources of PFAAs are many, such as from long-range transport, degradation of volatile precursors, atmospheric deposition, and direct emissions from manufacturing and industry [ 6 , 32 , 46 ].…”

“…The occurrence of PFAAs in water has been reported frequently, and tap water is even regarded as a major route of exposure to PFOA for adults in Korea [ 21 , 40 , 46 ]. Air sources of PFAAs are many, such as from long-range transport, degradation of volatile precursors, atmospheric deposition, and direct emissions from manufacturing and industry [ 6 , 32 , 46 ]. PFAAs and their precursors in indoor air/dust do exist, although their concentrations are relatively low, and this surely contributes to the daily intake of these contaminants [ 22 , 48 ].…”

Properties, performance and associated hazards of state-of-the-art durable water repellent (DWR) chemistry for textile finishing

“…Furthermore a reduced half-life of 10-17 years was modelled for particles that were 300 times smaller assuming that the degradation is surface mediated. In a follow up study soil half-lives of commercial FTACPs, placing large efforts to minimise effects of residuals on the results, soil degradation half-lives were determined to be 33-112 years (Washington et al, 2015). A study by Rankin et al (2014) with a synthesised FTACP (free of residuals, i.e.…”

Aerobic biodegradation of toluene-2,4-di(8:2 fluorotelomer urethane) and hexamethylene-1,6-di(8:2 fluorotelomer urethane) monomers in soils

“…Also the dynamics observed in these studies further indicates the role of microbial diversity, or the need thereof, in the breakdown of these substances to PFOA. These urethane monomers as well as the FT stearate and citrate monomers (Dasu et al, 2012 and, which are present as residuals in commercial products, are much more easily biodegraded than their corresponding polymeric substance (Russell et al, 2008(Russell et al, , 2010Washington et al, 2009Washington et al, , 2015. Efforts to reduce residuals in commercial products have been underway the past few years (USEPA, 2009;2015b); however, given longevity of some products and existing disposal sites, monomer degradation will clearly serve as an indirect source of PFCAs into the environment for the next few decades.…”