First Report of a Chinese PFOS Alternative Overlooked for 30 Years: Its Toxicity, Persistence, and Presence in the Environment

Abstract

This is the first report on the environmental occurrence of a chlorinated polyfluorinated ether sulfonate (locally called F-53B, C8ClF16O4SK). It has been widely applied as a mist suppressant by the chrome plating industry in China for decades but has evaded the attention of environmental research and regulation. In this study, F-53B was found in high concentrations (43-78 and 65-112 μg/L for the effluent and influent, respectively) in wastewater from the chrome plating industry in the city of Wenzhou, China. F-53B was not successfully removed by the wastewater treatments in place. Consequently, it was detected in surface water that receives the treated wastewater at similar levels to PFOS (ca. 10-50 ng/L) and the concentration decreased with the increasing distance from the wastewater discharge point along the river. Initial data presented here suggest that F-53B is moderately toxic (Zebrafish LC50-96 h 15.5 mg/L) and is as resistant to degradation as PFOS. While current usage is limited to the chrome plating industry, the increasing demand for PFOS alternatives in other sectors may result in expanded usage. Collectively, the results of this work call for future assessments on the effects of this overlooked contaminant and its presence and fate in the environment.

Tissue Distribution and Whole Body Burden of the Chlorinated Polyfluoroalkyl Ether Sulfonic Acid F-53B in Crucian Carp (Carassius carassius): Evidence for a Highly Bioaccumulative Contaminant of Emerging Concern

“…The substantially elevated concentrations of PFOS in Tangxun Lake have previously been attributed to the direct release from POSF production sources, 23,24 whereas the contamination profile of PFOS along Xiaoqing River was likely influenced by multiple diffuse sources. 32 Although concomitantly high concentrations of F-53B and PFOS have been observed in wastewater from metal plating facilities in China, 14 the differences in F-53B to PFOS ratios between Xiaoqing River and Tangxun Lake indicate that differences in their production sources may also lead to variability in their emission patterns and geographical distribution. A comparison with surface water concentrations of F-53B downstream of municipal wastewater facilities (10−50 ng/L) 14 further suggests that the concentrations in both Xiaoqing River and Tangxun Lake reflect relatively low levels of contamination.…”

“…3 Among the large number of alternative PFASs described in the patent literature, there are also many chemical structures with ether linkage(s) between perfluorinated carbons and/or a terminal fluorine atom replaced by chlorine. 2,13,14 While perfluoroalkyl ether carboxylic acids (PFECAs) have recently been taken into production to replace PFOA as emulsifiers in polymerization processes, some perfluoroalkyl ether sulfonic acids (PFESAs) have a significantly longer production history. 2,14 One important example of such an overlooked PFAS is the chlorinated polyfluoroalkyl ether sulfonic acid, F-53B (molecular formula ClCF 2 C 5 F 10 OCF 2 CF 2 SO 3 − ), which has been applied as a mist suppressant in hard chrome plating for more than 30 years in China.…”

“…2,13,14 While perfluoroalkyl ether carboxylic acids (PFECAs) have recently been taken into production to replace PFOA as emulsifiers in polymerization processes, some perfluoroalkyl ether sulfonic acids (PFESAs) have a significantly longer production history. 2,14 One important example of such an overlooked PFAS is the chlorinated polyfluoroalkyl ether sulfonic acid, F-53B (molecular formula ClCF 2 C 5 F 10 OCF 2 CF 2 SO 3 − ), which has been applied as a mist suppressant in hard chrome plating for more than 30 years in China. 2,14 In two recent publications, F-53B was ubiquitously detected in water and sludge samples from different parts of China.…”

“…2,14 One important example of such an overlooked PFAS is the chlorinated polyfluoroalkyl ether sulfonic acid, F-53B (molecular formula ClCF 2 C 5 F 10 OCF 2 CF 2 SO 3 − ), which has been applied as a mist suppressant in hard chrome plating for more than 30 years in China. 2,14 In two recent publications, F-53B was ubiquitously detected in water and sludge samples from different parts of China. 14,15 Given the structural similarities with PFOS, it has also been hypothesized that F-53B may be bioaccumulative and toxic.…”

“…2,14 In two recent publications, F-53B was ubiquitously detected in water and sludge samples from different parts of China. 14,15 Given the structural similarities with PFOS, it has also been hypothesized that F-53B may be bioaccumulative and toxic. 13,14 However, there is currently no data on the uptake and accumulation of this compound in biota.…”