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

TLDR

F‑53B, a chlorinated polyfluorinated ether sulfonate used as a mist suppressant in China’s chrome‑plating industry, has been largely overlooked in environmental studies despite its widespread use and potential for expanded application as a PFOS alternative. The authors call for future assessments of this overlooked contaminant’s environmental presence and fate. The study found F‑53B in high concentrations in chrome‑plating wastewater (43–78 and 65–112 µg/L), largely unremoved by existing treatment, with surface‑water levels comparable to PFOS (10–50 ng/L) that decline downstream, and demonstrated moderate toxicity (Zebrafish LC50‑96 h = 15.5 mg/L) and degradation resistance similar to PFOS.

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.