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TFAH reacts violently with water and is instantaneously degraded in TFA. However, in aqueous solution, the pH of the substance is naturally low and for testing under realistic environmentally conditions either the sodium salt (NaTFA) or pH adjustment are required.

To assess the biodegradation of NaTFA in water, two key studies are available.

The first study is a ready biodegradability test, performed by Van Ginkel in 1992, which allows to measure the biodegradability in an aerobic aqueous medium. The ready biodegradability was determined in the closed bottle test performed according to slightly modified OECD 301D, EEC 1984 Part C., and ISO Test Guidelines. The percentages biodegradation of NaTFA in the closed bottle test were 0% for 0, 7, 21, 28 and 77 days and 8% for 14 and 42 days. However, the results of the prolonged test are invalid because the differences of extremes of replicate values of the removal of the test chemical at 77 days are 95% (> 20%). Moreover, the result of 8% degradation at day 42 is probably an artifact due to the 40 % coefficient of variation between duplicate values of the control. In conclusion, NaTFA is not biodegraded in the closed bottle test (28 days) and should therefore not be classified as readily biodegradable.

The second study is an inherent biodegradability test, performed also by Van Ginkel in 1992, performed in compliance with the OECD Guideline 302 A and EEC Directive 87/302. NaTFA caused no reduction of the biodegradation of the NPOC present in primary settled waste water. Therefore, NaTFA is considered to be non-inhibitory to the activated sludge. Biodegradation of TFA has to lead to the formation of fluoride. Fluoride was not detected in the effluent of both SCAS units. This result also demonstrates that NaTFA is not biodegraded in the SCAS test.

Biodegradation testing in soil and sediment was not conducted for TFAH (according to column 2 of Annex IX of REACH) because direct and indirect exposure of soil or sediment is unlikely based on a low adsorption potential (log Kow = 0.25 (estimated by Kowwin v1.68); Koc = 10 L/Kg (estimated by Kocwin v2.00 with MCI method) or 4.026 L/Kg (estimated by Kocwin v2.00 with Kow method)).