Toxicity of trifluoroacetate to aquatic organisms

Abstract

Abstract-As a result of the atmospheric degradation of several hydrofluorocarbons and hydrochlorofluorocarbons, trifluoroacetate (TFA) will be formed. Through precipitation, TFA will enter aquatic ecosystems. To evaluate the impact on the aquatic environment, an aquatic toxicity testing program was carried out with sodium trifluoroacetate (NaTFA). During acute toxicity tests, no effects of NaTFA on water fleas (Daphnia magna) and zebra fish (Danio rerio) were found at a concentration of 1,200 mg/L. A 7-d study with duckweed (Lemna gibba G3) revealed a NOEC of 300 mg/L. On the basis of the results of five toxicity tests with Selenastrum capricornutum, we determined a NOEC of 0.12 mg/L. However, algal toxicity tests with NaTFA and Chlorella vulgaris, Scenedesmus subspicatus, Chlamydomonas reinhardtii, Dunaliella tertiolecta, Euglena gracilis, Phaeodactylum tricornutum, Navicula pelliculosa, Skeletonema costatum, Anabaena flos-aquae, and Microcystis aeruginosa resulted in EC50 values that were all higher than 100 mg/L. The toxicity of TFA to S. capricornutum could be due to metabolic defluorination to monofluoroacetate (MFA), which is known to inhibit the citric acid cycle. A toxicity test with MFA and S. capricornutum revealed it to be about three orders of magnitude more toxic than TFA. However, a bioactivation study revealed that defluorination of TFA was less than 4%. On the other hand, S. capricornutum exposed to a toxic concentration of NaTFA showed a recovery of growth when citric acid was added, suggesting that TFA (or a metabolite of TFA) interferes with the citric acid cycle. A recovery of the growth of S. capricornutum was also found when TFA was removed from the test solutions. Therefore, TFA should be considered algistatic and not algicidic for S. capricornutum. On the basis of the combined results of the laboratory tests and a previously reported semi-field study, we can consider a TFA concentration of 0.10 mg/L as safe for the aquatic ecosystem.

Rainwater trifluoroacetic acid (TFA) in Guangzhou, South China: Levels, wet deposition fluxes and source implication

“…Previous results displayed that TFA was of mildly phytotoxic (Berends et al, 1999;Boutonnet et al, 1999). Although the observed TFA levels in aqueous environment were all below the safety level of 0.10 mg L −1 (Berends et al, 1999), high levels have been reported as early as in 1990s. For instance, TFA concentrations were reported as high as 40,900 ng L −1 in Pyramid Lake of the United States (Zehavi and Seiber, 1996); and the levels beyond 1000 ng L −1 were also recorded in rainwater around the world (Frank et al, 1995;Wujcik et al, 1998;Von Sydow et al, 2000;Berg et al, 2000;Scott et al, 2006).…”

“…The persistence and water solubility of TFA make it potentially accumulate in some aquatic ecosystems where TFA may concentrate through water evaporation, especially in landlocked lakes (Tromp et al, 1995;Cahill et al, 2001;Wu and Chau, 2006), or in some hydrometeors, particularly in fog (Römpp et al, 2001). Previous results displayed that TFA was of mildly phytotoxic (Berends et al, 1999;Boutonnet et al, 1999). Although the observed TFA levels in aqueous environment were all below the safety level of 0.10 mg L −1 (Berends et al, 1999), high levels have been reported as early as in 1990s.…”

“…For instance, TFA concentrations were reported as high as 40,900 ng L −1 in Pyramid Lake of the United States (Zehavi and Seiber, 1996); and the levels beyond 1000 ng L −1 were also recorded in rainwater around the world (Frank et al, 1995;Wujcik et al, 1998;Von Sydow et al, 2000;Berg et al, 2000;Scott et al, 2006). Due to the continual input to the environment and the accumulation in terminal water bodies, TFA levels in aqueous environment would keep increasing in the coming decades and more attention should be paid on its potential adverse effects (Berends et al, 1999;Boutonnet et al, 1999;Wiegand et al, 2000). Thus, it is important to acquire information about the fate and sources of TFA in the environment.…”

Deposition and rainwater concentrations of trifluoroacetic acid in the United States from the use of HFO‐1234yf

“…It is not known whether the observed peak values arose from other sources of TFA, such as fluorinated polymers [Jordan and Frank, 1999] or fluorinated pesticides [Ellis and Mabury, 2000], or from a fast formation of TFA due to high HFC/HCFC and hydroxyl radical concentrations. Berends et al [1999] determined TFA toxicity levels for various aquatic organisms, including concentrations that had no observable effect on an organism. The most sensitive organism tested by Berends et al was the freshwater alga Raphidocelis subcapitata, with no observed effects at TFA concentrations of 100 μg L −1 .…”

Synthesis and Evaluation of New Nonflammable Cleaning Agents

“…Flammability is important because many industrial facilities are not equipped with safely handle flammable hydrocarbons. In addition, hydrocarbon containing an aromatic hydrocarbon, such as benzene, toluene, and xylene are being regulated due to its high toxicity on human body and environmental pollution [4,5]. Therefore, development of new environmentally acceptable cleaning agent would be highly desirable.…”