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Ecotoxicological information

Short-term toxicity to fish

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Description of key information

The 96-h LC50 is > 100 mg/L in zebra fish (Brachydanio rerio) for the structural analogues HFC 245fa and HFC 365mfc.

Key value for chemical safety assessment

LC50 for freshwater fish:
100 mg/L

Additional information

An acute toxicity study on HFC 227ea has been performed by Hoechst at a maximal concentration of 30 mg/l. The complete study report has not been retrieved and the study has been disregarded from the assessment.

The assessment of the possible aquatic toxicity of HFC 227ea has been carried out by considering available data on structurally analogue substances.

Experimental data for acute toxicity on fish are available for HFC 245fa (1,1,1,3,3 -pentafluoropropane) and HFC 365mfc (1,1,1,2,2 -pentafluorobutane).

In both cases, the studies were conducted in closed system to avoid substance volatilisation.

Both HFC 365mfc and HFC 245fa showed a low toxicity to fish and no LC50 was identified, as low mortality was observed up to the highest tested concentration for the other substances. Overall, a fish 96h LC50= 100 mg/l (i.e. the lowest experimental value determined for structural analogues) can be considered as a conservative estimation of the acute toxicity to fish for HFC 227ea.

HFC 245fa: The acute toxicity test was conducted in Oncorhynchus mykiss (rainbow trout). Fishes were exposed to 1, 10 and 100 mg/l HFC 245fa (nominal concentrations) in a close system (semi-static conditions) for 96 hours. Measured concentrations increased between renewals suggesting HFC-245fa has a slow rate of dissolution in the dilution medium under the conditions of the test. A condition of maximum attainable exposure was considered to have been achieved. No mortality was observed during the study. An LC50 > 100 mg/l based on nominal concentration was derived from the study (mean measured concentration = 81.8 mg/l).

HFC 365mfc: The acute toxicity of pentafluorobutane in zebra fish (Brachydanio rerio) was studied under semi-static conditions. The study was conducted at nominal concentrations of 0, 100, 150 and 200 mg/l pentafluorobutane. The substance was solubilised in ISO-water and the test was performed in closed system due to the high volatility of pentafluorobutane. 7 fishes/exposure group (3 vessels per group containing 2, 2 and 3 fishes, respectively) were exposed for 96 hours. Test solutions were renewed each day to avoid decrease of dissolved oxygen below the acceptable limits. Concentration of the test substance in the vessels was determined at the start of the study, before and after the test solution daily renewal and on the last day of the study. The difference among nominal and measured concentration was always below 20%. No mortality was observed during the test in the control and exposure group (LC50>200 mg/l nominal concentration). Sublethal effects (lower activity or fishes lying at the bottom of the flaskes) were observed at 200 mg/l (NOEC = 150 mg/l).