1,1-difluoroethane

Endpoint summary

Description of key information

Short-term toxicity to fish:Key study: The estimated 96 -h LC50 for fish is 326,948 mg/l (ECOSAR v1.1, EPA, USA).

Supporting study: An acute toxicity test with the analogue substance 1,1,1,2 -tetrafluoroethane on Rainbow trout (Oncorhynchus mykiss) was performed in accordance with the EU Method C.1 (Acute Toxicity for Fish). Fish were exposed for 96 hours to the test substance. Analytical monitoring was performed during test performance. No mortality was found after 96 h of exposure at mean measured concentrations of 180 and 300 mg/l, but symptoms of toxicity were observed at these concentrations (dark discoloration, quiescence, and sounding behaviour). No symptoms of toxicity occurred at a mean measured concentration of 87 mg/l. The 96h-LC50 (based on mortality) was determined to be 450 mg/l. Based on these results, the read-across approach was applied and the 96h-LC50 of 1,1 -difluoroethane in Rainbow trout was determined to be 291.31 mg/l.

Long-term toxicity to fish:Data waiving: In accordance with column 2 of REACH Annex IX, the study does not need to be conducted since the chemical safety assessment indicates that there is no need to investigate further the effects on aquatic organisms.

Short-term toxicity to aquatic invertebrates:Key study: The estimated 48-h EC50 for aquatic invertebrates is 171.337 mg/l

(ECOSAR v1.1, EPA, USA).

Supporting study: An acute toxicity test with the analogue substance 1,1,1,2 -tetrafluoroethane onDaphnia magnawas performed in accordance with the EU Method C.2 (Acute Toxicity for Daphnia).The test duration was 48 hours.The acute test withDaphnia magnashowed a steep concentration-immobility curve. At mean measured concentrations of 870 and 1,100 mg/l the immobility after 48 h was 0 and 100%, respectively. The 48h-EC50 was determined to be 980 mg/l based on mobility. On the basis of these results, the read-across approach was applied and the 48h-EC50 based on mobility of 1,1 -difluoroethane was determined to be 634.41 mg/l.

Long-term toxicity to aquatic invertebrates:Data waiving: In accordance with column 2 of REACH Annex IX, the study does not need to be conducted since the chemical safety assessment indicates that there is no need to investigate further the effects on aquatic organisms.

Toxicity to aquatic algae and cyanobacteria:Key study: The estimated 96 -h EC50 for algae and cyanobacteria is 91.613 mg/l

(ECOSAR v1.1, EPA, USA).

Toxicity to microorganisms:Data waiving: In accordance with Column 2 adaptation statement of REACH Annex VIII the study does not need to be conducted if there as no emission to a sewage treatment plant.

Supporting study: A bacterial growth inhibition test was carried out with the analogue substance 1,1,1,2 -tetrafluoroethane onPseudomonas putida.Based on the read-across approach from the analogue 1,1,1,2-tetrafluoroethane, the EC50 of 1,1-difluoroethane was determined to be > 472.57 mg/l based on growth inhibition.