Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Toxicity to algae for the longer chain C3 and C4 saturated fluorocarbons, HFC 245 fa  and HFC 365mfc, has been experimentally shown to be > 100 mg/l and for the shorter chain C1, HFC 32, QSAR data indicate a toxicity to algae also >100mg/l. Therefore it is concluded that mid-chain saturated fluorocarbon toxicity (1,1,1,2-tetrafluorethane) (EC50) will be >100mg/l.

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L

Additional information

1,1,1,2-tetrafluoroethane (HFC 134a) is a member of a category of saturated hydrofluorocarbons (HFCs) in the C1 to C4 range. Such HFCs contain only carbon, hydrogen and fluorine and are characterized by their inherent stability due to the strong C-F bond and their inability to dissociate into a conjugate base and proton. Their low boiling points means that the lower carbon members are gases at ambient temperature and pressure or, at the higher end of the carbon range, volatile liquids. The properties of stability and low boiling points make HFCs ideal refrigerants.

The common environmental fate of this range of HFCs is to partition to atmosphere, where they are slowly degraded by the action of hydroxyl radical. Their inherent chemical stability leads them to be of low toxicity to mammals, which has been demonstrated in extensive testing using very high exposure concentrations. Direct and indirect exposure of the aquatic compartment is unlikely, and any water-borne HFC with rapidly partition to air due to their low solubility and high volatility. Some non-standard aquatic toxicity tests demonstrate that aqueous solutions in equilibrium with atmospheric pressures of HFCs in closed systems to be of low toxicity to aquatic life. This has been shown for HFC 134a for the fish and daphnia endpoints. There is no data for algae for HFC 134a, but in accordance with the REACH Technical Guidance on the information requirements and chemical safety assessment Chapter R6: QSARs and grouping of chemicals, May 2008, the HFCs in the carbon range C1 to C4 can be considered to be a chemical category and thus it is possible to read across for the missing algae endpoint for HFC 134a to other members of the group for which data exist, namely HFC 32 (Difluoromethane), HFC 245fa (1,1,1,3,3-pentafluoropropane) and HFC 365mfc (1,1,1,3,3-pentafluorobutane).

Experimental data shows the toxicity to Algae of the longer C3 and C4 saturated fluorocarbons, HFC 245fa and HFC 365 mfc, to be >100mg/l. Similarly, QSAR data for the shorter chain C1 fluorocarbon, HFC 32 predicts a toxicity to Algea of >100mg/l.. Reading across to these results it is considered that toxicity (EC50) to algae of the C2 saturated fluorocarbons, including 1,1,1,2 -tetrafluoroethane (HFC 134a) will also be >100mg/l.