Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Although experimental data show 1,1,1,2 -tetrafluoroethane (HFC-134a) to be poorly degraded in the aquatic environment (Tobeta 1989), since it is a gas (boiling point -26°C) of low solubility, any that may be present in aqueous waste streams dicharged directly into rivers or lakes would be expected to have a half-life with respect to volatilisation of several days to a few weeks. A calculation with EpiWin software (US-EPA, 2009) suggest volatilisation half-lives of about 1 hour for rivers and 96 hours for lakes. Therefore HFC 134a is not expected to be persistent in the aquatic environment.

Similarly on account of its gasesous nature, exposure of sediments and soil to HFC 134a is unlikely. Moreover HFC 134a is neither expected to adsorb significantly to soil and sediment, nor to bioaccumulate in aquatic species due to its low potential for adsorption and bioaccumulation based on a measured log Kow of 1.06 (PAFT 1990).

As a conclusion, HFC 134a, when released to the environment, will enter almost exclusively into the ambient air; it has little tendency to partition to biota or soil. Because of its moderate sorption affinity, HFC 134a is expected to be mobile in soil. The most important degradation process occurs in the atmospheric compartment. That is the reason why no biodegradation simulation studies were conducted except the biodegradation screening test in water.

Consequently, it can be considered that HFC 134a is not expected to be persistent in the aquatic environment and soil.