Chlorotrifluoroethylene

Bioaccumulation: aquatic / sediment

Description of key information

In accordance with section 1 of REACH (Regulation (EC) No 1907/2006) Annex XI the bioaccumulation study required in section 9.3.2 Annex IX of REACH (Regulation (EC) No 1907/2006) is not proposed by the registrant as CTFE is a gas at ambient condition with a moderate water solubility and an high tendency to rapidly volatilise from water to the air.
On the basis of the properties of CTFE it is expected that the substance primarily and rapidly partitions to the atmosphere.
The EQC Fugacity III Model confirms that the whole amount of CTFE released to air remains in this compartment. The model was run assuming emission only to air. In case of an accidental emission, CTFE is only released to air, because CTFE is a volatile gas at ambient conditions with a boiling point ranging from -26.2°C to -26.8°C.

Additional information

Chlorotrifluoroethylene (CTFE) is a volatile gas at ambient conditions with a boiling point in the range of -26.2°C (The Beilstein database. Reference: Miller - 1951 ) to -26.8°C (The Beilstein database. Reference: Henne - 1948) a vapour pressure of 612 kPa at 25°C (ISCS No. 0685, NIOSH) . CTFE is also characterized by a moderate water solubility of 380 mg/L.

The value of water solubility of 380 mg/l was experimentally determined in a completely sealed system with an atmosphere saturated with CTFE. Althoughthe value of 380 mg/l itself reveals a moderate water solubility, it represents an overestimation of the actual water solubility of CTFE in the natural system since the experimental conditions did not represent the natural conditions.

The Henry’s Law constant of CTFE was calculated to be 31.500 Pa m3/mol (HENRYWIN v3.20, EPI Suite v4.0), suggesting that the substance is expected to rapidly volatilise from water to the air in fact the Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a: Endpoint Specific Guidance, Appendix R.7.1-4 indicates that substances with a Henry's Law constant of around 1 hPa m3/mole will rapidly volatilise from water.

In addition the EQC Fugacity III Model confirms that all the CTFE released to air remains in this compartment. The model was run assuming emission only to air. In case of an accidental emission, CTFE is only released to air, because CTFE is a volatile gas at ambient conditions with a boiling pointpointin the range of -26.2°C (The Beilstein database. Reference: Miller - 1951) to -26.8°C (The Beilstein database. Reference: Henne - 1948).

Hence, due to the gaseous nature of the substance and its partition to the atmosphere, as well as the consequent difficulty to appropriately test CTFE and provide meaningful results, no experimental bioaccumulation data are reported. However, in order to evaluate the bioaccumulation hazard profile of CTFE despite the fact that it is expected to rapidly partition to the atmosphere compartment, the result of the BCFBAF model ( v.3.0, EPI Suite v 4.0) is attached. The model prediction for CTFE yielded a BCF of 5.7 and a log K_owof 1.65.

According to Annex XIII of Regulation (EC) No 1907/2006 and to the Guidance on information requirements and chemical safety assessment Chapter R.11 (PBT Assessment, May 2008), a substance does not fulfil the criterion “bioaccumulative (B)” or “very bioaccumulative (vB)” if the BCF is below 2000 and 5000, respectively, or the log Kow is below 4.5, therefore CTFE is not expected to be bioaccumulative.