Registration Dossier

Physical & Chemical properties

Melting point / freezing point

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Key result for CAS# 297730-93-9:
Freezing point: -102°C (direct observation)
Key result for PFBA (degradation product), CAS# 375-22-4:
Freezing point (pressure not reported): -19.95 °C (method not reported)

Key value for chemical safety assessment

Additional information

Discussion for CAS# 297730-93-9:

The freezing point of CAS# 297730-93-9 was assessed in three studies. In the first study, CAS# 297730-93-9 held at -81°C in a freezer remained a liquid. In the second study, CAS# 297730-93-9 frozen in a liquid nitrogen-pentane slurry began to regain flowability at -102 °C. In the third study, CAS# 297730-93-9 was solidified in a chiller and regained flowability at -61 °C. Taken together, these results indicate that CAS# 297730-93-9 freezes at a temperature substantially below any that is likely to occur in the environment. The second study is accepted as the key result.

 

The determination of the freezing temperature in the first study was based on EEC-Directive 92/69EEC, A.1 and on OECD Guideline no. 102, and was GLP-compliant. It is therefore considered relevant and valid to this endpoint. The second study was not GLP compliant. No method cited in OECD TG102 is considered valid for freezing temperatures less than -100 °C. However, potential error in the method will not change the conclusion that the test substance freezes at a temperature substantially below any temperature likely to occur in the environment. Therefore, the second study is considered adequate for this endpoint. The third study is poorly documented and cannot be classified as to its reliability. Further, the study result conflicts with the limit established by the GLP-compliant study. Therefore, the result of the third study is set aside.

Discussion for PFBA (degradation product), CAS# 375-22-4:

The value was collected in the peer-reviewed Beilstein database and is considered reliable with restrictions. An additional freezing point of -17.5 °C was reported in a patent application with no further details. Though collected into Beilstein, the value from the key study was preferred because of somewhat greater detail on the test material.