Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Dissociation constant

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Administrative data

Link to relevant study record(s)

Description of key information

TFA, the hydrolysis product of TFAH, has a very low dissociation constant, indicating that the substance will exist primarily under its ionised form.

Key value for chemical safety assessment

pKa at 20°C:

Additional information

As TFAH readily decomposes, the study is technically not feasible. Data on the hydrolysis product TFA, which is the actual species present in the environment, is considered to be relevant.

The publication Bowden 1996 discusses published work on TFA dissociation constant, and adopts a mean of three pKa values of 0.47. For the purpose of the present dossier, the Merck index (reference handbook) value of pKa=0.3 will also be taken into account; the key value is calculated as the mean of Bowden's value, with a weight coefficient of 3, and Merck's value: (0.47*3 + 0.3)/4.