Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
dissociation constant
Type of information:
experimental study
Adequacy of study:
key study
Study period:
31 May 1976
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Qualifier:
no guideline followed
Principles of method if other than guideline:
The Hammett acidity function of PFBS was determined by taking the UV spectra of prepared solutions.
GLP compliance:
no
Dissociating properties:
yes
pKa:
-13.2
Temp.:
22 °C
Remarks on result:
other: ± 0.1
Remarks:
Hammett acidity function (rather than pKa)
pKa:
-12.5
Temp.:
37 °C
Remarks on result:
other: ± 0.3
Remarks:
Hammett acidity function (rather than pKa)

The Hammett acidity function (H0) is defined by the relationship:

H0 = pKBH+ + log [BH+]/[B]

Conclusions:
The Hammett acidity function of PFBS was determined to be -13.2 ± 0.1 at 22 ± 1 °C.
Executive summary:

The Hammett acidity function of PFBS was determined to be -13.2 ± 0.1 at 22 ± 1 °C and -12.5 ± 0.3 at 37 ± 1 °C. The experimental procedure was well-documented and included sufficient detail although did not follow a national standard method; therefore the data are considered reliable with restrictions.

Description of key information

The Hammett acidity function of PFBS was determined to be -13.2 ± 0.1 at 22 ± 1 °C.

Key value for chemical safety assessment

Additional information

The experimental procedure was well-documented and included sufficient detail although did not follow a national standard method; therefore the data are considered reliable with restrictions.