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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Description of key information

Several data on pKa are available:
- pka=4,75 (SPARC)
- pKa = 4,4 - 4,89 at 25°C (handbook data - HSDB)

Key value for chemical safety assessment

pKa at 20°C:
4.8

Additional information

The pKa of heptanoic acid has been estimated using SPARC (QSAR method) which is a software recommended by ECHA for predictions (Guidance on information requirements and chemical safety assessment Chapter R.7a: Endpoint specific guidance, table R.7 -36).


The estimated pKa is 4,75. This value is consistent with data coming from handbook : range of pKa between 4,4 and 4,89.


 


According to the Guidance on information requirements and chemical safety assessment Chapter R.7a: Endpoint specific guidance, R.7.1.17.3 (ECHA, 2008), if the estimated pKa by QSPR method is not in the environmentally-relevant pH range (5 -9), then a test is not necessary.


Therefore, heptanoic acid is considered to be almost entirely in the anion form.