Registration Dossier
Registration Dossier
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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.
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EC number: 203-838-7 | CAS number: 111-14-8
Dissociation constant
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.
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