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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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:
(Q)SAR
Adequacy of study:
key study
Study period:
2018
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source
Justification for type of information:
1. SOFTWARE
Sparc

2. MODEL (incl. version number)
Version from April 2018

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
OC1=CC=C(C=C1)C2=CC=C(O)C=C2

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: yes, Dissociation constant
- Unambiguous algorithm: no information available
- Defined domain of applicability: no information available, but the prediction is not performed if the test substance is not included in the domain of applucability of the QSAR
- Appropriate measures of goodness-of-fit and robustness and predictivity: no information available
- Mechanistic interpretation: no information available

5. APPLICABILITY DOMAIN
- Descriptor domain: no information available
- Structural and mechanistic domains: no information available
- Similarity with analogues in the training set: no information available

6. ADEQUACY OF THE RESULT
The determination of the dissociation constant with a QSAR allow to determine the form of the test item depending of the pH.
Qualifier:
according to guideline
Guideline:
other: REACH Guidance on QSARs R.6
GLP compliance:
not specified
Dissociating properties:
yes
No.:
#1
pKa:
9.42
Temp.:
20 °C
No.:
#2
pKa:
10.36
Temp.:
20 °C

The substance possess two phenyl groups which can be ionized depending of the pH. So it possess two pka.

Conclusions:
The test item possess two pka: 9.42 and 10.36.
Executive summary:

A QSAR was used to estimate the dissociation constant of the test item.

The commercial program SPARC was used.

The test item possess two pka: 9.42 and 10.36.

Description of key information

The dissociation constant of the test item was determined in a key study of Klimisch validity 2.

This study used a recognised QSAR for this calculation.

Key value for chemical safety assessment

pKa at 20°C:
9.42

Additional information

The test item possess two pka. The lowest pka value was used as a key value for chemical safety assessment in a worst case approach.