Registration Dossier

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:
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.