Phenol, 2-methoxy-, reaction products with 2,2-dimethyl-3-methylenebicyclo[2.2.1]heptane, hydrogenated

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption, other

Remarks:

estimation by QSAR

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: the study fulfil the validation criteria specified in the OECD Guidance Document on the validation of (Q)SAR models.

Principles of method if other than guideline:

A QSAR is a mathematical model relating one or more quantitative parameters derived from chemical structure to a quantitative measure of a property or activity.

GLP compliance:

no

Type of method:

other: QSAR

Specific details on test material used for the study:

4 isomers

Radiolabelling:

no

Remarks on result:

other: results detailed below

Compound	MIC Method	Kow Method	Sparc
1	3.451	3.556	5.091
2	3.451	3.556	5.098
3	3.460	3.556	5.096
4	3.435	3.578	5.170
Average Log Koc	3.449	3.562	5.114
Standard deviation (+/-)	0.010	0.011	0.038

The compounds tested are organic molecules made with carbon, hydrogen and oxygen. As such, they are included in the validity range the estimation programs.

Futhere more, for ‘KOCWIN’, the isomers tested are included in the molecular weight range of the training set compounds (32.04g /mol to 665.01 g/mol). The fragments obtained from the chemical structure of the compounds tested are presented in the training and the validation set.

We notice that the results obtained with the same estimation program for the 4 compounds are closed to each other. Indeed, the maximum standard deviation was observed with ‘Sparc’ (0.038). The information allow us to conclude that the structural difference between the all isomers present in test item do not have a significant impact of the partition coefficient. Based on the data obtained, we estimated that adsorption partition coefficient logarithm of the test item is equal or higher than 3.45.

Validity criteria fulfilled:

yes

Conclusions:

The log of the adsorption coefficient of the test item is equal or higher than 3.45

Description of key information

Due to the complex nature of the test item (UVCB), estimation of the adsorption coefficient was performed using QSAR. These estimations were done according to REACH guidance on QSARs R.6 May/July 2008.

Depending of the estimation programs used, the adsorption partition coefficient logarithm of the test item was between 3.35 and 5.11.

Additional information

Due to the complex nature of the test item and its surface active properties, predictions were investigated regarding the adsorption coefficient.

The experimental determination of this parameter will be very difficult and probably not possible to perform. Indeed, the methods described in recognized international guidelines (OECD 121) specify:

-         “The method may not work for surface active substances, inorganic compounds and moderate or strong organic acids and bases.”

The main representatives isomers have been chosen to perform QSAR predictions. The validities of the programs used for the estimation regarding the chosen isomers have been verified.