Phenol, mono- + distyrenated (MSP+DSP)

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Accepted, well-documented calculation method

Justification for type of information:

1. SOFTWARE
US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.

2. MODEL (incl. version number)
Model KOWWIN, version 1.68

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
Oc(c(ccc1)C(c(cccc2)c2)C)c1 (ECHA"s Reference Substance SMILES notation "CC(c1ccccc1)c2ccccc2O" results in the same structure)

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: yes, log Kow
- Unambiguous algorithm: yes
- Defined domain of applicability: see under Attached justification

5. APPLICABILITY DOMAIN
- Descriptor domain: specified by molecular fragments
- Similarity with analogues in the training set: yes
- Other considerations: for more detailed information see under Attached justification

6. ADEQUACY OF THE RESULT
Result of the prediction is used as information for the mono-substitued constituents of the registration substance phenol, styrenated and as weight of evidence information on the log Kow of the substance.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Software tool(s) used including version: US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.
- Model(s) used: Model KOWWIN, version 1.68
- Model description: see field 'Justification for non-standard information' and 'Attached justification'
- Justification of QSAR prediction: see field 'Justification for type of information' and 'Attached justification'

Type of method:

calculation method (fragments)

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2-(1-Phenylethyl)phenol; Phenol, 2-(1-phenylethyl)

Type:

log Pow

Partition coefficient:

3.67

Remarks on result:

other: value calculated

Reference 2

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Accepted, well-documented calculation method

Justification for type of information:

1. SOFTWARE
US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.

2. MODEL (incl. version number)
Model KOWWIN, version 1.68

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
Oc(c(cc(c1)C(c(cccc2)c2)C)C(c(cccc3)c3)C)c1 (ECHA"s Reference Substance SMILES notation "CC(c1ccccc1)c2ccc(O)c(c2)C(C)c3ccccc3" results in the same structure)

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: yes, log Kow
- Unambiguous algorithm: yes
- Defined domain of applicability: see under Attached justification

5. APPLICABILITY DOMAIN
- Descriptor domain: specified by molecular fragments
- Similarity with analogues in the training set: yes
- Other considerations: for more detailed information see under Attached justification

6. ADEQUACY OF THE RESULT
Result of the prediction is used as information for the di-substitued constituents of the registration substance phenol, styrenated and as weight of evidence information on the log Kow of the substance.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Software tool(s) used including version: US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.
- Model(s) used: Model KOWWIN, version 1.68
- Model description: see field 'Justification for non-standard information' and 'Attached justification'
- Justification of QSAR prediction: see field 'Justification for type of information' and 'Attached justification'

Type of method:

calculation method (fragments)

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2,4-Bis(1-phenylethyl)phenol; Phenol, 2,4-bis(1-phenylethyl)-

Type:

log Pow

Partition coefficient:

5.83

Remarks on result:

other: calculated value

Description of key information

For phenol, styrenated, no measured value for (log) Kow could be located. For the two components, mono(1-phenylethyl)phenol (MSP) and 2,4-bis(1-phenylethyl)phenol (DSP), measured and estimated log Kow values are available (MSP 3.03 and 3.67, respectively; DSP 6.24 and 5.83, respectively).

Taking into account the log Kow value of the supporting substance cumylphenol (3.8) and the measured and estimated values of MSP and DSP, the log Kow value for the chemical safety assessment of phenol, styrenated is selected slightly above the measured value of mono(1-phenylethyl)phenol.

Key value for chemical safety assessment

Log Kow (Log Pow):

3.67

at the temperature of:

20 °C

Additional information

For phenol, styrenated, no measured value for (log) Kow could be located. For the two main components of the substance, mono(1-phenylethyl)phenol (monostyrenated phenol, MSP, ca. 63 %) and 2,4-bis(1-phenylethyl)phenol (distyrenated phenol, DSP, ca. 31 %), log Kow values were estimated by calculation using the modelling program US EPA EPI Suite v.4.11, program component KOWWIN Program (v1.68). The calculated log Kow values are 3.67 and 5.83, respectively.

In a recent study according to OECD TG 117 (HPLC method) with an isomeric mixture of (1-phenylethyl)phenol (30.7 % of the 2-isomer (2-MSP) and 67.5 % of the 4 -isomer (4-MSP), log Kow values of 3.13 and 2.99 were determined resulting in a weighted average for the log Kow of 3.03.

For bis(1-phenylethyl)phenol (DSP), a measured log Kow value of 6.24 is reported.

For the (supporting) substance cumylphenol (monomethylstyrenated phenol), which is closely related to mono(1-phenylethyl)phenol (monostyrenated phenol), an experimental log Kow value of 3.8 has been determined. Estimated and measured log Kow values for both of the monosubstituted phenols (styrenated and methylstyrenated) are in good agreement.

Use of cumylphenol as supporting substance for phenol, styrenated is justified, as this substance is very similar to the monostyrenated components of phenol, styrenated (61 % of phenol, styrenated). Both substances differ only in one methyl group that in case of cumylphenol is additionally positioned at the C-atom bridging the two benzene rings. This is only a minor difference in chemical structure with regard to the entire molecule. Effects on physical and chemical properties will only be minor. Behaviour in the environment, ecotoxicological and toxicological properties are expected to be very similar.

As monostyrenated phenols contribute ca. 60 % to the total of phenol, styrenated (ca. two-thirds), the log Kow (3.67) value estimated by QSAR is used for the whole of the substance for further consideration in the chemical safety assessment. This value is higher than the experimental log Koc of the monostyrenated phenols, but it is used to account for the higher log Kow values of the other constituents of phenol, styrenated. Additional reasons are that PNECs calculated with the equilibrium partitioning method are lower when using lower log Kow values for input (or Koc values derived from lower log Kow values).

For cases in the assessment process when adsorption will be of importance, the higher log Kow values of distyrenated phenol will be accounted for.