Alcohols, C11-15-secondary, ethoxylated

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

03 September 2009 - 09 November 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to internationally accepted guidelines and to GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

5.9

Temp.:

25 °C

Remarks on result:

other: First chromatographic peak to be eluted

Type:

log Pow

Partition coefficient:

> 6.2

Temp.:

25 °C

Remarks on result:

other: Second chromatographic peak to be eluted

Type:

log Pow

Partition coefficient:

> 6.2

Temp.:

25 °C

Remarks on result:

other: Third chromatographic peak to be eluted

Conclusions:

Softanol 30 was found to have a Log10 Pow value in the range 5.9 to >6.2.

Reference 2

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE: Episuite 4.11

2. MODEL (incl. version number): LogKow predictions KOWWIN V1.68

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
Predictions have been made for combinations of shortest and longest carbon chain (C11-15) and shortest and longest ethoxy unit numbers (1-8). As the model uses a fragment method for predicting Log Pow, then any other permutation of structures of Softanol 30 will be within the predicted range.
“Alcohols, secondary C11 – C15, ethoxylated”, CAS number 68131-40-8.
Alcohols, secondary C11, ethoxy unit 3 (C17 H36 O4): CCCCCC(OCCOCCOCCO)CCCCC (short carbon chain, most common ethoxy unit number)
Alcohols, secondary C15, ethoxy unit 3 (C21 H44 O4): OCCOCCOCCOC(CCCCCCC)CCCCCCC (long carbon chain, most common ethoxy unit number)
Alcohols, secondary C11, ethoxylated unit 8 (C27 H56 O9): CCCCCC(OCCOCCOCCOCCOCCOCCOCCOCCO)CCCCC (short carbon chain, high ethoxy unit number)
Alcohols, secondary C11, ethoxylated unit 8 (C13 H28 O2): CCCCCC(OCCO)CCCCC (short carbon chain, low ethoxy unit number)

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: LogKow
- Unambiguous algorithm: LogKow predictions KOWWIN V1.68
- Defined domain of applicability:
1) Molecular weight (range of test data set: 18.02 to 719.92 g/mol; On-Line KOWWIN User’s Guide, Ch. 6.2.3 Estimation Domain)
2) Fragments: Number of instances of the identified fragments does not exceed the maximum number as listed in Appendix D (On-Line KOWWIN User’s Guide)
3) Fragments: Substance has a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient was developed (Appendix D, On-Line KOWWIN User’s Guide)
- Appropriate measures of robustness and predictivity: The test substance is not ionisable with a simple structure ideal for QSAR prediction. Furthermore it fully complies with the model domain and there is good reason to expect the prediction to be within the lowest estimated error band of less than or equal to 0.2 log units.
- Mechanistic interpretation:Log Kow is related to the partitioning of the substance from a lipid phase (n-octanol) into a polar phase (water). The equilibrium concentration in each phase will depend largely on the overall polarity of the molecule which is determined in the KOWWIN model by summation of estimated Log Kow values for identified fragments.

5. APPLICABILITY DOMAIN
- Descriptor domain: test substance is within the stated domain of the model – MWt in the range 18.02 to 719.92
- Structural and mechanistic domains: the test substance has no functional groups or other structural features not represented in the training set, and for which no fragment coefficient is available.The number of occurrences of each fragment in the test substance does not exceed the maximum number of that fragment that occurs in any individual compound in the training or the validation set.
- Similarity with analogues in the training set: not applicable to a fragment contribution method

6. ADEQUACY OF THE RESULT
Support for the registration of the test substance under REACH at > 1000 tonnes.
Approach for regulatory interpretation of the model result: The determination of the log kow of softanol 30 has been determined by the OECD 117. The HPLC method (OECD 117) resulted in a log Pow value of 6.2. An estimation of the log Pow was also conducted using QSAR in the aquatic risk assessment in line with the approach adopted in the HERA review on alcohol ethoxylate surfactants. The estimated value was Log Pow 5.3.
Outcome: the result is adequate and is regarded as the key value for risk assessment and classification.

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

REACH guidance on QSARs R.6, May/July 2008

Principles of method if other than guideline:

- Principle of test: QSAR calculation of Log Kow
- Short description of test conditions: use of KOWIN model version 1.68
- Parameters analysed / observed: a structure is divided into fragments (atom or larger functional groups) and coefficient values of each fragment or group are summed together to yield the log P estimate.

Type:

log Pow

Partition coefficient:

3.382

Remarks on result:

other: QSAR Episuite KOWIN 1.68

Remarks:

C11AE3 (short carbon chain with most common ethoxy unit number)

Type:

log Pow

Partition coefficient:

5.346

Remarks on result:

other: QSAR Episuite KOWIN 1.68

Remarks:

C15AE3 (long carbon chain with most common ethoxy unit number)

Type:

log Pow

Partition coefficient:

2.01

Remarks on result:

other: QSAR Episuite KOWIN 1.68

Remarks:

C11AE8 (short carbon chain with high ethoxy unit number)

Type:

log Pow

Partition coefficient:

3.931

Remarks on result:

other: QSAR Episuite KOWIN 1.68

Remarks:

C11AE1 (short carbon chain with low ethoxy unit number)

Details on results:

Predictions have been made for combinations of shortest and longest carbon chain (C11-15) and shortest and longest ETO (1-8). As the model uses a fragment method for predicting Log Pow, then any other permutation of structures of Softanol 30 will be within the predicted range.

Representative structures of Softanol 30

C11AE3 Short carbon chain with most common ethoxy unit number

Log Kow   = 3.3820

TYPE	NUM	LOGKOW FRAGMENT DESCRIPTION	COEFF	VALUE
Frag	2	-CH3   [aliphatic carbon]	0.5473	1.0946
Frag	14	-CH2-  [aliphatic carbon]	0.4911	6.8754
Frag	1	-CH    [aliphatic carbon]	0.3614	0.3614
Frag	1	-OH    [hydroxy, aliphatic attach]	-1.4086	-1.4086
Frag	3	-O-    [oxygen, aliphatic attach]	-1.2566	-3.7698
Const		Equation Constant		0.229

C15AE3 Long carbon chain with most common ethoxy unit number

Log Kow  = 5.3464

TYPE	NUM	LOGKOW FRAGMENT DESCRIPTION	COEFF	VALUE
Frag	2	-CH3   [aliphatic carbon]	0.5473	1.0946
Frag	18	-CH2-  [aliphatic carbon]	0.4911	8.8398
Frag	1	-CH    [aliphatic carbon]	0.3614	0.3614
Frag	1	-OH    [hydroxy, aliphatic attach]	-1.4086	-1.4086
Frag	3	-O-    [oxygen, aliphatic attach]	-1.2566	-3.7698
Const		Equation Constant		0.229

C11AE8 Short carbon chain with high ethoxy unit number

Log Kow = 2.0100

TYPE	NUM	LOGKOW FRAGMENT DESCRIPTION	COEFF	VALUE
Frag	2	-CH3   [aliphatic carbon]	0.5473	1.0946
Frag	24	-CH2-  [aliphatic carbon]	0.4911	11.7864
Frag	1	-CH    [aliphatic carbon]	0.3614	0.3614
Frag	1	-OH    [hydroxy, aliphatic attach]	-1.4086	-1.4086
Frag	8	-O-    [oxygen, aliphatic attach]	-1.2566	-10.0528
Const		Equation Constant		0.229

C11AE8 Short carbon chain with low ethoxy unit number

Log Kow = 3.93

TYPE	NUM	LOGKOW FRAGMENT DESCRIPTION	COEFF	VALUE
Frag	2	-CH3   [aliphatic carbon]	0.5473	1.0946
Frag	10	-CH2-  [aliphatic carbon]	0.4911	4.911
Frag	1	-CH    [aliphatic carbon]	0.3614	0.3614
Frag	1	-OH    [hydroxy, aliphatic attach]	-1.4086	-1.4086
Frag	1	-O-    [oxygen, aliphatic attach]	-1.2566	-1.2566
Const		Equation Constant		0.229

Conclusions:

The log Pow calculated by EpiSuite was ranging from 2.01 to 5.30 (worst case). Log Pow increased with lengthening alcohol chain but decreased with increasing ethoxy units.

Description of key information

Softanol 30 was found to have a Log10 Pow value in the range 5.9 to >6.2. An estimation of the log Pow was also conducted using QSAR in the aquatic risk assessment in line with the approach adopted in the HERA review on alcohol ethoxylate surfactants. The estimated value was Log Pow 5.3. This is regarded as the key value for risk assessment and classification.

Key value for chemical safety assessment

Log Kow (Log Pow):

5.3

at the temperature of:

25 °C