Registration Dossier

Diss Factsheets

Physical & Chemical properties

Partition coefficient

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
partition coefficient
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Estimation of Kow was made using REACH guidance recommended (R.7.1-24) softwares such as KOWWIN and SPARC
Justification for type of information:
See below under 'Overall remarks, attachments' for applicability domain.
Qualifier:
according to guideline
Guideline:
other: REACH Guidance on QSARs R.6, May/July 2008
Principles of method if other than guideline:
Since experimental determination of the partition coefficient n-octanol/water using OECD 107 or 117 was not applicable due to limits of the analytical detection method, the partition coefficient n-octanol/water was assessed by estimation. It was estimated through KOWWIN and SPARC/ACD computational methods recommended in chapter R.7a, in: Guidance on information requirements and chemical safety assessment (table R.7.1-24).
Type of method:
other: Computational methods using programs KOWWIN and SPARC as stated in table R.7.1-24 of the REACH guidance document
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
>= 3.05 - < 8.23
Remarks on result:
other: Mean value of log Pow estimated using KOWWIN, SPARC and/or ACD/LogP for octanoic acid, stearic acid and oleic acid, representing free fatty acids (substance class)
Key result
Type:
log Pow
Partition coefficient:
>= 9.3 - < 24.2
Remarks on result:
other: Mean value of log Pow estimated using KOWWIN, SPARC and/or ACD/LogP for the triglyceride of octanoic acid, stearic acid and oleic acid representing glycerides of fatty acids (substance class)
Type:
log Pow
Partition coefficient:
10.2 - <= 11.8
Remarks on result:
other: Mean value of logPow estimated using KOWWIN and ACD for the tocopherol nd beta-sitosterols representing unsaponifiable matters (substance class)
Type:
log Pow
Partition coefficient:
3.05 - <= 24.2
Remarks on result:
other: Mean value of logPow for the individual constituents estimated using KOWWIN, SPARC and/or ACD LogP
Type:
log Pow
Partition coefficient:
> 6
Remarks on result:
other: Mean value of LogPow for ≥90% of the individual constituents of the test substance
Details on results:
See below table for the estimation of the range of log Kow values for the individual substances of 'oils, vegetable,deodorizer distillates' as well as the attachment under the 'attached background material' for the details of the estimated results from EPISuite.

As per this table, the different QSAR models resulted in similar estimation values. The lower and upper limit of the average Log Kow values for individual constituents were:
Fatty acids: Estimations ranged from 3.05-8.23
Glycerides: Estimations ranged from 9.3-24.2
Unsaponifiable matter: Estimations ranged from 10.2-11.8
Based on the above estimations, the lower and upper limit of the Log Kow values for the test substance was considered to be 3 and 24. However, considering ≥90% of the individual constituents of the test substance, the overall log Kow of the test substance is considered to approximately exceed 6 and thus is considered to partition more into the lipophilic phase (represented by octanol).

See the PDF under 'attached background material' for the details of the estimated results from EPISuite:

The ACD/Log P estimations for the individual constituents can be retrieved through ChemSpider (http://www.chemspider.com/) or via the below specific webpages:
Octanoic acid: http://www.chemspider.com/Chemical-Structure.370.html?rid=26453fc3-0805-4fdd-8a4f-f781654f3f38
Stearic acid: http://www.chemspider.com/Chemical-Structure.5091.html?rid=c2801bfa-cf09-4078-9ecb-0840ca926f37
Oleic acid: http://www.chemspider.com/Chemical-Structure.393217.html?rid=80b792b4-b392-45b5-9eae-bddbe6ff4b75
Trioctanoin: http://www.chemspider.com/Chemical-Structure.10393.html?rid=26d83678-56e8-4306-8d84-2d885fabe6b9
Tristearin: http://www.chemspider.com/Chemical-Structure.10673.html?rid=a1968044-641c-49fa-89c9-eed205a883f8
Triolein: http://www.chemspider.com/Chemical-Structure.4593733.html?rid=83eb9bd2-2928-4c53-b08a-5b4c78e703d4
Tocopherol: http://www.chemspider.com/Chemical-Structure.14265.html?rid=1f624b6e-6650-47c1-9944-9f9ba081d027
Beta-sitosterols: http://www.chemspider.com/Chemical-Structure.192962.html?rid=a57b6480-8015-41e8-90e1-fcd7f3905a9c

As the test substance is composed of a number of different substances from different classes, a further statistical evaluation or the calculation of a weighted log Kow value is not considered meaningful.

Summary of the Kow estimations from the different QSAR models:

Substance Measured/Experimental KOWWIN v.168 SPARC  ACD/LogP (via ChemSpider) Average Log Kow ranges

C8 fatty acid

3.05 3.03   2.9 3.0 3.05-8.23*

C18 fatty acid

8.23 7.94 7.96 8.22 8.0

C18-unsatd. fatty acid (oleic acid)

7.64 7.73   7.7 7.7

C8 triglyceride

  9.20   9.33 9.3 9.3-24.2

C18 triglyceride 

  23.94 23.37 25.27 24.2

C18-unsatd. Triglyceride (triolein)

  23.29   23.71 23.5

Tocopherols

  11.63   11.9 11.8 10.2-11.8

Beta-sitosterol

 

9.65   10.73 10.2

*Range based on experimental Log Kow values

Conclusions:
Based on the modelling results for ≥90% of the individual constituents of the test substance, the overall log Kow of the test substance is considered to be more than 8 and thus is anticipated to partition more into the lipophilic phase (represented by octanol).
Executive summary:

The partition coefficient of 'oils, vegetable, deodorizer distillates' was estimated through computational methods recommended in chapter R.7a, in: Guidance on information requirements and chemical safety assessment. The estimations were performed with the programs KOWWIN, SPARC and/or ACD as stated in table R.7.1-24 of the REACH guidance document. As the test substance is a mixture of different constituents (i.e. glycerides of fatty acids, fatty acids and unsaponifiable matters (UMs)) the log Kow was determined for representative substances of each class present >10% to represent the lower and upperlimit of the test substance. Hence, the log Kow estimations were carried out for octanoic acid, stearic acid and oleic acid representing fatty acids and trioctanoin, tristearin and triolein representing glycerides of fatty acids and tocopherols and beta-sitosterols for the UMs. With regard to the UMs, although their concentration did not exceed 10% in the provided composition of the test substance to the lab, but they can vary between 0-40% depending on the vegetable oil feedstock type or the process efficiency of the deodorizer. Hence, the log Kow values for the UMs were additionally estimated for beta-sitosterols and tocopherols. As the estimated values via the different QSAR models did not show large variations, an average log Kow was determined for the individual constituents. The average estimated log Kow values using the different QSAR models ranged between 3.05 -8.23 for the fatty acids, 9.3 -24.2 for the glycerides of fatty acids and 10.2 -11.8 for the unsaponifiable matter. The values for the fatty acids were based on actual experimental values. Therefore, the lower and upper limit of log Kow of the individual constituents was estimated to be approx. 3 and 24 respectively. Overall, based on the modelling results for ≥90% of the individual constituents of the test substance, the overall log Kow of the test substance is considered to be more than 8 and thus is anticipated to partition more into the lipophilic phase (represented by octanol) (Meinerling, 2012; US EPA, 2012a).

Description of key information

The partition coefficient of 'oils, vegetable, deodorizer distillates' was estimated through computational methods recommended in chapter R.7a, in: Guidance on information requirements and chemical safety assessment. The estimations were performed with the programs KOWWIN, SPARC and/or ACD as stated in table R.7.1 -24 of the REACH guidance document.

Key value for chemical safety assessment

Log Kow (Log Pow):
6

Additional information

The range of log Kow for the different constituents of the test substance are estimated to be as follows:

3.05-8.23 (fatty acids)

9.3-24.2 (triglycerides)

10.2-11.8 (unsaponifiable matter)

Corresponding to the log Kow of more than 90% of the constituents, a log Kow of 6.0 was chosen. This represents higher exposure to soil and sediment as well as higher bioaccumulation potential in human body.

Categories Display