Glycerol trioctanoate

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:

From 27 Oct 2017 to 30 Jan 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Remarks:

Calculation method based on ratio of solubilities in water and n-octanol.

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

yes

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

yes

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)

Deviations:

yes

Principles of method if other than guideline:

Deviations:
1) Stability of the Analytical System and End Solutions: The analytical system and/or end solutions at the concentration level of 0.100 and 0.400 mg/L was found not to be stable since the coefficient of variation on the responses of the solutions was >20%.
Evaluation: All other parameters of the method were acceptable and no test item was detected in the water samples, therefore this deviation has no impact on the study.

2) n-Octanol solubility: Test item was performed at room temperature.
Evaluation: Test item dissolved immediately and therefor there was no time to mix the compound in the climate room at 20 °C, and therefore the deviation had no impact on the study.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

gas chromatography

Key result

Type:

log Pow

Partition coefficient:

> 6.7

Temp.:

20 °C

Details on results:

9.5. Results
9.5.1. Calculation Method
Pow Calculation
The Pow of the test item was calculated to be 1.3E10 (log Pow 10) using the Rekker calculation method.
pKa Values
No pKa values for acidic and basic groups in the molecular structure of the test item in the logarithm range of 1 - 14 were calculated.
9.5.2. n-Octanol solubility
After the stirring period, the test sample was clear and no undissolved test item was observed. It was concluded that the n-octanol solubility was > 1E3 g/kg.
9.5.3. Water solubility
The content of test item dissolved in the water sample was < 0.2 mg/L.
The pH of the aqueous samples was 7.0.
9.6. Conclusion
The estimation method was applied for the determination of the partition coefficient (Pow) of COCONAD RK.
The Pow value of the test item at 20°C was > 5.0E6.
It corresponds with a log Pow value of > 6.7.

Results

1.1.1.                 Calculation Method

P_owCalculation The P_owof the test item was calculated to be 1.3E¹⁰ (log P_ow10) using the Rekker calculation method.

pK_aValues No pK_avalues for acidic and basic groups in the molecular structure of the test item in the logarithm range of 1 - 14 were calculated.

1.1.2.                 n-Octanol solubility

After the stirring period, the test sample was clear and no undissolved test item was observed. It was concluded that the n-octanol solubility was > 1E³g/kg.

1.1.3.                 Water solubility

The content of test item dissolved in the water sample was < 0.2 mg/L.

The pH of the aqueous samples was 7.0.

1.2.                       Conclusion

The estimation method was applied for the determination of the partition coefficient (Pow)

The Pow value of the test item at 20°C was > 5.0 x 10⁶.

It corresponds with a log Pow value of > 6.7.

Conclusions:

The partition coefficient of the tested substances is estimated to be Log Kow > 6.7 at 20°C

Executive summary:

The objective of this study was to determine physico-chemical properties for Glycerol trioctanoate

The summary of the results is listed below:

Information	Guideline(s)	Result	Comment
Method validation	SANCO 3029	validated
Partition coefficient	EC A.8 OECD 107 OPPTS 830.7550	log Pow: >6.7	Estimation method

Reference 2

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

19th of February 2018

Reliability:

2 (reliable with restrictions)

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 v4.11

2. MODEL (incl. version number)
(KOWWIN v1.68 estimate)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
O=C(CCCCCCCCCCCCCCCCC)OCC(COC(=O)CCCCCCCCCCCCCCCCC)(COC(=O)CCCCCCCCCCCCCCCCC)COCC(COC(=O)CCCCCCCCCCCCCCCCC)(COC(=O)CCCCCCCCCCCCCCCCC)COC(=O)CCCCCCCCCCCCCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
Information on the OECD criteria as outlined by the applicant is provided below under "Any other information of materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Overall remarks, attachments" section.

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Qualifier:

according to guideline

Guideline:

other: Calculation based on KOWWIN v1.68, Estimation Programs Interface Suite™ for Microsoft® Windows v4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

Deviations:

no

GLP compliance:

no

Type of method:

calculation method (fragments)

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

SMILES : CCCCCCCC(=O)OCC(COC(=O)CCCCCCC)OC(=O)CCCCCCC
MOLECULAR FORMULA: C27H50O6
MOLECULAR WEIGHT : 470.70 g/mol

Key result

Type:

log Pow

Partition coefficient:

9.2

Remarks on result:

other: in this QSAR result pH and temperature are not reported.

Details on results:

-------+-----+--------------------------------------------+---------+--------
TYPE | NUM | LOGKOW FRAGMENT DESCRIPTION | COEFF | VALUE
-------+-----+--------------------------------------------+---------+--------
Frag | 3 | -CH3 [aliphatic carbon] | 0.5473 | 1.6419
Frag | 20 | -CH2- [aliphatic carbon] | 0.4911 | 9.8220
Frag | 1 | -CH [aliphatic carbon] | 0.3614 | 0.3614
Frag | 3 | -C(=O)O [ester, aliphatic attach] |-0.9505 | -2.8515
Const | | Equation Constant | | 0.2290
-------+-----+--------------------------------------------+---------+--------
Log Kow = 9.2028

Conclusions:

The partition coefficient in octanol/water, has been calculated using KOWWIN v1.68, Estimation Programs Interface Suite™ for Microsoft® Windows v4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.
The substance has been assumed to be 100% the main constituent of this mono-constituent substance. The result is Log Kow = 9.2

Description of key information

9.2 at 20 °C (QSAR calculation with the model Kowwin v1.68)

Key value for chemical safety assessment

Log Kow (Log Pow):

9.2

at the temperature of:

20 °C

Additional information

Based on difficulties for evaluating the partition coefficient for this type of substances, it was decided to do an estimation of the partition coefficient of the solubility of the substance in octanol and in water. However, it was not possible to determine an exact value of the solubility of the substance in n-octanol because it was totally miscible. Furthermore, it was also not possible to determine an exact value for soubility in water, as it was below the analysis quantification limit.

Therefore, due to the experimental difficulties found, the partition coefficient has been calculated using a QSAR tool (KOWWIN v1.68, Estimation Programs Interface Suite™ for Microsoft® Windows v4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.). This result is regarded as the key value.

A fully reliable experimental study, conducted according to OECD guideline, is available. However, as the result can not report an exact result, a QSAR estimation has been used instead.