2-benzyl-4-methyl-4a,5,6,7,8,8a-hexahydro-4H-benzo[d][1,3]dioxine

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 April to 21 June, 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP, but the result is slightly out of the applicability range of the method. The substance is adequately identified. Therefore validation applies with restrictions.

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

not specified

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Remarks:

GIPC; effective Jan.11, 2011, signed on Mar.11, 2011

Type of method:

flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

- Physical appearance: Light yellow translucent liquid.
- Storage conditions of test material: At room temperature protected from direct sunlight.

Analytical method:

gas chromatography

Key result

Type:

log Pow

Partition coefficient:

3.65

Temp.:

20 °C

Remarks on result:

other: pH not reported

Measured value:

40 mL of pre-saturated water and 4 mL of pre-saturated n-octanol were mixed with 0.4 mL of a 10 g/L stock solution and tubes were rotated for 15 min and centrifuged for 5 min at 3000 tr/min and 20 °C.

 

Three test were performed using three different ratios of n-octanol/water and the Log Pow values were determined as (3.63, 3.59, 3.75, 3.74, 3.60, 3.58) and the mean was calculated.

 

Table 1: Observed volumes and Log pow values

Volume	n-octanol: water	Ratio 40:4		Ratio 40:2		Ratio 40:8
	Replicate tube	1	2	1	2	1	2
	Water	40.0 mL	40.0 mL	40.0 mL	40.0 mL	40.0 mL	40.0 mL
	n-octanol stock solution	4.0 mL	4.0 mL	2.0 mL	2.0 mL	8.0 mL	8.0 mL
Nominal added amounts mg		9.65	9.65	4.82	4.82	19.3	19.3
Measured concentration in the n- octanol phase	Dilution	1000	1000	1000	1000	1000	1000
	Area	135.6	132.2	127.0	130.9	128.2	126.6
	mg/L	2485.4	2422.4	2328.2	2398.8	2349.1	2320.7
Measured concentration in the water phase	Dilution	0.4	0.4	0.4	0.4	0.4	0.4
	Area	79.2	85.3	57.0	59.4	81.1	83.5
	mg/L	0.58	0.63	0.42	0.44	0.60	0.62
	In n-octanol	9.942	9.690	4.656	4.798	18.793	18.566
	In water	0.023	0.025	0.017	0.017	0.024	0.025
	Total	9.965	9.715	4.673	4.815	18.817	18.591
	% nominal	103.3	100.7	96.9	99.8	97.5	96.3
	value
Calculated LogPow		3.63	3.59	3.75	3.74	3.60	3.58

*In the undiluted phase.

 

 

The mean LogPow value and observed interval were determined to be 3.65 (3.58 – 3.75). Validity criteria were fulfilled: the six LogPow values fell within a range of ± 0.3 units.

Conclusions:

The log Kow of the test substance was determined to be 3.65 at 20 °C.

Executive summary:

A GLP study was conducted to determine the octanol/water partition of test substance by the shake flask method according to EU method A.8.

Three tests were performed using three different ratios of n-octanol to water (40:4, 40:2, 40:8 ) and the concentration of test item was measured by means of validated GC-FID method. Two replicates per ratio were performed and the mean partition coefficient of the test item was calculated as final result.

The octanol/water partition of the test substance was determined to be 3.65 at 20 °C.

Description of key information

The mean LogKow of the substance was determined to be: 3.65 at 20 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

3.65

at the temperature of:

20 °C

Additional information

A reliable experimental study, conducted according to a recognized EC method and under GLP, is available.
It is considered as a key study, and the result is retained as key data.