4-methyl-2-(pentan-3-yl)tetrahydro-2H-pyran-4-ol

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Oct - 10 Dec 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. No deviation affected the quality of the study. The substance is adequately identified but some data on composition is missing. Therefore validation applies with restrictions.

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

effective 16/07/2008

Type of method:

flask method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Storage condition of test material: Room temperature protected from direct sunlight.

Analytical method:

gas chromatography

Type:

log Pow

Partition coefficient:

2.21

Temp.:

20 °C

pH:

5.7

Type:

log Pow

Partition coefficient:

2.19

Temp.:

20 °C

pH:

7.42

Type:

log Pow

Partition coefficient:

2.19

Temp.:

20 °C

pH:

9.36

Estimated value: 2.65 (QSAR determination, kowwin v1.67, EPISuite, EPA)

Measured value at pH 5

The pre-saturated water was previously added with phosphate buffer and adjusted to pH 4.68.

10 mL of pre-saturated water and 1 mL of pre-saturated n-octanol were mixed with 0.1 mL of a 10 g/L stock solution. The tubes were continuously rotated for 15 min at 19.3°C and the centrifuged for 10 min at 3000 rpm and 20°C.

The test was reproduced using half and twice, respectively, the above volume ratio.

Ratio 1:10, mean log Pow = 2.21

Ratio 2:10, mean log Pow = 2.21

Ratio 1:20, mean log Pow = 2.20

Mean log Pow and SD = 2.21 +/-0.01

The observed interval within the six log Pow values was [2.20 - 2.22] and the validity criteria was fulfilled (< +/-0.3 unit).

pH of the water phase was measured as 5.70.

Mass balance ranged between 84.4 and 90.2%.

Measured value at pH 7

The pre-saturated water was previously added with phosphate buffer and adjusted to pH 7.39.

10 mL of pre-saturated water and 1 mL of pre-saturated n-octanol were mixed with 0.1 mL of a 10 g/L stock solution. The tubes were continuously rotated for 15 min at 19.3°C and the centrifuged for 10 min at 3000 rpm and 20°C.

The test was reproduced using half and twice, respectively, the above volume ratio.

Ratio 1:10, mean log Pow = 2.20

Ratio 2:10, mean log Pow = 2.18

Ratio 1:20, mean log Pow = 2.19

Mean log Pow and SD = 2.19 +/-0.02

The observed interval within the six log Pow values was [2.16 - 2.20] and the validity criteria was fulfilled (< +/-0.3 unit).

pH of the water phase was measured as 7.42.

Mass balance ranged between 83.3 and 86.4%.

Measured value at pH 9

The pre-saturated water was previously added with phosphate buffer and adjusted to pH 9.73.

10 mL of pre-saturated water and 1 mL of pre-saturated n-octanol were mixed with 0.1 mL of a 10 g/L stock solution. The tubes were continuously rotated for 15 min at 19.3°C and the centrifuged for 10 min at 3000 rpm and 20°C.

The test was reproduced using half and twice, respectively, the above volume ratio.

Ratio 1:10, mean log Pow = 2.20

Ratio 2:10, mean log Pow = 2.19

Ratio 1:20, mean log Pow = 2.20

Mean log Pow and SD = 2.19 +/-0.01

The observed interval within the six log Pow values was [2.18 - 2.20] and the validity criteria was fulfilled (< +/-0.3 unit).

pH of the water phase was measured as 9.36.

Mass balance ranged between 84.1 and 85.6%.

Conclusions:

The substance has low potential to bioaccumulate in the environment, according to CLP classification criteria for aquatic chronic toxicity (log Kow <4).

Executive summary:

The partition coefficient of the test substance was determined under GLP according to EU A.8 guideline, flask method. Determinations were conducted at pH 5, 7 and 9, concentrations were measured using a GC-FID validated method. Individual results fulfilled the validity criteria for reproducibility, no pH-dependency was observed in this range, so the average value is retained.

The log Kow has been determined to be 2.20 at 20°C and pH 5.7 - 9.4.

Description of key information

The data is relevant for classification in aquatic chronic toxicity hazard class, according to CLP criteria:

The substance has low potential for bioaccumulation (log Kow<4).

Key value for chemical safety assessment

Log Kow (Log Pow):

2.2

at the temperature of:

20 °C

Additional information

A reliable experimental study, conducted according to a recognized EC method and under GLP, is available. Despite minor restrictions on test item identification, it is considered as a key study, and the result is retained as key data.