Sodium (2-butoxyethoxy)acetate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-08-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guideline 105 (“Water Solubility”)

Version / remarks:

adopted July 27, 1995

Deviations:

not applicable

Principles of method if other than guideline:

The determination of the log Pow using the respective OECD guideline methods was technically not feasible due to the intrinsic properties of the test item. Hence, the log Pow had to be estimated based on individual solubilities of the test item in water and 1-octanol.

GLP compliance:

no

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: P59564

Analytical method:

high-performance liquid chromatography

other: observation of precipitated substance particles in n-octanol

Key result

Type:

log Pow

Partition coefficient:

-1.89

Temp.:

20 °C

Remarks on result:

other: pH not determined

Details on results:

The individual results differed by 5.9% for 1-octanol solubility, which makes tests correct.
The solubility of the test item in 1-octanol was determined to be 5.679 +/- 0.28 g/L.
The water solubility of the test item was determined to be 443.4 +/- 21.2 g/L at 20 °C and pH = 13.5.
The Pow value of the test item was calculated by dividing the value for octanol solubility by the value for water solubility. With the previous results for water solubility and 1-octanol solubility, the estimation of the partition coefficient of the test item is: log Pow = log (5.679 g/L /443.4 g/L) = -1.89.

Table: 1-octanol solubility of the test item

Flask	Shaking duration (h)	Weighted sample in g/20 mL	Sum of peak areas of the signals	Water solubility of the test item g/L	Average g/L	Average g/L	Standard deviation g/L
OCT-1	24	234.6	771265	5.42685	5.486	5.679	0.28
OCT-2	24	238.5	869899	5.82335
OCT-3	24	210.0	716641	5.20915
OCT-4	48	213.1	727577	5.25235	5.550
OCT-5	48	223.2	770543	5.42385
OCT-6	48	248.6	907436	5.97435
OCT-7	72	244.0	923599	6.03810	5.999
OCT-8	72	266.2	1017082	6.419.3
OCT-9	72	234.4	799570	5.54015

Conclusions:

The log Pow of the test item was estimated based on individual solubilities of the test item in water and 1-octanol to be -1.89 at 20 °C.

Executive summary:

The determination of the log Pow using the respective OECD guideline methods was technically not feasible since the log Pow estimated by QSAR calculation using KOWWIN v1.68 was outside of the log Pow range set out in OECD TG 107 or 117. Hence, the log Pow has to be estimated based on individual solubilities of the test item in water and 1-octanol.

In each of 9 flasks, about 200 - 270 mg of the test item were added to 20 mL of 1-octanol. These solutions were shaken for 24, 48 and 72 hours. After each 24 hours 3 flasks were put aside. The samples were filtered through a 0.45 µm filter. The last filtrated solutions were analysed with HPLC-method. After determination of the test item concentration, the evaluation was carried out analogously to OECD TG 105 (water solubility). With the previous results for water solubility (443.4 +/- 21.2 g/L at 20 °C and pH = 13.5; please refer to IUCLID section 4.8) and 1-octanol solubility (5.679 +/- 0.28 g/L at 20 °C), the estimation of the partition coefficient of the test item was calculated as follows: log Pow = log (5.679 g/L /443.4 g/L) = -1.89 at 20 °C. As the concentrations measured in at least the two last days did not differ by more than 15% both for water and 1-octanol solubility, the test is regarded correct.

Description of key information

The log Pow of the test item was estimated based on individual solubilities of the test item in water and n-octanol to be -1.89 at 20 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

-1.89

at the temperature of:

20 °C

Additional information

The log Pow of the test item was estimated from its individual solubilities in water and in 1-octanol.

Key study

A study was carried out to estimate the log Pow of the test item from its individual solubility in water and in 1-octanol (Infrapark Baselland AG, 2018). In each of 9 flasks, about 200 - 270 mg of the test item were added to 20 mL of 1-octanol. These solutions were shaken for 24, 48 and 72 hours. After each 24 hours 3 flasks were put aside. The samples were filtered through a 0.45 µm filter. The last filtrated solutions were analysed with HPLC-method. After determination of the test item concentration in 1-octanol, the evaluation was carried out analogously to OECD TG 105 (water solubility). With the previous results for water solubility (443.4 +/- 21.2 g/L at 20 °C and pH = 13.5; please refer to IUCLID section 4.8) and 1-octanol solubility (5.679 g/L +/- 0.28 g/L), the estimation of the partition coefficient of the test item was calculated as follows: log Pow = log (5.679 g/L /443.4 g/L) = -1.89 at 20 °C. As the concentrations measured in at least the two last days did not differ by more than 15% both for water and 1-octanol solubility, the test is regarded correct (Infrapark Baselland, 2018).

Supporting information

Using KOWWIN v1.68 the partition coefficient of the test item was calculated to be -3.29. The substance is within the applicability domain of the model. Thus the estimation is considered to be accurate.

Conclusion

Based on the most reliable information (Infrapark Baselland AG, 2018), the log Pow of the test item is considered to be -1.89 at 20 °C. This result is supported by a QSAR prediction using KOWWIN v1.68 as the log Pow was calculated to be -3.29.