Hexanoic acid, 3,5,5-trimethyl-, 1,1'-[2-ethyl-2-[[(3,5,5-trimethyl-1-oxohexyl)oxy]methyl]-1,3-propanediyl] ester

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 November 2012 to 18 January 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

yes

Type of method:

flask method

Water solubility:

<= 0.002 g/L

Temp.:

20 °C

pH:

6.8

Remarks on result:

other: Shaking for 48 hours

Details on results:

On completion of the equilibration period, the samples were clear and colorless with excess test item present. After centrifugation, the supernatant was taken for analysis. The supernatant was visually observed to be clear/colorless and free from un-dissolved test item.
It was observed that the duplicate results for each of the three samples were somewhat inconsistent. This may have been in part due to variability in the extraction procedure or that the entire excess test item had not been removed from the samples even though they visually appeared to. For this reason the results were taken as limit values based on the highest result as a worst case scenario. Based on the representative structure of the test item, the water solubility
would be expected to be very low.
To investigate the variable results further, additional duplicate aliquots of the three samples were re-centrifuged and passed through a 0.2 μm filter. After extraction they were analyzed as previously. Curiously no test item peak was evident in the sample extracts. This suggested that either any excess test item present was removed by filtration or that the test item adsorbed to the filter. Although, in either case these results suggested the water solubility of the test item is very low.
No peak at the retention time of the test item was observed in the matrix blanks.

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L)
The water solubility of the test item has been determined to be less than or equal to 2.04 x 10-3 g/L of solution at 20.0 ± 0.5 °C.

Executive summary:

Method

The determination was carried out using the flask method, designed to be compatible with Method A6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995. The test system consists of purified water.

Conclusion

The water solubility of the test item has been determined to be less than or equal to 2.04 x 10 -03 g/L of solution at 20.0 ± 0.5 °C.

Description of key information

The water solubility of the test item has been determined to be less than or equal to 2.04 x 10-3 g/L of solution at 20.0 ± 0.5 °C (OECD 105 and EU Method A.6).

Key value for chemical safety assessment

Water solubility:

0.002 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test item has been determined to be less than or equal to 2.04 x 10-3 g/L of solution at 20.0 ± 0.5 °C. During the study (Fox 2013) it was observed that the duplicate results for each of the three samples were somewhat inconsistent. This may have been in part due to variability in the extraction procedure or that the entire excess test item had not been removed from the samples even though they visually appeared to. For this reason the results were taken as limit values based on the highest result as a worst case scenario. Based on the representative structure of the test item, the water solubility would be expected to be very low. This would correlate to the observed low water solubility of the read-across substances summarised below:

Water solubility is a property which generally decreases with increasing chain length and increasing molecular weight, respectively. The test item has a molecular weight of 554.45, which is comparable with EC 234-392-1. The water solubility of EC 234-392-1 is less than the detection limit of GC-FID, which is stated to be 0.3 µg/mL (i.e. 0.3 mg/L).

The solubility of CAS-No. 131459-39-7 (3,5,5-trimethylhexanoic acid mixed tetraesters with pentaerythritol and valeric acid) < 1 mg/L (0.353 mg/L at 20 °C).

Taken on a weight of evidence approach the actual water solubility of the test item can be expected to be equal to or less than 1 mg/L.

The justification for read-across is presented in Section 13 Assessment reports- Read-across justification.