Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-[2-[[2,2-dimethyl-3-[(1-oxododecyl)oxy]propylidene]amino]methylethyl]-.omega.-[2-[[2,2-dimethyl-3-[(1-oxododecyl)oxy]propylidene]amino]methylethoxy]-

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2004-09-27 - 2005-03-21

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

July 27th 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

31st July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Remarks:

and slow stirring method

Remarks on result:

other: No defined value for the solubility in water could be determined.

Details on results:

1. Pre-Test
The test item did not dissolve. The test showed that the solubility of the test item is far below 10 mg/L, therefore the column elution method had to be used.

2. Column elution method
All experiments failed because of the properties of the test item: the relative density of the test item is lower than the relative density of water and no adhesion on the various surfaces takes place, so that the test item always swims up from the layer, even against the flow. These pre-tests indicated that it was not possible to use the column elution method.

3. Slow stirring method
3.1 splitless injection
All measurements for the aldehyde and the carbon acid were below LOQ, so the solubility of the test item could be stated as being lower than 1 mg/L.

3.2 split injection
No reproducible results could be obtained from this experiment: five vessels, measured twice each, gave a mean of 0.04 mg/L with a standard deviation of 0.02 mg/L (RSD = 54%) and exclusion of one sample which showed values below the blank value. Carbon acid was determined in very small amounts at the LOD. It was assumed that the test item was decomposed. In a second slow-stirring experiment, one vessel was prepared in order to check if higher amounts of the test item were found when sampling and analysis would be performed directly. In this experiment, concentrations of 0.07 mg/L (after three days) and 0.03 mg/L (after six days) test item in water were determined.

4. Stability in Water
It could be perceived that the concentration of the aldehyde fell below the LOQ within the first hours after spiking. Carbon acid was not produced because of the strict absence of oxygen. An explanation for the decrease of aldehyd concentration can be hydrolysis or adsorption, but hydrolysis is more probable because of the increasing background peaks, which implement the formation of decomposition products. With these results, it is shown that the correct measurement of the solubility was not possible in the former experiments, because the reaction time in the aqueous phase is very critical, even in the absence of oxygen. In the slow-stirring experiment, this could not be detected due to the large surplus of test item. From this surplus, a dynamic equilibrium with test item constantly dissolving and hydrolysing gave irreproducible results.

Conclusions:

A defined value for the solubility in water could not be determined due to the test item properties: hydrolysis prevents the reaching of a solubility equilibrium.

Executive summary:

In the pre-test, a solubility of the test item below 10 mg/L was determined. The column elution method was chosen. Because of the properties of the test item, which consists of an oily liquid with low viscosity, no suitable carrier could be found. Therefore, the slow-stirring-method was chosen (draft OECD guideline, originally developed for the determination of log Pow) which avoids the formations of emulsions. In the main study, approx. 6 mL test item were given on 850 mL H2O under nitrogen and stirred at 20.0 ± 0.5 °C. Samples of all vessels showed values below LOQ of the analytical method (< 0.1 mg/L).

An additional experiment investigating the stability of the test item in water showed, that after spiking of deionized water giving a nominal concentration of 0.26 mg/L, the test item hydrolyses rapidly in contact with water, even in the absence of oxygen. (LAUS, 2005)

Reference 2

Endpoint:

water solubility

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is hydrolytically unstable at pH 4, 7 and 9 (half-life less than 12 hours)

Description of key information

In accordance with Annex VII, column 2, determination of water solubility does not need to be conducted as Sika Hardener LJ rapidly hydrolyses at pH 4, 7 and 9 with half life times under 12h (see section 5.1.2).

For risk assessment purposes the water solubility of the hydrolysis products, Aldehyde L, CAS 102985-93-3, was used, as it was considered to be the worst case. The other hydrolysis product, Polyoxpropylenediamine, CAS 9046-10-0, is miscible in water.

Key value for chemical safety assessment

Water solubility:

0.679 mg/L

at the temperature of:

25 °C

Additional information

1. waiver

In accordance with Annex VII, column 2, determination of water solubility does not need to be conducted as Sika Härter LJ rapidly hydrolyses at pH 4, 7 and 9 with half life times under 12h (see section 5.1.2).

2. supporting study

A study was conducted to determine the water solubility of 2,2-Dimethyl-3-lauroyloxy-propanal, one of the starting compounds of Hardener LJ and one of the hydrolysis products. A defined value for the solubility in water could not be determined due to the properties of 2,2-Dimethyl-3-lauroyloxy-propanal: hydrolysis prevents the reaching of a solubility equilibrium.

The column elution method was chosen to determine the water solubility. Because of the properties of the test item, which consists of a oily liquid with low viscosity, no suitable carrier could be found. Therefore, the slow-stirring-method was chosen (draft OECD guideline, originally developed for the determination of log Pow) which avoids the formations of emulsions. In the main study, approx. 6 mL test item were given on 850 mL H2O under nitrogen and stirred at 20.0 ± 0.5 °C. Samples of all vessels showed values below LOQ of the analytical method (< 0.1 mg/L).

An additional experiment investigating the stability of the test item in water showed, that after spiking of deionized water giving a nominal concentration of 0.26 mg/L, the test item hydrolyses rapidly in contact with water, even in the absence of oxygen (LAUS, 2005). The estimation of the water solubility of Aldehyde L was performed using US EPA EPIWIN WSKOW (version 1.41) program. A water solubility of 0.679 mg/L at 25 °C was estimated for Aldehyde L.

The other hydrolysis products, Polyoxpropylenediamine, CAS 9046-10-0, was determined to be miscible in water. Based on this information, the water solubility of Aldehyde L was chosen as the worst case and its water solubility was used for further risk assessment purposes.