Formaldehyde, oligomeric reaction products with diethylenetriamine and phenol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

yes

Type of method:

flask method

Key result

Remarks on result:

not determinable

Details on results:

As the test item was a liquid, the flask method was considered applicable.

Although the standard EC A.6 / OECD 105 methodology was initially attempted, it was considered after review of the preliminary test analysis and observations that it was not completely applicable to this test item. Therefore, a range of sample concentrations from a nominal 5 to 95% w/w were prepared for visually assessment. The visual assessment of the preliminary test samples was included with those of the definitive test to add extra information and assist in the assessment of the test results. The preliminary test sample concentrations were calculated as % w/w by assuming the 100 mL of water used weighed 100 g.

Up to approximately 25% w/w the observations suggested a majority of the test item dissolved in the water. As the test item was a complex mixture, the undissolved test item was probably mostly comprised of the least soluble components. Up to this concentration, some of the more water soluble components could be essentially fully dissolve. The test guidelines are not ideally suited to determining the water solubility of complex mixture as each component has a governing effect on the other components. As a simplistic description, the most soluble components will aid the dissolution of moderately soluble components which in turn aid the least soluble components; this is a so called “co-solvent effect”.

At higher concentrations, from approximately 50 to 95% w/w, the test item was observed to be miscible with water. At these concentrations there were enough water soluble components to keep all components and the water as a single solution.

From these results, it was evident that water solubility of the test item was loading rate dependent. This was not unexpected as the test item was a complex mixture. Therefore, as the solubility of the test item was loading rate dependent, a single definitive value was not possible.

Sample	Concentration (% w/w)	Observations	Solution pH
P1	0.09	colorless, clear liquid visually free of excess/undissolved test item	not taken
P2	0.99	Yellow, clear liquid with excess/undissolved test item	10.6
1	5.03	Amber, clear, non-viscous liquid with small amount of excess/undissolved test item	10.6
P3	9.10	Amber, clear liquid with a small amount of excess/undissolved test item 11.1 2 25.2 11.0 3 49.3 11.4 4 74.8 5 95.0	11.1
2	25.2	Dark amber, clear, non-viscous liquid with excess/undissolved test item	11.0
3	49.3	Dark amber, clear, non-viscous liquid visually free of excess/undissolved test item	11.4
4	74.8	Amber, clear viscous liquid visually free of excess/undissolved test item	not feasible
5	95.0	Amber, clear viscous (more so than Sample 4) liquid visually free of excess/undissolved test item	not feasible

Conclusions:

The water solubility of the test item at 20.0 ± 0.5 °C has been demonstrated to be loading rate dependent with at least a majority of the test item dissolving at all loading rates.
As the solubility of the test item was loading rate dependent, a single definitive value was not possible.

Executive summary:

Demonstrated to be loading rate dependent at 20.0 ± 0.5 °C with at least a majority of the test item dissolving at all loading rates, using the flask method, designed to be compatible with Method A.6 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.

As the solubility of the test item was loading rate dependent, a single definitive value was not possible.

Description of key information

The water solubility of the test item at 20.0 ± 0.5 °C has been demonstrated to be loading rate dependent with at least a majority of the test item dissolving at all loading rates.

As the solubility of the test item was loading rate dependent, a single definitive value was not possible.