Reaction product of 2,4-bis(2-methylbutan-2-yl)phenol and phosphorous pentoxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 February 2017 to 22 February 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Key result

Water solubility:

0.34 g/L

Conc. based on:

test mat.

Incubation duration:

5 d

Temp.:

20 °C

pH:

3

Details on results:

DEFINITIVE TEST RESULTS
Samples were taken from the three flasks at two time points: Day 4 and Day 5. Table 1 summarises the analytical measurements from the experiment. The between day difference between Day 4 and 5 was less than 15 %. No other sampling was required. The amount of test material dissolved in water was 0.34 g/L. The test temperature ranged from 19.6 to 20.3 °C (20.0 ± 0.35 °C).

OBSERVATIONS
No chemical instability was observed during the test. It was noted during method development that increasing amounts of un-dissolved test material in water led to increasing apparent solubility of the test material. The test material is a UVCB; therefore the increasing amount of material found in the water during method development may be due to preferentially soluble components in the test material or impurities.

Table 1: Results summary

Sample	Day 4 (g/L)	pH	Day 5 (g/L)	pH
Sample 1	0.33	3	0.34	3
Sample 2	0.34	3	0.36	3
Sample 3	0.34	3	0.35	3
Time point’s average test material concentration	0.34		0.35
Within day RSD (%)	1.7		2.8
Between day average test material concentration (g/L)	0.34
Between day difference (%)	2.6

RSD = Relative Standard Deviation

Conclusions:

Under the conditions of this study the test material had a water solubility of 0.34 g/L at 20.0 °C.

Executive summary:

The water solubility of the test material was determined in accordance with the standardised guideline OECD 105 under GLP conditions using the flask method.

A preliminary test was conducted in order to approximate the amount of test material that would dissolve in water and the time required to reach saturation. There was un-dissolved test material visible on the surface of the water in the preliminary test flask when observed after shaking overnight. Therefore the preliminary test indicated a water solubility of less than 1 g/L.

The flask method was used for determination of solubility. Based on the preliminary test results, three containers with lids were prepared containing 0.1 g of the test material in 100 mL of water. Flasks were placed in a water bath at 20.0 ± 0.5 °C with constant orbital shaking at 150 rpm until equilibrium was reached. Equilibrium was determined by either the observation that no un-dissolved test material remained, or, by two consecutive daily measurements of the dissolved test material being within 15 % of each other. An aliquot from each flask was collected after Day 4 and 5 for analysis. The between day difference between Day 4 and 5 was less than 15 % so no other sampling was required.

Under the conditions of this study the test material had a water solubility of 0.34 g/L at 20.0 °C.

Description of key information

Under the conditions of this study the test material had a water solubility of 0.34 g/L at 20.0 °C.

Key value for chemical safety assessment

Water solubility:

0.34 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test material was determined in accordance with the standardised guideline OECD 105 under GLP conditions using the flask method. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

A preliminary test was conducted in order to approximate the amount of test material that would dissolve in water and the time required to reach saturation. There was un-dissolved test material visible on the surface of the water in the preliminary test flask when observed after shaking overnight. Therefore the preliminary test indicated a water solubility of less than 1 g/L.

The flask method was used for determination of solubility. Based on the preliminary test results, three containers with lids were prepared containing 0.1 g of the test material in 100 mL of water. Flasks were placed in a water bath at 20.0 ± 0.5 °C with constant orbital shaking at 150 rpm until equilibrium was reached. Equilibrium was determined by either the observation that no un-dissolved test material remained, or, by two consecutive daily measurements of the dissolved test material being within 15 % of each other. An aliquot from each flask was collected after Day 4 and 5 for analysis. The between day difference between Day 4 and 5 was less than 15 % so no other sampling was required.

Under the conditions of this study the test material had a water solubility of 0.34 g/L at 20.0 °C.