tert-pentyl 2-ethylperoxyhexanoate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 29/08/2011 to 02/09/2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study was performed according to OECD Guideline 105 with GLP statement. This study is well documented but one of the values at 24h was lower than the other and one of the flasks of the 72h assay gave a significantly higher analytical result.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

. One of the replicates of the 72h assay gave an abnormal analytical result. The correspondent value was not retained for the data treatment.

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

2011-03-07

Type of method:

flask method

Key result

Water solubility:

17.6 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

4.64

Remarks on result:

other: Retained result.

Details on results:

During the analysis, the temperature was 20.06 +/- 0.15°C and the mean value of pH was 4.64.
One of the values at 24h was lower than the other, when one of the values at 72h gave a significantly higher analytical result. However, over the 72h period, the common measurement was approximately 17.6 mg/L, so this value is considered to be likely true solubility in pure water, while the solubility range is between 14.8 and 27.2 mg/L.
See table 4.8/1 in "Any other information on results incl. tables".

Table 4.8/1: Results of water solubility of the test item

Test	Results
Water solubility OECD 105 – Flask Methode	pH	Water solubility at 20°C, mg/L
Test T 24h Test T 48h Test T 72h	4.79 4.61 4.53	17.5 16.7 17.7	14.8 17.6 (27.2)
Retained result	4.64	17.6

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L)
The water solubility of the test item was approximately 17.6 mg/L at mean temperature of 20°C and at mean pH of 4.64.

Executive summary:

The water solubility of the test item was assessed according to the OECD Guideline 105 with GLP statement.

Two methods, the column elution method and the flask method which cover respectively solubilities below and above 10-² g/L are described in the OECD Guideline 105. As the water solubility was expected to be near 30 mg/L for the test item, it appeared that the flask method was best suited.

The test is preferably run at 20 +/- 0.5°C. The chosen temperature should be kept constant in all relevant parts of the equipment. The pH of each sample should be measured. Six 250 mL Schott flasks were used to mix 13.5 µL of the test item with 100 mL of ultrapure water. Flasks were placed in a temperature controlled oven at 30°C under magnetic stirring. After 24 hours, two flasks were removed and placed in another temperature controlled oven at 20 +/- 0.5°C during 24 hours. After separation of the upper phase by decantation, the concentration of the test item in the clear aqueous lower phase was then determined following the analytical method (HPLC/MS, detection limit of the method is 0.11 mg/L i.e 0.23 mg/L in the matrix and quantification limit is 0.38 mg/L i.e 0.75 mg/L in the matrix). The other flasks were treated similarly after initial equilibration at 30°C for 2 and 3 days respectively.

Water solubility results of each replicate are presented below:

- T.24h: test item concentration 17.5 - 14.8 mg/L (pH: 4.79);

- T.48h: test item concentration 16.7 - 17.6 mg/L (pH: 4.61);

- T.72h: test item concentration 17.7 - 27.2 mg/L (pH: 4.53).

During the analysis, the temperature was 20.06 +/- 0.15°C and the mean value of pH was 4.64.

One of the values at 24h was lower than the other, when one of the values at 72h gave a significantly higher analytical result (the correspondent value was not retained for the data treatment). However, over the 72h period, the common measurement was approximately 17.6 mg/L, so this value is considered to be likely true solubility in pure water, while the solubility range is between 14.8 and 27.2 mg/L.

Description of key information

OECD 105, GLP , Flask method, key study, validity 2:
Water solubility = 17.6 mg/L (14.8-27.2 mg/L) at 20°C and pH 4.64.

Key value for chemical safety assessment

Water solubility:

17.6 mg/L

at the temperature of:

20 °C

Additional information

One key study is available to assess the water solubility of the test substance, according to the OECD Guideline 105 with GLP statement. As the water solubility was expected to be near 30 mg/L for the test item, the flask method was performed.

During the analysis, the temperature was 20.06 +/- 0.15°C and the mean value of pH was 4.64.

One of the values at 24h was lower than the other, when one of the values at 72h gave a significantly higher analytical result (the correspondent value was not retained for the data treatment). However, over the 72h period, the common measurement was approximately 17.6 mg/L, so this value is considered to be likely true solubility in pure water, while the solubility range is between 14.8 and 27.2 mg/L.