Dioctanoyl peroxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

The slow-stirring technique was used instead of the column elution techniques

GLP compliance:

yes (incl. QA statement)

Type of method:

other: Slow-stirring method

Specific details on test material used for the study:

Chemical name: dioctanoyl peroxide
Trade name: Perkadox SE-8
CAS: 762-16-3
Batch/Lot no.: 1204350050
Purity: 99.2%
Composition: see CoA (Annex 2)
Appearance: White flakes
Expiry date: January 18, 2016
Storage: - 20°C

Key result

Water solubility:

ca. 7 µg/L

Conc. based on:

test mat.

Loading of aqueous phase:

0.1 mg/L

Incubation duration:

>= 1 - <= 5 h

Temp.:

20 °C

pH:

7

Remarks on result:

other: flasks were sampled after 1, 2, 3, 4 and 5 h of slow stirring

Details on results:

In the preliminary test a visual check on dissolution was done after the addition of increasing volumes of demineralized water to an aliquot of the test substance. After addition of 1 ml of demineralized water the white flakes of the test substance were dissolved, however oily type droplets were visible on the water surface. After addition of 1000 mL demineralized water these oily droplets were still present. A sample was taken from the middle of the test vessel and analyzed. The concentration was determined to be 3.1 mg/L test substance. This value was probably caused by test substance adsorbing to the pipette tip used to take the analysis sample.

In the definitive test the slow-stirring technique was applied. The definitive test was performed twice, because the first experiment was considered not to be reliable because of the difference between the measured values of the duplicate samples per time point. The determined result for water solubility of the test substance at the time points 1, 2, 3, 4 and 5 hours were all below the limit of quantification.

The pH value of the test solution at the different time points was measured to be 7. The temperature during the test varied between 19.3 and 19.8 °C.

The following quality criteria were met:
• The test temperature during the study was measured to be within the criteria, 20.0 ± 1.0°C.
• The individual results determined at subsequent time points differed not more than 15% during the final definitive test.

Conclusions:

The water solubility of dioctanoyl peroxide was determined at a temperature of 20°C and based on OECD guideline 105. The data on water solubility represent the saturation mass concentration of the test substance in water.

The determined final result for water solubility of the test substance was calculated to be lower than
10 µg/L, the limit of quantification. The water solubility was estimated to be 7 µg/L.

Executive summary:

The determined final result for water solubility of the test substance was calculated to be lower than

10 µg/L, the limit of quantification. The water solubility was estimated to be 7 µg/L.

Description of key information

The water solubility was determined to be 7 µg/ @ 20 oC.

Key value for chemical safety assessment

Water solubility:

7 µg/L

at the temperature of:

20 °C