Bis(4-methylbenzoyl)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:

7-9 October 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well conducted GLP study, according to OECD and EU guidelines, purity mentioned.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

Adopted May 12, 1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

September 1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Water solubility:

0.043 mg/L

Temp.:

20 °C

pH:

6

A schematic flowchart of the on-line system used is shown in Figure 1in the attachment. Representative HPLC chromatograms of a standard solution of DI-(4-METHYLBENZOYL)-PEROXID (INTEROX-PMBP), a water sample from Column I and a water sample from the blank column (Column IV) are shown in Figures 2, 3 and 4, respectively in the attachment.

The chromatograms of the water samples showed a number of peaks around the main component of the test substance. Whether these additional peaks represent possible degradation products andlor impurities with relatively high water solubility, was nor further investigated.

The chromatograms of the samples taken from the blank column at 20.0 ± 0.5°C did not-show any peak with the same retention as the test substance.

The water solubility estimated from preliminary test 1 was 6x10^-6g/L

The water solubility estimated from preliminary test 2 was 4.9x10^-5g/L at 21.0 ± 0.5°C (individual measurements not shown).

The results of the individual measurements of the first experiment (Column I) and the third experiment (Column III) of the main study are summarized in Table 1 and 2, respectively.

The mean water solubility, as determined for Column II, was 4.6x10^-5and 5.3x10^-5g/L at a flowrate of 23 and 12 ml/hour, respectively (further details not reported). Because the maximum deviation was 32 % at both flowrates, an additional experiment (i.e. Column III) was carried out.

The water solubility of the test substance was calculated to be 4.3x 10^-5g/l, as the mean value of the water solubilities as determined during the first experiment (Column I) and the third experiment (Column III). The maximum deviation between both water solubilities was calculated to be 14%. During the first experiment as well as during the second experiment, the coefficient of variation of at least 5 consecutive samples at each flowrate was<30%. The maximum deviation between the water solubilities as determined during the high and low flowrate was<30% for both experiments.The maximum deviation between the water solubilities of both experiments was<30%. According to the guidelines (OECD, EEC), the test was considered to be valid.

In conclusion, the water solubility of DI-(4-METHYLBENZOYL)-PEROXID (INTEROX-PMBP) at 20.0±0.5°Cwas determined to be 4.3x10^-5g/L, using the column elution method.

Conclusions:

The water solubility of bis(4-methylbenzoyl)peroxide at 20°C is 0.043mg/L.

Executive summary:

The determination of the water solubility was based on OECD Guideline No.105 Water solubility (column elution method - flask method) (1981) and EEC directive A.6 Water solubility(1984), using the column elution method.

The water solubility of bis(4-methylbenzoyl)peroxide at 20°C is 0.043mg/L.

Description of key information

 The water solubility of bis(4-methylbenzoyl)peroxide at 20°C is 0.043mg/L.

Key value for chemical safety assessment

Water solubility:

0.043 mg/L

at the temperature of:

20 °C

Additional information

Experimentally determined water solubility is 0.043 mg/L (insoluble, < 0.1 mg/L).