Dibutyl peroxydicarbonate

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is hydrolytically unstable at pH 4, 7 and 9 (half-life less than 12 hours)

Reference 2

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2019-09-28

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

Experimental determination of the water solubility is technically not possible because the substance decomposes during testing. However, as a value is required for exposure calculations, QSAR estimation is included as key value for chemical safety assessment. Please refer to QPRF/QMRF documentation for detailed information on model suitability.

Qualifier:

according to guideline

Guideline:

other: Guidance on information requirements and chemical safety assessment Chapter R.6: QSARs and grouping of chemicals

Version / remarks:

May 2008

Principles of method if other than guideline:

QSAR prediction using WSKOW v1.42 of EpiSuite v4.11. The QSAR program estimates the water solubility of an organic compound using the compound's log octanol-water partition coefficient (log Kow).

GLP compliance:

no

Type of method:

other: QSAR calculation

Specific details on test material used for the study:

SMILES: CCCCOC(=O)OOC(=O)OCCCC

Key result

Water solubility:

54.44 mg/L

Temp.:

25 °C

Remarks on result:

other: pH not available in QSAR prediciton.

Details on results:

see QPRF

Conclusions:

The estimated water solubility of the test item is 54.44 mg/L at 25 °C.

Executive summary:

The estimated water solubility of the test item is 54.44 mg/L at 25 °C. The estimation program used was WSKOWWIN v1.42 implemented in EpiSuite v4.11.

Description of key information

In accordance with REACH Annex VII, section 7.7, this study does not need to be conducted because the test item is not hydrolytically stable (see IUCLID section 5.1.2).

EpiSuite estimate: 54.44 mg/L [from Log Kow (WSKOW v1.42)];

Key value for chemical safety assessment

Water solubility:

54.44 mg/L

at the temperature of:

25 °C

Additional information

Due to the known tendency of the test item to fast hydrolysis in water the standard Tier 1 testing was not performed. To be able to experimentally verify the fast hydrolysis of the test item, samples were prepared in NMR tubes and repeated measurements were performed at room temperature (approx. 22°C). The test item was dissolved in acetonitrile-d3 and 100 µL of distilled water were subsequently added to start the hydrolysis reaction. Due to the need for modified testing conditions (-> high content of organic modifier acetonitrile-d3), the test was performed without adjustment of pH. (Please note: pH values can only be defined/adjusted for aqueous solutions; as the experiment had to be performed in an organic solvent due to the poor water solubility of the test item, adjustment of the pH is thus not possible.)

At room temperature (approx. 22°C) the test item was found to be instable upon addition of small amounts (100 µL) of water. Hydrolysis started immediately after addition of water to the test item dissolved in acetonitrile-d3. The analytical determination of the concentration of the intact test item at the t = 0 min was possible prior to addition of water. The first measurement of the test item after addition of water after approx. 17 min of hydrolysis time (incl. measuring time), showed hydrolysis at a level of approx. 19 %. The half-life as well as the hydrolysis rate constant at room temperature (approx. 22°C) could be estimated. For the given experimental set-up, the measured half-life of the test item without pH adjustment was 66.6 min.  For further details on the performance of the experimental hydrolysis study please refer to IUCLID chapter 5.1.2.