dimethyl 1,2-benzenedicarboxylate;reaction mass of: 1,2-dimethylpropylidene dihydroperoxide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 April 2002 - 31 May 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes

Type of method:

flask method

Water solubility:

1.73 g/L

Temp.:

20 °C

pH:

>= 3.5 - <= 3.6

Remarks on result:

other: MIPKP-T3 peak 2

Details on results:

Based on the results of the priliminary test it was decided to centrifuge the samples from the main study three times.

In the main study the test substance was stirred with double distilled water (in triplicate) at a nominal concentration of 1 g/ml. After each stirring period, the water mixture was still a two-phase system (water and test substance).
Duplicate samples were taken from each water mixture after 24, 48 or 72 hours of stirring. The supernatants obtained after three successive centrifugation steps (3500 g, 5 min., 20°C) were analysed. The temperature of the climate room was 20.0 ± 0.4°C during the performance of the test. The analytical results for the samples are summarised in the attached Table. No (significant) concentrations were measured in the blank water mixture for the components of concern.

After each stirring period (17 days; preliminary test or 24, 48 or 72 hours; main study), there was still a two-phase system (water and test substance). Analytical measurements on each the components of concern in the water phase gave the following results: Hydrogen peroxide appeared to be the component with the highest water solubility. The preliminary test showed that at a test substance:water ratio of 1:1 (v:v) the concentrations analysed were a factor of 2 higher than at a test substance:water ratio of 1:2 (v:v). At both concentration levels, the concentrations analysed were far above the nominal concentration, indicating that hydrogen peroxide might be formed due to reaction of the other compounds with

water. The main study confirmed this assumption and showed that hydrogen peroxide concentrations increased with stirring time. After 24 hours of stirring, the concentrations analysed were already higher than the nominal concentration of 1 g/ml (i.e. a test substance:water ratio of 1:1 (v:v». Based on Hydrogen peroxide, it was determined to be miscible with water in at least a 1:1 (v:v) ratio.

Both MIPKP-T4 and MIPK appeared to be good water soluble substances. Based on the results form the main study, it was concluded that MIPKP-T4 decomposes with time, whereas MIPK seems to be a decomposition product. Based on MIPK, the water solubility was determined to be ± 230 g/l, based on MIPKP-T4, the water solubility was estimated to be ± 201 g/l (maximum concentrations found in the aqueous samples).

MIPKP-T3 peak 1 and MIPKP-T3 peak 2 appeared to be the least water soluble components. For both components, a slight decrease in concentration was observed over the duration of the main study. Therefore, the solubility of the test substance based on MIPKPT3 peak 1 and MIPKP-T3 peak 2 is reported as the average of the 24 hours samples. Based on MIPKP-T3 peak 1, the water solubility was determined to be 2.53 g/l. Based on MIPKP-T3 peak 2, the water solubility was determined to be 1.73 g/l.

Conclusions:

Interpretation of results (migrated information): soluble (1000-10000 mg/L)
During the test, hydrogen peroxide is formed as a result of the reaction of the other peroxidic compounds with water. Based on Hydrogen peroxide, it was determined to be miscible with water in at least a 1:1 (v:v) ratio.
During the test MIPK is formed as a result of the reaction of the other peroxidic compounds with water. Based on MIPK, the water solubility was determined to be ≥ 230 g/l.
Based on MIPKP-T4, the water solubility was estimated to be ≥ 201 g/l.
Based on MIPKP-T3 peak 1, the water solubility was determined to be 2.53 g/l.
Based on MIPKP-T3 peak 2, the water solubility was determined to be 1.73 g/l.

Executive summary:

Guidelines and test method

The flask method was used to determine the water solubility and was based on the following guidelines:

OECD guideline for testing of chemicals no. 105: "Water Solubility", Adopted July 27,1995.

EEC Directive 92/69 EEC, Part A, Methods for the determination of physico-chemical properties, A.6: "Water solubility". EEC Publication no. L383, December 1992.

Quantification

Measurements were performed on the following components: Hydrogen peroxide, MIPK, MIPKP-T4 and MIPKP-T3. Due to the fact that DMP, which was used for preparation of this formulation, is a very well known compound, which cannot be determined in the same chromatographic run as the other compounds due to a large difference in sensitivity (see also Notox Project 338805 "Development and validation of an analytical method for Trigonox R-938"), analyses were not based on this compound.

Test results

After each stirring period (17 days; preliminary test or 24, 48 or 72 hours; main study), there was still a two-phase system (water and test substance). Test temperature: 20.0 ± 0.5°C (preliminary test) and 20.0 ± 0.4°C

(main study). Analytical measurements on each of the components of

concern in the water phase gave the following results:

During the test, hydrogen peroxide is formed as a result of the reaction of the other peroxidic compounds with water. Based on Hydrogen peroxide, it was determined to be miscible with water in at least a 1:1 (v:v) ratio.

During the test MIPK is formed as a result of the reaction of the other peroxidic compounds with water. Based on MIPK, the water solubility was determined to be ± 230 g/l. Based on MIPKP-T4, the water solubility was estimated to be ± 201 g/l. Based on MIPKP-T3 peak 1, the water solubility was determined to be 2.53 g/l. Based on MIPKP-T3 peak 2, the water solubility was determined to be 1.73 g/l.

Description of key information

After each stirring period (17 days; preliminary test or 24, 48 or 72 hours; main study), there was still a two-phase system (water and test substance).

Test temperature: 20.0 ± 0.5°C (preliminary test) and 20.0 ± 0.4°C (main study). Analytical measurements on each of the components of concern in the water phase gave the following results:

During the test, hydrogen peroxide is formed as a result of the reaction of the other peroxidic compounds with water.

Based on Hydrogen peroxide, it was determined to be miscible with water in at least a 1:1 (v:v) ratio.

During the test MIPK is formed as a result of the reaction of the other peroxidic compounds with water.

Based on MIPK, the water solubility was determined to be ± 230 g/l. Based on MIPKP-T4, the water solubility was estimated to be ± 201 g/l. Based on MIPKP-T3 peak 1, the water solubility was determined to be 2.53 g/l. Based on MIPKP-T3 peak 2, the water solubility was determined to be 1.73 g/l.

Key value for chemical safety assessment

Water solubility:

1.73 mg/L

at the temperature of:

20 °C