Reaction products of Dihydro-3-(tetrapropenyl)furan-2,5 dione with propane-1,2,diol

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 January 2016 to 07 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: REACH guidance on (Q)SARs R.6

Version / remarks:

May/July 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

no

Estimation method (if used):

- Due to issues with the water solubility analysis, which meant that only a less than figure could be reported for the diester, and the issues with validation of an analytical method at multiple pH levels it was decided in consultation with the Sponsor that it would not be possible to perform definitive hydrolysis testing on the test material and get reliable results. As a result, it was decided that calculated values would be provided for hydrolysis using Estimation Program Interface (EPI ver. 4.1) software.

HYDROWIN:
- HYDROWIN estimates aqueous hydrolysis rate constants and half-lives of a variety of chemical structure classes for which hydrolysis may be significant.
- The rate at which a substance hydrolyses is estimated by the HYDROWIN™ model. This model estimates the rate at which a chemical will react with water. Hydrolysis processes are pH sensitive and are an important degradation process at typical environmental pH ranges (pH 5 to 9). HYDROWIN™ estimates acid- and base-catalysed rate constants for esters, carbamates, epoxides, halomethanes, and certain alkyl halides. HYDROWIN™ provides estimations by converting acid, neutral, and base rate constants to half-lives at pH 7 and 8.
- Therefore, if any of these functional groups are not present, HYDROWIN™ does not return an estimated hydrolysis constant.
- For chemicals with a rapid hydrolysis half-life it is important to assess the hydrolysis product. A hydrolysis half-Life between 1 hour and 14 days assess both the parent compound and the hydrolysis product, and a hydrolysis half-Life > 14 days assess the parent compound.

Transformation products:

not specified

Key result

pH:

7

DT50:

6.685 yr

Type:

other: Monoester

Key result

pH:

8

DT50:

244.164 d

Type:

other: Monoester

Key result

pH:

7

DT50:

5.224 yr

Type:

other: Diester

Key result

pH:

8

DT50:

190.817 d

Type:

other: Diester

Details on results:

- Calculated values for hydrolysis were estimated using the HYDROWIN model.
- The rate at which a chemical reacts with water is predicted by HYDROWIN. Hydrolysis is pH sensitive and HYDROWIN provides estimations by converting acid, neutral and base rate constants to half-lives at pH 7 and pH 8.
- HYDROWIN™ estimates acid- and base-catalysed rate constants for esters, carbamates, epoxides, halomethanes, and certain alkyl halides by using fragments taken from a fragment library. In the case of the constituents of the test material, fragments for these were not available from the fragment library, so substitutes were used. The substitutes used were as follows:
The monoester:

Ester R1-C (=O) –O-R2

where:
R1 is iso-propyl- and
R2 is iso-propyl-

The diesterl:

Ester R1-C (=O) –O-R2

where:
R1 is iso-butyl- and
R2 is iso-butyl- and

Ester R1-C (=O) –O-R2

where:
R1 is iso-propyl-
R2 is iso-propyl-
 
- Based on the predicted values, hydrolysis appears to be a very slow process especially at neutral conditions (pH 7).
- The acid: The EPI suite software could not estimate a hydrolysis rate constant for the chemical structure of the acid. The software estimates hydrolysis based on esters, carbamates, epoxides, halomethanes (containing 1-3 halogens), specific alkyl halides and phosphorous esters only.
- The monoester: Half-life (kb) – pH 7 = 6.685 years, pH 8 = 244.164 days.
- The diester: Half-life (kb) – pH 7 = 5.224 years, pH 8 = 190.817 days.

Validity criteria fulfilled:

not specified

Conclusions:

Based on the predicted values, hydrolysis appears to be a very slow process especially at neutral conditions (pH 7).
The acid: The EPI suite software could not estimate a hydrolysis rate constant for the chemical structure of the acid.
The monoester: Half-life (kb) – pH 7 = 6.685 years, pH 8 = 244.164 days.
The diester: Half-life (kb) – pH 7 = 5.224 years, pH 8 = 190.817 days.

Executive summary:

The hydrolysis of the test material was investigated using calculation methods.

Due to issues with the water solubility analysis, which meant that only a less than figure could be reported for the diester, and the issues with validation of an analytical method at multiple pH levels it was decided , in consultation with the Sponsor, that it would not be possible to perform definitive hydrolysis testing on the test material and get reliable results. As a result, it was decided that calculated values would be provided for hydrolysis using Estimation Program Interface (EPI ver. 4.1) software. The rate at which a substance hydrolyses is estimated by the HYDROWIN™ model. This model estimates the rate at which a chemical will react with water.

Based on the predicted values, hydrolysis appears to be a very slow process especially at neutral conditions (pH 7).

The acid: The EPI suite software could not estimate a hydrolysis rate constant for the chemical structure of the acid.

The monoester: Half-life (kb) – pH 7 = 6.685 years, pH 8 = 244.164 days.

The diester: Half-life (kb) – pH 7 = 5.224 years, pH 8 = 190.817 days.

Description of key information

HYDROWIN™ estimates acid- and base-catalysed rate constants for esters, carbamates, epoxides, halomethanes, and certain alkyl halides by using fragments taken from a fragment library. In the case of the constituents of the test material, fragments for these were not available from the fragment library, so substitutes were used.

Based on the predicted values, hydrolysis appears to be a very slow process especially at neutral conditions (pH 7):

The acid: The EPI suite software could not estimate a hydrolysis rate constant for the chemical structure of the acid.

The monoester: Half-life (kb) – pH 7 = 6.685 years, pH 8 = 244.164 days.

The diester: Half-life (kb) – pH 7 = 5.224 years, pH 8 = 190.817 days.

As it was not possible to experimentally generate a value for this substance, and EPI Suite was unable to predict the hydrolysis for the substance as a whole or for all of the individual components, it is not considered possible to predict the hydrolysis for this substance.

Additional information

The hydrolysis of the test material was investigated using calculation methods.

Due to issues with the water solubility analysis, which meant that only a less than figure could be reported for the diester and the issues with validation of an analytical method at multiple pH levels it was decided, in consultation with the Sponsor, that it would not be possible to perform definitive hydrolysis testing on the test material and get reliable results. As a result, it was decided that calculated values would be provided for hydrolysis using Estimation Program Interface (EPI ver. 4.1) software. The rate at which a substance hydrolyses is estimated by the HYDROWIN™ model. This model estimates the rate at which a chemical will react with water.

Based on the predicted values, hydrolysis appears to be a very slow process especially at neutral conditions (pH 7):

The acid: The EPI suite software could not estimate a hydrolysis rate constant for the chemical structure of the acid.

The monoester: Half-life (kb) – pH 7 = 6.685 years, pH 8 = 244.164 days.

The diester: Half-life (kb) – pH 7 = 5.224 years, pH 8 = 190.817 days.

As it was not possible to experimentally generate a value for this substance, and EPI Suite was unable to predict the hydrolysis for the substance as a whole or for all of the individual components, it is not considered possible to predict the hydrolysis for this substance.