Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
5th March 1993 to 1st October 1993
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
Deviations:
no
Principles of method if other than guideline:
The study report states that the test was performed in accordance with EEC 84/449 Method C10. However, this test method does not refer to a hydrolysis study and hence is considered to be a typographical error in the report.
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Purity: 97.3% (considered as 100%)
Batch number: 9236-23
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
Samples were taken at different time intervals (0, 17, 21, 27, 41, 65, 89, 113 and 120 h) and stored at 4°C until assay by high performance liquid chromatography (HPLC).
At pH 4 degradation was observed to occur before time point 17 hours; therefore, a second test was performed with two additional time points 2.4 and 3.5 hours.
Buffers:
- pH: pH 4, 7 and 9 buffers were used
- Type and final molarity of buffer: Not specified
- Composition of buffer: Not specified
Estimation method (if used):
N/A
Details on test conditions:
TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: The test was performed in 25 mL volumetric flasks.
- Sterilisation method: Not specified
- Lighting: The samples were placed in the dark at 50 °C.
- Measures taken to avoid photolytic effects: The samples were placed in the dark.
- Measures to exclude oxygen: Not specified
- Details on test procedure for unstable compounds: N/A
- Details of traps for volatile: N/A
- If no traps were used, is the test system closed/open: Not specified
- Is there any indication of the test material adsorbing to the walls of the test apparatus?: Not specified

TEST MEDIUM
- Volume used/treatment: Not specified
- Kind and purity of water: Not specified
- Preparation of test medium: Not specified
- Renewal of test solution: Not specified
- Identity and concentration of co-solvent: The stock solution of the test article was prepared in acetonitrile.

OTHER TEST CONDITIONS
- Adjustment of pH: Not specified
- Dissolved oxygen: Not specified
Duration of test
Duration:
120 d
Temp.:
50 °C
Initial conc. measured:
50 other: mg/L in acetonitrile (concentration of stock solution)
Number of replicates:
For each pH, two samples of 12.5 µL each were prepared in a volumetric flask and the volume made up with the appropriate buffer.
Positive controls:
no
Negative controls:
no
Statistical methods:
Not specified

Results and discussion

Preliminary study:
A preliminary study was performed but the results are not specified.
Test performance:
None specified
Transformation products:
not measured
Details on hydrolysis and appearance of transformation product(s):
Not specified
Dissipation DT50 of parent compoundopen allclose all
pH:
4
Temp.:
50 °C
DT50:
1.78 h
Remarks on result:
other: Hydrolysis rate constant is essentially zero. r2 = 0.786
pH:
7
Temp.:
50 °C
DT50:
> 120 h
Remarks on result:
other: Hydrolysis rate constant is essentially zero. r2 = 0.292
pH:
9
Temp.:
50 °C
DT50:
> 120 h
Remarks on result:
other: Hydrolysis rate constant is essentially zero. r2 = 0.180
Other kinetic parameters:
Not specified
Details on results:
Under the experimental conditions described, the half-time (T1/2) of the test article was :
- pH 4: T1/2 = 1.78 hours
- pH 7: T1/2 > 5 days
- pH 9: T1/2 > 5 days

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
At each pH 4, the half life was equal to 1.78 hours.
At pH 7 and 9, less than 10% hydrolysis is observed after 5 days.
Executive summary:

The hydrolysis study was performed in accordance with OECD Guideline 111 and EEC Directive 84/449 Method C.7.

At each pH 4, the half life was equal to 1.78 hours. At pH 7 and 9, less than 10% hydrolysis is observed after 5 days.