Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 6 March to 20 September 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to the OECD Guideline and it is GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

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
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Physical state: clear colorless liquid
- Storage condition of test material: room temperature in the dark

Study design

Analytical monitoring:
yes
Details on sampling:
An aliquot of each sample was diluted by a factor of 5 using acetone.
Buffers:
The test system used sterile buffer Solutions at pH's 4, 7 and 9
Details on test conditions:
Preparation of the Sample Solutions
Stock solutions were prepared in glass flasks at a nominal concentration of 100 mg/L in the three buffer solutions. A 1% co-solvent of acetone was used to aid dissolution. The stock solutions were split into individual sealed glass vials (with no headspace) for each data point. The sample solutions were shielded from light whilst maintained at the test temperature.
Duration of test
Duration:
120 h
Temp.:
50 °C
Number of replicates:
Duplicate standard solutions of test item were prepared in acetone: water (80:20 v/v) at a nominal concentration of 20 mg/L.

Results and discussion

Preliminary study:
An initial attempt of the preliminary test indicated a significant decrease in the test item concentration over time at 50ºC; whereas, based on the chemical structure of the test item it was expected to be stable towards hydrolysis at the test temperature and pH. Consequently, it was suspected that the loss of test item was possibly due to volatility issues, and thus, testing was repeated using sealed glass vials but with no headspace above the sample solutions.
Test performance:
The pH of the sample solutions remained at the nominal pH±0.2 during testing.
No significant peaks were observed at the approximate retention time of the test item on analysis of any matrix blank solutions.

Any other information on results incl. tables

pH 4 at 50ºC

 Time (Hours)  Concentration (g/L)    % of mean initial concentration  
   A  B  A  B
 0  0.0999  0.0974  -  -
 24  0.0972  0.0976  98.5  99.0
 120  0.0958  0.0973  97.1  98.6

Result: Less than 10% hydrolysis after 5 days at 50ºC, equivalent to a half-life greater than 1 year at 25ºC

pH 7 at 50ºC

 Time (Hours)  Concentration (g/L)    % of mean initial concentration  
   A  B  A  B
 0  0.0994  0.0999
 24  0.0978 0.0963  98.1  96.6 
 120  0.0959  0.0961 96.1  96.4 

Result: Less than 10% hydrolysis after 5 days at 50ºC, equivalent to a half-life greater than 1 year at 25ºC.

pH 9 at 50ºC

Time (Hours)  Concentration (g/L)   % of mean initial concentration
A B  A B
0 0.0976 0.0988 - -
24 0.0948 0.0950 96.6 96.7
 120  0.0934 0.0948  95.1  96.5 

Result: Less than 10% hydrolysis after 5 days at 50ºC, equivalent to a half-life greater than 1 year at 25ºC

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The estimated half-life of the test item at 25ºC for pH 4, 7 and 9 has been shown to be greater than 1 year.
Executive summary:

Assessment of hydrolytic stability was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH and Method 111 of the OECD Guideline. The estimated half-life of the test item at 25ºC for pH 4, 7 and 9 has been shown to be greater than 1 year.