Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2004-11-03 to 2004-11-25
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant and proprietary study report.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report Date:
2004

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Qualifier:
according to
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Molecular mass: 122.98 g/mol
Batch No.: sampling from 2004-08-23
Sample no./year: 04-36205-001
Content of test substance: 96.1%
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Not relevant.
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
5 mL of the hydrolysis test solutions are pipetted into a 15 mL polypropylene tube, 2 mL internal standard solution was added. This mixture was agitated by a vibrator for two minutes. After phase separation the organic phase was analyzed by GC.
A recovery test was performed. The recovery rate was 75 %. This recovery rate was not considered as the concentrations of the hydrolysis test are normalized.
Buffers:
pH 4: buffer solution pH 4, citric acid / sodium hydroxide / sodium chloride, Riedel de Haen Art. No. 33543, ready to use solution.
pH 7: buffer solution pH 7, potassium dihydrogen phosphate / Di-sodium hydrogen phosphate, Riedel de Haen Art. No. 33546, ready to use solution.
pH 9: buffer solution pH 9, borax / hydrochloric acid, Riedel de Haen Art. No. 33548, ready to use solution.
Estimation method (if used):
The kinetics of hydrolysis is assumed to be a pseudo-first order at fixed pH and temperature.
When it is not practicable to directly determine a rate constant for a particular temperature, it is usually possible to estimate the constant through the use of the Arrhenius relationship in which the logarithm of rate constants at other temperatures is plotted against the reciprocal of the absolute temperature (K).
Details on test conditions:
All preparations were performed with concentrations of 216mg/L and a volume of 200mL. Due the low water solubility of the substance 1 % acetonitrile was added. The buffer solutions described above were used. These preparations were shaked in a water bath at 50 °C.

Results and discussion

Transformation products:
not specified
Details on hydrolysis and appearance of transformation product(s):
In this hydrolysis study the breakdown products are not identified.
Dissipation DT50 of parent compoundopen allclose all
pH:
4
Temp.:
50 °C
DT50:
1.4 h
pH:
7
Temp.:
50 °C
DT50:
1.2 h
pH:
9
Temp.:
50 °C
DT50:
1.6 h
Details on results:
All half-times are less than 2.4 hours at 50°C, therefore no additional tests at other temperatures had to be performed.

Any other information on results incl. tables

According to OECD 111 (EC C.7) a hydrolysis test was performed in buffer solutions (pH 4, pH7, pH9) at 50 °C. Following results were obtained. The degradation reaction is given by pseudo-first order reaction and the rate constant ( first order reaction) is given by:

 

t(1/2)

K (1/s)

pH 4

1.4 hours

1.38783E-04

pH 7

1.2 hours

1.55476E-04

pH 9

1.6 hours

1.20283E-04

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
According to OECD 111 (EC C.7) a hydrolysis test was performed in buffer solutions (pH 4, pH7, pH9) . All half-times are less than 2.4 hours at 50°C, therefore no additional tests at other temperatures had to be performed.
Executive summary:

According to OECD 111 (EC C.7) a hydrolysis test was performed in buffer solutions (pH 4, pH7, pH9) . All half-times are less than 2.4 hours at 50°C, therefore no additional tests at other temperatures had to be performed.