Registration Dossier

Administrative data

Endpoint:
water solubility
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because the substance is hydrolytically unstable at pH 4, 7 and 9 (half-life less than 12 hours)
Cross-reference
Reason / purpose:
data waiving: supporting information
Reference
Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
27-Feb-17 to 26-Apr-17.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Deviations:
not applicable
Principles of method if other than guideline:
Hydrolysis tests were performed at 20 ± 0.5 °C until at least 80 % or more of the test item
were hydrolyzed. Hydrolysis was examined in demineralized water and in aqueous buffer
solutions at pH 4, 7 and 9. Aliquots of the hydrolysis systems were collected at several time
points and analysed immediately by Headspace (HS)-GC-MS to follow the formation of the
expected hydrolysis product 2-propanol. Analysis of the intact test item complex was
considered to be not possible.
GLP compliance:
yes (incl. certificate)
Specific details on test material used for the study:
Certificate of analysis provided in the study report.
Radiolabelling:
no
Analytical monitoring:
yes
Details on sampling:
Aliquots of the test solutions (1.0 mL) were transferred into individual autosampler vials. These aliquots were measured with HS-GC-MS without delay.
Buffers:
Aqueous buffer solutions were prepared as follows:
pH 4 (0.05 M) Citrate Buffer: 23 g of potassium dihydrogen citrate were dissolved in 1 L of water.
An aliquot of 0.50 L was mixed with 0.09 L of 0.1 M NaOH and filled up with water to 1 L to
give a pH of 4.
pH 7 (0.05 M) Phosphate Buffer: 13.6 g of potassium dihydrogen phosphate were dissolved in 1 L of water. An aliquot of 0.50 L was mixed with 0.296 L of 0.1 M NaOH and filled up with water to 1 L to give a pH of 7.
pH 9 (0.05 M) Borate Buffer: 19 g of sodium tetraborate decahydrate were dissolved in 1 L of water. An aliquot of 0.85 L was mixed with 0.15 L of 0.1 M HCl (prepared from 10 M HCl, Merck,
32 %) to give a pH of 9.
Details on test conditions:
50 μL of the spike solution (25 mg/mL XP 475) were diluted in a final volume of 500 mL of each buffer solution or in 500 mL of demineralized water in glass bottles and shaken vigorously. The resulting concentration of XP 475 was 2.5 mg/L (approx. 10 -5 mol/L). Two replicate test solutions were prepared for water and each buffer solution.
Duration:
2 min
pH:
4
Temp.:
20 °C
Remarks:
Hydrolysis tests were performed at 20 ± 0.5 °C until at least 80 % or more of the test item
was hydrolyzed.
Duration:
2 min
pH:
7
Temp.:
20 °C
Remarks:
Hydrolysis tests were performed at 20 ± 0.5 °C until at least 80 % or more of the test item
was hydrolyzed.
Duration:
2 min
pH:
9
Temp.:
20 °C
Remarks:
Hydrolysis tests were performed at 20 ± 0.5 °C until at least 80 % or more of the test item
was hydrolyzed.
Number of replicates:
2
Positive controls:
no
Negative controls:
no
Transformation products:
yes
No.:
#1
No.:
#2
No.:
#3
Key result
pH:
4
Temp.:
20 °C
DT50:
< 2 min
Type:
not specified
Key result
pH:
7
Temp.:
20 °C
DT50:
< 2 min
Type:
not specified
Key result
pH:
9
Temp.:
20
DT50:
< 2 min
Validity criteria fulfilled:
yes
Conclusions:
Within the first couple of minutes more than 80 % or more of the amount of test item dosed
was already hydrolysed to form 2-propanol. The half-life of the test item is estimated to be
shorter than 2 minutes in demineralised water and in the pH 4, pH 7 and pH 9 aqueous buffer
solutions.

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion