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Hydrolysis

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Reference
Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
02 March 2012 - 04 April 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Analytical monitoring:
yes
Details on sampling:
- Sampling intervals for the parent/transformation products: 0, 24, 120 and 144h
- Sampling method: not specified
- Sampling intervals/times for pH measurements: 0, 24, 120 and 144h
- Sampling intervals/times for sterility check: no further sterility checks done
- Sample storage conditions before analysis: not specified
- Other observation, if any (e.g.: precipitation, color change etc.): no other observations reported
Buffers:
- pH: 4, 7, 9
- Type and final molarity of buffer: potassium hydrogen phthalate (pH 4; 5 mmol/L); disodium hydrogen orthophosphate (anhydrous, 3 mmol/L) / potassium dihydrogen orthophosphate (2 mmol/L) / sodium chloride (2 mmol/L) pH 7; disodium tetraborate (1 mmol/L) / sodium chloride (2 mmol/L) pH 9.
Details on test conditions:
TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: stoppered glass flasks
- Sterilisation method: buffer solutions were sterilised; not further specified
- Lighting: flasks were shielded from light
- Measures to exclude oxygen: treatment of buffer solutions: ultrasonication and degassing with nitrogen
- If no traps were used, is the test system closed/open: closed
- Is there any indication of the test material adsorbing to the walls of the test apparatus?: no
Duration:
144 h
Temp.:
50 °C
Initial conc. measured:
0.9 - 1.1 g/L
Number of replicates:
Individual vessels were used for each data point.
Positive controls:
no
Negative controls:
no
Statistical methods:
Not applicable
Preliminary study:
The preliminary test revealed that the substance is hydrolytically stable. No further test was performed.
Transformation products:
no
pH:
4
Temp.:
50 °C
DT50:
> 1 yr
Remarks on result:
hydrolytically stable based on preliminary test
pH:
7
Temp.:
50 °C
DT50:
> 1 yr
Remarks on result:
hydrolytically stable based on preliminary test
pH:
9
Temp.:
50 °C
DT50:
> 1 yr
Remarks on result:
hydrolytically stable based on preliminary test
Details on results:
At all three pH values there was less than 10% degradation observed over a 5-days period at 50°C. This is equivalent to an extrapolated half-life time at 25 °C of > 1 year).
Validity criteria fulfilled:
yes
Conclusions:
The substance is concluded to be hydrolytically stable under the conditions of the test. Extrapolated half-life time at 25 °C: > 1 year.
Executive summary:

Hydrolysis of N-methylmorpholine oxide at 0.6 -1.1 g/L was studied shielded from light at 50 °C in aqueous buffered solutions at pH 4 (potassium hydrogen phthalate, 5 mmol/L), 7 (disodium hydrogen orthophosphate, anhydrous, 3 mmol/L / potassium dihydrogen orthophosphate, 2 mmol/L / sodium chloride, 2 mmol/L) and 9 (disodium tetraborate, 1 mmol/L / sodium chloride, 2 mmol/L) for 6 days. the experiment was conducted in accordance with the OECD guideline 111, and in compliance with GLP standards. Samples were analysed at 0, 1, 5 and 6 days. Details on analytical methods are not available.

At test termination the concentration of the parent compound decreased by less than 10% from day 0 at every pH tested.

The half-life/DT50 (50% decline time) of N-methylmorpholine oxide was > 1 year at every pH tested (4, 7 and 9).

The study is classified acceptable and satisfies the guideline requirements for hydrolysis study.

Description of key information

The key value for hydrolysis was obtained from a 5-day preliminary test at pH 4, 7 and 9 and 50 °C. In this GLP test in accordance with OECD Test Guideline 111 no significant (< 10%) degradation was observed (Walker, 2012).

Key value for chemical safety assessment

Half-life for hydrolysis:
1 yr
at the temperature of:
25 °C

Additional information