4-methylmorpholine 4-oxide, monohydrate

Hydrolysis

Link to relevant study record(s)

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

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

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