3-C12-18-(even numbered)-alkylamido-N,N-dimethylpropan-1-amino oxide

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000-03-06 - 2000-03-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name: NINOX HCDO, N-(3-N,N-dimetylaminooxidetrimethylene)alkylamide
- CAS 68155-09-9
- Purity: 92.32%
- Lot/batch no.: 876 TK - Sample number VI
- Physical state: off white paste
- Storage conditions of test material: room temperature, in the dark

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products:
- Sampling method: sample solutions were prepared in stoppered glass flasks at a nominal concentration of 2 g/L in the three buffer solutions. The solutions were shielded from light whilst maintained at the test temperature.
- Sampling methods for the volatile compounds, if any:
- Sampling intervals/times for pH measurements:
- Sampling intervals/times for sterility check:
- Sample storage conditions before analysis:
- Other observation, if any (e.g.: precipitation, color change etc.):

Buffers:

- pH: 4, 7 and 9
- Composition of buffer: Buffer solution 4: Citric acid (0.013 mol/dm3), sodium hydroxide (0.025 mol/dm3), hydrochloric acid (0.013 mol/dm3); bufer solution 7: disodium hydrogen phosphate (0.01 mol/dm3), potassium dihydrogen phosphate (0.008 mol/dm3); buffer solution 9: disodium tetraborate (0.013 mol/dm3), hydrochloric acid (0.005 mol/dm3)

Duration:

120 h

Number of replicates:

2

Transformation products:

not measured

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Details on results:

TEST CONDITIONS

MINOR TRANSFORMATION PRODUCTS
Maximum concentrations in % of the applied amount
- at pH4: 1.99 g/L
- at pH7: 2.36 g/L
- at pH9: 2.66 g/L

Validity criteria fulfilled:

yes

Conclusions:

There was less than 10% hydrolysis after 5 days at 50°C at pH 4, 7 and 9. The estimated half-lives at 25°C of NINOX HCDO at pH 4, 7 and 9 are > 1 year.

Description of key information

The assessment of hydrolytic stability of the substance was carried out according to the EU Method C.7 (Lumsden, 2000). The test item was determined to be hydrolytically stable at pH 4, 7 and 9, with estimated half-lives greater than 1 year at 25°C.  The study is given a Klimisch score of 1, was conducted under GLP and is considered as the key study for endpoint coverage.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C