1-Octanamine, N,N-dimethyl-, N-oxide

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 1st, 2007 - July 09th, 2008

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Analytical purity: 82.3%
- Purity test date: Not available
- Lot/batch No.: GN-8
- Expiration date of the lot/batch: Not available
- Appearance: Amber coloured, extremely viscous liquid
- Storage: In the dark at room temperature
- Additional information on test material used for the study: It was attempted to purify the substance to a purity of >80% by using an alternative synthetic route, as opposed to the usual commercial route of synthesis which results in a purity of the substance of approximately 40% in water. This alternative synthetic route generated the substance at 82.3% purity, however it also generated an impurity (methanol at 4.0%) which is not present in the commercial substance. Based on the classification and labelling of methanol, it is considered that this additional impurity would not have an influence on any of the endpoints discussed in this dossier other than the acute oral toxicity study. Therefore all studies (including the one covering this endpoint) contained in this dossier (other than the acute oral toxicity study) were conducted on the 82.3% pure substance containing the 4.0% methanol impurity. The acute oral toxicity study has been conducted on the commercially generated substance at a purity of approximately 40% in water.

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products: 0, 2.4, 24 and 120 hours

Buffers:

- pH: 4 / Composition of buffer: Potassium hydrogen phthalate (0.05 mol/L)
- pH: 7 / Composition of buffer: Disodium hydrogen orthophosphate anhydrous (0.03 mol/L), potassium dihydrogen orthophosphate (0.02 mol/L) and sodium chloride (0.02 mol/L)
- pH: 9 / Composition of buffer: Disodium tetraborate (0.01 mol/L) and sodium chloride (0.02 mol/L)

Details on test conditions:

- Type, material and volume of test flasks, other equipment used: Glass flasks
- Measures taken to avoid photolytic effects: Samples shielded from light
- Measures to exclude oxygen: Ultrasonification and degassing with nitrogen
- If no traps were used, is the test system closed: Stoppered flasks
- Is there any indication of the test material adsorbing to the walls of the test apparatus? None

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

1.03 g/L

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

1.01 g/L

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

1.02 g/L

Transformation products:

no

% Recovery:

97.4

pH:

4

Temp.:

50 °C

Duration:

120 h

% Recovery:

95.3

pH:

7

Temp.:

50 °C

Duration:

120 h

% Recovery:

94.1

pH:

9

Temp.:

50 °C

Duration:

120 h

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Type:

not specified

Remarks on result:

other: less than 10% hydrolysis after 5 days at 50°C

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Type:

not specified

Remarks on result:

other: less than 10% hydrolysis after 5 days at 50°C

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Type:

not specified

Remarks on result:

other: less than 10% hydrolysis after 5 days at 50°C

Validity criteria fulfilled:

yes

Conclusions:

At pH 4, 7 and 9, less than 10% hydrolysis of the test material was recorded after 5 days at 50°C. This is equivalent to a half-life greater than 1 year at 25°C.

Executive summary:

The hydrolysis as a function of pH of the test material was investigated in a GLP-compliant study performed in accordance with EU Method C.7. At pH 4, 7 and 9, less than 10% hydrolysis of the test material was recorded after 5 days at 50°C. This is equivalent to a half-life greater than 1 year at 25°C.

Description of key information

The hydrolysis as a function of pH of the test material was investigated in a GLP-compliant study performed in accordance with EU Method C.7. At pH 4, 7 and 9, less than 10% hydrolysis of the test material was recorded after 5 days at 50°C. This is equivalent to a half-life greater than 1 year at 25°C.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C

Additional information

The hydrolysis as a function of pH of the test material was determined in a GLP-compliant study performed in accordance with standard methods, without deviations. The study is considered as reliable (Klimisch 1) and was selected as key study for the endpoint.