Cyclopentane, methoxy-

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 March 2003 - 07 April 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted in compliance with EC and OECD test guidelines, and in compliance with GLP, so the study is considered reliable without restriction.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (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: 99.9%
- Lot/batch No.: 020618

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products: Immediately after spiking of buffer solution (t=0), 2.4 hours, and 5 days.
- Sampling method: Liquid-liquid extraction using dichloromethane
- Sampling methods for the volatile compounds, if any: N/A - samples were transferred to glass vials to give a minimum of headspace.

Buffers:

pH 4 buffer
0.1M potassium dihydrogen citrate solution was adjusted to pH 4.0 with 1M sodium hydroxide, with the temperature of the buffer solution at 50°C ± 0.5°C.

pH 7 buffer
0.1M potassium dihydrogen orthophosphate solution was adjusted to pH 7.0 with 1M sodium hydroxide, with the temperature of the buffer solution at 50°C ± 0.5°C.

pH 9 buffer
0.1M solution of potassium chloride and boric acid was adjusted to pH 9.0 with 1M sodium hydroxide, with the temperature ofthe buffer solution at 50°C ± 0.5°C.

Duration:

5 d

pH:

4

Temp.:

50

Duration:

5

pH:

7

Temp.:

50

Duration:

5 d

pH:

9

Temp.:

50

Number of replicates:

Performed in duplicate for each pH

Positive controls:

no

Negative controls:

yes

Transformation products:

not measured

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Under the test conditions, NZE did not undergo hydrolysis giving final recoveries of 107.9% at pH 4, 107.5% at pH 7 and 104.5% at pH 9 after 5 days at 50°C.

According to the test method it can be estimated that:

10% hydrolysis occurring in 5 days at 50°C is equivalent to a half-life time of 1 year at 25°C.

50% hydrolysis occurring in 2.4 hours at 50°C is equivalent to a half-life time of 1 day at 25°C.

Applying these criteria to the results obtained for NZE, the half-life at 25°C can be estimated as being greater than 1 year at pH4, pH7 and pH9.

Conclusions:

The results indicate that at 25°C, NZE will possess a half-life time of greater than 1 year at pH 4, pH 7 and pH 9.

Description of key information

Half-life greater than 1 year at 25°C at pH4, pH7, and pH9.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C

Additional information

A determination of the abiotic degradation (hydrolysis) potential of the substance was conducted (Huntingdon Life Sciences, 2003). The study was performed according to OECD method 111 and EC test guideline C7, and was conducted in compliance with GLP.

After a period of 5 days at 50°C, the substance did not undergo hydrolysis at pH4, pH7, or pH9.

The results indicate that at 25°C, the substance will have a half-life of greater than 1 year at pH4, pH7, and pH9.