Cyclohexanemethanol, 4-(1-methylethyl)-

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 April 2012 to 26 July 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)

Version / remarks:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Statement of compliance in accordance with Directive 2004/9/EC (inspected on July 10, 2012 / signed on September 7, 2012)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Purity test date: 29-Feb-12

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

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

Buffers:

pH 4: potassium hydrogen phthalate 0.005 mol dm-3
pH 7: Disodium hydrogen orthophosphate (anhydrous) 0.003 mol dm-3; Potassium dihydrogen orthophosphate 0.002 mol dm-3; Sodium chloride 0.002 mol dm-3
pH 9: Disodium tetraborate 0.001 mol dm-3; Sodium chloride 0.002 mol dm-3

Estimation method (if used):

Not applicable

Details on test conditions:

Sample solutions were prepared in stoppered glass flasks at a nominal concentration of 1 x 10-2 g/L in the three buffer solutions. A 1% co-solvent of tetrahydrofuran (THF) was used to aid solubility.

The concentration of each solution did not exceed the lesser of 0.01 mol/L or half the water solubility.

The test solutions were split into individual vessels for each data point.

The solutions were shielded from light whilst maintained at the test temperature.

A solution was prepared by weighing test item (0.1132 g) and dissolving in THF. This solution was diluted with pH 4, 7 and 9 buffers to give concentrations of 11.3 mg/L in each buffer.

Sample solutions at pH 4, 7 and 9 were maintained at 50.0 ± 0.5 °C for a period of 5 days.

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

10.6 mg/L

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

10.6 mg/L

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

9.9 mg/L

Number of replicates:

2 replicates per pH

Positive controls:

no

Negative controls:

no

Preliminary study:

pH 4: Less than 10% hydrolysis after 5 days at 50ºC, equivalent to a half-life greater than 1 year at 25ºC.
pH 7: Less than 10% hydrolysis after 5 days at 50ºC, equivalent to a half-life greater than 1 year at 25ºC.
pH 9: Less than 10% hydrolysis after 5 days at 50ºC, equivalent to a half-life greater than 1 year at 25ºC.

Transformation products:

no

Details on hydrolysis and appearance of transformation product(s):

Not applicable

% Recovery:

> 95.5 - < 98.8

pH:

4

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

> 98.3 - < 98.4

pH:

7

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

> 105.8 - < 107.6

pH:

9

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Remarks on result:

hydrolytically stable based on preliminary test

Other kinetic parameters:

None

Details on results:

Testing was originally performed at a working level of approximately 100 mg/L however at this concentration some issues were encountered with the test item not being fully soluble in the buffer solutions even with the use of a co-solvent. The excess test item was removed from the solution and the testing continued, however an apparent reduction in the test item concentration over time was observed with poor repeatability of results even from samples taken for the same time points. This was attributed to a combination of two factors. The first being that the excess test item was not entirely removed from the stock solutions, so when the stocks were split into separate test vessels there were variable quantities of excess added to each vessel causing inconsistent results. The second factor was possible loss of test item through volatilization from the test vessels.

To eliminate these problems the testing was repeated at a lower concentration to solve the solubility issue and using headspace vials for the test vessels in order to ensure a tight seal therefore reducing loss of test item through volatilization.

Results with reference substance:

Not applicable

Validity criteria fulfilled:

yes

Conclusions:

The test item was determined to be hydrolytically stable at pH 4, 7 and 9 (t½ > 1 year at 25 °C). No additional testing was performed at pH 1.2, 37.0 ± 0.5 °C.

Executive summary:

Assessment of hydrolytic stability of the test substance was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The test substance was determined to be hydrolytically stable at pH 4, 7 and 9 (t½ > 1 year at 25 °C).

Description of key information

According to OECD 111 the test item was determined to be hydrolytically stable at pH 4, 7 and 9 (t½ > 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

Assessment of hydrolytic stability of the registered substance was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The substance was determined to be hydrolytically stable at pH 4, 7 and 9 (t½ > 1 year at 25 °C).