(4E)-4-methyl-5-(4-methylphenyl)pent-4-enal

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other:

Remarks:

This study was not performed according to GLP. However, this study is well documented and is considered reliable with restrictions.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

13 April 2004

Deviations:

no

Principles of method if other than guideline:

The aim of the study is to assess the stability of the substance in a series of simple media simulating perfumery applications. The test media are standard aqueous buffers at pH 2, pH 5, pH 7, pH 8.5 and pH 12 containing 1% of non ionic surfactant. The tests are done in accelerated conditions at 40 °C during ca. one month.

GLP compliance:

no

Specific details on test material used for the study:

No additional information

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

200 – 300 ppm of raw material are dissolved in the pH buffer containing the surfactant (Arkopal N 150) and put into storage in an oven at 40°C. Small aliquots of the test solution are extracted with an organic solvent (typically cyclohexane or ethyl acetate) containing a hydrocarbon standard (typically C12, C17 or C20) on a regular basis throughout the test (typically at time = 0, 0.25, 1, 2, 4, 7, 15, 21 and 28 days). The extracts are analyzed by GC-FID and the results are plotted as (Area/Area Std) expressed in [%]. The measurement at time = 0 is set at 100% and the succeeding measurements are calculated relatively to the time = 0 measurement. Therefore the curves represent the percentage of product remaining in the test solution at the time of analysis.

Buffers:

Buffer solutions:
pH 2 (± 0.1) buffer: Reference Handbook of Chemistry and Physics buffer type A
pH 5 (± 0.1) buffer: Reference Handbook of Chemistry and Physics buffer type C
pH 7 (± 0.1) buffer: Reference Handbook of Chemistry and Physics buffer type D
pH 8.5 (± 0.1) buffer: Reference Handbook of Chemistry and Physics buffer type F
pH 12 (± 0.1) buffer: Reference Handbook of Chemistry and Physics buffer type I

Estimation method (if used):

Not applicable

Details on test conditions:

No data

Duration:

28 d

pH:

2

Temp.:

40 °C

Initial conc. measured:

> 200 - < 300 other: ppm

Duration:

28 d

pH:

5

Temp.:

40 °C

Initial conc. measured:

> 200 - < 300 other: ppm

Duration:

28 d

pH:

7

Temp.:

40 °C

Initial conc. measured:

> 200 - < 300 other: ppm

Duration:

28 d

pH:

8.5

Temp.:

40 °C

Initial conc. measured:

> 200 - < 300 other: ppm

Duration:

28 d

pH:

12

Temp.:

40 °C

Initial conc. measured:

> 200 - < 300 other: ppm

Number of replicates:

1

Positive controls:

no

Negative controls:

no

Statistical methods:

None

Preliminary study:

No data

Test performance:

No data

Transformation products:

no

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

Results showed that the disappearance of the parent compound after 5 and 28 days at 40 °C at pH 5 is less than 10 %. At pH 7 and 8.5, the disappearance of the parent compound is between 30 and 70% after 28 days at 40°C. At higher pH (pH of 12), the parent compound rapidly disappears as of day 1.

% Recovery:

100

pH:

2

Temp.:

40 °C

Duration:

1 d

% Recovery:

50

pH:

2

Temp.:

40 °C

Duration:

20 d

% Recovery:

100

pH:

5

Temp.:

40 °C

Duration:

1 d

Remarks on result:

other: Registered substance is hydrolytically stable, less than 5% disappeared after 28 days.

% Recovery:

98

pH:

5

Temp.:

40 °C

Duration:

28 d

Remarks on result:

other: registered substance is hydrolytically stable, less than 5% disappeared after 28 days.

% Recovery:

88

pH:

7

Temp.:

40 °C

Duration:

5 d

% Recovery:

69

pH:

7

Temp.:

40 °C

Duration:

28 d

% Recovery:

85

pH:

8.5

Temp.:

40 °C

Duration:

1 d

% Recovery:

50

pH:

8.5

Temp.:

40 °C

Duration:

9.6 d

% Recovery:

50

pH:

12

Temp.:

40 °C

Duration:

0.2 d

pH:

2

Temp.:

40 °C

DT50:

ca. 20 d

pH:

8.5

Temp.:

40 °C

DT50:

ca. 9.6 d

pH:

12

Temp.:

40 °C

DT50:

ca. 0.2 d

Other kinetic parameters:

None

Details on results:

No additional information

Results with reference substance:

None

Validity criteria fulfilled:

not applicable

Conclusions:

The disappearance of the parent compound after 28 days at 40 °C and at environmentally relevant pH (comprised between 5 and 8.5) is comprised between less than 5 and 70 %.
Half-life values were determined at the following pH:
pH Half-life (day)
2 20
8.5 9.6
12 0.2

Executive summary:

Hydrolysis study was performed similar to OECD Guideline No. 111. The aim of the study is to assess the stability of the substance in a series of simple media simulating perfumery applications. The test media are standard aqueous buffers at pH 2, pH 5, pH 7, pH 8.5 and pH 12 containing 1% of non ionic surfactant (Arkopal N 150). The tests are done in accelerated conditions at 40 °C during 28 days.

200 – 300 ppm of raw material are dissolved in the pH buffer containing the surfactant (Arkopal N 150) and put into storage in an oven at 40°C. Small aliquots of the test solution are extracted with an organic solvent (typically cyclohexane or ethyl acetate) containing a hydrocarbon standard (typically C12, C17 or C20) on a regular basis throughout the test (typically at time = 0, 0.25, 1, 2, 4, 7, 15, 21 and 28 days). The extracts are analyzed by GC-FID and the results are plotted as (Area/Area Std) expressed in [%]. The measurement at time = 0 is set at 100% and the succeeding measurements are calculated relatively to the time = 0 measurement. Therefore the curves represent the percentage of product remaining in the test solution at the time of analysis.

 The disappearance of the parent compound after 28 days at 40 °C is circa 70% at pH 2, less than 5% at pH 5, circa 31% at pH 7 and circa 70% at pH 8.5, and 100% disappearance at pH 12.

Description of key information

As the registered substance is not readily biodegradable, a GLP hydrolysis study does need to be conducted, in accordance with REACH Annex VIII column 2. One study was available:

A non-GLP stability test was performed on the registered substance with a method similar to OECD Guideline No. 111, in accelerated conditions at 40 °C during 28 days. The disappearance of the substance after 28 days at 40 °C and at environmentally relevant pH (comprised between 5 and 8.5) is comprised between less than 5% and 70%.