4-chlorobenzonitrile

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline available

Principles of method if other than guideline:

secondary literature

GLP compliance:

not specified

Radiolabelling:

not specified

Analytical monitoring:

no

pH:

7

Temp.:

85 °C

Initial conc. measured:

1.4 mg/L

Transformation products:

yes

No.:

#1

pH:

7.7

Temp.:

85 °C

DT50:

5.5 d

Remarks on result:

other: concentration maximum of 4-chlorobenzamide after 17 days of incubation

Validity criteria fulfilled:

not specified

Conclusions:

4-Chlorobenzonitrile was transformed at 85°C (first-order reaction kinetics) to 4-chlorobenzoamid. The hydrolysis half-life was determined to be 5.5 days.

Executive summary:

The transformation of 4-chlorobenzonitrile was studied in pure water.

Experiments at 85 °C demonstrate that 4-chlorobenzonitrile is hydrolyzed to 4-chlorobenzamide.

The hydrolysis half-life was determined to be 5.5 days.

Description of key information

The hydrolysis half-life of 4-chlorobenzonitrile at 37 °C at pH 7.7 is 170 days.
Transformation products are 4-chlorobenzoic acid and 4-chlorobenzamide.

Key value for chemical safety assessment

Half-life for hydrolysis:

170 d

at the temperature of:

37 °C

Additional information

The transformation of 4-chlorobenzonitrile was studied in pure water and in buffered distilled water (pH 7.7).

Experiments at 85 °C demonstrate that 4-chlorobenzonitrile is hydrolyzed to 4-chlorobenzoic acid through the intermediate 4-chlorobenzamide. No intermediates were detected at 37°C.

The hydrolysis half-life in water at 85 °C and 37 °C were determined to be 5.5 days and 170 days, respectively.

Hydrolysis of 4-chlorobenzonitrile was also followed by incubation of 0.14 mg/L = 1 µmol/L test substance in sediment samples of an eutrophic pond situated in the Netherlands at 22 °C and pH = 7.3. Hydrolysis was terminated by addition of acetonitrile.

The hydrolysis half-life in anaerobic sediment, being 18 +/- 2 d, was much lower than the hydrolysis half-life determined in water at pH 7.7. However, in control experiments using sterile water, the test substances (various nitriles) were not hydrolyzed. Therefore, biological degradation processes cannot totally be excluded.

Hence, the hydrolysis half-life at 37 °C in water of 170 days is used as key value.