C.I. Acid Yellow 246

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 December 1984 to 21 December 1984

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)

Deviations:

not specified

GLP compliance:

yes

Specific details on test material used for the study:

Product: Monoazo Yellow HT 2025
Identification: FAT 20'306/B

Radiolabelling:

not specified

Analytical monitoring:

yes

Details on sampling:

Samples were determined after 5 days at 50 °C and pH 4, 7 and 9.

Estimation method (if used):

The concentration of the residual test substance is determined by high performance chromatography according to the Ciba-Geigy method AAK 77/84.

Details on test conditions:

Hydrolysis of the active ingredient at 50 °C and pH 4, 7 and 9.
Information on the sterility: The buffer solutions are heated before use for 15 minutes at 121 °C.
Information on excluding oxygen: The reaction flasks were rinsed with nitrogen during 15 minutes.
Information on avoiding photolytic effects: Only brown glass reaction flasks are used.

Duration:

5 d

pH:

4

Temp.:

50 °C

Duration:

5 d

pH:

7

Temp.:

50 °C

Duration:

5 d

pH:

9

Temp.:

50 °C

Number of replicates:

duplicate

Positive controls:

no

Negative controls:

no

Statistical methods:

N/A

Preliminary study:

Hydrolysis of the active ingredient at 50 °C and pH 4, 7 and 9. Monoazo Yellow HT 2025 is at pH 4,7, 9 and 50 °C stable. It has a half-life time longer than one year at pH 4,7, 9 and 25 °C.

Test performance:

Solution for calibration:
80 - 90 mg of Monoazo Yellow HT 2025 (related to 100 % pure substance) are accurately weighed into a 50 ml volumetric flask, solved and diluted to 50 ml with buffer solution pH 7.0 (59.2 ml 0.1 N NaOH + 100 ml 0.1 M monopotassiumphosphate to 200 ml with water). 2.00 ml of this solution are diluted with 1.0 ml buffer solution pH 7.0 and water to 25.0 ml.

Solution for the test:
80 - 90 mg of Monoazo Yellow HT 2025 (related to 100 % pure substance) are accurately weighed into a 50 ml volumetric flask, solved and diluted with the test buffer solution (pH 4.0, 7.0 or 9.0) to 50.0 ml. After the hydrolysis time 2.00 ml of this solution is neutralized (with 0.1 N NaOH or 0.1 N HCl) and diluted with 1.0 ml buffer solution pH 7.0 and water to 25.0 ml.

Transformation products:

not measured

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Type:

(pseudo-)first order (= half-life)

Validity criteria fulfilled:

yes

Conclusions:

FAT 20306/B is stable at pH 4,7, 9 and 50 °C stable. It has a half-life time longer than one year at pH 4,7, 9 and 25 °C.

Executive summary:

A GLP-compliant study was performed with FAT 20306/B according to the OECD guideline 111. Based on the study results, the test substance is stable at pH 4,7, 9 and 50 °C stable. It has a half life time longer than one year at pH 4,7, 9 and 25 °C.

Description of key information

A GLP-compliant study was performed with FAT 20306/B according to the OECD guideline 111. Based on the study results, the test substance is stable at pH 4,7, 9 and 50 °C stable. It has a half life time longer than one year at pH 4,7, 9 and 25 °C.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C

Additional information

FAT20306 is stable under environmentally relevant conditions with a half-life of more than one year across the entire pH range. Thus, significant abiotic degradation in the environment is not expected.