C.I. Acid Yellow 246

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 June 1987 to 02 July 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Version / remarks:

As per internal SOP method A.37

Deviations:

no

Principles of method if other than guideline:

As per internal SOP method A.37

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

33 d

Initial conc.:

51 mg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

DOC removal

Parameter:

% degradation (DOC removal)

Value:

51

Sampling time:

33 d

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Conclusions:

FAT 20306/C showed a biodegradability rate of 51 % in a Zahn-Wellens test.

Executive summary:

A Zahn-Wellens test was carried out with FAT 20306/C according to internal SOP method of CIBA A.37. The initial concentration was 51 mg/L and tested for 33 days. Based on the test results, test substance showed a biodegradability rate of 51 % and thus, inherent biodegradation is stated, without fulfilling the specific requirement.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 July 1984 to 15 August 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (old version) (Ready Biodegradability: Modified AFNOR Test)

Deviations:

yes

Remarks:

Sterilisation instead of steril filtration; Determination of bacteria concentration: by plating; Temperature: 23 ± 1°C

GLP compliance:

no

Specific details on test material used for the study:

Test substance FAT-20306/B
Storage: room temperature
Appearance: solid

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

Details on inoculum:

Strain/Inoculation: Mixture of polyvalent bacteria collected on 10.7.84: - effluent of a domestic sewage treatment plant (ARA Rhein)
Bacteria concentration: 8.9 x 10E5 /ml

Duration of test (contact time):

28 d

Initial conc.:

40 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Water / Nutrient: According to the specification of the OECD Method 301 A
Lighting: indirect daylight

Reference substance:

other: Glucose

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

28 d

Results with reference substance:

Biodegradation corrected by the blank control and measured as Doc (mg/1) was 98 % (28th day)

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

FAT-20306/B is not readily biodegradable.

Executive summary:

The study was performed according to the OECD guideline 301 A, Modified AFNOR-Test to determine the biodegradation of the test substance in percent of DOC (Dissolved Organic Carbon). The biodegradation (28d) of FAT-20'306/B was 0 % while degradation of the Reference Substance (glucose) >96 %. This showed that the test substance is not readily biodegradable under the conditions of this test.

Description of key information

The test substance is not readily biodegradable, but inherently biodegradable, not fulfilling specific criteria.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, not fulfilling specific criteria

Type of water:

freshwater

Additional information

The ready biodegradability test was performed according to the OECD Test Method 301 A, Modified AFNOR-Test. The biodegradation (28 d) of FAT-20306/B was 0 %. This showed that the test substance is not readily biodegradable under the conditions of this test. Two reports about BOD5 and COD tests are available and used as supportive studies. The results indicated the BOD5/COD ratio was 0 % (BOD₅= 0 mg O2/g; COD=1609 mg O2/g), which means the test substance is not readily biodegradable. However, when tested for inherent biodegradability in a Zahn-Wellens test according to OECD method 302B, the substance showed a DOC removal of 44 and 51 % within 28 and 33 days respectively. Thus, inherent biodegradability was found although the test method criterion was not met. In conclusion, the test substance is not readily biodegradable but shows inherent biodegradability, not fulfilling specific criteria.