Reaction mass of Disodium dihydroxy[2-{[5-(hydroxy-kO)-3-methyl-1-(4-sulfophenyl)-1H-pyrazol-4-yl]diazenyl-kN1}benzoato(3-)-kO]chromate(2-) and Sodium hydroxy[2-{[5-(hydroxy-kO)-3-methyl-1-(4-sulfophenyl)-1H-pyrazol-4-yl]diazenyl-kN1}benzoato(3-)-kO]chromate(1-)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening test, other

Remarks:

Inherent biodegradation test was performed

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

None

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Principles of method if other than guideline:

None

GLP compliance:

yes

Specific details on test material used for the study:

None

Oxygen conditions:

aerobic

Inoculum or test system:

other: Activated sludge of a communal sewage treatment plant

Details on inoculum:

Activated sludge of a communal sewage treatment plant Ara Reinach collected on 02.08.94

Duration of test (contact time):

28 d

Initial conc.:

150 mg/L

Based on:

DOC

Details on study design:

Water / Nutrient: according to the specifications of the OECD guideline
Temperature: 22.0 ± 3 °C (room temperature)
Test duration: 28 days
Lighting: indirect daylight
Estimation Technique: TOC/DOC Analyzer SHIMADZU TOC-5000

Reference substance:

diethylene glycol

Preliminary study:

None

Test performance:

None

Key result

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

28 d

Remarks on result:

other: Standard deviation not available

Details on results:

- The biodégradation of FAT - 20'041/C measured as DOC after 28 days corrected by the blank control is: 0 % (average of 2 tests running in parallel)
- Adsorption after 3 hours: 2.3 %

Results with reference substance:

TThe biodégradation, corrected by the blank control and measured as DOC (mg/l) is: 99.5 % 8th day (average of 2 tests running in parallel).

None

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Biodegradation of the test substance after 28 days was 0 %.

Executive summary:

The inherent biodegradability of FAT 20041/C was determined in a 28 days Zahn-Wellens Test according to the OECD Guideline for Testing of Chemicals, No. 302B. The test substance was tested in a concentration of 150 mg/l. The reference substance used was diethylene glycol. The biodegradation of the test substance FAT - 20'041/C after 28 days was 0 %, while the biodegradation of the reference substance after 8 days was 99.5 %.

Description of key information

ACID YELLOW 104 was considered to be not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The inherent biodegradability of FAT 20041/C was determined in a 28-days study according to the OECD Guideline for Testing of Chemicals, No. 302B. The test substance was tested in a concentration of 150 mg/l. The reference substance was diethylene glycol. Based on the results of the study, biodegradation of the test substance after 28 days was 0 %.

The biochemical oxygen demand of FAT 20041/B is determined by measuring the dissolved oxygen concentration before and after 5 days incubation at 20 °C in different test concentrations diluted in water saturated with dissolved oxygen. Based on the results, the BOD5 of FAT 20041/B: 0 mg O2/g.

The chemical oxygen demand of FAT 20041/B is determined by measuring the dissolved oxygen concentration before and after 5 days incubation at 20 °C in different test concentrations diluted in water saturated with dissolved oxygen. Based on the results, the COD of FAT 20041/B: 809 mg O2/g.

Based on these results the corresponding BOD5/COD quotient is equivalent to zero, so no biodegradation is expected.

 

Other supporting studies for FAT 20041/A were also performed with following results:

COD - 314 mg O2/g

BOD5 - 0 mg O2/g

Additionally, by the nature of their design and use, acid dyes are not intended to be readily biodegradable as this would assist in the rapid destruction of the dyestuff, rendering it unfit for purpose. As such, it is accepted that such substances are not readily biodegradable under relevant environmental conditions. A published study (Pagga & Brown, 1986) describes the results of the testing of 87 dyestuffs in short-term aerobic biodegradation tests. The authors of this publication concluded that dyestuffs are very unlikely to show any significant biodegradation in such tests and that 'there seems little point in carrying out such test procedures’ on dyestuffs.

There are ISO, European, American (AATCC) and national standards for the colour fastness of dyes. Dyes are required to have specific fastness properties. If the dyes were biodegradable, it would not be possible for them to have these fastness properties.