Disodium [3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-4-hydroxybenzenesulphonato(3-)][1-[[2-hydroxy-5-(phenylazo)phenyl]azo]-2-naphtholato(2-)]chromate(2-)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Method A-12

Deviations:

not specified

GLP compliance:

no

Specific details on test material used for the study:

Name: FAT 21095/A
Purity: 80 %

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

31 d

Initial conc.:

20 mg/L

Parameter followed for biodegradation estimation:

TOC removal

Parameter:

% degradation (TOC removal)

Value:

3

Sampling time:

31 d

Remarks on result:

other: Biological elimination (Activated sludge dynamic test)

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

The biological elimination rate of FAT 21095/A is found to be 3 %.

Executive summary:

A study was performed to determine the biological elimination of FAT 21095/A at the end of 31 day exposure period. The test was performed according to a CIBA guideline Method A-12. At the end of 31 days the biological elimination rate of FAT 21095/A was found to be 3 %, indicating the test substance as not readily biodegradable.

Description of key information

The biological elimination rate of FAT 21095/A is found to be 3 % after an exposure period of 31 days.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

A study was performed to determine the biological elimination rate of FAT 21095/A at the end of 31 day exposure period. The test was performed according to a guideline which is equivalent or similar to OECD test guideline 303 A (confirmatory test).

Normal test duration is 4 weeks. The first 10 days represent the time needed for production of the sludge as well as the adaption phase of the bacteria on the test substance. Bioelimination is calculated as the arithmetic mean of the individual values after the setup time. At the end of 31 days the biological elimination of FAT 21095/A was found to be 3 %, indicating the test substance is non-biodegradable. In two supporting studies, following BOD and COD values were found:

BOD: 0 mg/g O2

COD: 1019.61 mg O2/g test material.

Relevant is the BOD5/COD quotient which is equal to 0, therefore, the substance is not expected to be rapidly degradable. Taking all the data into account, the test substance FAT 21095 is considered to be non-biodegradable.