Disodium hydrogen bis[3-hydroxy-4-[(2-hydroxy-1-naphthyl)azo]naphthalene-1-sulphonato(3-)]chromate(3-)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: screening test, other

Remarks:

inherent biodegradation; dyes are supposed not to be ready biodegradable

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

June 1985 - August 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with GLP, adapted sludge performed on a similar substance

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

adapted sludge

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

Adapted sludge from a 2B-day Modified Zahn-wellens Test (OECD 3O2 B)

Duration of test (contact time):

28 d

Initial conc.:

57.5 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Parameter:

% degradation (DOC removal)

Value:

69.5

Sampling time:

20 d

Remarks on result:

other: adapted sludge

Parameter:

% degradation (DOC removal)

Value:

68

Sampling time:

28 d

Remarks on result:

other: adapted sludge

Validity criteria fulfilled:

yes

Interpretation of results:

other: inherently biodegradable with adapted sludge

Conclusions:

The biodegradability of the analogue substance in the static test after 20 days is 69%.This test was performed with adapted sludge (adaptation: 28 days) because of unusual result of the first test with non-adapted sludge (see Project A 1194)

Executive summary:

The inherent biodegradability properties of the analogue substance was tested following OECD302B in a static test, showing, after 20 days, a biodegradation of 69%.

This test was performed with adapted sludge (adaptation: 28 days) because of unusual result of the first test with non-adapted sludge (see Project A 1194). The substance is inherently biodegradable with adapted sludge.

Reference 2

Endpoint:

biodegradation in water: screening test, other

Remarks:

inherent biodegradation; dyes are supposed not to be ready biodegradable

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

05.01.1994 - 02.02. 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with GLP statement performed on analogue substance performed on a similar substance

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EU Method C.9 (Biodegradation: Zahn-Wellens Test)

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Sludge of a biological sewage treatment plant(ARA-Therwil) collected on 04.01.94

Duration of test (contact time):

28 d

Initial conc.:

150 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Reference substance:

diethylene glycol

Parameter:

% degradation (DOC removal)

Value:

26.8

Sampling time:

28 d

Details on results:

The bioelimination of FAT - 20'052/F measured as DOC after 28 days corrected by theblank control is: 26.8 % (average of 2 tests running in parallel)Adsorption after 3 hours: 29.2 %

Results with reference substance:

The bioelimination, corrected by the blank control and measured as DOC (mg/l) is: 98.8 %16th day

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

The inherent biodegradability of the test item was determined in a 28 days Zahn-Wellens -Test according to the OECD Guideline for Testing of Chemicals, No. 302B, showing a bioelemination of 26.8%.

Executive summary:

The inherent biodegradability of the test item was determined in a 28 days Zahn-Wellens -Test according to the OECD Guideline for Testing of Chemicals, No. 302B, Paris 1981 and the EEC-Directive, L133 (pp. 99-105) Volume 31, May 88.

 

The test was performed in compliance with the Good Laboratory Practice (GLP) Regulations of Switzerland.

 

The test substance was tested in concentration of 150 mg/l DOC. The reference substance Diethylenglycol was also tested in a concentration of 150 mg/l DOC.

 

Result:

The bioelimination of the test substance after 28 days is: 26.8 %

The bioelimination of the reference substance after 16 days is: 98.8 %

Description of key information

Biodegradation=69% after 20d, adapted activated sludge (Clariant, 1985a)
Biodegradation=26.8% after 28d, activated sludge (Huntsman,1994) 
Biodegradation=13% after 32d, activated sludge (Clariant, 1985)

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Additional information

Inherent biodegradability was tested on the analogue substance following OECD 302 B in three different studies. The biodegradation resulted to be 13 % and 26.8 % in two static tests with the non adapted activated sludge (Clariant 1985 and Huntsman 1994, respectively) while another test conducted with adapted sludge showed degradation equal to 69%.

The study with the 13% after 32days of exposure is however not considered since the substance resulted toxic to the bacteria. In fact, the value of degradation after 26 days in the same test resulted equal to 30%.

Criteria for inherent biodegradation are as follows:

elimination > 20% can be considered as evidence of primary inherent biodegradability

elimination > 70% can be regarded as evidence of ultimate inherent biodegradability.

Both studies (Clariant 1985a with adapted sludge and Huntsman 1994 with non-adapted sludge) show percentages of degradation in the range between 20 -70% in 28 days. Therefore the classification as inherently biodegradable was chosen as representative of the potential for biodegradation of the substance.

Based on the read across considerations, the same result of inherent biodegradability can be applied to the target substance