Disodium [2-hydroxy-3-[(2-hydroxy-1-naphthyl)azo]-5-nitrobenzene-1-sulphonato(3-)][1-[(2-hydroxy-4-nitrophenyl)azo]-2-naphtholato(2-)]chromate(2-)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Remarks:

COD

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental start / end date: 07 July 1995; Study completion date: 23 August 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.6 (Degradation: Chemical Oxygen Demand)

Deviations:

yes

Remarks:

Mean of 2 determinations instead of 3

GLP compliance:

yes

Specific details on test material used for the study:

Code number: FAT 20013/C
Batch-Nr: 220
Purity: ca 70 %
Appearance: solid
Solubility: 1 g/L miscible (in water)
Storage: room temperature
Expiration date: 12/99

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Duration of test (contact time):

2 h

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

other: Potassium hydrogen phthalate solution (Merck-Nr. 11769)

Remarks on result:

other: COD is available

Key result

Parameter:

COD

Value:

824 mg O2/g test mat.

Results with reference substance:

The COD of the reference substance is: 198 mg O2/I.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The COD of the test substance FAT 20013 is: 824 mg O2/g.

Executive summary:

A study was carried out according to DIN 38409 - H 41-1 (1980) corresponding to EEC Directive 92 / 69 / C.6. (1992) for chemical oxygen demand of FAT 20013/C. A predeterminated amount of the test substance in water is oxidized by potassium dichromate in a strong sulphuric acid medium with silver sulphate as a catalyst under reflux for 2 hours. The residual dichromate is determined by titration with standardized ferrous ammonium sulphate. The test substance was tested with a sample weight of 3.53 and 3.76 mg. The reference substance was Potassium hydrogen phthalate. It was tested with 20 ml of a 0.17 g/l solution.

Based on the findings of the study; following results were obtained.

The COD of the test substance FAT 20013/C is: 824 mg O2/g.

The COD of the reference substance is: 198 mg O2/l.

In another Inherent biodegradation study conducted as per OECD test guideline 302C, the BOD5 of test substance was determined to be 0 mg O2/g. The resultant ratio of BOD:COD is therefore zero, indicating that the substance is not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental starting date: 14 February 1996; Experimental termination date: 13 March 1996; Study completion date: 16 April 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Deviations:

yes

Remarks:

The test substance was running in duplicate instead in triplicate.

GLP compliance:

yes

Specific details on test material used for the study:

Code number: FAT 20013/C
Batch-Nr: 220
Purity: ca. 70 %
Appearance: solid
Solubility: 1 g/L miscible (in water)
Storage: room temperature
Expiration date: 12/99

Oxygen conditions:

aerobic

Inoculum or test system:

other: Mixture of polyvalent bacteria collected on February 13, 1996 in the aeration tank of a domestic sewage treatment plant, PRO RHENO Basel communal

Details on inoculum:

Test organism
Strain / Inoculation Mixture of polyvalent bacteria collected on February 13, 1996 in the aeration tank of a domestic sewage treatment plant, PRO RHENO Basel communal.
Bacteria concentration: 100 mg/l suspended solids

Duration of test (contact time):

28 d

Initial conc.:

30 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

This test method was based on the following conditions:
- test chemicals as sole organic carbon sources
- no adaptation of micro-organisms to the test chemicals

Tested chemicals were inoculated in the testing vessels with micro-organisms. During the test period, the Biochemical Oxygen Demand was measured continuousily by means of a BOD-meter. Biodegradability was calculated on the basis of the theoretical oxygen demand (ThOD) or less satisfactorily COD, if the ThOD could not be calculated.

Optionally, primary biodégradation could be determinated by analysis of dissolved organic carbon (DOC) at the beginning and the end of the test.

Reference substance:

benzoic acid, sodium salt

Remarks:

[Merck No. 6290]

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

The biodégradation of FAT 20013/C corrected by the inoculum control and measured as BOD versus ThOD was 0 % after 28 days. The BOD5 after 5 days was 0 mg O2/g

Parameter:

BOD5

Value:

0 mg O2/g test mat.

Remarks on result:

other: After 5 days

Results with reference substance:

Biodegradation after 28 days of the reference substance was 88 %

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:

A study was performed to determine the percent biodegradation of FAT 20013/C. An inherent biodegradability of FAT 20013/C was determined in a 28 days MITI (II) - Test according to the OECD Guideline for Testing of Chemicals, No. 302C.

The test substance was tested in a concentration of 30 mg/l. The reference substance (Sodium benzoate) was tested in a concentration of 100 mg/l.

Based on the results of the study, biodegradation of the test substance after 28 days was 0 %.The bioderdation of reference substance after 28 days was found to be 88%, thereby validating the study.

Description of key information

A key study was performed to determine the percent biodegradation of FAT 20013. An inherent biodegradability of FAT 20013/C was determined in a 28 days MITI (II) - Test according to the OECD Guideline for Testing of Chemicals, No. 302C. The test substance was tested in a concentration of 30 mg/l. The reference substance (Sodium benzoate) was tested in a concentration of 100 mg/l. Based on the results of the study, biodegradation of the test substance after 28 days was 0 %. In another key study, chemical oxygen demand was calculated according to DIN 38409 - H 41-1 (1980) corresponding to EEC Directive 92 / 69 / C.6. (1992). The test substance was tested with a sample weight of 3.53 and 3.76 mg. The reference substance was Potassium hydrogen phthalate. It was tested with 20 ml of a 0.17 g/l solution. The COD of the test substance FAT 20013 is: 824 mg O2/g. A supporting study was performed to determine the biochemical oxygen demand of FAT 20013 by measuring the dissolved oxygen concentration before and after 5 days incubation at 20 °C. Based on the findings from the study, the BOD5 of FAT 20013/A is 19.0 mg O2/g test material. The relevant BOD5/COD quotient is <0.5, therefore the substance is not indicative of rapid degradation. Taking the data from key study and supporting studies into consideration, the test substance FAT 20013 is considered to be not biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed