Reaction mass of 1,5-dihydroxy-4-nitro-8-(phenylamino)anthraquinone and 1,8-dihydroxy-4-nitro-5-(phenylamino)anthraquinone

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997

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 C (Inherent Biodegradability: Modified MITI Test (II))

Deviations:

yes

Remarks:

Inoculum was run alone instead of in duplicate and the test substance was run in duplicate instead of in triplicate.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Code number: FAT 92504/A
Batch-No.: 1/95
Purity: 46 %
Appearance: solid blue
Solubility: <0.1 g/l [in water]
Storage: room temperature
Expiration date: 04/1999
ThOD: 1.57 mg 02/mg [ThOD calculated without nitrification]

Oxygen conditions:

aerobic

Inoculum or test system:

other: Mixture of polyvalent bacteria collected from the aration tank of a domestic sewage treatment plant

Details on inoculum:

Mixture of polyvalent bacteria collected on May 20, 1997 from the aeration tank of a domestic sewage treatment plant, PRO RHENO Basel communal.
The pH value of the sludge was 7.7.

Duration of test (contact time):

28 d

Initial conc.:

7.3 other: mg/ 250 ml test medium

Based on:

test mat.

Initial conc.:

7.5 other: mg/ 250 ml test medium

Based on:

test mat.

Initial conc.:

7.6 other: mg/ 250 ml test medium

Based on:

test mat.

Initial conc.:

47.1 other: mg/30 mg

Based on:

ThOD

Details on study design:

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

The test was performed in a Voith Sapromat.
Tested chemicals were inoculated in the testing vessels with microorganisms. During the test
period, the Biochemical Oxygen Demand was measured continuousily by means of a BODmeter.
Biodegradability was calculated on the basis of the theoretical oxygen demand (ThOD)
or of the COD, if the ThOD could not be calculated.

Reference substance:

benzoic acid, sodium salt

Remarks:

tested in a concentration of about 167 mg ThOD/100 mg

Preliminary study:

None

Test performance:

The test was considered valid because:
- the difference of extremes values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d. window was less than 20%. [ 10-d. window: the 10 days immediately following the attainment of 10% biodégradation.]
- the degradation of the reference substance at day 7: >/= 40%
- the degradation of the reference substance at day 14: >/= 65%
- the abiotic degradation of the steril control at day 28 was not: >10%

Key result

Parameter:

other: BOD/ThOD

Value:

0

Remarks on result:

other: %

Parameter:

other: BOD5

Value:

0

Remarks on result:

other: mg O2/g

Key result

Parameter:

BOD5*100/ThOD

Remarks on result:

other: 0 %

Parameter:

BOD5

Value:

0 mg O2/g test mat.

Results with reference substance:

Biodegradation of the reference substance after 28 days: 100 %

Reference substance:

The biodégradation of the reference substance corrected by the blank control and measured as BOD versus ThOD was:

92 % after 7 days

97 % after 14 days

100 % after 28 days

Abiotic control:

The abiotic degradation measured as BOD was: 4 % after 28 days

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

FAT 92504/A was not biodegradable.

Executive summary:

The inherent biodegradability of FAT 92504/A was determined in a 28 days Modified MITI (II) - Test according to the OECD Guideline for Testing of Chemicals No 302C (adopted 1981).

The test substance and the reference substance were tested in a concentration of about 47.10 mg ThOD/30 mg and 167 mg ThOD/100 mg, respectively.

Results:

Mean value of the biodégradation of FAT 92504/A after 28 days: 0 %

Biodegradation of the reference substance after 28 days: 100 %

The biochemical oxygen demand (BOD5) after 5 days was: 0 mg O2/g

Conclusion:

On the basis of the present study the test substance FAT 92504/A was not biodegradable.

Description of key information

The inherent biodegradability of FAT 92504/A was determined in a 28 days Modified MITI (II) - Test according to the OECD Guideline for Testing of Chemicals No 302C (adopted 1981). Mean value of the biodégradation of FAT 92504/A after 28 days was found to be 0 %. The biochemical oxygen demand (BOD5) after 5 days was 0 mg O2/g. Hence, FAT 92504/A was not biodegradable in this study. The chemical oxygen demand (COD) of FAT 92504/A was assessed according to DIN 38409 - H 41-1 (1980) corresponding to EEC Directive 92 / 69 / C.6. (1992). In this study, the COD of FAT 92504/A was determined to be 666 mg O2/g. Taking the related BOD5 -result of 0 mg O2/g and the COD of 666 mg O2/g into account, the relevant BOD5/COD quotient is <0.5. This indicatesFAT 92504/A should be considered to be not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater