Chromate(2-), [5-(diethylamino)-2-[(2-hydroxy-4-nitrophenyl)azo]phenolato(2-)][5-hydroxy-6-[(2-hydroxy-4-nitrophenyl)azo]-1-naphthalenesulfonato(3-)]-, sodium

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Remarks:

BOD5/COD

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

From June 8 to 14, 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

The test was conducted by means of Read Across approach. The reliability of the source study report is 1. Further information was attached at section 13

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

ISO 5815 (Water quality - Determination of Biochemical Oxygen Demand after 5 Days (BOD5) - Dilution and Seeding Method)

Deviations:

yes

Remarks:

Aerate over night after addition of the inoculum

Principles of method if other than guideline:

Internal Method: SAV 01 000 03

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

other: Seeding water of an urban waste water

Duration of test (contact time):

ca. 5 d

Initial conc.:

ca. 6 mg/L

Based on:

test mat.

Initial conc.:

ca. 13 mg/L

Based on:

test mat.

Initial conc.:

ca. 26 mg/L

Based on:

test mat.

Initial conc.:

ca. 51.9 mg/L

Based on:

test mat.

Initial conc.:

ca. 103.9 mg/L

Based on:

test mat.

Initial conc.:

ca. 207.7 mg/L

Based on:

test mat.

Initial conc.:

ca. 415.5 mg/L

Based on:

test mat.

Initial conc.:

ca. 830.9 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 20 ± 1 °C

Reference substance:

other: D(+) - Glucose / L-Glutamic acid

Parameter:

% degradation (O2 consumption)

Remarks on result:

not determinable

Parameter:

BOD5

Value:

ca. 4 mg O2/g test mat.

Parameter:

BOD5*100/COD

Value:

ca. 0.8

Remarks on result:

other: dimensionless value

Results with reference substance:

207 mg O2/l

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

BOD5 = 4 mg O2/g
BOD5/COD= 0.008

Executive summary:

Methods:

The Biological Oxygen Demand of test substance was determined according to the ISO 5815 (Water quality - Determination of Biochemical Oxygen Demand after 5 Days (BOD5) - Dilution and Seeding Method).

Results:

BOD5 = 4 mg O2/g

BOD5/COD= 0.008

Reference 2

Endpoint:

biodegradation in water: screening test, other

Remarks:

BOD5/COD

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

From June 6 to 7, 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

The test was conducted by means of Read Across approach. The reliability of the source study report is 1. Further information was attached at section 13

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: DEV DIN 38*409 - H 41-1 (1980)

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

Mean of 2 determinations instead of 3

Principles of method if other than guideline:

Internal Method: SAV 02 000 02

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Duration of test (contact time):

ca. 2 h

Initial conc.:

ca. 10 other: mg

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 148 ± 3 °C

Reference substance:

other: Potassium hydrogen phthalate

Parameter:

% degradation (O2 consumption)

Remarks on result:

not determinable

Parameter:

COD

Value:

ca. 496 mg O2/g test mat.

Parameter:

BOD5*100/COD

Value:

ca. 0.8

Results with reference substance:

COD = 198 mg O2/l

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

COD = 496 mg O2/g
BOD5/COD = 0.008

Executive summary:

Methods:

The Chemical Oxygen Demand of test substance was determined according to the DEV DIN 38*409 - H 41-1 (1980), similar to EU Method C.6 (Degradation: Chemical Oxygen Demand).

Results:

COD = 496 mg O2/g

BOD5/COD = 0.008

Reference 3

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

From April 20 to May 18, 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The test was conducted by means of Read Across approach. The reliability of the source study report is 1. Further information was attached at section 13

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EEC-Directive, L133 (pp. 99-105) Volume 31, May 88.

Deviations:

no

Principles of method if other than guideline:

Internal method: SAV:13 000 02

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

other: Sludge of a biological sewage treatment plant

Details on inoculum:

- Source of inoculum: Sludge of a biological sewage treatment plant
- Laboratory culture: (ARA-Reinach) collected on 19.4.94
- Initial cell/biomass concentration: 930 mg/l

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 150 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Water / Nutrient: according to the specification of the EEC L133 (pp. 99-105) Volume 31 resp. OECD Method 302B.
- Test temperature: 22.0 ± 3°C
- Lighting: indirect daylight
- Estimation Technique: TOC/DOC Analyzer/ SHIMADZU TOC-5000

Reference substance:

diethylene glycol

Parameter:

% degradation (DOC removal)

Value:

ca. 22.9

Sampling time:

28 d

Parameter:

% degradation (DOC removal)

Value:

ca. 25.3

Sampling time:

3 h

Remarks on result:

other: adsorption

Results with reference substance:

bioelimination of the reference substance after 14 days is : 99.7 %

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Bioelimination of test substance measured as DOC after 28 days corrected by the blank control is: 22.9 %
Adsorption after 3 hours: 25.3 %

Executive summary:

Methods:

The inherent biodegradability of test substance was determined in a 28 days Zahn-Wellens -test according to the OECD Guideline for Testing of Chemicals, No. 302B, 1981.

 

Results:

Bioelimination of test substance measured as DOC after 28 days corrected by the blank control is: 22.9 %.

Adsorption after 3 hours: 25.3 %

Description of key information

DOC removal (28 d) = 22.9 %; adsorption after 3h = 25.3 %

BOD5/COD= 0.008  

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Additional information

No studies on the "Biodegradation in water" are available for the substance in itself.

Nevertheless studies have been conducted with an analogue molecule (Similar Substance 01). Further information are reported in the Read Across justification attached to section 13.

Different available tests may be valuable that give information on biodegradability. Missing the Ready biodegradability test.

 

Inherent biodegradability 

The inherent biodegradability was determined in a Zahn-Wellens, test according to the OECD Guideline for Testing of Chemicals, No. 302B, Paris 1981. The test has been performed in compliance with the Procedures and Principles of Good Laboratory Practice , regulation of Switzerland. The test substance and the reference substance Diethylenglycol, respectively, were tested in concentrations of 150 mg/l DOC.

The biodegradation of the test substance after 28 days was 22.9 %, with adsorption after 3 h of 25.3 %. The biodegradation of the reference substance after 9 days was 99.7 %.

 

BOD5/COD ratio

Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) are the most commonly used parameters for the characterization of the biodegradability capacity.

COD results are typically higher than BOD5 values, and the ratio between vary depending on the characteristics of the substrate. This ratio has been commonly used as an indicator for biodegradation capacity, the "Biodegradability index" (B.I.).

As indicated in ECHA Guidance requirement R.7B, the BOD5 test is a traditional biodegradation test that is now replaced by the ready biodegradability tests. Therefore, this test should not be performed today for assessment of the ready biodegradability of substances.

Older test data may, however, be used when no other degradability data are available.

Studies on BOD5 and COD are available for this substance, therefore they have been used together with the inherent biodegradability OECD 302.B, in the weight of evidence approach for this substance.

COD was measured according to Method A-16. Details of the method have been not reported. The COD measured was 496 mg/g O2.

BOD5 was measured according to Method A-15. Details of the method have been not reported. The BOD5 measured was 4 mg/g O2, at concentration of 100 mg/L.

The ratio BOD5/COD is 0.008.

This result is in line with the BOD5/COD value calculated in other tests reported in the file attached below.

Based on the rests of the considered tests, the substance is expected to be Not Readily Biodegradable