Bis[3-[[4-[benzylmethylamino]phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium] tetrachlorozincate(2-)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

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

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

abstract

Remarks:

The test was conducted on a similar substance, the complete justification for the Read Across approach is reported at section 13. The original Reliability of the test is 4

Qualifier:

according to guideline

Guideline:

other: CIBA GEIGY AG internal method 15

Qualifier:

according to guideline

Guideline:

other: CIBA GEIGY AG internal method 16

Principles of method if other than guideline:

The biological oxygen demand BOD is the amount of oxygen needed to degrade organic substances present in waste water with the help of bacteria (and other microorganisms present in sludge). The expression BOD5 represents the oxygen consumption within 5 days of incubation at 20 °C. Various dilutions of a substance solution in oxygen saturated water will be measured for its oxygen content before and after such an incubation period.

Within this procedure chemical oxygen demand (COD) is defined as the equivalent amount of oxygen in terms of amount of potassium dichromate that is consumed by reacting with the oxidizable components of 1 g of sample material dissolved in 1 liter water under the given reaction conditions.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Duration of test (contact time):

ca. 21 d

Initial conc.:

ca. 500 mg/L

Based on:

test mat.

Initial conc.:

ca. 5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks on result:

not determinable

Parameter:

BOD5

Value:

ca. 0 mg O2/g test mat.

Parameter:

COD

Value:

ca. 1 011 mg O2/g test mat.

Key result

Parameter:

BOD5*100/COD

Value:

ca. 0 other: %

Biochemical Oxygen Demand or BOD is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The term also refers to a chemical procedure for determining this amount. This is not a precise quantitative test, although it is widely used as an indication of the organic quality of water, therefore is not be used as quantitative date about ready biodegradation.

Interpretation of results:

not readily biodegradable

Conclusions:

BOD5 = 0 mg/g O2
COD = 1011 mg/g O2
BOD5/COD = 0

Executive summary:

The substance has been tested for biodegradation according to the CIBA GEIGY AG internal method 15, 16 that are similar to OECD 301C and EEC EU C.6.

The substance shows the following results:

BOD5 = 0 mg/g O2

COD = 1011 mg/g O2

BOD5/COD = 0

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

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

abstract

Remarks:

The test was conducted on a similar substance, the complete justification for the Read Across approach is reported at section 13. The original Reliability of the test is 4

Qualifier:

according to guideline

Guideline:

other: CIBA GEIGY AG internal method A-15

Qualifier:

according to guideline

Guideline:

other: CIBA GEIGY AG internal method A-16

Principles of method if other than guideline:

internal method A-15, A-16

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Duration of test (contact time):

ca. 5 d

Initial conc.:

ca. 50 mg/L

Based on:

test mat.

Initial conc.:

ca. 10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Remarks on result:

not determinable

Parameter:

BOD5

Value:

ca. 80 mg O2/g test mat.

Parameter:

COD

Value:

ca. 1 150.56 mg O2/g test mat.

Key result

Parameter:

BOD5*100/COD

Value:

ca. 6.95

Remarks on result:

other: BOD5/COD = 0.06

Biochemical Oxygen Demand or BOD is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The term also refers to a chemical procedure for determining this amount. This is not a precise quantitative test, although it is widely used as an indication of the organic quality of water, therefore is not be used as quantitative date about ready biodegradation.

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

BOD5 = 80 mg/g O2
COD = 1270.1 mg/g O2
BOD5/COD = 0.0695

Executive summary:

The substance has been tested for biodegradation according to the internal method A-15, A-16 that are similar to German guidelinelines DEV-H4 and DEV-H5.

BOD5 = 80 mg/g O2

COD = 1270.1 mg/g O2

BOD5/COD = 0.0695

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

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

abstract

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

not specified

Principles of method if other than guideline:

internal method A-37

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Activated sludge should be taken from a municipal waste water treatment plant which has been rinsed with
municipal water for 2 times.
- Concentration of sludge: The activated sludge is prepared one day before the start of the experiment, ventilated overnight and adjusted to a concentration of 600 mg/L.

Duration of test (contact time):

ca. 31 d

Initial conc.:

ca. 50 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

diethylene glycol

Parameter:

% degradation (O2 consumption)

Value:

ca. 5

Sampling time:

28 d

Interpretation of results:

not readily biodegradable

Conclusions:

The substance shows a biodegradation of 5%, therefore is not inherently biodegradable.

Executive summary:

The substance has been tested for inherently biodegradation according to the method OECD 302B. After a test period of 31 days the substance shows a degradation of 5%, therefore is not inherent biodegradable.

Description of key information

expected non-readily biodegradable

Additional information

No data are available on the substance in itself therefore, in order to assess the biodegradation potential of the target substance, the Read Across approach was selected.

Two rapidly biodegradation test (BOD5/COD) and one inherently biodegradation test conducted on the Similar Substance 1 are available.

The first screening study [Huntsman Textile Effects (Germany) GmbH, 1976] was performed according to an internal procedure, which are similar to internationally accepted guideline. The concentration of Similar substance 1 was 94 % and the substance shows a BOD5 = 0 and a COD = 1011 mg/g O2.

Also the second screening study of ready biodegradability [Huntsman Textile Effects (Germany) GmbH, 1978], was performed following the Ciba Geigy AG internal methods. In this case, the concentration of Similar substance 1 was 92 % and the BOD5 and COD resulted to be 80 and 1151 mg/g O2, respectively.

According to the indications provided in the ECHA guidance r7b, despite the information on the 5 -day biochemical oxygen demand (BOD5) cannot be used for classification purposes, it can be considered as an indication of non-readily biodegradation potential.

Based on the screening tests results, it can expected that the substance would not degradate in short period.

This expectation is confirmed by the study of inherent biodegradation conducted according the guideline OECD 302B [Huntsman Textile Effects GmbH, 1987]: after 28 days of test period, no biodegradation was recorded.

The complete Read Across Justification has been attached at section 13.