Hydrogen bis[2,4-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]chromate(1-)

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:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

the complete read across justification is detailed in section 13, source study has reliability 2.

Principles of method if other than guideline:

The 5-day Biological Oxygen Demand (BOD5) was measured at 10 g/l (at 5, 10, 20 or 25 ml/500 ml).
The Chemical Oxygen Demand (COD) was measured by titration.

GLP compliance:

no

Oxygen conditions:

not specified

Inoculum or test system:

not specified

Details on inoculum:

no data

Duration of test (contact time):

5 d

Details on study design:

no data

Preliminary study:

no data

Test performance:

no data

Remarks on result:

other: BOD5/COD

Details on results:

none

Parameter:

BOD5

Value:

27 mg O2/g test mat.

Parameter:

COD

Value:

1 021 mg O2/g test mat.

Results with reference substance:

no data

% BOD5/COD = 3

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

Under the test conditions, the substance showed low biodegradation potential.

Executive summary:

Method

The study was conducted to evaluate the biodegradation potential of the test substance (at ca. 75 % purity) via BOD5 and COD determination.

Results

The ratio of these values was equivalent to 0.03, suggesting low biodegradation potential of the substance under the test conditions.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Remarks:

prediction

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

QSAR estimation

Qualifier:

no guideline required

Principles of method if other than guideline:

QSAR dyes R&C report produced by version QSAR dyes RC 2.0 Developed by Milano Chemometrics and QASR research group Dept. Earth and Environmental Science, University Milano
Bicocca, Italy.

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Validity criteria fulfilled:

not applicable

Remarks:

estimation by prediction tool

Interpretation of results:

not readily biodegradable

Conclusions:

Based on prediction carried out with the prediction tool, the substance resulted as non ready biodegradable.

Executive summary:

Results

The substance was predicted to be not ready biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

other: expert judgement based on available data

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Guideline:

other: REACH Guidance on QSARs R.6

Inoculum or test system:

other: expert judgement

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Validity criteria fulfilled:

not applicable

Remarks:

Expert judgement and estimation by QSAR dyes

Interpretation of results:

not readily biodegradable

Conclusions:

Based on prediction carried out with QSAR dyes, the substance resulted as non ready biodegradable.

Executive summary:

Method

Estimate of probability of rapid biodegradation relying on QSAR dyes. The overall assessment is based on the responses given by different predictive models for biodegradability under various conditions: linear and non-linear models, ultimate and primary survey models, MITI linear and non-linear models, anaerobic linear model.

Results

The substance was predicted to be not ready biodegradable.

Description of key information

The substance is considered as not readily biodegradable based QSAR prediction and expert judgemenet

Additional information

No information is available on the substance itself, thus the assessment relied on a read across approach. Solvent Orange 062 and Similar Substance 01 are chromium complexes with 2 ligands. In both cases, the 2 ligands have the same chemical structure, i.e. a phenyl ring connected via diazo bond to a phenyl pyrazole. These ligands show minor differences in the position of substituents, i.e. hydroxy and nitro gorups, as well as in the presence of a sulfonate group in Similar Substance 01.

Due to the lack of data from ready biodegradability tests, data on BOD5/COD ratio of Simialr Substance 01 was used for the assessement. No evidence of rapid degradation was found in the available study, where a BOD5/COD = 3 % was found.

Moreover, Solvent Orange 062 was predicted to be non ready biodegradable by QSAR dyes prediction tool.

On these bases, Solvent Orange 062 was considered as non rapidly degradable.