Disodium 4,4'-bis(2-hydroxynaphthalen-1-ylazo)biphenyl-2,6'-disulphonate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: screening test, other

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

The prediction has been carried out by means of QSAR prediction, using the following
model:
• “ISIDA Consensus – Ready Biodegradability (RB) classification model”. The
relative QMRF is available as attached file (“5.2.1 - EC 233-439-3 - Acid Red
97_ISIDA_QMRF”).
• “VEGA Ready Biodegradation model”. The relative QMRF is available as
attached file (“5.2.1 - EC 233-439-3 - Acid Red 97_VEGA_QMRF.pdf”).

Data source

Reference

Reference Type:

other company data

Title:

Unnamed

Year:

2020

Materials and methods

Principles of method if other than guideline:

In-silico predictions (QSAR) have been used to cover the present endpoint. The aim of these predictions is to contribute through a weight of evidence approach to the assessment of the Ready Biodegradability in order to satisfy the REACH requirements for the registration dossier using non-testing methods.
A total of two independent QSAR models have been applied.

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 4,4'-bis(2-hydroxynaphthalen-1-ylazo)biphenyl-2,6'-disulphonate

EC Number:

233-439-3

EC Name:

Disodium 4,4'-bis(2-hydroxynaphthalen-1-ylazo)biphenyl-2,6'-disulphonate

Cas Number:

10169-02-5

Molecular formula:

C32H20N4Na2O8S2

IUPAC Name:

NA

Specific details on test material used for the study:

CAS number 10169-02-5
EC number 233-439-3
Chemical name Acid Red 97
Structural formula C32 H20 N4 Na2 O8 S2
SMILES [Na+].[Na+].[O-]S(=O)(=O)C1=CC(=CC=C1C1=CC=C(C=C1S([O-])(=O)=O)N=NC1C2=CC=CC=C2C=CC=1O)N=NC1C2=CC=CC=C2C=CC=1O

Results and discussion

% Degradation

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Value:

< 60

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Any other information on results incl. tables

The test material QPRF for the ISIDA model is available as attached file ("5.2.1 - EC
233-439-3 - Acid Red 97_ISIDA_QPRF.xlsx“).
The test material QPRF for the VEGA model is available as attached file ("5.2.1 - EC
233-439-3 - Acid Red 97_VEGA_QPRF.xlsx“), as well as the produced output report
automatically generated by the VEGA model ("5.2.1 - EC 233-439-3 - Acid Red
97_VEGA_modelreport.pdf“).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Both applied models predict the test material as NON Readily Biodegradable.
The degradation % of the test substance can be considered to be <60 %: this value corresponds to the threshold necessary to define a substance as readily biodegradable as defined by OECD 301c.
The test material fulfils the model's applicability domain, satisfying the defined reliability criteria. Moreover, structural analogues with known experimental data have been found in the model training set, supporting the outcome of the test material. Thus, the prediction can be considered adequate for data-gap filling for the present endpoint.