N-(2-ethylhexyl)-1-[[2-methyl-4-[(2-methylphenyl)azo]phenyl]azo]naphthalen-2-amine

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening test, other

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

June 2019

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:

An attempt was made to determine ready biodegradation expermentally using the Closed bottle test (OECD 301D). Due to the poor solubility of the test item in mineral medium an attempt was made to direct dose the substance into each test bottle. However due to the physical form of the material (viscous liquid/borderline solid), it was not possible to accurately weigh the required sample amount.

It was technically not possible to determine the ready biodegradability of the test substance.

A QSAR approach using BIOWIN is therefore used. A copy of hte expert opinion from the test lab is attached.

SOFTWARE
: BIOWIN version 4.11

SMILES USED AS INPUT FOR THE MODEL
: Cc3ccccc3N=Nc4cc(c(cc4)N=Nc1c(ccc2ccccc12)NCC(CC)CCCC)C

SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL : Please see attached justifcation documentation which provides detailed information on the model used.

APPLICABILITY DOMAIN
: Please see attached justifcation documentation which provides detailed information on the model used.

ADEQUACY OF THE RESULT : The results support a conclusion of NOT readily biodegradeable, which will be used for assessment against CLP criteria for environmental hazards.

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARS R.6

Version / remarks:

Version of May 2008

Deviations:

no

Principles of method if other than guideline:

The US EPA Suite software was used to predict the ready biodegredation of Solvent Red 19E. At attempt was made to determine ready biodegredation experimentally ising the Closed bottle method, however due to the physical form of the material it was not technically possible. BIOWIN was used, which contains 7 separatemodels for predicting Biodegradation. All 7 models concluded that the test substance would be NOT readily biodegradeable.

GLP compliance:

no

Specific details on test material used for the study:

QSAR: Smiles input code used: Cc3ccccc3N=Nc4cc(c(cc4)N=Nc1c(ccc2ccccc12)NCC(CC)CCCC)C

Oxygen conditions:

other: QSAR used, not applicable

Inoculum or test system:

other: QSAR used, not applicable

Key result

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks:

NOT readily bioodegradable

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Biowin1 (Linear Model Prediction) : Does Not Biodegrade Fast

Biowin2 (Non-Linear Model Prediction): Does Not Biodegrade Fast

Biowin3 (Ultimate Biodegradation Timeframe): Recalcitrant

Biowin4 (Primary Biodegradation Timeframe): Weeks

Biowin5 (MITI Linear Model Prediction) : Not Readily Degradable

Biowin6 (MITI Non-Linear Model Prediction): Not Readily Degradable

Biowin7 (Anaerobic Model Prediction): Does Not Biodegrade Fast

Ready Biodegradability Prediction: NO

Validity criteria fulfilled:

not applicable

Interpretation of results:

not readily biodegradable

Conclusions:

Solvent Red 19E is expected to be NOT readily biodegradable.

Executive summary:

An attempt was made to measure the biodegradation of Solvent Red 19E experimentally using the closed bottle method. However due to the physical form of the sample, the test could not be completed (was technically not possible to weight the required amount of material). The US EPA BIOWIN software was used to predict the ready biodegradability of Solvent Red 19E.  This model uses 7 separate models.  All 7 models predicted that the test substance would NOT be readily biodegradable.

Description of key information

The test substance is non-soluble in mineral medium. For this reason, a test solution or dispersion of the test substance in mineral medium could not be prepared. It was attempted to use direct dosing of the test substance into each test bottle. In the testing guidelines it is recommended that the concentration of the test substance in mineral medium should be in the range 2 to 5 mg/L. Taking into account the volume of glass vessels routinely used for the testing (280 mL), the amounts of this substance which need to be weighed are 0.56 to 1.4 mg. With respect to the physical properties of the test substance (viscous liquid/borderline waxy solid) it was not possible to exactly weigh out suitably small amounts of the test substance to allow the correct performance of study.

A QSAR approach was therefore used. BIOWIN v4.11 was used to predict the biodegradation of Solvent Red 19E. This QSAR tool uses 7 different models. All 7 models predicted that Solvent Red 19E would be NOT readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

other: Not applicable: QSAR used.