4,5-dichloro-2-nitroaniline

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening tests

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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 limited documentation / justification

Justification for type of information:

The supporting QMRF report has been attached.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Principles of method if other than guideline:

Prediction was done using OECD QSAR tool box v.3.3

GLP compliance:

not specified

Specific details on test material used for the study:

Name ( IUPAC):4,5-Dichloro-2-nitroaniline
Molecular formula:C6H4Cl2N2O2
Molecular weight: 207.016 g/mol
Smilies:Nc1cc(Cl)c(Cl)cc1[N+]([O-])=O
Inchi:1S/C6H4Cl2N2O2/c7-3-1-5(9)6(10(11)12)2-4(3)8/h1-2H,9H2
Substance type: Organic

Oxygen conditions:

aerobic

Inoculum or test system:

other: Microorganisms

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation:

other: BOD

Key result

Parameter:

other: % degradation by BOD

Value:

0.444

Sampling time:

28 d

Remarks on result:

other: other details not available

Details on results:

The test chemical 4,5-Dichloro-2-nitroaniline showed 0.44 % biodegradation by using BOD parameter in 28 days.

The prediction was based on dataset comprised from the following descriptors: BOD
Estimation method: Takes average value from the 6 nearest neighbours
Domain  logical expression:Result: In Domain

(((((((("a" or "b" or "c" or "d" or "e" or "f" )  and "g" )  and "h" )  and "i" )  and "j" )  and "k" )  and ("l" and ( not "m") )  )  and ("n" and "o" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Anilines (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Strong binder, NH2 group by Estrogen Receptor Binding

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as SNAr OR SNAr >> Nucleophilic aromatic substitution OR SNAr >> Nucleophilic aromatic substitution >> Activated halo-benzenes by Protein binding by OECD ONLY

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as SNAr OR SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds OR SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds >> Activated aryl and heteroaryl compounds by Protein binding by OASIS v1.3 ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Radical OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitroaniline Derivatives OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitroarenes with Other Active Groups OR SN1 OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation >> Nitroarenes with Other Active Groups OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroaniline Derivatives OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroarenes with Other Active Groups OR SN2 OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 >> Nitroarenes with Other Active Groups by DNA binding by OASIS v.1.3 ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as SN1 OR SN1 >> Nitrenium Ion formation OR SN1 >> Nitrenium Ion formation >> Aromatic nitro OR SN1 >> Nitrenium Ion formation >> Primary aromatic amine by DNA binding by OECD ONLY

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as days - weeks by Biodeg primary (Biowin 4) ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 1) ONLY

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 2) ONLY

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Class 3 (unspecific reactivity) by Acute aquatic toxicity classification by Verhaar (Modified) ONLY

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Phenols and Anilines by Acute aquatic toxicity MOA by OASIS ONLY

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Known precedent reproductive and developmental toxic potential AND NO2-alkyl/NO2-benzene derivatives (8b) AND Polyhalogenated benzene derivatives (8c) by DART scheme v.1.0

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Dihalogen-, dinitro-phenol and their ester derivatives (8e) OR Not known precedent reproductive and developmental toxic potential by DART scheme v.1.0

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 138 Da

Domain logical expression index: "o"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 218 Da

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

The test chemical 4,5-Dichloro-2-nitroaniline showed 0.44 % biodegradation by using BOD parameter and microorganisms as inoculum in 28 days. By this value of percent biodegradation it is concluded that test chemical 4,5-Dichloro-2-nitroaniline is not readily biodegradable.

Executive summary:

Biodegradability of test chemical 4,5-Dichloro-2-nitroaniline is predicted using OECD QSAR tool box v.3.3 using log Kow as preimary descriptor. The test chemical 4,5-Dichloro-2-nitroaniline showed 0.44 % biodegradation by using BOD parameter  and microorganisms as inoculum in 28 days. By this value of percent biodegradation it is concluded that test chemical 4,5-Dichloro-2-nitroaniline is not readily biodegradable.

Description of key information

Biodegradability of test chemical 4,5-Dichloro-2-nitroaniline is predicted using OECD QSAR tool box v.3.3 using log Kow as preimary descriptor. The test chemical 4,5-Dichloro-2-nitroaniline showed 0.44 % biodegradation by using BOD parameter  and microorganisms as inoculum in 28 days. By this value of percent biodegradation it is concluded that test chemical 4,5-Dichloro-2-nitroaniline is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Predicted data for the target compound 4,5-Dichloro-2-nitroaniline (CAS no. 6641-64-1) and supporting weight of evidence studies for its read across substance were reviewed for the biodegradation end point which are summarized as below

 

 In a prediction biodegradability of test chemical 4,5-Dichloro-2-nitroaniline is estimated using OECD QSAR tool box v.3.3 using log Kow as primary descriptor. The test chemical 4,5-Dichloro-2-nitroaniline showed 0.44 % biodegradation by using BOD parameter  and microorganisms as inoculum in 28 days. By this value of percent biodegradation it is concluded that test chemical 4,5-Dichloro-2-nitroaniline is not readily biodegradable.

 

 Another prediction done by using Estimation Programs Interface Suite (EPI suite, 2017) to estimate the biodegradation potential of the test chemical 4,5-Dichloro-2-nitroaniline (CAS No: 6641-64-1) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 4,5-Dichloro-2-nitroaniline is not readily biodegradable.

 

 In a supporting weight of evidence study from authoritative database (J Check, 2017) the read across chemical 4-Chlor-2-nitroanilin (CAS no. 89-63-4) was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analyzed by using three parameters that are BOD, TOC and GC. The initial concentration of read across chemical was 100 mg/L and study design is of standard type. After 2 weeks read across chemical showed 0 % degradation by all three parameters BOD, TOC and GC so it is concluded that read across chemical 4-Chlor-2-nitroanilin is not readily biodegradable.

 

In another supporting weight of evidence study from authoritative database (J Check, 2017) read across chemical 1,2-Dichloro-4-nitrobenzene (CAS no. 99-54-7) was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analyzed by using three parameters that are BOD, TOC and GC. The initial concentration of read across chemical was 100 mg/L and study design is of standard type. After 4 weeks (28 days) read across chemical1,2-Dichloro-4-nitrobenzene showed 0.0 % degradation by BOD and TOC parameter and 7 % degradation by GC parameter in 28 days so it is concluded that read across chemical1,2-Dichloro-4-nitrobenzene is not readily biodegradable.

 

On the basis of above results for target chemical 4,5-Dichloro-2-nitroaniline (CAS no. 6641-64-1) (from OECD QSAR tool box v3.4 and EPI suite, 2017) and for its read across substance (from authoritative database), it is concluded that the test substance 4,5-Dichloro-2-nitroaniline is not readily biodegradable in nature.