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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
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:
Data is predicted using OECD QSAR toolbox version 3.4 and QMRF report has been attached
Reference:
Composition 0
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
Prediction was done by using OECD QSAR toolbox v3.4
GLP compliance:
not specified
Test material information:
Composition 1
Specific details on test material used for the study:
- Name of the test material: 2-({4-[bis(2-hydroxyethyl)amino]-2-methylphenyl}diazenyl)-5-nitrobenzonitrile
- IUPAC name: 2-({4-[bis(2-hydroxyethyl)amino]-2-methylphenyl}diazenyl)-5-nitrobenzonitrile
- Molecular formula: C18H19N5O4
- Molecular weight: 369.38 g/mole
- Substance type: Organic
- SMILES:Cc1cc(N(CCO)CCO)ccc1N=Nc1ccc(N(=O)=O)cc1C#N
Analytical monitoring:
not specified
Details on sampling:
No data available
Vehicle:
not specified
Details on test solutions:
No data available
Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
No data available
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
36.36 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: no other details

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

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

Domain logical expression index: "a"

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

Domain logical expression index: "b"

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) >> Nitro Azoarenes OR SN1 OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitro Azoarenes by DNA binding by OASIS v.1.4 ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Not possible to classify according to these rules by DPRA Lysine peptide depletion

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Low reactive OR Low reactive >> N-substituted aromatic amides by DPRA Lysine peptide depletion

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OASIS v1.4

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group >> Carboxylic Acid Amides OR Acylation >> Acylation involving an activated (glucuronidated) ester group OR Acylation >> Acylation involving an activated (glucuronidated) ester group >> Arenecarboxylic Acid Esters OR Acylation >> Direct acylation involving a leaving group OR Acylation >> Direct acylation involving a leaving group >> Carboxylic Acid Amides OR Acylation >> Ester aminolysis OR Acylation >> Ester aminolysis >> Amides OR AN2 OR AN2 >> Michael addition to activated double bonds OR AN2 >> Michael addition to activated double bonds >> alpha,beta-Unsaturated Carbonyls and Related Compounds OR AN2 >> Michael-type addition to quinoid structures  OR AN2 >> Michael-type addition to quinoid structures  >> Carboxylic Acid Amides OR AN2 >> Michael-type addition to quinoid structures  >> N-Substituted Aromatic Amines OR Schiff base formation OR Schiff base formation >> Schiff base formation with carbonyl compounds OR Schiff base formation >> Schiff base formation with carbonyl compounds >> Aromatic carbonyl compounds OR SN1 OR SN1 >> Carbenium ion formation (enzymatic) OR SN1 >> Carbenium ion formation (enzymatic) >> Carbenium ion by Protein binding by OASIS v1.4

Domain logical expression index: "g"

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: "h"

Referential boundary: The target chemical should be classified as Reactive unspecified by Acute aquatic toxicity MOA by OASIS ONLY

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Alcohol AND Amine AND Aromatic compound AND Azo compound AND Hydroxy compound AND Nitrile AND Nitro compound AND Primary alcohol AND Tertiary amine AND Tertiary mixed amine by Organic functional groups, Norbert Haider (checkmol)

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Secondary alcohol by Organic functional groups, Norbert Haider (checkmol)

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as (!Undefined)Group All Lipid Solubility < 0.01 g/kg AND (!Undefined)Group CN Lipid Solubility < 0.4 g/kg AND Group All Melting Point > 200 C AND Group CN Aqueous Solubility < 0.1 g/L AND Group CN Melting Point > 180 C AND Group CN Molecular Weight > 290 g/mol AND Group CN Vapour Pressure < 0.001 Pa by Skin irritation/corrosion Exclusion rules by BfR

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Group CNS log Kow < -2 by Skin irritation/corrosion Exclusion rules by BfR

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of log Kow which is >= -1.35

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of log Kow which is <= 3.37

Validity criteria fulfilled:
not specified
Conclusions:
EC50 value of target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be 36.36 mg/L when exposed to Desmodesmus subspicatus for 72 hrs.
Executive summary:

Toxicity to aquatic algae and cynobacteria of target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated by using OECD QSAR tool box v3.4 using Log kow as primary descriptor and considering five closest read across substances. EC50 value of target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be 36.36 mg/L when exposed to Desmodesmus subspicatus for 72 hrs.

This EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 category as per the CLP criteria

Description of key information

Toxicity to aquatic algae and cynobacteria :

Toxicity to aquatic algae and cynobacteria of target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated by using OECD QSAR tool box v3.4 using Log kow as primary descriptor and considering five closest read across substances. EC50 value of target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be 36.36 mg/L when exposed to Desmodesmus subspicatus for 72 hrs.

This EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 category as per the CLP criteria

Key value for chemical safety assessment

EC50/LC50 for freshwater algae:
36.36 mg/L

Additional information

Toxicity to aquatic algae and cynobacteria :

Toxicity to aquatic algae and cynobacteria of target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated by using OECD QSAR tool box v3.4 using Log kow as primary descriptor and considering five closest read across substances. EC50 value of target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be 36.36 mg/L when exposed to Desmodesmus subspicatus for 72 hrs.

This EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 category as per the CLP criteria.

The above prediction was suppportted by experimental data summarized in Assessment for the Challenge Propanenitrile, 3-[ethyl[3-methyl-4 -[(6-nitro-2-benzothiazolyl) azo]phenyl]amino]- (Disperse Red 179) Environment Canada Health Canada 2010 for the structurally similar read across substance 16889-10-4 (2-[[4-[(2-cyanoethyl)ethylamino]phenyl]azo]-5-nitrobenzonitrile).

2-[[4-[(2-cyanoethyl)ethylamino]phenyl]azo]-5-nitrobenzonitrile when subjected on Scenedesmus subspicatus for 72 hrs the effect concentration (EC50) was observed as >10 mg/l.

Another structurally similar read across substance was summarized in the same referance 31482-56-1 (3-[ethyl[4-[(4-nitrophenyl) azo]phenyl]amino]propiononitrile).

3-[ethyl[4-[(4-nitrophenyl)azo]phenyl]amino]propiononitrile when subjected on Scenedesmus subspicatus for 72 hrs the effect concentration (EC50) was observed as 52 mg/l.

Based on the above data for the Target as well as the read across substance and by applying weight of evidence