2-chloro-4-nitrophenol

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

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 from OECD QSAR toolbox version 3.3 and the QMRF report has been attached.

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done using the OECD QSAR toolbox version 3.3.

GLP compliance:

not specified

Specific details on test material used for the study:

- IUPAC Name: 2-chloro-4-nitrophenol
- Common Name: Nitrofungin
- Mol. formula: C6H4ClNO3
- Molecular Weight: 173.555 g/mol
- Smiles: c1(cc(c(O)cc1)Cl)[N+](=O)[O-]
- InChI: 1S/C6H4ClNO3/c7-5-3-4(8(10)11)1-2-6(5)9/h1-3,9H
- Substance type: Organic
- Physical state: Solid

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test temperature:

21 ± 1 ºC

pH:

7.9 ± 0.2

Nominal and measured concentrations:

Estimated data

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

188.292 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

other: Population

Remarks on result:

other: Growth inhibition

The prediction was based on dataset comprised from the following descriptors: EC50
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 ( not "k") )  )  and ("l" and ( not "m") )  )  and ("n" and ( not "o") )  )  and ("p" and ( not "q") )  )  and ("r" and ( not "s") )  )  and ("t" and ( not "u") )  )  and ("v" and ( not "w") )  )  and ("x" and ( not "y") )  )  and ("z" and ( not "aa") )  )  and "ab" )  and ("ac" and ( not "ad") )  )  and ("ae" and ( not "af") )  )  and ("ag" and "ah" )  )

Domain logical expression index: "a"

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

Domain logical expression index: "b"

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

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Aromatic nitro by DNA binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Moderate binder, OH grooup by Estrogen Receptor Binding

Domain logical expression index: "e"

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

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Phenols by Aquatic toxicity classification by ECOSAR

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 Phenols and Anilines by Acute aquatic toxicity MOA by OASIS ONLY

Domain logical expression index: "i"

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

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Phenols by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Anilines (Hindered) by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Phenols by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Benzyl Alcohols by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Aromatic alcohol  [-OH] AND Aromatic chloride   [-CL] AND Aromatic nitro  [-NO2] AND Aromatic-H AND Benzene by Bioaccumulation - metabolism alerts

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Biphenyl OR -C=CH  [alkenyl hydrogen] by Bioaccumulation - metabolism alerts

Domain logical expression index: "p"

Referential boundary: The target chemical should be classified as Aromatic alcohol  [-OH] AND Aromatic chloride   [-CL] AND Aromatic nitro  [-NO2] AND Aromatic-H AND Benzene by Bioaccumulation - metabolism alerts

Domain logical expression index: "q"

Referential boundary: The target chemical should be classified as -CH2-  [cyclic] OR -CH2-  [linear] OR Four or more fused cyclic rings by Bioaccumulation - metabolism alerts

Domain logical expression index: "r"

Referential boundary: The target chemical should be classified as Aromatic alcohol  [-OH] AND Aromatic chloride   [-CL] AND Aromatic nitro  [-NO2] AND Aromatic-H AND Benzene by Bioaccumulation - metabolism alerts

Domain logical expression index: "s"

Referential boundary: The target chemical should be classified as Aromatic-CH3 by Bioaccumulation - metabolism alerts

Domain logical expression index: "t"

Referential boundary: The target chemical should be classified as Aromatic alcohol  [-OH] AND Aromatic chloride   [-CL] AND Aromatic nitro  [-NO2] AND Aromatic-H AND Benzene by Bioaccumulation - metabolism alerts

Domain logical expression index: "u"

Referential boundary: The target chemical should be classified as Aromatic ether  [-O-aromatic carbon] by Bioaccumulation - metabolism alerts

Domain logical expression index: "v"

Referential boundary: The target chemical should be classified as Nitro-aromatic (Genotox) AND Structural alert for genotoxic carcinogenicity by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "w"

Referential boundary: The target chemical should be classified as Pentachloro phenol (Nongenotox) by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "x"

Referential boundary: The target chemical should be classified as Not known precedent reproductive and developmental toxic potential by DART scheme v.1.0

Domain logical expression index: "y"

Referential boundary: The target chemical should be classified as NO2-alkyl/NO2-benzene derivatives (8b) by DART scheme v.1.0

Domain logical expression index: "z"

Referential boundary: The target chemical should be classified as Not known precedent reproductive and developmental toxic potential by DART scheme v.1.0

Domain logical expression index: "aa"

Referential boundary: The target chemical should be classified as Polyhalogenated benzene derivatives (8c) by DART scheme v.1.0

Domain logical expression index: "ab"

Similarity boundary:Target: Oc1ccc(N(=O)=O)cc1Cl
Threshold=40%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "ac"

Referential boundary: The target chemical should be classified as Nitrophenols/ Halophenols (Energy metabolism dysfuntion) Rank B by Repeated dose (HESS)

Domain logical expression index: "ad"

Referential boundary: The target chemical should be classified as Chlorphentermine (Hepatotoxicity) Alert by Repeated dose (HESS)

Domain logical expression index: "ae"

Referential boundary: The target chemical should be classified as Moderate binder, OH grooup by Estrogen Receptor Binding

Domain logical expression index: "af"

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

Domain logical expression index: "ag"

Parametric boundary:The target chemical should have a value of log Kow which is >= 0.968

Domain logical expression index: "ah"

Parametric boundary:The target chemical should have a value of log Kow which is <= 2.75

Validity criteria fulfilled:

not specified

Conclusions:

EC50 value was estimated to be 188.292 mg/l for Species Pseudokirchneriella subcapitata for 72 hrs duration when exposed to 2-chloro-4-nitrophenol (619-08-9).

Executive summary:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the six closest read across substances, the toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Target substance 2-chloro-4-nitrophenol (619-08-9). EC50 value was estimated to be 188.292 mg/l for Species Pseudokirchneriella subcapitata for 72 hrs duration when exposed to 2-chloro-4-nitrophenol (619-08-9).

Based on this value it can be concluded that the substance2-chloro-4-nitrophenolis considered as nontoxic to aquatic environment as per the criteria mentioned in CLP regulation. 

Description of key information

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the six closest read across substances, the toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Target substance 2-chloro-4-nitrophenol (619-08-9). EC50 value was estimated to be 188.292 mg/l for Species Pseudokirchneriella subcapitata for 72 hrs duration when exposed to 2-chloro-4-nitrophenol (619-08-9).

Based on this value it can be concluded that the substance2-chloro-4-nitrophenolis considered as nontoxic to aquatic environment as per the criteria mentioned in CLP regulation. 

Key value for chemical safety assessment

EC50 for freshwater algae:

188.292 mg/L

Additional information

Based on the various experimental data and prediction data for the target chemical as well as RA chemical which was selected on the basis of structure similarity study have been reviewed to determine the toxic nature of 2-chloro-4-nitrophenol (619-08-9 on the growth of algae. The studies are as mentioned below:

In the first predicted weight of evidence report for the 2-chloro-4-nitrophenol (619-08-9) from SSS (QSAR, 2017) toxicity study was carried out. Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the six closest read across substances, the toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Target substance 2-chloro-4-nitrophenol (619-08-9). EC50 value was estimated to be 188.292 mg/l for Species Pseudokirchneriella subcapitata for 72 hrs duration when exposed to 2-chloro-4-nitrophenol (619-08-9). Based on this value it can be concluded that the substance2-chloro-4-nitrophenolis considered as nontoxic to aquatic environment as per the criteria mentioned in CLP regulation. 

 

Similarly in the second weight of evidence study for the read across chemical 3 – Nitrobenzene sulfonic acid (127-68-4) (from ABITEC lab, 2016) Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 3 – Nitrobenzene sulfonic acid according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the limit concentration 100 mg/L. Effects on the growth rate of the organism were studied. The NOEC for the test substance, 3 – Nitrobenzene sulfonic acid, sodium salt, in Desmodesmus subspicatus was determined to be 100 mg/L on the basis of effects on growth rate in a 72 hour study. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as toxic as per the CLP criteria.

 

Similarly in the third weight of evidence study for the read across chemical Aminobenzene (62-53-3) j-check, 2017. Determination of short-term toxicity of chemical Aminobenzene on aquatic green algae. Test was performed in the static system. After the exposure of chemical effect concentration was measured at which 50% growth inhibited by chemical. Based on the growth inhibition of green algae, the EC50 was 110 mg/l and the NOEC was 3.7 mg/l. based on the biomass and area under the growth curve, the EC50 was 41 mg/l and the NOEC was 11 mg/l. Thus based on the EC50 (110 mg/l) chemical Aminobenzene (Aniline) consider as nontoxic and cannot be classified as per the CLP classification criteria.

 

Thus based on the above data sources for target chemical 2-chloro-4-nitrophenol (619-08-9) from various experimental studies and predicted studies from QSAR, ABITEC report, and j-check it was summarized that the chemical was nontoxic to aquatic algae and can be consider to be not classified as toxic as per the CLP classification criteria.