2-chloro-4-nitrophenol

Endpoint summary

Description of key information

Acute oral toxicity: 

Acute oral toxicity dose (LD50) was predicted based on OECD QSAR toolbox 1351 mg/kg bw, experimental study done by Deichmannet al(Toxicology of Drugs and Chemicals, P. 169, 1969), Richard J. Lewis, Sr.(Sax's Dangerous Properties of Industrial Materials. 12th Edition, 2012) and National Technical Reports Library (1992), 900 mg/kg bw and different studies available on structurally similar read across substance 3,5-Dichloronitrobenzene (618-62-2) 390 mg/kg bw and 1,2-dichloro-4-nitrobenzene (99-54-7)953 mg/kg bw. All these studies concluded that the LD50 value is between 300 - 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 2-chloro-4-nitrophenol can be classified as category IV of acute oral toxicity.

Acute Dermal toxicity: 

Acute Dermal toxicity dose (LD50) was predicted based on OECD QSAR toolbox 1731 mg/kg bw, experimental study done by National Technical Reports Library (1992)Range of 1500 – 2000 mg/kg bw,and differentstudies available on structurally similar read across substance 4-nitrophenol (100-02-7) 1024 mg/kg bw and 1-Chloro-3-nitrobenzene (121-73-3) 890 mg/kg bw. All these studies concluded that the LD50 value isbetween 300 - 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 2-ethoxynaphthalene-1-carbonyl chloride can be classified as category IV of acute dermal toxicity.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

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 3.3 and the supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: estimated

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.3

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

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

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

not specified

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

not specified

Doses:

1351 mg/kg bw

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

not specified

Statistics:

not specified

Preliminary study:

not specified

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 351 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality were observed

Mortality:

not specified

Clinical signs:

other: not specified

Gross pathology:

not specified

Other findings:

not specified

The prediction was based on dataset comprised from the following descriptors: LD50
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 ( not "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 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 SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Aromatic nitro by DNA binding by OECD

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> P450 Mediated Activation to Isocyanates or Isothiocyanates OR Acylation >> P450 Mediated Activation to Isocyanates or Isothiocyanates >> Benzylamines-Acylation OR Michael addition OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Alkyl phenols OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Arenes OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Hydroquinones OR Michael addition >> Polarised Alkenes-Michael addition OR Michael addition >> Polarised Alkenes-Michael addition >> Alpha, beta- unsaturated esters OR No alert found OR SN1 >> Carbenium Ion Formation OR SN1 >> Carbenium Ion Formation >> Allyl benzenes OR SN1 >> Carbenium Ion Formation >> Diazoalkanes OR SN1 >> Iminium Ion Formation OR SN1 >> Iminium Ion Formation >> Aliphatic tertiary amines OR SN1 >> Nitrenium Ion formation >> Aromatic azo OR SN1 >> Nitrenium Ion formation >> Primary aromatic amine OR SN1 >> Nitrenium Ion formation >> Secondary aromatic amine OR SN1 >> Nitrenium Ion formation >> Tertiary aromatic amine OR SN1 >> Nitrenium Ion formation >> Unsaturated heterocyclic azo OR SN2 OR SN2 >> Direct Acting Epoxides and related OR SN2 >> Direct Acting Epoxides and related >> Epoxides OR SN2 >> SN2 at an sp3 Carbon atom OR SN2 >> SN2 at an sp3 Carbon atom >> Aliphatic halides by DNA binding by OECD

Domain logical expression index: "i"

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: "j"

Referential boundary: The target chemical should be classified as No alert found OR Non-covalent interaction OR Non-covalent interaction >> DNA intercalation OR Non-covalent interaction >> DNA intercalation >> DNA Intercalators with Carboxamide Side Chain OR Non-covalent interaction >> DNA intercalation >> Fused-Ring Nitroaromatics OR Radical >> Radical mechanism by ROS formation OR Radical >> Radical mechanism by ROS formation >> Polynitroarenes OR Radical >> Radical mechanism via ROS formation (indirect) >> Fused-Ring Nitroaromatics OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitro Azoarenes OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitroaniline Derivatives OR Radical >> Radical mechanism via ROS formation (indirect) >> p-Substituted Mononitrobenzenes OR SN1 >> Carbenium ion formation OR SN1 >> Carbenium ion formation >> Alpha-Haloethers OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Fused-Ring Nitroaromatics OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitro Azoarenes OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroaniline Derivatives OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitrobiphenyls and Bridged Nitrobiphenyls OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Polynitroarenes OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> p-Substituted Mononitrobenzenes OR SN2 >> SN2 at sp3-carbon atom OR SN2 >> SN2 at sp3-carbon atom >> Alpha-Haloethers by DNA binding by OASIS v.1.3

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Aromatic Amine Type Compounds AND Halogenated Aromatic Hydrocarbon Type Compounds AND Phenol Type Compounds by Oncologic Primary Classification

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Halogenated Nitroaromatic Type Compounds by Oncologic Primary Classification

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of log Kow which is >= 1.53

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of log Kow which is <= 3.1

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

LD50 was estimated to be 1351 mg/kg bw, when Wistar male and female rats were treated with 2-chloro-4-nitrophenol by oral gavage route.

Executive summary:

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for  2-chloro-4-nitrophenol (619 -08 -9). The LD50 was estimated to be 1351 mg/kg bw, when Wistar male and female rats were treated with 2-chloro-4-nitrophenol by oral gavage route.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 351 mg/kg bw

Quality of whole database:

Data is Klimicsh 2 and QSAR toolbox 3.3

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

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 (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

Data is predicted using OECD QSAR toolbox version 3.3 and the supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: estimated

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.3

GLP compliance:

not specified

Test type:

other: 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

Species:

rabbit

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

not specified

Type of coverage:

other: Dermal

Vehicle:

not specified

Details on dermal exposure:

not specified

Duration of exposure:

not specified

Doses:

1731 mg/kg

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

not specified

Statistics:

not specified

Preliminary study:

not specified

Sex:

not specified

Dose descriptor:

LD50

Effect level:

1 731 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality was observed

Mortality:

not specified

Clinical signs:

other: not specified

Gross pathology:

not specified

Other findings:

not specified

The prediction was based on dataset comprised from the following descriptors: LD50
Estimation method: Takes average value from the 8 nearest neighbours
Domain  logical expression:Result: In Domain

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

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 No alert found by Protein binding by OECD

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates OR SN2 OR SN2 >> Epoxides and Related Chemicals OR SN2 >> Epoxides and Related Chemicals >> Epoxides OR SN2 >> SN2 reaction at sp3 carbon atom OR SN2 >> SN2 reaction at sp3 carbon atom >> Alkyl halides OR SNAr OR SNAr >> Nucleophilic aromatic substitution OR SNAr >> Nucleophilic aromatic substitution >> Activated halo-benzenes by Protein binding by OECD

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as High (Class III) by Toxic hazard classification by Cramer (original) ONLY

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Phenols by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Aromatic amines OR Inclusion rules not met OR Ketones by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Bioavailable by Lipinski Rule Oasis ONLY

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of log Kow which is >= -0.555

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of log Kow which is <= 4.67

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

LD50 was estimated to be 1731 mg/kg bw when rabbits were treated with 2-chloro-4-nitrophenol by dermal application.

Executive summary:

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for  2-chloro-4-nitrophenol (619 -08 -9). The LD50 was estimated to be 1731 mg/kg bw when rabbits were treated with 2-chloro-4-nitrophenol by dermal application.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 731 mg/kg bw

Quality of whole database:

Data is Klimicsh 2 and QSAR toolbox 3.3

Additional information

Acute oral toxicity:

In different studies, 2-chloro-4-nitrophenol (CAS no: 619-08-9) has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments in rodents, i.e. most commonly in rats for 2-chloro-4-nitrophenol along with the study available on structurally similar read across substance 3,5-Dichloronitrobenzene (618-62-2) and 1,2-dichloro-4-nitrobenzene (99-54-7). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies. The studies are summarized as below –

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 2-chloro-4-nitrophenol (619 -08 -9). The LD50 was estimated to be 1351 mg/kg bw, when Wistar male and female rats were treated with 2-chloro-4-nitrophenol by oral gavage route.

In the experimental study done by Deichmannet al(Toxicology of Drugs and Chemicals, P. 169, 1969), Richard J. Lewis, Sr.(Sax's Dangerous Properties of Industrial Materials. 12th Edition, 2012) and National Technical Reports Library (1992), the acute oral toxicity of 2-chloro-4-nitrophenol was tested in 23 Sprague dawley Male and Female rats by administering the test substance through stomach tube. The dose concentrations used were 700, 800, 900 and 1000 mg/kg in 50% suspension in corn oil (Vehicle). Rats were observed for clinical signs, body weight, organ weights, and histopathology, examinations. Mortality was observed in 700 mg/kg (2/5), 800 mg/kg (2/5), 900 mg/kg (4/8) and 1000 mg/kg (5/5). Excessive salivation and moderate diarrhoea was observed in animals those are survived overnight period after dosing. Liver damage was observed by macroscopic examination. Thus, LD50 was placed at 900 mg/kg bw, when Sprague dawley rats were treated with 2-chloro-4-nitrophenol (619-08-9) orally.

The above study supported by EUROPEAN COMMISSION – European Chemicals Bureau (IUCLID Dataset, 2000), for the structurally similar read across substance3,5-Dichloronitrobenzene (618-62-2) in rats. The acute oral toxicity was tested in 24 Sprague dawley Male and Female rats. The dose concentrations used were 250, 500 and 1000 mg/kg in 50% suspension in peanut oil (Vehicle). Rats were observed for clinical signs. Mortality occurred during the first 2 days of observation. At 250 mg/kg – 2 animals were died out of 8. At 500 mg/kg – 5 animals were died out of 8 and at 1000 mg/kg – All animals were died. Signs of dyspnea were observed. Sedation effect was observed. Therefore, LD50 was considered to be 390 mg/kg bw, when Sprague dawley rats were treated with 3,5-Dichloronitrobenzene (618-62-2) orally.

This is further supported by ChemIDplus (2017) and National Technical Reports Library (1991), for the structurally similar read across substance1,2-dichloro-4-nitrobenzene (99-54-7) in rats. The acute oral toxicity was tested in 50 Male ChR-CD rats at the dose concentration of 800, 1300, 1500, 1800, and 2000 mg/kg bw.The test material dissolved as a suspension in corn oil (Vehicle) 30% in 1300, 1500, 1800 and 2000 mg/kg and 15% 800 mg/kg. The dose was administered via Intragastric Intubation route.Animals were observed for clinical signs and body weight for 14 days. D. J. Firney method was used to calculate LD50. After 14 days of observation mortality was observed as - At 800 mg/kg –3 animals were died out of 10, At 1300 mg/kg –9 animals were died out of 10, At 1500 mg/kg –8 animals were died out of 10, At 1800 mg/kg and 2000 mg/kg –All animals were died. Clinical signs such as, Prostration, pallor, weakness, rapid breathing and cyanosis was observed in animals. The detail signs are mentioned in table. Weight loss was observed. Therefore, LD50 was considered to be 953 mg/kg bw with 95% confidential limit 693-1124 mg/kg bw, when Male ChR-CD rats were treated with 1,2-dichloro-4-nitrobenzene orally.

Thus, based on the above studies on 2-chloro-4-nitrophenol (CAS no: 619-08-9) and it’s read across substances, it can be concluded that LD50 value is between 300 - 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 2-chloro-4-nitrophenol can be classified as category IV of acute oral toxicity.

Acute Dermal toxicity:

In different studies, 2-chloro-4-nitrophenol (CAS no: 619-08-9) has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments in rodents, i.e. most commonly in rabbits and rats for 2-chloro-4-nitrophenol along with the study available on structurally similar read across substance 4-nitrophenol (100-02-7) and 1-Chloro-3-nitrobenzene (121-73-3). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies. The studies are summarized as below –

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute dermal toxicity was estimated for 2-chloro-4-nitrophenol (619 -08 -9). The LD50 was estimated to be 1731 mg/kg bw when rabbits were treated with 2-chloro-4-nitrophenol by dermal application.

In the experimental study done by National Technical Reports Library (1992), the acute dermal toxicity of 2-chloro-4-nitrophenol was tested in 7 New Zealand White Male and Female rabbits by applying the test substance to the closely clipped, intact skin of rabbits and the treated areas covered with plastic shield to prevent loss of the sample. The dose concentrations used were 750, 1000, 1500, 2000, 2250, 3000 and 4000 mg/kg in 50% suspension in corn oil (Vehicle). Rabbits were observed for clinical signs, body weight, organ weights, and histopathology, examinations. 50% mortality was observed in treated rabbits. During the observation animals were survived from 6 hours to overnight period. Animals were experienced lethargy after few hours of dosing. The survivors were inactive and had a poor appetite. Body weight was noted in Table for all the animals. At autopsy, visceral changes observed macroscopically were confined to tissue discoloration underneath the area of treatment. Therefore, LD50 was considered in the Range of 1500 – 2000 mg/kg bw, when New Zealand White rabbits were treated occlusively with 2-chloro-4-nitrophenol (619-08-9) by dermal application.

This is further supported by EUROPEAN COMMISSION – European Chemicals Bureau (IUCLID Dataset, 2000), for the structurally similar read across substance 4-nitrophenol (100-02-7), the acute dermal toxicity was tested in Female rats at the concentration of 1024 mg/kg. 50% mortality was observed. Therefore, LD50 was considered to be 1024 mg/kg bw, when Female rats were treated with 4-nitrophenol (100-02-7) by dermal application.

The above study supported by EUROPEAN COMMISSION – European Chemicals Bureau (IUCLID Dataset, 2000), for the structurally similar read across substance 1-Chloro-3-nitrobenzene (121-73-3), the acute dermal toxicity was tested in male rats at the concentration of 890 mg/kg. 50% mortality was observed. Therefore, LD50 was considered to be 890 mg/kg bw, when Male rats were treated with 1-Chloro-3-nitrobenzene (121-73-3) by dermal application.

Thus, based on the above studies on 2-chloro-4-nitrophenol (CAS no: 619-08-9) and it’s read across substances, it can be concluded that LD50 value is between 300 - 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 2-chloro-4-nitrophenol can be classified as category IV of acute dermal toxicity.

Justification for classification or non-classification

Based on the above studies and prediction on 2-chloro-4-nitrophenol (CAS no: 619-08-9) and it’s read across substances, it can be concluded that LD50 value is between 300 - 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 2-chloro-4-nitrophenol can be classified as category IV for acute oral and dermal toxicity.