2-chloro-4-nitroaniline

H302: Harmful if swallowed [Warning Acute toxicity, oral]

H411: Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P264, P270, P273, P301+P317, P330, P391, and P501 (click each P-code to see the statement)

H302 (55.6%): Harmful if swallowed [Warning Acute toxicity, oral]

H312 (44.4%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H411 (55.6%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P264, P270, P273, P280, P301+P317, P302+P352, P317, P321, P330, P362+P364, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 117 reports by companies from 3 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

Not Classified

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

A fire in your laboratory involving this chemical should be extinguished with a dry chemical, carbon dioxide or halon extinguisher. (NTP, 1992)

Powder, alcohol-resistant foam, water spray, carbon dioxide.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place. (Extra personal protection: P2 filter respirator for harmful particles). Do NOT let this chemical enter the environment.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

PREVENT DISPERSION OF DUST! Do not eat, drink, or smoke during work. Wash hands before eating.

SMALL SPILLS AND LEAKAGE: If you spill this chemical, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with alcohol followed by washing with a strong soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

STORAGE PRECAUTIONS: You should store this material in a refrigerator. (NTP, 1992)

MINIMUM PROTECTIVE CLOTHING: When working with this chemical, you should wear an impervious full-body suit equipped with an air line respirator or a self-contained breathing apparatus.

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter.

RECOMMENDED GLOVE MATERIALS: Permeation data indicate that butyl rubber gloves may provide protection to contact with this compound. Butyl rubber over latex gloves is recommended. However, if this chemical makes direct contact with your gloves, or if a tear, hole or puncture develops, remove them at once. (NTP, 1992)

Local exhaust or breathing protection. Protective gloves. Safety spectacles.

2-chloro-4-nitroaniline is a yellow crystalline powder. (NTP, 1992)

Yellow solid; [Hawley] Yellow powder; [MSDSonline]

Yellow needles from water

225 to 228 °F (NTP, 1992)

Flash point = 205 °C

Very soluble in ether, ethanol, acetic acid

Soluble in alcohol, benzene, ether; slightly soluble in water and strong acids

0.000485 [mmHg]

log Kow = 2.14

Henry's Law constant = 0.54X10-9 atm-cu m/mol at 25 °C

pKa = -0.94 (conjugate acid)

126.1 Ų [M-H]- [CCS Type: DT; Buffer gas: N2; Ionization: ESI-; Dataset: TOXCAST; Source Identifier: DTXSID4021973]

15N nuclear magnetic resonance spectrum

Chemical shift

Crystal structure

Formula unit

Space group

Spin-spin coupling constant

Unit cell

Unit cell parameter

Nitrogen Compounds -> Nitroanilines

Insoluble in water.

Nitro, Nitroso, Nitrate, and Nitrite Compounds, Organic

Aryl Halides

Amines, Aromatic

2-CHLORO-4-NITROANILINE can react with oxidizing materials. (NTP, 1992)

The substance decomposes on burning producing toxic and corrosive gases, including nitrogen oxides.

Neurotoxin - Other CNS neurotoxin

Methemoglobinemia - The presence of increased methemoglobin in the blood; the compound is classified as secondary toxic effect

LD50 Mouse oral 1250 mg/kg bw

LD50 Rat oral 6430 mg/kg bw

IN ALL CASES CONSULT A DOCTOR. INHALATION: Symptoms: Blue skin. Blue lips or finger nails. Dizziness. Headache. Nausea. Shortness of breath. Confusion. Convulsions. Unconsciousness. Symptoms may be delayed. First aid: Fresh air, rest. Refer for medical attention. SKIN: Symptoms: Redness. First aid: Remove contaminated clothes. Rinse skin with plenty of water or shower. EYES: Symptoms: Redness. Pain. First aid: First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor. INGESTION: Symptoms: Blue skin. Blue lips or finger nails. Dizziness. Headache. Nausea. Shortness of breath. Confusion. Convulsions. Unconsciousness. Symptoms may be delayed. First aid: Rest. Refer for medical attention.

Routine checking of lips, tongue and nail beds of exposed personnel for signs of cyanosis. /Protect/ from exposure those individuals with anemia, cardiovascular or pulmonary diseases.

/LABORATORY ANIMALS: Acute Exposure/ Not sensitizing /to/ guinea pigs.

/LABORATORY ANIMALS: Acute Exposure/ Slightly irritating /to eyes of/ rabbit.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ When admin orally to rats @ 0.1-0.2 LD50 for 30 days, o-chloro-p-nitroaniline caused transformation of hemoglobin into methemoglobin, nitrosylhemoglobin, and sulfhemoglobin, in addition to decreases in oxyhemoglobin, but total level of hemoglobin remained unchanged.

/ALTERNATIVE and IN VITRO TESTS/ The toxicity of 4-chloro-2-nitroaniline (4C2NA) and 2-chloro-4-nitroaniline (2C4NA) was investigated on isolated rat hepatocytes following 1-3 hours of exposure to 0.2 and/or 2 mM of these xenobiotics. The higher of the two concentrations appeared to induce a statistically significant loss of cellular viability (p less than 0.01 compared to control), judged by Trypan Blue staining, after 3 hours of incubation with these substances means = 58, SD = 7%; and means = SD = 7%; for 4C2NA and 2C4NA, respectively). Furthermore, both chloronitroanilines produced an hepatocellular and microsomal damage demonstrated by conspicuous changes in LDH and G-6-Pase activities (p < 0.01). The exposure to 2 mM of both 4C2NA and/or 2C4NA produced a marked depletion of the intracellular pool of GSH after 3 hours (13 mM/10+6 and 10 mM/10+6 cells, respectively; p < 0.01). ...

For more Non-Human Toxicity Excerpts (Complete) data for 1-AMINO-2-CHLORO-4-NITROBENZENE (7 total), please visit the HSDB record page.

EC50 Daphnia magna (/water flea/) 10-18 mg/L/48 hr; immobilization.

EC50 Scenedesmus pannonicus (algae) 12 mg/L/96 hr; growth rate.

LC50 Chaetogammarus marinus (aquatic arthropod) 7.1 mg/L/96 hr. /Conditions of bioassay not specified/

LC50 Poecilia reticulata (/guppy/) 24 mg/L/96 hr; static, freshwater.

For more Ecotoxicity Values (Complete) data for 1-AMINO-2-CHLORO-4-NITROBENZENE (11 total), please visit the HSDB record page.

/AQUATIC SPECIES/ The Dreissena-Monitor is a biological early warning system for the continuous monitoring of river water quality, based on the valve movements of two groups of 42 zebra mussels (Dreissena polymorpha). Laboratory experiments with ... 2-chloro-4-nitro-aniline were conducted in combination with suspended particles (a mixture of stinging nettle powder, bentonite, and quartz powder). An increase of suspended particles up to a nominal concentration of 540 mg/L within 5 min did not evoke any reactions by the mussels significantly different from normal. The distribution between water and solids was analyzed for ... 2-chloro-4-nitroaniline, with the result that /it/ ... did not bind to the particles at all. The behavior of the zebra mussels revealed that the detection of 2-chloro-4-nitro-aniline was not affected by the presence of suspended matter. ...

2-Chloro-4-nitroaniline's production and use as an intermediate in the manufacture of both disperse and basic dyes and in the manufacture of niclosamid, a molluscicide, may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 4.8X10-4 mm Hg at 25 °C indicates 2-chloro-4-nitroaniline will exist solely as a vapor in the atmosphere. Vapor-phase 2-chloro-4-nitroaniline will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 4 days. 2-Chloro-4-nitroaniline does contain chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, 2-chloro-4-nitroaniline is expected to have moderate mobility based upon an estimated Koc values of 350. However, anilines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group, suggesting that mobility may be much lower in some soils. Volatilization from moist soil surfaces is not expected to be an important fate process based upon a Henry's Law constant of 9.5X10-9 atm-cu m/mole. 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants; therefore, biodegradation is not an important environmental fate process. If released into water, 2-chloro-4-nitroaniline is expected to adsorb to suspended solids and sediment based upon the estimated Koc. 2-Chloro-4-nitroaniline showed only a 12% loss over 8 days in a water-based medium due to abiotic factors. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's Henry's Law constant. An estimated BCF of 9 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to 2-chloro-4-nitroaniline may occur through dermal contact with this compound at workplaces where 2-chloro-4-nitroaniline is produced or used. (SRC)

2-Chloro-4-nitroaniline's production and use as an intermediate in the manufacture of both disperse and basic dyes(1,2) and in the manufacture of niclosamid, a molluscicide(3), may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 350(SRC), determined from a log Kow of 2.14(2) and a regression-derived equation(3), indicates that 2-chloro-4-nitroaniline is expected to have moderate mobility in soil(SRC). Volatilization of 2-chloro-4-nitroaniline from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 9.5X10-9 atm-cu m/mole(4). 2-Chloro-4-nitroaniline is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-4 mm Hg(SRC), determined from a fragment constant method(5). 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants(6); therefore, biodegradation is not an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 350(SRC), determined from a log Kow of 2.14(2) and a regression-derived equation(3), indicates that 2-chloro-4-nitroaniline is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 9.5X10-9 atm-cu m/mole(4). The stability of 2-chloro-4-nitroaniline in standardized aqueous medium was monitored at room temperature; a 12% loss of 2-chloro-4-nitroaniline was noted over a 8 day period due to either volatilization or abiotic transformation of this compound(5). According to a classification scheme(6), an estimated BCF of 9(SRC), from its log Kow(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants(8); therefore, biodegradation is not an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-chloro-4-nitroaniline, which has an estimated vapor pressure of 4.8X10-4 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2-chloro-4-nitroaniline is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 4 days(SRC), calculated from its rate constant of 3.9X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 2-Chloro-4-nitroaniline contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

AEROBIC: The biodegradability of 2-chloro-4-nitroaniline was measured using both the semistatic OECD test and the dynamic system, Pitter test. 2-Chloro-4-nitroaniline is considered non-biodegradable (half-life of much greater than 4 weeks) using both non-adapted and adapted inoculum for both tests(1). Using a modification of the Pitter test where the first step is an acclimation of a mixed microbial population to 2-chloro-4-nitroaniline (at 25 mg/L) in a semi-continuous activated sludge system followed by a die-away test in closed flasks, only a slight amount of degradation occurred. The initial inoculum was a 1:1 mixture of activated sludge from a domestic sewage plant and a solution containing organic material extracted from river mud. In the semi-continuous activated sludge system, 80% of the added 2-chloro-4-nitroaniline was still present after 17 days using both the mixed inoculum and an activated sewage sludge(2). 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants(2).

2-Chloro-4-nitroaniline is used in the manufacture of the molluscicide niclosamide(1). Degradation of (14)C-labeled niclosamide was studied in river and pond sediments (water:sediment ratio is 10-20:1) incubated under aerobic and anaerobic conditions over a 128 day period at 25 °C. Niclosamide degraded rapidly under these conditions with a half-life of 1.1 to 3.9 days in sediment; 1-amino-2-chloro-4-nitrobenzene, a hydrolytic product of niclosamide, was detected at concentrations of 1.8 ug (aerobic river sediment), 10.6 ug (aerobic pond sediment), 13.6 (anaerobic river sediment) and 25.6 ug (anaerobic pond sediment), following 32 days exposure to C-14 labelled niclosamide at a concentration of 1ug/mL in the overlying water; 2-chloro-4-nitraniline concentration in all samples was <1.0 ug after 93 days(2).

The rate constant for the vapor-phase reaction of 2-chloro-4-nitroaniline with photochemically-produced hydroxyl radicals has been estimated as 3.9X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 4 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The stability of 2-chloro-4-nitroaniline in standardized aqueous medium was monitored at room temperature; a 12% loss of 2-chloro-4-nitroaniline was noted over an 8 day period due to either volatilization or abiotic transformation of this compound(2). 2-Chloro-4-nitroaniline is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). 2-Chloro-4-nitroaniline does contain chromophores that absorb at wavelengths >290 nm(3,4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 9 was calculated in fish for 2-chloro-4-nitroaniline(SRC), using a log Kow of 2.14(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of 2-chloro-4-nitroaniline is estimated as 350(SRC), using a log Kow of 2.14(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2-chloro-4-nitroaniline is expected to moderate mobility in soil. However, anilines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group(4,5), suggesting that mobility may be much lower in some soils(SRC). The log Koc of 2-chloro-4-nitroaniline was measured as 2.36 in Yangtze river sediment (37.1% sand, 49.3% silt, 13.6% clay, 1.28% organic carbon, pH 7.44)(1). The log Koc was also measured as 3.63 in modified clay(6). These values correspond to Koc values of 230 and 4300, respectively(SRC).

The Henry's Law constant for 2-chloro-4-nitroaniline is 9.5X10-9 atm-cu m/mole(1). This Henry's Law constant indicates that 2-chloro-4-nitroaniline is expected to be essentially nonvolatile from water surfaces(2). 2-Chloro-4-nitroaniline is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-4 mm Hg(SRC), determined from a fragment constant method(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 737 workers (none of these are female) are potentially exposed to 2-chloro-4-nitroaniline in the US(1). Occupational exposure to 2-chloro-4-nitroaniline may occur through dermal contact with this compound at workplaces where 2-chloro-4-nitroaniline is produced or used(SRC).

EC50 Daphnia magna (/water flea/) 10-18 mg/L/48 hr; immobilization.

EC50 Scenedesmus pannonicus (algae) 12 mg/L/96 hr; growth rate.

LC50 Chaetogammarus marinus (aquatic arthropod) 7.1 mg/L/96 hr. /Conditions of bioassay not specified/

LC50 Poecilia reticulata (/guppy/) 24 mg/L/96 hr; static, freshwater.

For more Ecotoxicity Values (Complete) data for 1-AMINO-2-CHLORO-4-NITROBENZENE (11 total), please visit the HSDB record page.

/AQUATIC SPECIES/ The Dreissena-Monitor is a biological early warning system for the continuous monitoring of river water quality, based on the valve movements of two groups of 42 zebra mussels (Dreissena polymorpha). Laboratory experiments with ... 2-chloro-4-nitro-aniline were conducted in combination with suspended particles (a mixture of stinging nettle powder, bentonite, and quartz powder). An increase of suspended particles up to a nominal concentration of 540 mg/L within 5 min did not evoke any reactions by the mussels significantly different from normal. The distribution between water and solids was analyzed for ... 2-chloro-4-nitroaniline, with the result that /it/ ... did not bind to the particles at all. The behavior of the zebra mussels revealed that the detection of 2-chloro-4-nitro-aniline was not affected by the presence of suspended matter. ...

2-Chloro-4-nitroaniline's production and use as an intermediate in the manufacture of both disperse and basic dyes and in the manufacture of niclosamid, a molluscicide, may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 4.8X10-4 mm Hg at 25 °C indicates 2-chloro-4-nitroaniline will exist solely as a vapor in the atmosphere. Vapor-phase 2-chloro-4-nitroaniline will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 4 days. 2-Chloro-4-nitroaniline does contain chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, 2-chloro-4-nitroaniline is expected to have moderate mobility based upon an estimated Koc values of 350. However, anilines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group, suggesting that mobility may be much lower in some soils. Volatilization from moist soil surfaces is not expected to be an important fate process based upon a Henry's Law constant of 9.5X10-9 atm-cu m/mole. 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants; therefore, biodegradation is not an important environmental fate process. If released into water, 2-chloro-4-nitroaniline is expected to adsorb to suspended solids and sediment based upon the estimated Koc. 2-Chloro-4-nitroaniline showed only a 12% loss over 8 days in a water-based medium due to abiotic factors. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's Henry's Law constant. An estimated BCF of 9 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to 2-chloro-4-nitroaniline may occur through dermal contact with this compound at workplaces where 2-chloro-4-nitroaniline is produced or used. (SRC)

2-Chloro-4-nitroaniline's production and use as an intermediate in the manufacture of both disperse and basic dyes(1,2) and in the manufacture of niclosamid, a molluscicide(3), may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 350(SRC), determined from a log Kow of 2.14(2) and a regression-derived equation(3), indicates that 2-chloro-4-nitroaniline is expected to have moderate mobility in soil(SRC). Volatilization of 2-chloro-4-nitroaniline from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 9.5X10-9 atm-cu m/mole(4). 2-Chloro-4-nitroaniline is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-4 mm Hg(SRC), determined from a fragment constant method(5). 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants(6); therefore, biodegradation is not an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 350(SRC), determined from a log Kow of 2.14(2) and a regression-derived equation(3), indicates that 2-chloro-4-nitroaniline is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 9.5X10-9 atm-cu m/mole(4). The stability of 2-chloro-4-nitroaniline in standardized aqueous medium was monitored at room temperature; a 12% loss of 2-chloro-4-nitroaniline was noted over a 8 day period due to either volatilization or abiotic transformation of this compound(5). According to a classification scheme(6), an estimated BCF of 9(SRC), from its log Kow(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants(8); therefore, biodegradation is not an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-chloro-4-nitroaniline, which has an estimated vapor pressure of 4.8X10-4 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2-chloro-4-nitroaniline is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 4 days(SRC), calculated from its rate constant of 3.9X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 2-Chloro-4-nitroaniline contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

AEROBIC: The biodegradability of 2-chloro-4-nitroaniline was measured using both the semistatic OECD test and the dynamic system, Pitter test. 2-Chloro-4-nitroaniline is considered non-biodegradable (half-life of much greater than 4 weeks) using both non-adapted and adapted inoculum for both tests(1). Using a modification of the Pitter test where the first step is an acclimation of a mixed microbial population to 2-chloro-4-nitroaniline (at 25 mg/L) in a semi-continuous activated sludge system followed by a die-away test in closed flasks, only a slight amount of degradation occurred. The initial inoculum was a 1:1 mixture of activated sludge from a domestic sewage plant and a solution containing organic material extracted from river mud. In the semi-continuous activated sludge system, 80% of the added 2-chloro-4-nitroaniline was still present after 17 days using both the mixed inoculum and an activated sewage sludge(2). 2-Chloro-4-nitroaniline is regarded as non-biodegradable in the aquatic environment as well as in communal and industrial sewage treatment plants(2).

2-Chloro-4-nitroaniline is used in the manufacture of the molluscicide niclosamide(1). Degradation of (14)C-labeled niclosamide was studied in river and pond sediments (water:sediment ratio is 10-20:1) incubated under aerobic and anaerobic conditions over a 128 day period at 25 °C. Niclosamide degraded rapidly under these conditions with a half-life of 1.1 to 3.9 days in sediment; 1-amino-2-chloro-4-nitrobenzene, a hydrolytic product of niclosamide, was detected at concentrations of 1.8 ug (aerobic river sediment), 10.6 ug (aerobic pond sediment), 13.6 (anaerobic river sediment) and 25.6 ug (anaerobic pond sediment), following 32 days exposure to C-14 labelled niclosamide at a concentration of 1ug/mL in the overlying water; 2-chloro-4-nitraniline concentration in all samples was <1.0 ug after 93 days(2).

The rate constant for the vapor-phase reaction of 2-chloro-4-nitroaniline with photochemically-produced hydroxyl radicals has been estimated as 3.9X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 4 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The stability of 2-chloro-4-nitroaniline in standardized aqueous medium was monitored at room temperature; a 12% loss of 2-chloro-4-nitroaniline was noted over an 8 day period due to either volatilization or abiotic transformation of this compound(2). 2-Chloro-4-nitroaniline is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). 2-Chloro-4-nitroaniline does contain chromophores that absorb at wavelengths >290 nm(3,4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 9 was calculated in fish for 2-chloro-4-nitroaniline(SRC), using a log Kow of 2.14(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of 2-chloro-4-nitroaniline is estimated as 350(SRC), using a log Kow of 2.14(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2-chloro-4-nitroaniline is expected to moderate mobility in soil. However, anilines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group(4,5), suggesting that mobility may be much lower in some soils(SRC). The log Koc of 2-chloro-4-nitroaniline was measured as 2.36 in Yangtze river sediment (37.1% sand, 49.3% silt, 13.6% clay, 1.28% organic carbon, pH 7.44)(1). The log Koc was also measured as 3.63 in modified clay(6). These values correspond to Koc values of 230 and 4300, respectively(SRC).

The Henry's Law constant for 2-chloro-4-nitroaniline is 9.5X10-9 atm-cu m/mole(1). This Henry's Law constant indicates that 2-chloro-4-nitroaniline is expected to be essentially nonvolatile from water surfaces(2). 2-Chloro-4-nitroaniline is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-4 mm Hg(SRC), determined from a fragment constant method(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 737 workers (none of these are female) are potentially exposed to 2-chloro-4-nitroaniline in the US(1). Occupational exposure to 2-chloro-4-nitroaniline may occur through dermal contact with this compound at workplaces where 2-chloro-4-nitroaniline is produced or used(SRC).

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Do not transport with food and feedstuffs. Marine pollutant.