2-amino-4-nitrophenol

This chemical does not meet GHS hazard criteria for < 0.1% (1 of 2184) of reports.

H302 (97.8%): Harmful if swallowed [Warning Acute toxicity, oral]

H312 (92.4%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H315 (94.3%): Causes skin irritation [Warning Skin corrosion/irritation]

H319 (99.4%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H332 (92.4%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H335 (94.3%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H351 (92.6%): Suspected of causing cancer [Warning Carcinogenicity]

P203, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P317, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 2184 reports by companies from 18 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 1 of 2184 reports by companies.

There are 17 notifications provided by 2183 of 2184 reports by companies with hazard statement code(s).

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.

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

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P261, P264, P264+P265, P270, P272, P280, P301+P317, P302+P352, P305+P351+P338, P321, P330, P333+P317, P337+P317, P362+P364, and P501 (click each P-code to see the statement)

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. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. 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. Phenols are very toxic poisons AND corrosive and irritating, so that inducing vomiting may make medical problems worse. IMMEDIATELY call a hospital or poison control center and locate activated charcoal, egg whites, or milk in case the medical advisor recommends administering one of them. If advice from a physician is not readily available and the victim is conscious and not convulsing, give the victim a glass of activated charcoal slurry in water or, if this is not available, a glass of milk, or beaten egg whites and IMMEDIATELY transport victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, assure 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.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. A water spray may also be used. (NTP, 1992)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-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)

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.

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with 60-70% ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with 60-70% ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a 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 protect this chemical from exposure to light. Keep the container tightly closed under an inert atmosphere, and store under refrigerated temperatures. (NTP, 1992)

MINIMUM PROTECTIVE CLOTHING: If Tyvek-type disposable protective clothing is not worn during handling of this chemical, wear disposable Tyvek-type sleeves taped to your gloves.

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. (NTP, 1992)

2-amino-4-nitrophenol appears as orange prisms or yellow powder. No odor. (NTP, 1992)

Yellow-brown or orange solid; [HSDB] Gold colored powder; [MSDSonline]

Orange prisms from water

Yellow-brown leaflets containing water of crystallization

Yellow-brown to orange prisms

293 to 297 °F (anhydrous) (NTP, 1992)

80-90 °C /Monohydrate/; 143-145 °C /Anhydrous/

less than 1 mg/mL at 68 °F (NTP, 1992)

Soluble in ethanol, diethyl ether, acetic acid, warm benzene

Soluble in acetone

In water, 925 mg/L at 23 °C

0.0000352 [mmHg]

log Kow = 1.26

When heated to decomposition it emits toxic fumes of /nitrogen oxides./

pKa1 = 3.1 /amine/; pKa2 = 7.6 /phenol/ at 25 °C

When heated to decomposition it emits toxic fumes of NOx.

Diffusion

Electron conductivity

Fluorescence

Kinetic properties

Viscosity

Nitrogen Compounds -> Nitrophenols

Cosmetic ingredients (2-Amino-4-Nitrophenol) -> CIR (Cosmetic Ingredient Review)

Insoluble in water.

Nitro, Nitroso, Nitrate, and Nitrite Compounds, Organic

Phenols and Cresols

Amines, Aromatic

Oxidation of this chemical may occur in the presence of air and violent decomposition may occur if it is allowed to dry out completely at elevated temperatures. It is stable when stored protected from light and under nitrogen for two weeks at temperatures up to 140 °F, and storage under nitrogen for up to 24 weeks at room temperature (77 °F) should produce no loss of stability. This chemical is incompatible with acids, acid chlorides, acid anhydrides, chloroformates and strong oxidizing agents. It is also incompatible with iron. (NTP, 1992)

Safe in the present practices of use and concentration. Ingredient, concentration, and use information are available in documents discoverable at https://cir-reports.cir-safety.org

IDENTIFICATION AND USE: 2-Amino-4-nitrophenol is an orange prismatic solid. It can also be found as a yellow brown leaflets or yellow prisms. It is soluble in ethanol, diethyl ether, acetic acid and warm benzene. It is soluble in acetone and water. This chemical is used in the production of mordant and acid dyes. It is also used as an antioxidant and light stabilizer in butyl rubbers, and as a catalyst in the production of hexadiene. It was also formerly used in hair dyes. HUMAN EXPOSURE AND TOXICITY: Individuals may be exposed to this chemical through inhalation and dermal contact where the material is used or produced. The general population may be exposed to this chemical via inhalation and dermal contact with consumer products containing 2-amino-4-nitrophenol. There is inadequate evidence fo the carcinogenicity of this chemical in humans. ANIMAL STUDIES: 2-Amino-4-nitrophenol produced allergic contact dermatitis in guinea pigs. There is limited evidence for the carcinogenicity of this compound in experimental animals. The chemical induced sister chromatid exchange and chromosomal aberrations in Chinese hamster ovary cells. Neither micronuclei, chromosomal aberrations or dominant lethal effects were induced in rodents exposed in vivo. 2-Amino-4-nitrophenol was mutagenic in Salmonella typhimurium strains TA98 and TA100 with metabolic activation. It was not mutagenic in Salmonella typhimurium strains TA1535 or TA1537.

Evaluation: There is inadequate evidence in humans for the carcinogenicity of 2-amino-4-nitrophenol. There is limited evidence in experimental animals for the carcinogenicity of 2-amino-4-nitrophenol. Overall evaluation: 2-Amino-4-nitrophenol is not classifiable as to its carcinogenicity to humans (Group 3).

2-Amino-4-nitrophenol

Group 3: Not classifiable as to its carcinogenicity to humans

Volume 57: (1993) Occupational Exposures of Hairdressers and Barbers and Personal Use of Hair Colourants; Some Hair Dyes, Cosmetic Colourants, Industrial Dyestuffs and Aromatic Amines

2-Amino-4-Nitrophenol

TR-339: Toxicology and Carcinogenesis Studies of 2-Amino-4-Nitrophenol (CASRN 99-57-0) in F344/N Rats and B6C3F1 Mice (Gavage Studies) (1988 )

07/14/87

Some Evidence

No Evidence

Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity of 2-amino-4-nitrophenol for male F344/N rats, as shown by increased incidences of renal cortical (tubular cell) adenomas. The incidences of renal tubular cell hyperplasia were also increased in male rats exposed to 2-amino-4-nitrophenol. The survival of male rats that received 2-amino-4-nitrophenol was reduced compared with survival of vehicle control male rats. There was no evidence of carcinogenic activity of 2-amino-4-nitrophenol for female F344/N rats or for male or female B6C3F1 mice that received 125 or 250 mg/kg per day.

Neurotoxin - Other CNS neurotoxin

LD50 Rat ip 246 mg/kg

LD50 Rat oral 2400 mg/kg

LD50 Mouse ip 143 mg/kg

/LABORATORY ANIMALS: Acute Exposure/ This study tested 33 dyes in guinea pigs using a modified Buehler and Klecak method for open epicutaneous testing. The dyes were tested at an induction concentration of 10% and challenge concentrations of 10.0%, 5.0%, and 2.5%. Nine of the 33 dyes tested /including 2-amino-4-nitrophenol/ produced positive allergic reactions in the guinea pig model ... . When eight of the nine positive dyes were retested using a 1% induction concentration, five dyes /including 2-amino-4-nitrophenol/ produced allergic contact dermatitis at a 1% challenge concentration., /2-Amino-4-nitrophenol did not produce allergic contact dermatitis at /a 0.5% challenge concentration ...

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ This compound was tested (by gavage) at doses up to 250 mg/kg bw for two years in F344 rats and B6C3F1 mice. The incidence of tumors in mice was not increased, but in male rats there was a low but still significant (p=0.035) incidence of renal tubular-cell adenomas. Nephropathy was also observed in the male rats.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ ...Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity of 2-amino-4-nitrophenol for male F344/N rats, as shown by increased incidences of renal cortical (tubular cell) adenomas. The incidences of renal tubular cell hyperplasia were also increased in male rats exposed to 2-amino-4-nitrophenol. The survival of male rats that received 2-amino-4-nitrophenol was reduced compared with survival of vehicle control male rats. There was no evidence of carcinogenic activity of 2-amino-4-nitrophenol for female F344/N rats or for male or female B6C3F1 mice that received 125 or 250 mg/kg/day.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Two-generation reproduction ... studies were conducted in Sprague-Dawley rats receiving topical applications of six oxidative hair-coloring formulations /including/ ... 2-amino-4-nitrophenol ... The dye solutions were mixed with an equal volume of 6% hydrogen peroxide prior to application. In the reproduction study the samples were applied topically twice weekly throughout the growth, mating, gestation and lactation phases of the F0 parents to the weaning of the F1a and F2b litters. Fertility, gestation and fetal viability indices and body weights were evaluated ... and these were compared with the values for the three concurrent control groups. ... In the reproduction phase the application of hair dyes had no adverse effect on the fertility of the males or females, or on gestation, lactation and weaning indices. The average number weaned per litter and the mean body weights of the weanlings were comparable among the treated and control groups. ...

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

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=99-57-0]

During the 15-day studies, rats and mice received doses of 0, 313, 625, 1,250, 2,500, or 5,000 mg/kg. All rats that received 2,500 or 5,000 mg/kg and all female rats that received 1,250 mg/kg died before the end of the studies. Final mean body weights of chemically exposed rats surviving to the end of the studies were comparable to those of vehicle controls. Diarrhea was observed in all groups of exposed rats except those receiving 313 mg/kg. All mice that received 2,500 or 5,000 mg/kg, 2/5 males and all females that received 1,250 mg/kg, and 1/5 females that received 313 mg/kg died before the end of the studies. Final mean body weights of exposed mice surviving until the end of the studies were comparable to those of vehicle controls.

In 13-week studies, F344/N rats and B6C3F1 mice of each sex received 2-amino-4-nitrophenol at doses of 0, 62.5, 125, 250, 500, or 1,000 mg/kg. All rats that received 1,000 mg/kg and 2/10 males and 2/10 females that received 500 mg/kg died before the end of the studies. The final mean body weight of male rats that received 500 mg/kg was reduced 10% compared with that of vehicle controls; final mean body weights of all other surviving exposed rat groups were comparable to those of vehicle controls. Diarrhea and lethargy were observed for rats that received 500 or 1,000 mg/kg. All male mice and most females that received 1,000 mg/kg and 4/10 females that received 500 mg/kg died before the end of the studies. Final mean body weights of chemically exposed mice were comparable to those of vehicle controls. No compound-related clinical signs were observed in mice during the studies. Mineralization of the renal cortex and degeneration of the renal tubular epithelium were observed in male and female rats that received 1,000 mg/kg and in males that received 500 mg/kg. Degeneration and necrosis of the renal tubular epithelium was observed in 5/10 male and 3/10 female mice that received 1,000 mg/kg.

In the 2-year studies, rats and mice received 2-amino-4-nitrophenol at doses of 0, 125, or 250 mg/kg. Mean body weights of male rats that received 250 mg/kg were 8%-10% lower than those of vehicle controls throughout most of the 2-year study. Mean body weights of female rats were comparable to those of vehicle controls. Soft stools and occasional diarrhea were observed in chemically exposed rats starting 6 months after the beginning of the studies. Survival of male rats that received 250 mg/kg was markedly lower than that of vehicle controls after week 89 (final survival: vehicle control, 32/50; 125 mg/kg group, 24/50; 250 mg/kg group, 10/50). Survival of female rats was comparable among all groups (final survival: 25/50; 27/50; 31/50). Mean body weights of male and female mice that received 250 mg/kg were comparable to those of vehicle controls; the mean body weights of female mice that received 125 mg/kg were as much as 17% greater than that of vehicle controls. Survival of all mouse groups was comparable during the 2-year studies (final survival: male--28/50; 29/50; 23/50; female--28/50; 31/50; 30/50). ... Pigmentation of the small and large intestines was present in exposed rats but not in vehicle controls. Ulcers and erosive lesions of the digestive tract were observed in male rats that received 250 mg/kg and to a lesser extent in male rats that received 125 mg/kg. A carcinoma of the colon occurred in one male rat that received 250 mg/kg; no other neoplasms were observed in the gastrointestinal tract of rats. No pigmentation, ulcers, or erosive lesions were found in the digestive tract of mice. The severity of nephropathy was markedly greater in exposed male rats than in vehicle controls. Associated with the nephropathy were nonneoplastic lesions indicative of reduced renal function and secondary hyperparathyroidism, including parathyroid hyperplasia, mineralization of various organs, and fibrous osteodystrophy. Renal tubular cell hyperplasia (1/50; 4/48; 5/50) and renal cortical (tubular cell) adenomas (0/50; 1/48; 3/50) occurred in male rats. Renal cortical adenomas are infrequently observed in male F344/N rats (historical incidence, 0.5%). More preputial gland adenomas or carcinomas (combined) were observed in low dose male rats than in vehicle controls (3/50; 10/48; 3/50), whereas the incidences of clitoral gland neoplasms were decreased in dosed female rats (9/50; 6/50; 1/49). Hemangiomas or hemangiosarcomas (combined) occurred in male mice that received 2-amino-4-nitrophenol (0/50; 1/50; 5/50); each tumor was present at a different site. The historical control incidence is 11% at the study laboratory and 6% in 2-year NTP studies. ...Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity of 2-amino-4-nitrophenol for male F344/N rats, as shown by increased incidences of renal cortical (tubular cell) adenomas. The incidences of renal tubular cell hyperplasia were also increased in male rats exposed to 2-amino-4-nitrophenol. The survival of male rats that received 2-amino-4-nitrophenol was reduced compared with survival of vehicle control male rats. There was no evidence of carcinogenic activity of 2-amino-4-nitrophenol for female F344/N rats or for male or female B6C3F1 mice that received 125 or 250 mg/kg/day.

2-Amino-4-nitrophenol was mutagenic in Salmonella typhimurium strains TA98 and TA100 with metabolic activation. 2-Amino-4-nitrophenol was not mutagenic in strains TA 1535 or TA 1537. 2-Amino-4-nitrophenol was mutagenic in the mouse lymphoma L5178Y/TK+/- assay without metabolic activation. It was not tested with activation. 2-Amino-4-nitrophenol induced sister chromatid exchanges (SCEs) and chromosomal aberrations in Chinese hamster ovary cells in the presence and absence of metabolic activation.

2-Amino-4-nitrophenol's production and subsequent use in the production of mordant and acid dyes and hair dyes may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 3.5X10-5 mm Hg at 25 °C indicates 2-amino-4-nitrophenol will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase 2-amino-4-nitrophenol 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 2.3 days. Particulate-phase 2-amino-4-nitrophenol will be removed from the atmosphere by wet or dry deposition. Ultraviolet spectra of 2-amino-4-nitrophenol show maxima at 308 and 370 nm, indicating that this compound absorbs light at environmental wavelengths; therefore it may be susceptible to direct photolysis by sunlight. If released to soil, 2-amino-4-nitrophenol is expected to have high mobility based upon an estimated Koc of 120. The pKa of the phenol group on 2-amino-4-nitrophenol is 7.6, indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 2.2X10-12 atm-cu m/mole. If released into water, 2-amino-4-nitrophenol is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Incomplete data are available regarding the biodegradation of 2-amino-4-nitrophenol; however, Nocardia v. was not able to use this compound as a carbon source under aerobic conditions. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. An estimated BCF of 3.6 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-amino-4-nitrophenol may occur through inhalation and dermal contact with this compound at workplaces where it is produced or used. The general population may be exposed to 2-amino-4-nitrophenol via inhalation and dermal contact with hair dye and other consumer products containing 2-amino-4-nitrophenol. (SRC)

2-Amino-4-nitrophenol's production and subsequent use in the production of mordant and acid dyes(1) and hair dyes(2) may result in its release to the environment through various waste streams.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 120(SRC), determined from a log Kow of 1.26(2) and a regression-derived equation(3), indicates that 2-amino-4-nitrophenol is expected to have high mobility in soil(SRC). The pKa of the phenol group on 2-amino-4-nitrophenol is 7.6(4), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization of 2-amino-4-nitrophenol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.2X10-12 atm-cu m/mole(SRC), using a fragment constant estimation method(6). 2-Amino-4-nitrophenol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.5X10-5 mm Hg(SRC), determined from a fragment constant method(7). Incomplete data are available regarding the biodegradation of 2-amino-4-nitrophenol in water; however, Nocardia v. was not able to use this compound as a carbon source under aerobic conditions(8).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 120(SRC), determined from a log Kow of 1.26(2) and a regression-derived equation(3), indicates that 2-amino-4-nitrophenol is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 2.2X10-12 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 3.6(SRC), from its log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Incomplete data are available regarding the biodegradation of 2-amino-4-nitrophenol in water; however, Nocardia v. was not able to use this compound as a carbon source under aerobic conditions(7).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-amino-4-nitrophenol, which has an estimated vapor pressure of 3.5X10-5 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 2-amino-4-nitrophenol 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 2.3 days(SRC), calculated from its rate constant of 7.0X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 2-Amino-4-nitrophenol may also react with nitrate radicals in the atmosphere(4). Particulate-phase 2-amino-4-nitrophenol may be removed from the air by wet or dry deposition(SRC). Ultraviolet spectra of 2-amino-4-nitrophenol show maxima at 308 and 370 nm(5), indicating that this compound absorbs light at environmental wavelengths; therefore it may be susceptible to direct photolysis by sunlight(SRC).

2-Amino-4-nitrophenol (0.025% w/v) was not used as a carbon source for Nocardia v. when measured for visible growth over a period of 16 days at 30 °C(1).

The rate constant for the vapor-phase reaction of 2-amino-4-nitrophenol with photochemically-produced hydroxyl radicals has been estimated as 7.0X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.3 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 2-Amino-4-nitrophenol may also react with nitrate radicals in the atmosphere(2). 2-Amino-4-nitrophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Ultraviolet spectra of 2-amino-4-nitrophenol show maxima at 308 and 370 nm(4), indicating that this compound absorbs light at environmental wavelengths; therefore it may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3.6 was calculated for 2-amino-4-nitrophenol (SRC), using a log Kow of 1.26(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.

The Koc of 2-amino-4-nitrophenol is estimated as 120(SRC), using a log Kow of 1.26(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2-amino-4-nitrophenol is expected to have high mobility in soil. The pKa of the phenol group on 2-amino-4-nitrophenol is 7.6(4), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). However, anilines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group(6,7), suggesting that mobility may be much lower in some soils(SRC).

The Henry's Law constant for 2-amino-4-nitrophenol is estimated as 2.2X10-12 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 2-amino-4-nitrophenol is expected to be essentially nonvolatile from water surfaces(2). 2-amino-4-nitrophenol's Henry's Law constant indicates that volatilization from moist soil surfaces may not occur(SRC). 2-Amino-4-nitrophenol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.5X10-5 mm Hg(SRC), determined from a fragment constant method(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 20,256 workers (17,049 of these were female) were potentially exposed to 2-amino-4-nitrophenol in the US(1). Occupational exposure to 2-amino-4-nitrophenol may occur through inhalation and dermal contact with this compound at workplaces where it is produced or used. The general population may be exposed to 2-amino-4-nitrophenol via inhalation and dermal contact with hair dye and other consumer products containing 2-amino-4-nitrophenol(SRC).

2-Amino-4-nitrophenol's production and subsequent use in the production of mordant and acid dyes and hair dyes may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 3.5X10-5 mm Hg at 25 °C indicates 2-amino-4-nitrophenol will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase 2-amino-4-nitrophenol 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 2.3 days. Particulate-phase 2-amino-4-nitrophenol will be removed from the atmosphere by wet or dry deposition. Ultraviolet spectra of 2-amino-4-nitrophenol show maxima at 308 and 370 nm, indicating that this compound absorbs light at environmental wavelengths; therefore it may be susceptible to direct photolysis by sunlight. If released to soil, 2-amino-4-nitrophenol is expected to have high mobility based upon an estimated Koc of 120. The pKa of the phenol group on 2-amino-4-nitrophenol is 7.6, indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 2.2X10-12 atm-cu m/mole. If released into water, 2-amino-4-nitrophenol is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Incomplete data are available regarding the biodegradation of 2-amino-4-nitrophenol; however, Nocardia v. was not able to use this compound as a carbon source under aerobic conditions. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. An estimated BCF of 3.6 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-amino-4-nitrophenol may occur through inhalation and dermal contact with this compound at workplaces where it is produced or used. The general population may be exposed to 2-amino-4-nitrophenol via inhalation and dermal contact with hair dye and other consumer products containing 2-amino-4-nitrophenol. (SRC)

2-Amino-4-nitrophenol's production and subsequent use in the production of mordant and acid dyes(1) and hair dyes(2) may result in its release to the environment through various waste streams.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 120(SRC), determined from a log Kow of 1.26(2) and a regression-derived equation(3), indicates that 2-amino-4-nitrophenol is expected to have high mobility in soil(SRC). The pKa of the phenol group on 2-amino-4-nitrophenol is 7.6(4), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization of 2-amino-4-nitrophenol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.2X10-12 atm-cu m/mole(SRC), using a fragment constant estimation method(6). 2-Amino-4-nitrophenol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.5X10-5 mm Hg(SRC), determined from a fragment constant method(7). Incomplete data are available regarding the biodegradation of 2-amino-4-nitrophenol in water; however, Nocardia v. was not able to use this compound as a carbon source under aerobic conditions(8).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 120(SRC), determined from a log Kow of 1.26(2) and a regression-derived equation(3), indicates that 2-amino-4-nitrophenol is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 2.2X10-12 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 3.6(SRC), from its log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Incomplete data are available regarding the biodegradation of 2-amino-4-nitrophenol in water; however, Nocardia v. was not able to use this compound as a carbon source under aerobic conditions(7).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-amino-4-nitrophenol, which has an estimated vapor pressure of 3.5X10-5 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 2-amino-4-nitrophenol 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 2.3 days(SRC), calculated from its rate constant of 7.0X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 2-Amino-4-nitrophenol may also react with nitrate radicals in the atmosphere(4). Particulate-phase 2-amino-4-nitrophenol may be removed from the air by wet or dry deposition(SRC). Ultraviolet spectra of 2-amino-4-nitrophenol show maxima at 308 and 370 nm(5), indicating that this compound absorbs light at environmental wavelengths; therefore it may be susceptible to direct photolysis by sunlight(SRC).

2-Amino-4-nitrophenol (0.025% w/v) was not used as a carbon source for Nocardia v. when measured for visible growth over a period of 16 days at 30 °C(1).

The rate constant for the vapor-phase reaction of 2-amino-4-nitrophenol with photochemically-produced hydroxyl radicals has been estimated as 7.0X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.3 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 2-Amino-4-nitrophenol may also react with nitrate radicals in the atmosphere(2). 2-Amino-4-nitrophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Ultraviolet spectra of 2-amino-4-nitrophenol show maxima at 308 and 370 nm(4), indicating that this compound absorbs light at environmental wavelengths; therefore it may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3.6 was calculated for 2-amino-4-nitrophenol (SRC), using a log Kow of 1.26(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.

The Koc of 2-amino-4-nitrophenol is estimated as 120(SRC), using a log Kow of 1.26(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2-amino-4-nitrophenol is expected to have high mobility in soil. The pKa of the phenol group on 2-amino-4-nitrophenol is 7.6(4), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). However, anilines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group(6,7), suggesting that mobility may be much lower in some soils(SRC).

The Henry's Law constant for 2-amino-4-nitrophenol is estimated as 2.2X10-12 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 2-amino-4-nitrophenol is expected to be essentially nonvolatile from water surfaces(2). 2-amino-4-nitrophenol's Henry's Law constant indicates that volatilization from moist soil surfaces may not occur(SRC). 2-Amino-4-nitrophenol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.5X10-5 mm Hg(SRC), determined from a fragment constant method(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 20,256 workers (17,049 of these were female) were potentially exposed to 2-amino-4-nitrophenol in the US(1). Occupational exposure to 2-amino-4-nitrophenol may occur through inhalation and dermal contact with this compound at workplaces where it is produced or used. The general population may be exposed to 2-amino-4-nitrophenol via inhalation and dermal contact with hair dye and other consumer products containing 2-amino-4-nitrophenol(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.