2-amino-5-nitrophenol

H315 (95%): Causes skin irritation [Warning Skin corrosion/irritation]

H319 (> 99.9%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H335 (94.9%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H351 (92.7%): Suspected of causing cancer [Warning Carcinogenicity]

H411 (97.5%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P203, P261, P264, P264+P265, P271, P273, P280, P302+P352, P304+P340, P305+P351+P338, P318, P319, P321, P332+P317, P337+P317, P362+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 2175 reports by companies from 15 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.

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

P261, P272, P280, P302+P352, P321, P333+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-5-nitrophenol appears as brown amorphous granules or powder. Melting point 198-202 °C.

Olive-brown, brown, or orange solid; [HSDB] Green crystalline solid; [MSDSonline]

Olive-brown, brown to orange crystalline solid

Orange needles when recrystallized from water

388 to 396 °F (decomposes) (NTP, 1992)

205.8 °C

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

Slightly soluble in water

Soluble in ethanol, acetone, and benzene

Soluble in deuterated DSMO

0.0000352 [mmHg]

125.3 Ų [M-H]- [CCS Type: DT; Buffer gas: N2; Ionization: ESI-; Dataset: TOXCAST; Source Identifier: DTXSID1020063]

Nitrogen Compounds -> Nitrophenols

Cosmetic ingredients (2-Amino-5-Nitrophenol) -> CIR (Cosmetic Ingredient Review)

Is slowly oxidized by air at room temperature. Insoluble in water.

Nitro, Nitroso, Nitrate, and Nitrite Compounds, Organic

Phenols and Cresols

Amines, Aromatic

2-AMINO-5-NITROPHENOL is a mild reducing agent. Incompatible with strong oxidizing agents. Reacts slowly with oxygen in the air at room temperature. Stable at temperatures up to 140 °F for two weeks when kept in the dark and under nitrogen. Stable under nitrogen for up to 24 weeks 77 °F. Incompatible with strong bases (NTP, 1992). Incompatible with acid chlorides and acid anhydrides.

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

Evaluation: There is inadequate evidence in humans for the carcinogenicity of 2-amino-5-nitrophenol. There is limited evidence in experimental animals for the carcinogenicity of 2-amino-5-nitrophenol. Overall evaluation: 2-Amino-5-nitrophenol is not classifiable as to its carcinogenicity to humans (Group 3).

2-Amino-5-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-5-Nitrophenol

TR-334: Toxicology and Carcinogenesis Studies of 2-Amino-5-Nitrophenol (CASRN 121-88-0) in F344/N Rats and B6C3F1 Mice (Gavage Studies) (1988 )

03/04/87

Some Evidence

No Evidence

Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity for male F344/N rats that received 100 mg/kg 2-amino-5-nitrophenol, as shown by the increased incidence of acinar cell adenomas of the pancreas. Reduced survival of male F344/N rats that received 200 mg/kg decreased the sensitivity of this group for detecting a carcinogenic response. There was no evidence of carcinogenic activity for female rats that received 100 or 200 mg/kg per day. Marginally increased incidences of preputial or clitoral gland adenomas or carcinomas (combined) occurred in male and female F344/N rats administered 200 mg/kg 2-amino-5-nitrophenol. There was no evidence of carcinogenic activity for B6C3F1 mice that received 400 mg/kg 2-amino-5-nitrophenol; reduced survival of B6C3F1 mice that received 800 mg/kg caused this group to be considered inadequate for detecting a carcinogenic response.

The LD50 of 2-amino-5-nitrophenol in rats has been reported to be greater than 4000 mg/kg bw by oral administration and greater than 800 mg/kg bw by ip injection ... .

LD50 Mouse oral >1250 mg/kg to < 2500 mg/kg

LD50 Rat oral >2500 mg/kg

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/ Male Charles River CD rats (10 per group) received intraperitoneally either 2-amino-4-nitrophenol, 2-amino-5-nitrophenol, or 4-amino-2-nitrophenol in a 10% aqueous DMSO solution. The LD50 for 2-amino-4-nitrophenol was reported to be 246 mg/kg, the LD50 for 2-amino-5-nitrophenol was reported to be greater than 800 mg/kg, and the LD50 for 4-amino-2-nitrophenol was reported to be 302 mg/kg.

/LABORATORY ANIMALS: Acute Exposure/ 2-Amino-4-nitrophenol, 2-amino-5-nitrophenol, and 4-amino-2-nitrophenol were orally administered to groups of five Charles River CD rats of each sex in an oil-in-water emulsion. The LD50 values for 2-amino-4-nitrophenol and 2-amino-5-nitrophenol were greater than 4000 mg/kg and the LD50 for 4-amino-2-nitrophenol was calculated to be 33 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-5-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-5-nitrophenol/ produced allergic contact dermatitis at a 1% challenge concentration ... , two at a 0.5% challenge concentration ( /including/ 2-amino-5-nitrophenol ... ), and one at a 0.25% challenge concentration (2-amino-5-nitrophenol). DNCB at a 0.5% induction/challenge concentration was used as a positive control. ...

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ ... Sixty B6C3F-1 mice were divided into six groups containing five mice/sex/group. The mice received either twelve doses of 2-amino-5-nitrophenol or corn oil (control material) at one of the following doses: 0, 313, 625, 1250, 2500, or 5000 mg/kg over a 16-day period. Clinical observations were performed twice daily, body weights were recorded weekly, and animals were necropsied. Nineteen mice died prior to the end of the study. Two males and five females died in the 5000 mg/kg group, three males and three females died in the 2500 mg/kg group, one female died in the 625 mg/kg group and two vehicle control males died. No significant difference in body weights occurred between treated and control animals and clinical observations were limited to loose stools in the males in the 5000 mg/kg group and two males were prostrate for the first week of the study in the 2500 mg/kg group. The LD50 in mice was greater than 1250 mg/kg but less than 2500 mg/kg.

For more Non-Human Toxicity Excerpts (Complete) data for 2-AMINO-5-NITROPHENOL (14 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=121-88-0]

Sixteen-Day and Thirteen-Week Studies: During the 16-day studies, F344/N rats of each sex received 0, 156, 313, 625, 1,250, or 2,500 mg/kg 2-amino-5-nitrophenol by gavage in corn oil vehicle. One of the five males that received 2,500 mg/kg, 1/5 females that received 1,250 mg/kg, and 2/5 females that received 313 mg/kg died before the end of the studies. Final mean body weights of rats that received 1,250 or 2,500 mg/kg were 11% and 30% lower than that of vehicle controls for males and 9% and 13% lower for females. B6C3F1 mice of each sex received doses of 0, 313, 625, 1,250, 2,500, or 5,000 mg/kg 2-amino-5-nitrophenol. Two of five males and 5/5 females that received 5,000 mg/kg, 3/5 males and 3/5 females that received 2,500 mg/kg, 3/5 females that received 1,250 mg/kg, 1/5 females that received 625 mg/kg, and 2/5 male vehicle controls died before the end of the studies. Final mean body weights of chemically exposed mice were not different from those of the vehicle controls. Rats that received 625, 1,250, or 2,500 mg/kg and male mice that received 5,000 mg/kg had loose stools. In 13-week studies, F344/N rats and B6C3F1 mice of both sexes received 0, 100, 200, 400, 800, or 1,600 mg/kg 2-amino-5-nitrophenol by gavage in corn oil. Five of 10 male and 2/10 female rats that received 1,600 mg/kg, 1/10 male and 3/10 female rats that received 800 mg/kg, and 1/10 male rats that received 400 mg/kg died before the end of the studies. Final mean body weights of males that received 400, 800, or 1,600 mg/kg were 10%, 25%, and 43% lower than that of vehicle controls. The final mean body weight of females that received 1,600 mg/kg was 16% lower that of vehicle controls. Four of 10 male and 3/10 female mice that received 1,600 mg/kg died before the end of the 13-week studies. The final mean body weight of male mice that received 1,600 mg/kg was 11% lower than that of vehicle controls; male and female mice that received 1,600 mg/kg appeared lethargic. During the 13-week studies, acute/chronic perivasculitis of vessels of the cecum and colon was observed in rats that received 400, 800, or 1,600 mg/kg and in mice that received 1,600 mg/kg.

Body Weight and Survival in the Two-Year Studies: Mean body weights of rats receiving 200 mg/kg were 5%-10% lower than those of vehicle controls after week 33 for males and 4%-5% lower than those of vehicle controls after week 93 for females. Survival of male rats was significantly lower than that of vehicle controls after week 99 for the 100 mg/kg dose group and after week 75 for the 200 mg/kg dose group (final survival: vehicle control, 33/50; 100 mg/kg group, 16/50; 200 mg/kg group, 4/50). Survival of female rats was comparable to that of vehicle controls (30/50; 32/50; 29/50). Loose or poorly formed stools were observed for male rats and occasionally for females that received 200 mg/kg. Mean body weights of mice that received 800 mg/kg were 8%-11% lower than those of vehicle controls between weeks 29 and 74 for males and 8%-13% lower than those of vehicle controls after week 69 for females; mean body weights of mice that received 400 mg/kg were greater than those of vehicle controls after week 69 for males and 5%-9% lower than those of vehicle controls after week 69 for females. Survival of mice that received 800 mg/kg was significantly reduced compared with that of vehicle controls after week 20 for males and week 22 for females and was not considered adequate to evaluate a carcinogenic response (final survival--male: vehicle control, 31/50; 400 mg/kg group, 36/50; 800 mg/kg group, 12/50; female: 37/50; 36/50; 10/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Pigmentation was present at increased incidences in all groups of chemically exposed animals and was characterized by varying amounts of an orange, granular pigment present in the fibrous connective tissue of the lamina propria, in the submucosa, and around vessels in the submucosa of the cecum and colon. Pigmentation of the rectum was observed at increased incidences in male rats that received 100 mg/kg, male and female rats that received 200 mg/kg, and both groups of chemically exposed mice. No pigmentation was found in the intestines of vehicle control rats or mice. Associated with pigmentation was an increased incidence of acute/chronic inflammation in the cecum and colon of all groups chemically exposed rats and mice; this inflammation was similar to that observed in the 13-week studies but was of greater severity. Acute/chronic inflammation was also present in the rectum of male rats that received 100 mg/kg, male and female rats that received 200 mg/kg, and male mice that received 800 mg/kg. The incidence of pancreatic acinar cell adenomas was significantly increased (P<0.002) in male rats that received 100 mg/kg 2-amino-5-nitrophenol (vehicle control, 1/50; 100 mg/kg, 10/50; 200 mg/kg, 3/49); the increase was considered to be associated with chemical exposure. The reduced survival of male rats that received 200 mg/kg markedly reduced the sensitivity of this group for detecting the presence of neoplasms. The incidences of adenomas or carcinomas (combined) of the preputial or clitoral glands were marginally increased in male or female rats that received 200 mg/kg 2-amino-5-nitrophenol (preputial gland: 3/50; 2/50; 5/50; clitoral gland: 3/50; 3/50; 7/50). Neoplasms found in the intestinal tract of 3/50 male rats that received 100 mg/kg (one leiomyoma of the small intestine, one adenocarcinoma of the jejunum, one leiomyoma of the cecum), 2/50 male rats that received 200 mg/kg (one lipoma and one osteosarcoma of the cecum), and 1/50 female rats that received 200 mg/kg (one leiomyoma of the cecum) were not considered to be the result of chemical exposure. No compound-related neoplasms were found in mice exposed to 2-amino-5-nitrophenol in the 2-year studies.

2-Amino-5-nitrophenol's production and use as an intermediate in the manufacture of azo dyes and its use as a dye in semi-permanent hair coloring products and limited use in permanent hair coloring products 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-5-nitrophenol will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase 2-amino-5-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 41 hours. Particulate-phase 2-amino-5-nitrophenol will be removed from the atmosphere by wet or dry deposition. 2-Amino-5-nitrophenol contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, 2-amino-5-nitrophenol is expected to have high mobility based upon an estimated Koc of 85. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 7.8X10-13 atm-cu m/mole. Biodegradation data were not available. If released into water, 2-amino-5-nitrophenol is expected to adsorb to suspended solids and sediment based upon the estimated Koc. 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 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-5-nitrophenol may occur through dermal contact with this compound at workplaces where 2-amino-5-nitrophenol is produced or used. Use data indicates that the general population may be exposed to 2-amino-5-nitrophenol via dermal contact with consumer products containing 2-amino-5-nitrophenol. (SRC)

2-Amino-5-nitrophenol's production and use as an intermediate in the manufacture azo dyes, which are used for coloring synthetic resins, lacquers, inks and wood stains and its use as a dye in semi-permanent hair coloring products and limited use in permanent hair coloring products(1) 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 85(SRC), determined from a structure estimation method(2), indicates that 2-amino-5-nitrophenol is expected to have high mobility in soil(SRC). Volatilization of 2-amino-5-nitrophenol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.8X10-13 atm-cu m/mole(SRC), using a fragment constant estimation method(3). 2-Amino-5-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(4). Biodegradation data were not available(SRC, 2007).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 85(SRC), determined from a structure estimation method(2), indicates that 2-amino-5-nitrophenol is 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 7.8X10-13 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 0.99(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions(3). Biodegradation data were not available(SRC, 2007).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-amino-5-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-5-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 41 hours(SRC), calculated from its rate constant of 9.4X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase 2-amino-5-nitrophenol may be removed from the air by wet or dry deposition(SRC).

The rate constant for the vapor-phase reaction of 2-amino-5-nitrophenol with photochemically-produced hydroxyl radicals has been estimated as 9.4X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 41 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 2-Amino-5-nitrophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). 2-Amino-5-nitrophenol contains chromophores that absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3 was calculated in fish for 2-amino-5-nitrophenol(SRC), using an estimated log Kow of 0.99(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).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 2-amino-5-nitrophenol can be estimated to be 85(SRC). According to a classification scheme(2), this estimated Koc value suggests that 2-amino-5-nitrophenol is expected to have high mobility in soil(SRC).

The Henry's Law constant for 2-amino-5-nitrophenol is estimated as 7.8X10-13 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 2-amino-5-nitrophenol is expected to be essentially nonvolatile from water surfaces(2). 2-Amino-5-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 14,512 workers (11,827 of these are female) are potentially exposed to 2-amino-5-nitrophenol in the US(1). Occupational exposure to 2-amino-5-nitrophenol may occur through dermal contact with this compound at workplaces where 2-amino-5-nitrophenol is produced or used(SRC). Use data indicates that the general population may be exposed to 2-amino-5-nitrophenol via dermal contact with consumer products containing 2-amino-5-nitrophenol(SRC).

2-Amino-5-nitrophenol's production and use as an intermediate in the manufacture of azo dyes and its use as a dye in semi-permanent hair coloring products and limited use in permanent hair coloring products 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-5-nitrophenol will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase 2-amino-5-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 41 hours. Particulate-phase 2-amino-5-nitrophenol will be removed from the atmosphere by wet or dry deposition. 2-Amino-5-nitrophenol contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, 2-amino-5-nitrophenol is expected to have high mobility based upon an estimated Koc of 85. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 7.8X10-13 atm-cu m/mole. Biodegradation data were not available. If released into water, 2-amino-5-nitrophenol is expected to adsorb to suspended solids and sediment based upon the estimated Koc. 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 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-5-nitrophenol may occur through dermal contact with this compound at workplaces where 2-amino-5-nitrophenol is produced or used. Use data indicates that the general population may be exposed to 2-amino-5-nitrophenol via dermal contact with consumer products containing 2-amino-5-nitrophenol. (SRC)

2-Amino-5-nitrophenol's production and use as an intermediate in the manufacture azo dyes, which are used for coloring synthetic resins, lacquers, inks and wood stains and its use as a dye in semi-permanent hair coloring products and limited use in permanent hair coloring products(1) 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 85(SRC), determined from a structure estimation method(2), indicates that 2-amino-5-nitrophenol is expected to have high mobility in soil(SRC). Volatilization of 2-amino-5-nitrophenol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.8X10-13 atm-cu m/mole(SRC), using a fragment constant estimation method(3). 2-Amino-5-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(4). Biodegradation data were not available(SRC, 2007).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 85(SRC), determined from a structure estimation method(2), indicates that 2-amino-5-nitrophenol is 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 7.8X10-13 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 0.99(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions(3). Biodegradation data were not available(SRC, 2007).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-amino-5-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-5-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 41 hours(SRC), calculated from its rate constant of 9.4X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase 2-amino-5-nitrophenol may be removed from the air by wet or dry deposition(SRC).

The rate constant for the vapor-phase reaction of 2-amino-5-nitrophenol with photochemically-produced hydroxyl radicals has been estimated as 9.4X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 41 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 2-Amino-5-nitrophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). 2-Amino-5-nitrophenol contains chromophores that absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 3 was calculated in fish for 2-amino-5-nitrophenol(SRC), using an estimated log Kow of 0.99(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).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 2-amino-5-nitrophenol can be estimated to be 85(SRC). According to a classification scheme(2), this estimated Koc value suggests that 2-amino-5-nitrophenol is expected to have high mobility in soil(SRC).

The Henry's Law constant for 2-amino-5-nitrophenol is estimated as 7.8X10-13 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 2-amino-5-nitrophenol is expected to be essentially nonvolatile from water surfaces(2). 2-Amino-5-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 14,512 workers (11,827 of these are female) are potentially exposed to 2-amino-5-nitrophenol in the US(1). Occupational exposure to 2-amino-5-nitrophenol may occur through dermal contact with this compound at workplaces where 2-amino-5-nitrophenol is produced or used(SRC). Use data indicates that the general population may be exposed to 2-amino-5-nitrophenol via dermal contact with consumer products containing 2-amino-5-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.