2-aminophenol

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

H332: Harmful if inhaled [Warning Acute toxicity, inhalation]

H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]

P203, P261, P264, P270, P271, P280, P301+P317, P304+P340, P317, P318, P330, P405, and P501 (click each P-code to see the statement)

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

H332 (> 99.9%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H341 (> 99.9%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]

Aggregated GHS information provided per 2299 reports by companies from 9 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]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P260, P261, P264, P270, P272, P273, P280, P301+P317, P302+P352, P319, P321, P330, P333+P317, P362+P364, P391, and P501 (click each P-code to see the statement)

H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]

P203, P260, P261, P264, P270, P272, P280, P301+P317, P302+P352, P308+P316, P318, P319, P321, P330, P333+P317, P362+P364, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Refer for medical attention.

Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give a slurry of activated charcoal in water to drink. Refer for medical attention .

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. 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. (NTP, 1992)

This compound is not very flammable but any fire involving this compound may produce dangerous vapors. You should evacuate the area. All firefighters should wear full-body protective clothing and use self-contained breathing apparatuses. You should extinguish any fires involving this chemical with a dry chemical, carbon dioxide, foam, or halon extinguisher. (NTP, 1992)

Use alcohol-resistant foam, carbon dioxide, water spray, powder.

Use dry chemical, carbon dioxide, or alcohol foam extinguishers. Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Storage containers and parts of containers may rocket great distances, in many directions. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors or shows any signs of deforming), withdraw immediately to a secure position ... The only respirators recommended for fire fighting are self-contained breathing apparatuses that have full facepieces and are operated in a pressure-demand or other positive-pressure mode. /Anisidines/

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Use foam, dry chemical, or carbon dioxide. Keep run-off water out of sewers and water sources. /Aminophenols/

Excerpt from ERG Guide 152 [Substances - Toxic (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)

Personal protection: chemical protection suit and particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

Spill handling: keep dust under control. Use a vacuum or wet method to reduce dust during clean-up. Do not sweep. Evacuate persons not wearing protective equipment from area of spill or leak until clean-up is complete. Remove all ignition sources. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Ventilate area after clean-up is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection of your regional office of the federal EPA for specific recommendations. /Aminophenols/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity 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 and plant life; and conformance with environmental and public health regulations.

Incineration. /Aminophenols/

... Disposable natural rubber latex gloves and disposable PVC gloves should not be used repeatedly for handling the hair dye products /p-aminophenol, m-aminophenol, o-aminophenol, and p-phenylenediamine/.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. /Aminophenols/

Personnel protection: Avoid breathing dusts, and fumes from burning material. Keep upwind ... Avoid bodily contact with the material ... Do not handle broken packages unless wearing appropriate personal protective equipment. /Aminophenols/

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, you should dampen the solid spill material with alcohol, then transfer the dampened material to a suitable container. Use absorbent paper dampened with alcohol 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 alcohol followed by washing with a strong soap and water solution. Do not reenter the contaminate 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)

Store in an area without drain or sewer access. Well closed. Separated from oxidants and food and feedstuffs.

Store in tightly closed containers in a cool, well-ventilated area. Aminophenols must be stored to avoid contact with strong oxidizers (such as chlorine, bromine, and fluorine), since violent reactions occur. /Aminophenols/

0.65 [mg/m3]

7.0 [mg/m3]

43 [mg/m3]

A harmful concentration of airborne particles can be reached quickly when dispersed, especially if powdered.

The substance may cause effects on the blood. This may result in the formation of methaemoglobin. The effects may be delayed. Medical observation is indicated.

Repeated or prolonged contact may cause skin sensitization.

MINIMUM PROTECTIVE CLOTHING: When working with this chemical, you should wear impervious coveralls, shoe covers and 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.

RECOMMENDED GLOVE MATERIALS: Permeation data indicate that polyvinyl chloride gloves may provide protection to contact with this compound. Polyvinyl chloride over latex gloves is recommended. However, if this chemical makes direct contact with your gloves remove them at once. (NTP, 1992)

Wear protective gloves and clothing to prevent any reasonable probability of skin contact ... Wear dust-proof chemical goggles and face shield unless full facepiece respiratory protection is worn. /Aminophenols/

P3 filter respirator for toxic particles.

NO open flames.

STRICT HYGIENE!

Use local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear safety goggles.

Do not eat, drink, or smoke during work.

O-aminophenol appears as off-white crystals or beige powder. (NTP, 1992)

Crystals, rapidly becoming brown; [HSDB]

COLOURLESS-TO-WHITE CRYSTALS. TURNS DARK ON EXPOSURE TO AIR OR LIGHT.

Crystals, rapidly becoming brown

White orthorhombic bipyramidal needles from benzene or water

White crystals; turn brown with age

COLORLESS RHOMBIC NEEDLES OR PLATES

Sublimes at 307 °F at 11 mmHg (NTP, 1992)

Sublimes at 153 °C

243 °C @760 [mm Hg]

342 to 343 °F (NTP, 1992)

170-174 °C

MP: 172-173 °C; sublimes on further heating

168 °C (334 °F) - closed cup

>175 °C c.c.

less than 0.1 mg/mL at 70 °F (NTP, 1992)

1 g dissolves in 50 mL cold water, 23 mL alcohol

Slightly soluble in toluene, chloroform, and cold water; soluble in ethanol, and hot water, very soluble in acetonitrile, ethyl acetate, acetone, dimethyl sulfoxide

Soluble in ethyl ether; very soluble in ethanol; slightly soluble in benzene, trifluoroacetic acid

In water, 2.0X10+3 mg/L at 20 °C

Solubility in water, g/100ml at 20 °C: 1.7

1.328 (NTP, 1992) - Denser than water; will sink

1.328 g/cu cm at 25 °C

1.3 g/cm³

Relative vapor density (air = 1): 3.77

0.0005 [mmHg]

negligible

log Kow = 0.62

Crystals readily becoming gray on exposure to light /Hydrochloride/

When heated to decomposition it emits toxic /nitroxides/.

Positive

Agilent XCT

Electrospray ionization

formic acid (5.3nM)

MeCN (80%)

DOI:10.1007/s13361-016-1563-1

Negative

ammonia (10nM)

DOI:10.1021/acs.analchem.7b00595

4.84 (at 20 °C)

Protect from air and light. Insoluble in water.

Phenols and Cresols

Amines, Aromatic

O-AMINOPHENOL can react with oxidizing agents. (NTP, 1992) THF forms explosive products with 2-aminophenol [Lewis 3227].

Incompatible with acids, acid chlorides, and anhydrides, chloroformates, strong oxidizing agents.

Strong oxidants. /Aminophenols/

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

2-Aminophenol interacts with both adult and fetal hemoglobin, forming methemoglobin. In comparison to its isomers, 3-aminophenol and 4-aminophenol, 2-aminophenol is the most effective in forming methemoglobin. Since methemoglobin cannot bind oxygen like hemoglobin can, elevated levels of methemoglobin cause a condition called methemoglobinemia, which can result in tissue hypoxia. (L1613, A2862)

No indication of carcinogenicity to humans (not listed by IARC).

2-Aminophenol may act as a skin sensitizer and cause contact dermatitis. In addition, inhalation of large amounts can cause methemoglobinemia and bronchial asthma. (T21)

The substance can be absorbed into the body by ingestion, through the skin and by inhalation of its aerosol.

Oral (L138) ; inhalation (L138)

See Ingestion.

MAY BE ABSORBED!

Redness.

Blue lips, fingernails and skin. Confusion. Convulsions. Cough. Dizziness. Headache. Laboured breathing. Nausea. Unconsciousness. Symptoms may be delayed.

2-Aminophenol may cause contact dermatitis. Signs and symptoms of methemoglobinemia may include shortness of breath, cyanosis, mental status changes, headache, fatigue, exercise intolerance, dizziness and loss of consciousness. Severe methemoglobinemia can result in dysrhythmias, seizures, coma, and death. (T21, L1613)

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

Skin Sensitizer - An agent that can induce an allergic reaction in the skin.

Asthma - Reversible bronchoconstriction (narrowing of bronchioles) initiated by the inhalation of irritating or allergenic agents.

o-Aminophenol

PDF Document

Inadequate information to assess carcinogenic potential

SCREEN Current

PPRTV Current

LD50: 1250 mg/kg (Oral, Mouse) (T14)

LD50: 37 mg/kg (Subcutaneous), Rat) (T14)

LD50: 200 mg/kg (Intrapertioneal, Mouse) (T14)

LD50 Rat oral 1300 mg/kg

LD50 Rat sc 37 mg/kg

LD50 Mouse oral 1250 mg/kg

LD50 Mouse ip 200 mg/kg

Methemoglobinemia can be treated with supplemental oxygen and methylene blue 1% solution administered intravenously slowly over five minutes followed by IV flush with normal saline. Methylene blue restores the iron in hemoglobin to its normal (reduced) oxygen-carrying state. (L1613)

An investigation was carried out of the effects of ortho-aminophenol (95556) (o-AP), meta-aminophenol (591275) (m-AP), para-aminophenol (123308) (p-AP) & acetaminophen (103902) (AAP) on the induction of preneoplastic lesions in the liver & kidney of male Fischer-344-rats by N-ethyl-N-hydroxyethylnitrosamine (13147256) (EHEN). The rats in this 52 wk investigation included those give 0.1% EHEN in their drinking water for 2 wk & then, beginning 1 wk later, given 0.8% of either o-AP, m-AP, p-AP or AAP in the basal diet for 49 wk; those given EHEN & thereafter only the basal diet; & those given one of the test cmpds without prior EHEN admin. Body, liver & kidney weights were determined for sacrificed rats, & liver sections were subjected to immunohistochemical exam of glutathione-S-transferase placental type (GSTP) positive foci. The numbers of GSTP positive foci in the liver were significantly decreased in rats given o-AP, m-AP, p-AP or AAP after EHEN as compared to values for rats given EHEN alone. However, lowered incidences of GSTP positive foci were observed only in rats given o-AP or AAP after EHEN. Only p-AP & AAP gave significantly higher incidences of microadenoma & adenoma in the kidney.

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Aniline and related compounds/

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patent can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Aniline and related compounds/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Administer 1% solution methylene blue if patient is symptomatic with severe hypoxia, cyanosis, and cardiac compromise not responding to oxygen. ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aniline and related compounds/

/SIGNS AND SYMPTOMS/ Short term exposure: Aminophenols can be absorbed through the skin, thereby increasing exposure. Can cause lung irritation. Poisonous if swallowed. These chemicals lower the blood's ability to carry oxygen (methemoglobinemia). This condition causes a bluish color to the skin and lips, headaches, dizziness; higher exposures can result in unconsciousness and death. Irritates eyes, skin, and respiratory tract. Skin contact can cause burning sensation and rash ... May produce dermatitis, methemoglobinemia, bronchial asthma, and restlessness. Long term exposure: prolonged or repeated contact can cause blood damage, skin disorders, liver, kidney, and brain damage. Aminophenols may cause mutations, and there is limited teratogenic evidence. Skin allergy or asthma may develop; future exposures, even in low doses, can cause symptoms to occur. /Aminophenols/

/SIGNS AND SYMPTOMS/ o-Aminophenol is not readily absorbed through intact skin but may prove to be a sensitizing agent with resultant contact dermatitis. Inhalation of dust in excessive amounts may cause methemoglobinemia (cyanosis), irritation of mucosal membranes, and in rare instances, a bronchial asthma.

/SIGNS AND SYMPTOMS/ Inhalation of dust should be avoided because if it is inhaled in excessive amounts it may cause methemoglobinemia. In rare instances, o-aminophenol have caused a bronchial asthma.

/SIGNS AND SYMPTOMS/ Similar to ortho & para cmpd. Not readily absorbed through intact skin, but may prove to be sensitizing agent with resultant contact dermatitis. Inhalation of dust ... In excessive amt ... May cause methemoglobinemia. In rare instances o & p-aminophenol have caused bronchial asthma.

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

/LABORATORY ANIMALS: Acute Exposure/ ... The following chemicals: one negative control: 4-Aminobenzoic Acid, three sensitizers: 2,4-dinitrochlorobenzene (DNCB), Hexyl cinnamic aldehyde (HCA), 2-Aminophenol (2-APC) and two irritations: potassium hydroxide (KOH), sodium lauryl sulfate (SLS) were /tested in a modified local lymph node assay (LLNA)/ ... Significant increase in ear thickness and weight were found in groups of KOH, SLS and DNCB (above 0.5%) (P < 0.05), which could be considered as irritants, whereas irritation was not found in 2-APC and HCA. In the allergic test, three sensitizers showed positive, but different sensitivity was found among each index. HCA, DNCB and 2-APC could all obviously augment the weight of lymph node and the lymphocyte count in different groups (P < 0.05). Conspicuous proliferation of lymphocyte were found in DNCB (all group), HCA (above the middle dose) and 2-APC (high dose) by CCK-8 ...

/LABORATORY ANIMALS: Acute Exposure/ A dose of 0.5 g /2-aminophenol/ (pulverized crystals) was applied to clipped skin of 6 New Zealand white rabbits according to 3 protocols: under occlusive patch (Official French cosmetic method and AFNOR method) or semiocclusive patch (OECD method). Primary cutaneous irritation indices under 3 protocols was zero.

/LABORATORY ANIMALS: Acute Exposure/ Using a protocol that complied with the main requirements of 3 protocols (French, AFNOR, OCDE) doses of 100 mg powdered (ground if necessary /2-aminophenol/ were instilled into the lower conjunctival cul-de-sac of one eye of each rabbit; the other eye constituted the control. Groups of 6 New Zealand white rabbits. Observations /were carried out/ at 1 hr, 1, 2, 3, 4, and 7 days. Scoring system based on the AFNOR recommendations: acute ocular irritation index: 9.83/110 after 24 hr; mean ocular irritation index: 2.33/110 after 2 days (110 - theoretical maximum score, from total of 80 (cornea) + 10 (iris) + (20 conjunctiva). Results: slightly irritating.

/LABORATORY ANIMALS: Acute Exposure/ Hen's egg chorioallantoic membrane test: slight irritant at concentration of 1.5%; non-irritant at 0.5% ... Slight irritant at 1%.

For more Non-Human Toxicity Excerpts (Complete) data for 2-Aminophenol (45 total), please visit the HSDB record page.

LD50 Coturnix coturnix japonica (Japanese Quail) oral 316 mg/kg bw endpoint: mortality

LD50 Coturnix coturnix japonica (Japanese Quail) oral 316 mg/kg bw endpoint: mortality

LD50 House Sparrow oral 316 mg/kg bw

LD50 Redwinged Blackbird oral > 1000 mg/kg bw

LD50 Starling oral > 1000 mg/kg bw

LC50; Species: Danio rerio (zebra danio, eggs); Conditions: freshwater, static, 26 °C, dissolved oxygen >7 mg/L; Concentration: 0.033 mg/L (0.033-0.034 mg/L) (33 ug/L (33-34 ug/L)) for 72 hr /formulated product, 99% pure/

/BIRDS and MAMMALS/ Ip injection of 50 mg/kg /of 2-Aminophenol/ in Japanese quail produced a peak of 25% methemoglobin in the blood after 10 min.

2.50e+02

3.30e+03

7.90e+01

4.00e+00

3.00e-02

4.00e-03

Volatile

7.60e+02

9.80e+03

2.40e+02

This substance may be hazardous to the environment. Special attention should be given to aquatic organisms.

2-Aminophenol's production and use as a dyeing agent for furs, hair and leather, and in the manufacturing of pharmaceuticals may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 5X10-4 mm Hg at 25 °C indicates 2-aminophenol will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase 2-aminophenol 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 5 hours. Particulate-phase 2-aminophenol will be removed from the atmosphere by wet or dry deposition. 2-Aminophenol absorbs light at wavelengths 281 nm and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, 2-aminophenol is expected to have high mobility based upon an estimated Koc of 90. 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. Measured pKa values are 4.72 and 9.71, for the amine and hydroxy functional groups, respectively; 2-aminophenol is amphoteric and behaves either as a weak acid or weak base; the basic character usually predominates. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 2X10-10 atm-cu m/mole. Utilizing a respirometry screening test, 45% of the theoretical BOD was reached in 10 days indicating that biodegradation is an important environmental fate process. If released into water, 2-aminophenol is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Under denitrifying conditions in sediment, 2-aminophenol was mineralized following a long lag phase at a rate of 12.9 umol/L/day and was not mineralized under methanogenic conditions in a 26-week sediment grab sample study. 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-aminophenol may occur through dermal contact with this compound at workplaces where 2-aminophenol is produced or used. Use data indicate that the general population may be exposed to 2-aminophenol via dermal contact with consumer products, particularly hair dye products, containing 2-aminophenol. (SRC)

2-Aminophenol's production and use as a dyeing agent for furs, hair(1,2) and leather(2) and in the manufacturing of pharmaceuticals(1) 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 90(SRC), determined from a structure estimation method(2), indicates that 2-aminophenol is expected to have high mobility in soil(SRC). However, anilines are expected to bind strongly to humus or organic matter in soils due to the high reactivity of the aromatic amino group(3,4), suggesting that mobility may be much lower in some soils(SRC). Measured pKa values are 4.72 and 9.71(5), for the amine and hydroxy functional groups, respectively(6); 2-aminophenol is amphoteric and behaves either as a weak acid or weak base; the basic character usually predominates(5). Volatilization of 2-aminophenol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2X10-10 atm-cu m/mole(SRC), using a fragment constant estimation method(7). 2-Aminophenol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 5X10-4 Hg at 25 °C(SRC), determined from a fragment constant method(8). Based on screening tests, 2-aminophenol is expected to biodegrade; when present at 100 mg/L, in a respirometry screening test using an activated sludge inoculum, 45% of the theoretical BOD was reached in 10 days(9). A rate constant of 0.279X10-2 per hour was measured for 2-aminophenol in a screening test using a non-adapted activated sludge inoculum(10). Under denitrifying conditions in sediment, 2-aminophenol was mineralized following a long lag phase at a rate of 12.9 umol/L/day(11). It was not mineralized under methanogenic conditions in a 26-week sediment grab sample study(11).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 90(SRC), determined from a structure estimation method(2), indicates that 2-aminophenol 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 2X10-10 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 its log Kow of 0.62(6) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). 2-Aminophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Based on screening tests, 2-aminophenol is expected to biodegrade when present at 100 mg/L, in a respirometry screening test using an activated sludge inoculum, 45% of the theoretical BOD was reached in 10 days(7). A rate constant of 0.279X10-2 per hour was measured for 2-aminophenol in a screening test using a non-adapted activated sludge inoculum(8). Under denitrifying conditions in sediment, 2-aminophenol was mineralized following a long lag phase at a rate of 12.9 umol/L/day(9). It was not mineralized under methanogenic conditions in a 26-week sediment grab sample study(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-aminophenol, which has an estimated vapor pressure of 5.0X10-4 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-aminophenol 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 5 hours(SRC), calculated from its rate constant of 7.4X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase 2-aminophenol may be removed from the air by wet or dry deposition(SRC). 2-Aminophenol absorbs light at wavelengths 281 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

AEROBIC: In a screening study using a soil inoculum and 2-aminophenol at 15 ppm, >64 days were required for total loss of UV absorbancy due to cleavage of the benzene ring(1). 2-Aminophenol, present at 100 mg/L, in an electrolytic respirometry screening test using an activated sludge inoculum, reached 45% of the theoretical BOD in 10 days(2). A rate constant of 0.279X10-2 per hour was measured for 2-aminophenol in a screening test using a non-adapted activated sludge inoculum(3). 2-Aminophenol, at 200 mg/L chemical oxygen demand reached 95% removal in 5 days in a screening test using acclimated activated sludge at 100 mg/L(4). Screening tests using activated sludge adapted to either phenol or a mixture of cresols reported rate constants of 1.86X10-3(5) and 6.73X10-3(6), respectively, for the biodegradation of 2-aminophenol.

ANAEROBIC: 88% of the theoretical gas production was reached over 60 days in a screening study using methanogenic primary digesting sludge when 2-aminophenol was present; a lag phase of 15 days was noted(1). In an anaerobic screening study using 100 mg-C/L sewage and 2-aminophenol at 30 mg-C/L, 100% degradation, measured by loss of DOC, was reached within 10 days(2). 2-Aminophenol, incubated in sediment under denitrifying conditions, showed an initial lag phase of 2.7 to 4.7 weeks followed by degradation at a rate of 12.9 umol/L/day; 138% of theoretical N2 was recovered over the 25-week study(3). 2-Aminophenol was not mineralized under methanogenic conditions in a 26-week sediment grab sample study(3). 2-Aminophenol was not degraded in 10% anaerobic sludge over 8 weeks(4).

The rate constant for the vapor-phase reaction of 2-aminophenol with photochemically-produced hydroxyl radicals has been estimated as 7.4X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 2-Aminophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). The reaction of hydroxyl radicals with neutral solutions of 2-aminophenol results in the formation of the 2-aminophenoxyl radical(3). 2-Aminophenol absorbs light at wavelengths of 281 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC). 2-Aminophenol is expected to undergo fairly rapid oxidation in the presence of air(4). Measured pKa values are 4.72 and 9.71(4), for the amine and hydroxy functional groups, respectively(5); 2-aminophenol is amphoteric and behaves either as a weak acid or weak base; the basic character usually predominates(4).

An estimated BCF of 3 was calculated in fish for 2-aminophenol(SRC), using a log Kow of 0.62(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-aminophenol can be estimated to be 90(SRC). According to a classification scheme(2), this estimated Koc value suggests that 2-aminophenol is expected to have high 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(3-4), suggesting that mobility may be much lower in some soils(SRC). Measured pKa values are 4.72 and 9.71(5), for the amine and hydroxy functional groups, respectively(6); 2-aminophenol is amphoteric and behaves either as a weak acid or weak base; the basic character usually predominates(5). At pH 8.4, 25.5% of added 2-aminophenol is sorbed by an organoclay(7). The sorptive capacity of clays for amine-substituted phenolic sorbate decreased with increasing pH above the corresponding pKa(8).

The Henry's Law constant for 2-aminophenol is estimated as 2X10-10 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 2-aminophenol is expected to be essentially nonvolatile from water surfaces(2). 2-Aminophenol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 5.0X10-4 mm Hg(SRC), determined from a fragment constant method(3).

According to the 2006 TSCA Inventory Update Report, the number of workers reasonably likely to be exposed in the industrial manufacturing, processing, and use of 2-aminophenol is 1 to 99 persons; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 19,664 workers (14,753 of these were female) were potentially exposed to 2-aminophenol in the US(1). Occupational exposure to 2-aminophenol may occur through dermal contact with this compound at workplaces where 2-aminophenol is produced or used(SRC). Use data indicate that the general population may be exposed to 2-aminophenol via dermal contact with consumer products, particularly hair dye products, containing 2-aminophenol(SRC).

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity 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 and plant life; and conformance with environmental and public health regulations.

Incineration. /Aminophenols/

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Health: Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. /Aminophenols/

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Fire or Explosion: Combustible material: may burn but does not ignite readily. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form. /Aminophenols/

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... . As an 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. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. /Aminophenols/

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. /Aminophenols/

For more DOT Emergency Guidelines (Complete) data for 2-Aminophenol (8 total), please visit the HSDB record page.

UN 2512; Aminophenols (o-, m-, p-)

IMO 6.1; Aminophenols (o-, m-, p-)

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Do not transport with food and feedstuffs.

Symbol: Xn; R: 20/22-68; S: (2)-28-36/37

UN Hazard Class: 6.1; UN Pack Group: III