2-Aminophenol

Nitrogen Compounds -> Amino Phenols

Dye

Cosmetic ingredients (o-Aminophenol) -> CIR (Cosmetic Ingredient Review)

Hair dyeing

log Kow = 0.62

0.62

0.57

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

1.328 g/cu cm at 25 °C

1.3 g/cm³

Crystals, rapidly becoming brown

White orthorhombic bipyramidal needles from benzene or water

White crystals; turn brown with age

COLORLESS RHOMBIC NEEDLES OR PLATES

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

168 °C (334 °F) - closed cup

>175 °C c.c.

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

Sublimes at 153 °C

243 °C @760 [mm Hg]

When heated to decomposition it emits toxic /nitroxides/.

170-174 °C

342 to 343 °F (NTP, 1992)

170-174 °C

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

174 °C

Warning

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

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

Warning

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

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

Chemical: Phenol, 2-amino-

Chemical: Phenol, amino-

Status: Active Update: 19-02-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/19856

2-Aminophenol: Does not have an individual approval but may be used under an appropriate group standard

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

Combustible. Gives off irritating or toxic fumes (or gases) in a fire.

Skin sensitization is the greatest hazard from industrial exposure. Occupational asthma and methemoglobinemia have been reported after dust inhalation. [HSDB from Patty, F. (ed.). Industrial Hygiene and Toxicology: Volume II: Toxicology. 2nd ed. New York: Interscience Publishers, 1963. 2131] Can induce methemoglobinemia; A skin sensitizer; [ICSC]

European Commission, ESIS; IUCLID Dataset, 2-Aminophenol (95-55-6) (2000 CD-ROM edition).[Available from, as of June 7, 2010: http://esis.jrc.ec.europa.eu/]

Elder RL; J Am Coll Toxicol 7 (3): 279-334 (1988). Final report on the safety assessment of p-aminophenol, m-aminophenol & o-aminophenol. Review liver, immune system, reproduction, mutagenicity, embryotoxicity, kinetics, methemoglobinemia, renal tubular necrosis, photosensitization, skin irritation, eye irritation, & carcinogenicity of hair dye.

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.

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.

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/

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/

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.

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/

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.

... 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.

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.

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/

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).

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

Oral (L138) ; inhalation (L138)

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)

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)

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).

Recovery in urine for 24 hr of a single oral dose of 1 g in rabbits (strain and sex not given) was 95% of the administered dose: 11% unchanged o-aminophenol, 2-4% acetamidophenol, 15% aminophenolsulfate, 52% aminophenylglucuronide, 13% acetamidophenylglucuronide.

Yields 3-aminoacetechol in rabbit; yields o-aminophenyl-beta-glucuronide in guinea pig, mouse, rabbit; yields o-aminophenylsulfate in rabbit, mouse; yields 4-aminoresorcinol probably in rabbit.

Yields 3-aminoacetechol in rabbit. Yields o-aminophenyl-beta-d-glucuronide in guinea pig, mouse, rabbit. /From table/

Yields o-aminophenyl sulfate in rabbit, mouse. Yields 4-aminoresorcinol probably in rabbit. /From table/

For more Metabolism/Metabolites (Complete) data for 2-Aminophenol (8 total), please visit the HSDB record page.

Recovery in urine for 24 hr of a single oral dose of 1 g in rabbits (strain and sex not given) was 95% of the administered dose ...

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

CIR ingredient: o-Aminophenol

Used in dyes for furs and hair, as a developer in photography, and an intermediate for pharmaceuticals. [HSDB]

Photographic Processing [Category: Other]

Manufacture of azo and sulfur dyes ... hydrochloride used in dyeing fur, hair, leather, etc.

Dyeing furs and hair ... Manufacture of pharmaceuticals

/2-Aminophenol is/ a strong reducing agent and is employed as a photographic developer ... it also acts as a corrosion inhibitor in paints and as an anticorrosion-lubricating agent in 2-cycle engine fuels. 2-Aminophenol is a principal intermediate in the synthesis of such heterocyclic systems as oxyquinolines, phenoxazines, and benzoxazoles (which are inflammation inhibitors) ... 2-Aminophenol is specifically used for shading leather, fur, and hair from grays to yellowish brown. It has also found application in the determination and extraction of certain precious metals.

(1977) 3.01X10+7 G (PRINCPL CUSTMS DISTS)

(1979) 4.73X10+7 G (PRINCPL CUSTMS DISTS)

(1977) PROBABLY GREATER THAN 2.27X10+6 GRAMS

(1979) PROBABLY GREATER THAN 2.27X10+6 GRAMS

Production figures for the aminophenols are scarce, the compounds usually being classified along with many other aniline derivatives. Most production of the technical grade materials (95% purity) occurs on-site as they are chiefly used as intermediate reactants in continuous chemical syntheses. World production of the fine chemicals (99% purity) is probably no more than a few hundred metric tons yearly... /Aminophenols/

Phenol, 2-amino- is listed as a High Production Volume (HPV) chemical (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).

For more U.S. Production (Complete) data for 2-Aminophenol (6 total), please visit the HSDB record page.

Phenol, 2-amino-: ACTIVE

Also available as the hydrochloride