4-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]

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]

P203, P261, P264, P270, P271, P273, P280, P301+P317, P304+P340, P317, P318, P330, P391, P405, and P501 (click each P-code to see the statement)

H302+H332 (29.1%): Harmful if swallowed or if inhaled [Warning Acute toxicity, oral; acute toxicity, inhalation]

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

H317 (34.3%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H332 (99.5%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H341 (100%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H373 (34.3%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

H400 (98.6%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P203, P260, P261, P264, P270, P271, P272, P273, P280, P301+P317, P302+P352, P304+P340, P317, P318, P319, P321, P330, P333+P317, P362+P364, P391, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 364 reports by companies from 21 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]

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

H334: May cause allergy or asthma symptoms or breathing difficulties if inhaled [Danger Sensitization, respiratory]

H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]

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

P203, P233, P260, P261, P264, P264+P265, P270, P271, P272, P273, P280, P284, P301+P317, P302+P352, P304+P340, P305+P351+P338, P318, P319, P321, P330, P333+P317, P337+P317, P342+P316, P362+P364, P391, P403, P405, and P501 (click each P-code to see the statement)

H316: Causes mild skin irritation [Warning Skin corrosion/irritation]

H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]

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

P203, P233, P260, P261, P264, P264+P265, P270, P271, P272, P280, P284, P301+P317, P302+P352, P304+P340, P305+P351+P338, P308+P316, P317, P318, P319, P321, P330, P332+P317, P333+P317, P337+P317, P342+P316, P362+P364, P403, P405, 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. 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)

Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)

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)

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/

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.

... 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/

SMALL SPILLS AND LEAKAGE: If a spill of this chemical occurs, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with acetone and transfer the dampened material to a suitable container. Use absorbent paper dampened with acetone to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with acetone 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)

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/

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)

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/

P-aminophenol appears as white or reddish-yellow crystals or light brown powder. Turns violet when exposed to light. (NTP, 1992)

Dry Powder

White or reddish-yellow crystals or light-brown powder that turns violet when exposed to light; [CAMEO]

Orthorhombic plates from water

White plates from water

Colorless crystals

White or reddish yellow crystals turn violet on exposure to light

543 °F at 760 mmHg (Decomposes) (NTP, 1992)

284 °C at 760 mm Hg, decomposes; 167 °C at 8.0 mm Hg; 150 °C at 3.0 mm Hg; 130.2 °C at 0.3 mm Hg

BP: Can be sublimed at 0.3 mm Hg and 110 °C without decomposition ... forms salts with acids and bases ... Deteriorates under the influence of air and light ... Commercial product usually pink ... MP of commercial product 186 °C

187.5 °C

367 to 369 °F (NTP, 1992)

367-369 °F

187.50 °C. @ 760.00 mm Hg

195 °C (383 °F) - closed cup

less than 1 mg/mL at 73 °F (NTP, 1992)

Solubility in water: 0.39% at 0 °C; 0.65% at 24 °C; 0.80% at 30 °C; in ethyl methyl ketone: 9.3% at 58.5 °C; in absolute ethanol: 4.5% at 0 °C; practically insoluble in benzene and chloroform

Slightly soluble in toluene, diethyl ether, ethanol, cold water; soluble in acetonitrile, ethyl acetate, acetone, hot water; very soluble in dimethylsulfoxide.

Very soluble in ethanol; insoluble in benzene, chloroform; slightly soluble in trifluoroacetic acid; soluble in alkalies

In water, 1.6X10+3 mg/L at 20 °C

16.0 mg/mL

4-Aminophenol crystals exist in two forms. The alpha form (from alcohol, water, or ethyl acetate) is the more stable and has an orthorhombic pyramidal structure, density 1.290 g/cu cm /alpha-4-Aminophenol/

0.00004 [mmHg]

4.0X10-5 mm Hg at 25 °C

log Kow = 0.04 at pH 7.4

Deteriorates under influence of air and light

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

Positive

Agilent XCT

Electrospray ionization

formic acid (5.3nM)

MeCN (80%)

DOI:10.1021/acs.analchem.7b00096

Negative

ammonia (10nM)

DOI:10.1021/acs.analchem.7b00595

pK1 = 5.48 at 25 °C (conjugate acid)

pK2 = 10.46

Heat of formation = -190.6 kJ/mol

4-Aminophenol crystals exist in two forms. The less stable beta form (from acetone) exists as acicular crystals that turn into the alpha form on standing; they are orthorhombic bipyramidal or pyramidal /beta-4-Aminophenol/

Insoluble in water.

Phenols and Cresols

Amines, Aromatic

P-AMINOPHENOL is sensitive to: Heat (decomposition forming HCN, nitrous vapors, CO); water (CO2); reacts violently with acids, bases, alcohols and amines causing fire and explosion hazards [Handling Chemicals Safely 1980 p. 647].

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

4-Aminobiphenyl requires metabolic activation in order to exert its toxicity. This is catalyzed by N-hydroxylation via cytochrome P450 1A2, then followed by O-sulfation and O-acetylation by sulfotransferase 1A1 and arylamine N-acetyltransferase 2. The metabolites of 4-aminobiphenyl then form adducts with DNA, inducing mutations. 4-Aminobiphenyl and its metabolites may also cross the placenta and have fetal effects. (1, 2, 3, 4). It is also though that the mode of action involves metabolic activation by N-hydroxylation, followed by N-esterification leading to the formation of a reactive electrophile, which binds covalently to DNA, principally to deoxyguanosine, leading to an increased rate of DNA mutations and ultimately to the development of cancer. In humans and dogs, the urinary bladder urothelium is the target organ, whereas in mice it is the bladder and liver; in other species, other tissues can be involved. Differences in organ specificity are thought to be due to differences in metabolic activation versus inactivation (A15085).

Not listed by IARC.

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

Oral (L138) ; inhalation (L138)

4-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.

p-Aminophenol

2 x 10^-2 mg/kg-day

2 x 10^-1 mg/kg-day

PDF Document

PPRTV Current

LC50 (rat) =>5 mg/m3/1H

LD50: 375 mg/kg (Oral, Rat) (T14)

LD50 Rat oral 375 mg/kg

LD50 Rat oral 671 mg/kg

LD50 Rat oral 1270 mg/kg

LD50 Mouse oral 420 mg/kg

For more Non-Human Toxicity Values (Complete) data for 4-Aminophenol (6 total), please visit the HSDB record page.

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)

p-Aminophenol (pAP, 225 mg/kg) administration to rats induced renal failure and has been associated with markers of endoplasmic reticulum (ER) stress, as well as calpain and caspase-12 activation in kidneys. To determine the importance of ER stress and calpain during pAP-induced nephrotoxicity, rats were pretreated with low, nontoxic, doses of ER stress inducers or with the selective calpain inhibitor PD150606 (3 mg/kg). Prior ER stress induced by tunicamycin and oxidized dithiothreitol did not result in protection against renal failure, but PD150606 administration was protective and decreased significantly the rise in creatinine and blood urea nitrogen observed after 24-hr post-pAP administration. pAP-induced XBP1 upregulation was not modified by calpain inhibition, but a trend to lower GRP94 induction was determined, suggesting that pAP-induced ER stress was mostly calpain independent. In contrast, pAP-induced caspase-12 cleavage products were significantly decreased with PD150606 pretreatment, demonstrating that caspase-12 activation was calpain dependent ...

The effects of a glutathione depletor, buthionine sulfoximine (BSO) and biliary cannulation on the nephrotoxicity of p-aminophenol (PAP) have been investigated in the F344 rat. Pretreatment with BSO completely protected against the nephrotoxicity of a 50 mg/kg dose of PAP, assessed by clinical chemistry, renal histopathology, and (1)H-NMR urinalysis. Biliary cannulation partially protects against nephrotoxicity induced by 100 mg/kg PAP. These data suggest that the nephrotoxicity of PAP may be due in part to the formation of a proximate toxic metabolite in the liver which is excreted in the bile, subsequently reabsorbed and transported via the systemic circulation to the kidney where the toxic effects occur.

Screening tests revealed that aniline increased urine trimethoprim (TMP) excretion in rat. The study attempted to investigate the effect of aniline under conditions of repeated exposure on the course of TMP excretion with urine. ... Three groups of rats (10 rats each) were used. Group I was exposed for 12 days (6 hr a day) to aniline vapour. Group II received TMP only. Group III was exposed both to aniline & TMP. Concns of TMP & p-aminophenol (an aniline metabolite) were determined in the 24 hr urine samples after 1, 6, & 12 days. The exposure to aniline vapors was found to cause almost 3-fold incr of TMP removal. No effect of TMP on p-aminophenol excretion was observed.

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/

/HUMAN EXPOSURE STUDIES/ An examination of 31 employees from a chemical factory producing 4-aminophenol (PAP) and other aromatic compounds was conducted using single 48-hr occlusive patches with five of the suspected chemicaIs. Ten of the 31 employees reacted positively to PAP in petrolatum at one or more of the applied doses. Generally dose related, these responses ranged from 1+ at 0.1% PAP (1/31) to 2+ (3/31) and 3+ (1/31) at 1% PAP, with 6/10 employees having 1+ reactions at 0.5% PAP. PAP did not induce primary irritant contact dermatitis in any of the 5 controls, and none of the 31 sensitized subjects who were tested with PAP had cross sensitization when later challenged with dinitrochlorobenzene.

/HUMAN EXPOSURE STUDIES/ Aqueous solutions of 1.0% 3-aminopheol (MAP) and 0.5% 4-aminophenol (PAP) were tested for depigmentation and discoloration after repeated topical application to the skin on one of the forearms of 26 volunteers (20 black and 6 white). The subjects were separated into 2 groups of 13; 1 group received 0.1 5 mL applications of the PAP solution, and the other group received 0.1 5 mL of the MAP solution. Sites were washed by the subjects 1 hr after application of the solutions. The solutions were applied to the same sites for 3 consecutive days the first week and for 4 consecutive days the second and third weeks. Three days after the 11th application, the subjects' arms were evaluated for "circumscribed areas on either forearm in which the skin color appeared different from that of the surrounding area." Subjects were asked to comment on the test procedure or any adverse effects experienced during the study. There was no evidence of skin color changes, lightening or darkening, in any of the 6 white subjects. No lightening of skin color was observed in any of the black subjects. A slight darkening of the skin of 2 black subjects treated with the PAP solution was noted. Slight to moderate primary skin irritation was found in I subject after three to seven applications of the PAP solution.

/HUMAN EXPOSURE STUDIES/ In 80 patients, positive to at least one hapten of the para group (para-phenylenediamine, diaminodiphenylmethane, benzocaine, PPD mix), patch tests were carried out with freshly prepared solutions of para-phenylenediamine (PPD) and of 3 selected aromatic compounds related structurally to PPD (para-aminophenol, ortho-aminophenol, hydroquinone). The number of positive reactions correlated with the rate of decomposition of the substances as evaluated by high-pressure liquid chromatography. PPD, which was almost decomposed after 24 hr, gave the highest number of positive reactions, followed by ortho-aminophenol and by para-aminophenol, while hydroquinone, which was oxidized to the extent of 35%, did not give any reactions ... The results suggest that the rate of decomposition and therefore the amount of quinone(s) generated, might be the key to eliciting patch test responses to oxidizable aromatic haptens.

/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/

For more Human Toxicity Excerpts (Complete) data for 4-Aminophenol (16 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ 10 albino rats (five male and five female, COX-SD strain) weighing 216 - 314 g were exposed by inhalation to undiluted sample at a delivery rate of approx 5.91 mg/L of air at a flow rate of 3.0 L/min for a period of 60 min plus 19 min for equilibration. All of the animals survived the 60 min exposure and the 14 day observation period which followed.

/LABORATORY ANIMALS: Acute Exposure/ The acute dermal LD50 of a sample when applied as a 50% w/w suspension in a 1% aqueous gum tragacanth to the intact and abraded skin of male and female New Zealand albino rabbits weighing 2.35 - 3.07 kg, was found to be > 8,000 mg/kg bw. No mortality. This was the largest practicable dose under the conditions of the test.

/LABORATORY ANIMALS: Acute Exposure/ Using clipped New Zealand rabbits with occlusive patches with doses of 0.5 g which remained in contact with the skin for 4 or 23 hr, no cutaneous effects were observed.

/LABORATORY ANIMALS: Acute Exposure/ In rabbits, a 2.5% (w/v) preparation failed to produce any toxic effects /in the eye/.

For more Non-Human Toxicity Excerpts (Complete) data for 4-Aminophenol (85 total), please visit the HSDB record page.

LC50; Species: Oncorhynchus mykiss (rainbow trout); Concentration: 1.2 mg/L for 96 hr /Conditions of bioassay not specified/

LC50; Species: Oncorhynchus mykiss (rainbow trout); Concentration: 1.2 mg/L for 96 hr /Conditions of bioassay not specified/

EC50; Species: Tetrahymena thermophila (ciliate protozoa, B-III); Conditions: freshwater; Concentration: 16.4 mg/L (16400 ug/L) for 90 minutes; Effect: Behavioral changes, general

EC50; Species: Tetrahymena thermophila (ciliate protozoa, B-III); Conditions: freshwater; Concentration: 0.31 mg/L (310 ug/L) for 48 hr; Effect: Population growth rate

EC50; Species: Tetrahymena thermophila (ciliate protozoa, B-III); Conditions: freshwater; Concentration: 0.44 mg/L (440 ug/L) for 48 hr; Effect: Population growth rate

For more Ecotoxicity Values (Complete) data for 4-Aminophenol (6 total), please visit the HSDB record page.

1.30e+03

1.60e+04

4.00e+02

4.00e+00

1.50e-01

2.00e-02

Volatile

3.80e+03

4.90e+04

1.20e+03

4-Aminophenol's production and use as a photographic developer; as a dyeing agent for textiles, fur, feathers, hair; in pharmaceuticals; as an antioxidant; as an oil additive and as a chemical intermediate may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 4X10-5 mm Hg at 25 °C indicates 4-aminophenol will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase 4-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 4-aminophenol will be removed from the atmosphere by wet or dry deposition. 4-Aminophenol absorbs light at wavelengths of 294 nm and, therefore, may be susceptible to direct photolysis by sunlight. If released to soil, 4-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 5.48 and 10.46, for the amine and hydroxy functional groups, respectively. 4-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 3.6X10-10 atm-cu m/mole. Biodegradation results are mixed. Utilizing the Japanese MITI test, 6% of the Theoretical BOD was reached in 4 weeks; using acclimated activated sludge, an 87% COD was noyed in 5 days. If released into water, 4-aminophenol is expected to adsorb to suspended solids and sediment based upon the estimated Koc. 4-Aminophenol, under aerobic conditions, seems to biodegrade as shown by studies where 85 and 100% of 10 mg/L 4-aminophenol was degraded in river and seawater, respectively, however at 50 mg/L no biodegradation was observed. Under denitrifying and methanogenic conditions in sediment, 4-aminophenol was mineralized following a long lag phase at a rate of 15.7 and 20 umol/L/day, respectively. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. BCFs of 10-39 and 15-46 in carp (Cyprinus carpio) suggest bioconcentration in aquatic organisms is low to moderate. 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 4-aminophenol may occur through inhalation and dermal contact with this compound at workplaces where 4-aminophenol is produced or used. Use data indicate that the general population may be exposed to 4-aminophenol via dermal contact with consumer products, particularly hair dye products, containing 4-aminophenol. (SRC)

4-Aminophenol's production and use as a photographic developer; as a dyeing agent for textiles, fur, feathers, hair; in pharmaceuticals; as an antioxidant; as an oil additive(1) and as a chemical intermediate(2) 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 4-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 5.48(5) and 10.46(6), for the amine and hydroxy functional groups, respectively(7). 4-Aminophenol is amphoteric and behaves either as a weak acid or weak base; the basic character usually predominates(8). Volatilization of 4-aminophenol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.6X10-10 atm-cu m/mole(SRC), based upon its vapor pressure, 4X10-5 mm Hg(9), and water solubility, 16,000 mg/L(10). 4-Aminophenol is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(9). A 6% of theoretical BOD using activated sludge in the Japanese MITI test(11) suggests that biodegradation may not be important environmental fate process in soil(SRC). However, 87% chemical oxygen demand removal was reached in 5 days in a screening test using acclimated activated sludge at 100 mg/L and 4-aminophenol at 200 mg/L chemical oxygen demand(12).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 90(SRC), determined from a structure estimation method(2), indicates that 4-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 3.6X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 4X10-5 mm Hg(4), and water solubility, 16,000 mg/L(5). According to a classification scheme(6), BCFs of 10-39 and 15-46 in carp (Cyprinus carpio)(7) suggest bioconcentration in aquatic organisms is low to moderate(SRC). 4-Aminophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). 4-Aminophenol, under aerobic conditions, seems to biodegrade as shown by studies where 85 and 100% of 10 mg/L 4-aminophenol was degraded in river and seawater, respectively, however at 50 mg/L no biodegradation was observed(8). Under denitrifying and methanogenic conditions in sediment, 4-aminophenol was mineralized following a long lag phase at a rate of 15.7 and 20 umol/L/day, respectively(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 4-aminophenol, which has a vapor pressure of 4X10-5 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 4-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 4-aminophenol may be removed from the air by wet or dry deposition(SRC). 4-Aminophenol absorbs light at wavelengths of 294 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

AEROBIC: 4-Aminophenol, present at 100 mg/L, reached 6% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/L in the Japanese MITI test(1). Total loss of UV absorbancy due to cleavage of the benzene ring was reported in 16 days in a screening study using a soil inoculum and 4-aminophenol at 5 ppm(2). 4-Aminophenol, present at 100 mg/L, in an electrolytic respirometry screening test using an activated sludge inoculum, was not biodegraded over a 10-day period as measured by BOD(3). 4-Aminophenol, at 200 mg/L chemical oxygen demand reached 87% removal in 5 days in a screening test using acclimated activated sludge at 100 mg/L(4). 4-Aminophenol, present at 50 and 10 mg/L was degraded by 0 and 85%, respectively, in river water and 0 and 100% in seawater, respectively(5).

ANAEROBIC: 20% of the theoretical gas production was reached over 60 days in a screening study using methanogenic primary digesting sludge when 4-aminophenol was present; a lag phase of 57 days was noted(1). 4-Aminophenol at 30 mg-C/L was not degraded over a 28-day period, measured by removal of dissolved organic carbon, in an anaerobic screening study using 100 mg-C/L sewage(2). 4-Aminophenol, incubated in sediment under denitrifying conditions, showed an initial lag phase of 2.7 to 4.7 weeks followed by mineralization at a rate of 15.7 umol/L/day; 89% of theoretical N2 was recovered over the 30-week study(3). 4-Aminophenol was mineralized at a rate of 20 umol/L/day following a lag phase of 6.5 to 9 weeks under methanogenic conditions in a 26-week sediment grab sample study(3). 15% of the theoretical methane production was reached in 150 days with a 70-day lag period in an anaerobic screening study using 2-nitrophenol-adapted sludge; the study was run under methanogenic conditions with 1000 mg/L 4-aminophenol(4). No mineralization of 4-aminophenol was reported for the same study repeated using non-adapted sludge(4). 45.5% of the theoretical methane production was reached in 220 days with a 70-day lag period when 4-aminophenol was supplied to 2-nitrophenol-adapted granular sludge as the sole carbon source(5). 4-Aminophenol was not degraded over a 29-week period in anaerobic freshwater lake sediment or over an 8-week period when incubated with 2 different anaerobic municipal digested sludge samples(6). 4-Aminophenol was not degraded in 10% anaerobic sludge over 8 weeks(7).

The rate constant for the vapor-phase reaction of 4-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). 4-Aminophenol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). 4-Aminophenol is expected to undergo fairly rapid oxidation in the presence of air(3) and may be susceptible to direct photolysis due to its absorption in the environmental UV spectrum (UV max = 294 nm)(3). Measured pKa values are 5.48(4) and 10.46(5), for the amine and hydroxy functional groups, respectively(6). 4-Aminophenol is amphoteric and behaves either as a weak acid or weak base; the basic character usually predominates(3).

BCFs of 10-39 and 15-46 in carp (Cyprinus carpio) were reported for a 8 week study using 1.5 and 0.15 mg/L 4-aminophenol, respectively(1). According to a classification scheme(2), these BCFs suggest the potential for bioconcentration in aquatic organisms is low to moderate(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 4-aminophenol can be estimated to be 90(SRC). According to a classification scheme(2), this estimated Koc value suggests that 4-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 5.48(5) and 10.46(6), for the amine and hydroxy functional groups, respectively(7). 4-Aminophenol is amphoteric and behaves either as a weak acid or weak base; the basic character usually predominates(8).

The Henry's Law constant for 4-aminophenol is estimated as 3.6X10-10 atm-cu m/mole(SRC) derived from its vapor pressure, 4X10-5 mm Hg(1), and water solubility, 16,000 mg/L(2). This Henry's Law constant indicates that 4-aminophenol is expected to be essentially nonvolatile from water surfaces(3). 4-Aminophenol is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

According to the 2006 TSCA Inventory Update Report, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of 4-aminophenol is 100 to 999; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 49,882 workers (37,110 of these were female) were potentially exposed to 4-aminophenol in the US(1). Occupational exposure to 4-aminophenol may occur through dermal contact with this compound at workplaces where 4-aminophenol is produced or used(SRC). Use data indicate that the general population may be exposed to 4-aminophenol via dermal contact with consumer products, particularly hair dye products, containing 4-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 4-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.