ANILINE

Aniline
(Phenylamine; aminobenzene)
CAS 62-53-3

C₆H₅NH₂

Colorless, oily liquid; darkens to brown on exposure to air and light
bp 184 °C, mp -6 °C
Moderately soluble in water (3.5 g/100 mL at 20 °C)

Sweet, amine-like odor detectable at 0.6 to 10 ppm

3.2 (air = 1.0)

0.7 mmHg at 20 °C

70 °C

615 °C

LD₅₀ oral (rat) 250 mg/kg

LD₅₀ skin (rabbit) 820 mg/kg

LC₅₀ inhal (rat) 478 ppm

PEL (OSHA) 5 ppm (19 mg/m³)--skin

TLV-TWA (ACGIH) 2 ppm (7.6 mg/m³)--skin

Moderately toxic if swallowed, inhaled, or absorbed through the skin; causes skin and eye irritation.

Aniline is a moderate skin irritant, a moderate to severe eye irritant, and a skin sensitizer in animals. Aniline is moderately toxic via inhalation and ingestion. Symptoms of exposure (which may be delayed up to 4 hours) include headache, weakness, dizziness, nausea, difficulty breathing, and unconsciousness. Exposure to aniline results in the formation of methemoglobin and can thus interfere with the ability of the blood to transport oxygen. Effects from exposure at levels near the lethal dose include hypoactivity, tremors, convulsions, liver and kidney effects, and cyanosis.

Aniline has not been found to be a carcinogen or reproductive toxin in humans. Some tests in rats demonstrate carcinogenic activity. However, other tests in which mice, guinea pigs, and rabbits were treated by various routes of administration gave negative results. Aniline produced developmental toxicity only at maternally toxic dose levels but did not have a selective toxicity for the fetus. It produces genetic damage in animals and in mammalian cell cultures but not in bacterial cell cultures.

Aniline is a combustible liquid (NFPA rating = 2). Smoke from a fire involving aniline may contain toxic nitrogen oxides and aniline vapor. Toxic aniline vapors are given off at high temperatures and form explosive mixtures in air. Carbon dioxide or dry chemical extinguishers should be used to fight aniline fires.

Reacts violently with strong oxidizing agents, including nitric acid, peroxides, and ozone.

Aniline should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C. In particular, aniline should only be used in areas free of ignition sources, and quantities greater than 1 liter should be stored in tightly sealed metal containers in areas separate from oxidizers.

In the event of skin contact, immediately wash with soap and water and remove contaminated clothing. In case of eye contact, promptly wash with copious amounts of water for 15 min (lifting upper and lower lids occasionally) and obtain medical attention. If aniline is ingested, obtain medical attention immediately. If inhaled, move the person to fresh air and seek medical attention at once.

In the event of a spill, remove all ignition sources, soak up the aniline with a spill pillow or absorbent material, place in a covered metal container, label clearly, and dispose of properly. Respiratory protection may be necessary in the event of a large spill or release in a confined area.

Excess aniline and waste material containing this substance should be placed in a covered metal container, clearly labeled, and handled according to your institution's waste disposal guidelines.

The information in this LCSS has been compiled by a committee of the National Research Council from literature sources and Material Safety Data Sheets and is believed to be accurate as of July 1994. This summary is intended for use by trained laboratory personnel in conjunction with the NRC report Prudent Practices in the Laboratory: Handling and Disposal of Chemicals. This LCSS presents a concise summary of safety information that should be adequate for most laboratory uses of the title substance, but in some cases it may be advisable to consult more comprehensive references. This information should not be used as a guide to the nonlaboratory use of this chemical.

Copyright 1995 National Academy of Sciences. All rights reserved.