TOLUENE

Toluene
(Methylbenzene, toluol, phenylmethane)
CAS 108-88-3

C₆H₅CH₃

Colorless liquid
bp 111 °C, mp -95 °C
Poorly soluble in water (0.05 g/100 mL)

Aromatic, benzene-like odor detectable at 0.16 to 37 ppm (mean = 1.6 ppm)

3.14 (air = 1.0)

22 mmHg at 20 °C

4 °C

480 °C

LD₅₀ oral (rat) 2650 to 7530 mg/kg

LD₅₀ skin (rabbit) 12,124 mg/kg

LC₅₀ inhal (rat) 26,700 ppm (1 h)

PEL (OSHA) 200 ppm (750 mg/m³)

STEL (OSHA) 150 ppm (560 mg/m³)

TLV-TWA (ACGIH) 50 ppm (188 mg/m³)--skin

Highly flammable liquid and vapor.

The acute toxicity of toluene is low. Toluene may cause eye, skin, and respiratory tract irritation. Short-term exposure to high concentrations of toluene (e.g., 600 ppm) may produce fatigue, dizziness, headaches, loss of coordination, nausea, and stupor; 10,000 ppm may cause death from respiratory failure. Ingestion of toluene may cause nausea and vomiting and central nervous system depression. Contact of liquid toluene with the eyes causes temporary irritation. Toluene is a skin irritant and may cause redness and pain when trapped beneath clothing or shoes; prolonged or repeated contact with toluene may result in dry and cracked skin. Because of its odor and irritant effects, toluene is regarded as having good warning properties.

The chronic effects of exposure to toluene are much less severe than those of benzene. No carcinogenic effects were reported in animal studies. Equivocal results were obtained in studies to determine developmental effects in animals. Toluene was not observed to be mutagenic in standard studies.

Toluene is a flammable liquid (NFPA rating = 3), and its vapor can travel a considerable distance to an ignition source and "flash back." Toluene vapor forms explosive mixtures with air at concentrations of 1.4 to 6.7% (by volume). Hazardous gases produced in fire include carbon monoxide and carbon dioxide. Carbon dioxide and dry chemical extinguishers should be used to fight toluene fires.

Contact with strong oxidizers may cause fires and explosions.

Toluene should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C, supplemented by the additional precautions for dealing with highly flammable substances (Chapter 5.F). In particular, toluene should be used only 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 toluene is ingested, do not induce vomiting. Obtain medical attention immediately. If large amounts of this compound are 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 toluene with a spill pillow or absorbent material, place in an appropriate container, and dispose of properly. Respiratory protection may be necessary in the event of a large spill or release in a confined area.

Excess toluene and waste material containing this substance should be placed in an appropriate 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.