CARBON TETRACHLORIDE

Carbon tetrachloride
(Tetrachloromethane)
CAS 56-23-5

CCl₄

Colorless liquid
bp 77 °C, mp -23 °C
Insoluble in water (0.05 g/100 mL)

Ethereal, sweet, pungent odor detectable at 140 to 584 ppm (mean = 252 ppm)

5.3 (air = 1.0)

91 mmHg at 20 °C

Noncombustible

LD₅₀ oral (rat) 2350 mg/kg

LD₅₀ skin (rabbit) >20 g/kg

LC₅₀ inhal (rat) 8000 ppm (4 h)

PEL (OSHA) 2 ppm (13 mg/m³)

TLV-TWA (ACGIH) 5 ppm (32.5 mg/m³)--skin

STEL (ACGIH) 10 ppm (65 mg/m³)

Low to moderate acute toxicity; harmful to the liver, kidneys, and central nervous system.

The acute toxicity of carbon tetrachloride is low to moderate. Inhalation of carbon tetrachloride can produce symptoms such as dizziness, headache, fatigue, nausea, vomiting, stupor, and diarrhea. This substance is a depressant of the central nervous system, and inhalation of high concentrations causes damage to the liver, heart, and kidneys. Exposure to 1000 to 2000 ppm for 30 to 60 min can be fatal to humans. Ingestion of carbon tetrachloride leads to similar toxic effects, and swallowing as little as 4 mL can be lethal. Carbon tetrachloride irritates the skin, and prolonged contact may cause dryness and cracking. This substance is also slowly absorbed through the skin. Carbon tetrachloride liquid and vapor are also irritating to the eyes. The odor of carbon tetrachloride does not provide adequate warning of the presence of harmful concentrations.

Carbon tetrachloride shows carcinogenic effects in animal studies and is listed by IARC in Group 2B ("possible human carcinogen"). It is not classified as a "select carcinogen" according to the criteria of the OSHA Laboratory Standard. Prolonged or repeated exposure to this substance may result in liver and kidney damage. There is some evidence from animal studies that carbon tetrachloride may be a developmental and reproductive toxin in both males and females.

Carbon tetrachloride is noncombustible. Exposure to fire or high temperatures may lead to formation of phosgene, a highly toxic gas.

Carbon tetrachloride may react explosively with reactive metals such as the alkali metals, aluminum, magnesium, and zinc. It can also react violently with boron and silicon hydrides, and upon heating with DMF.

Carbon tetrachloride should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C.

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 carbon tetrachloride is ingested, 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, soak up carbon tetrachloride 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 carbon tetrachloride 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.