carbon tetrachloride


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Related to carbon tetrachloride: Carbon tetrachloride poisoning

carbon tetrachloride

(tĕ'trəklôr`īd) or

tetrachloromethane

(tĕ'trəklôr'əmĕth`ān), CCl4, colorless, poisonous, liquid organic compound that boils at 76.8°C;. It is toxic when absorbed through the skin or when inhaled. It reacts at high temperatures to form the poisonous gas phosgene. Carbon tetrachloride is used in the production of Freon refrigerants, e.g., Freon-12 (dichlorodifluoromethane). Because it is not flammable and is a good solvent for fats, oils, and greases, it is often used commercially for dry cleaning and for degreasing metals. It is sometimes used in fire extinguishers, since its vapors are denser than air and serve to smother a flame. Its use in the home as a spot remover should be avoided because of its poisonous nature.

Carbon Tetrachloride

 

(also tetrachloromethane), CCl4, a colorless liquid, with a sweetish odor, a melting point of –22.9°C, a boiling point of 76.8°C, and a density of 1.593 g/cm3(at 20°C). Carbon tetrachloride is practically insoluble in water but is soluble in many organic solvents. It forms azeotropic mixtures with water (boiling point 66°C; 95.9 percent CCl4), methanol (55.7°C; 79.4 percent CCl4), and other liquids. It readily dissolves oils, greases, waxes, and many natural and synthetic resins and rubbers. Under ordinary conditions, it is resistant to the action of air, light, and concentrated acids; in the presence of iron or aluminum, it is decomposed by water into CO2 and HCl. It interacts with the alcoholates of the alkali metals to form orthocarbonic-acid esters: CCI4 + 4NaOC2H5 → 4NaCI + C(OC2H5)4; it takes part in the telomerization reaction together with olefins. The chlorine atoms in carbon tetrachloride can be replaced with F, Br, or I. For example, the Freons CCl3F and CCl2F2 are commercially prepared from CCl4 and HF.

Carbon tetrachloride is produced by the chlorination of methane or carbon disulfide, as well as by other methods. It is widely used in various industrial sectors as an incombustible fire-resistant solvent.

Poisoning. Carbon tetrachloride enters the body through the respiratory organs and the skin, inducing a narcotic effect on the central nervous system, a slightly irritating effect on the skin, and a toxic effect on the liver, kidneys, and other organs. Acute poisoning is accompanied by headache, vertigo, weakness, nausea, and vomiting. Severe poisoning cause dyspnea, cyanosis, and an increase in body temperature; strong agitation, loss of consciousness, sense disturbances, and paralysis are possible, as are sometimes toxic emphysema and hepatitis. Chronic poisoning is characterized by gastrointestinal disorders, weight loss, and anemia, as well as by irritation of the eyes and mucosa of the upper respiratory tract. Indications of severe cases are toxic hepatitis, poly-neuritis, and kidney damage. Carbon tetrachloride induces dermatitis on contact with the skin.

Preventive measures include the replacement of carbon tetrachloride with less toxic solvents, prevention of carbon tetrachloride vapors from entering inhaled air, and personal safety measures. Preliminary and periodic medical examinations are also helpful.

A. A. KASPAROV and V. N. FROSIN

carbon tetrachloride

[′kär·bən te·trə′klȯr‚īd]
(organic chemistry)
CCl4 Colorless dense liquid, specific gravity 1.595, slightly soluble in water; used as a dry-cleaning agent.

carbon tetrachloride

a colourless volatile nonflammable sparingly soluble liquid made from chlorine and carbon disulphide; tetrachloromethane. It is used as a solvent, cleaning fluid, and insecticide. Formula: CCl4
References in periodicals archive ?
Vitamin E has the ability to prevent the damage caused by carbon tetrachloride.
Ramadan Hassanien, "Hepatoprotective effect of cold-pressed Syzygium aromaticum oil against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats," Pharmaceutical Biology, vol.
Increased enzyme activity was found in the carbon tetrachloride positive control values (25.4 [+ or -] 1.86 U/mg protein; p < 0.050 compared with the control and the supplemented groups).
The extract was concentrated with a rotary evaporator and a portion (40 g) of the concentrated methanol extract was fractionated by the modified Kupchan partitioning protocol [9] into pet-ether (5.5 g) carbon tetrachloride (4.5 g) chloroform (4.0 g) and aqueous (14.0 g) soluble materials.
Key words: Hepatotoxicity carbon tetrachloride (CCl4) corosolic acid DNA damage.
An aliquot of the concentrated ethanol extract was fractionated by the modified Kupchan method (Saha et al., 2012) and the resultant partitioned were evaporated to dryness with a rotary evaporator to yield hexane, carbon tetrachloride and chloroform soluble materials.
The in-vivo antioxidant effect of the methanol extract of Afzelia africana SM seed on carbon tetrachloride (CCl4)-induced oxidative stress in rats was investigated.
Carbon tetrachloride (C[Cl.sub.4]) is a well-known hepatotoxin that is widely used to induce toxic hepatic injuries in experimental animals models [5, 6].
A new synthetic protocol developed by a research team from UNIST, a leading Korean university, has revealed that boron/nitrogen co-doping is only feasible when carbon tetrachloride (CCl4) is treated with boron tribromide (BBr3) and nitrogen (N2) gas.
As of mid-July, Hanford contractors have treated approximately 7.8 billion gallons of groundwater and removed approximately 55 tons of contaminants, including nitrate, carbon tetrachloride, hexavalent chromium, uranium, and technetium-99.
Extract of Mangifera indica has been shown to exhibit hepatoprotective activity in carbon tetrachloride intoxicated albino rats (Singh et al., 2010).