Винилхлорид

Описание

Vinyl chloride is a colorless, flammable gas with a sweet ethereal odor. It is shipped as a liquefied compressed gas. Contact of the liquid with the skin can result in freezing or frostbite. Vinyl chloride has been established as a human carcinogen. In addition, acute effects of vinyl chloride exposure include irritation of the skin and eyes on contact. Inhalation of concentrations of more than 500 ppm produces mild anesthesia.
Anhydrous vinyl chloride does not corrode metals at normal temperatures and pressures, but in the presence of moisture and elevated temperatures, vinyl chloride accelerates the corrosion of iron and steel at elevated temperatures. Vinyl chloride polymerizes readily when exposed to air, sunlight, heat, or oxygen, although it is chemically stable as shipped with an inhibitor (phenol).

Химические свойства

Vinyl chloride is a flammable gas at room temperature, and is usually encountered as a cooled liquid. The colorless liquid forms a vapor which has a pleasant, ethereal odor. The odor threshold is variously given as 260 ppm, 3,000 ppm (NJ fact sheet), 4000 ppm (NY fact sheet) in air and 3.4 ppm in water (EPA Toxicological profile). Shipped as a liquefied compressed gas.

Физические свойства

Colorless, liquefied compressed gas with a faint, sweetish odor

Использование

In the plastics industry to manufacture of polyvinyl chloride; in organic syntheses. Has been used as refrigerant, spray can propellant.

Методы производства

VC was first synthesized in 1835 by Henri Victor Regnault in the laboratory of Justus von Liebig. Industrial production of VC began in 1930s. Ninety-eight percent is used for polyvinyl chloride (PVC) production and the remaining 2% for polyvinylidene chloride and chlorinated solvents. The most common method for the production ofVC monomer is based on cracking ethylene dichloride. Over 95% of VC produced worldwide in 2006 was made by this method. A less common method is by hydrochlorination of acetylene. VC has been produced commercially in the United States for over 70 years.

Определение

ChEBI: A monohaloethene that is ethene in which one of the hydrogens has been replaced by a chloro group.

Общее описание

A colorless gas with a sweet odor. Easily ignited. Shipped as a liquefied gas under own vapor pressure. Contact with the unconfined liquid may cause frostbite by evaporative cooling. Leaks may be liquid or vapor. Vapors are heavier than air. May asphyxiate by the displacement of air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Suspected carcinogen. Used to make plastics, adhesives, and other chemicals.

Реакции воздуха и воды

Highly flammable. Forms polymeric peroxides that are explosive [Bretherick 1979. p. 164].

Профиль реактивности

VINYL CHLORIDE is peroxidizable. Forms explosive polymeric peroxides in contact with air (in the presence of any of a variety of catalysts) [Bretherick 1979. p. 164]. Long storage in contact with air increases the concentration of the polyperoxides to hazardous levels [MCA Case History 1551. 1969]. The peroxides may initiate exothermic polymerization of the remaining material [Handling Chemicals Safely 1980.p. 958; Bretherick 1979. p. 160]. Light-sensitive. Many oxidizing agents apparently initiate polymerization (oxides of nitrogen, O2, etc.). May react with very hot water or steam to produce toxic fumes.

Опасность

The vapor density is 2.16, which is heavier than air. It is toxic by inhalation, ingestion, and skin absorption. Vinyl chloride is a known human carcinogen. The TLV is 5 ppm in air. The four-digit UN identification number is 1086. The NFPA 704 designation is health 2, flammability 4, and reactivity 2; uninhibited, the values would be higher for reactivity. The primary uses are in making polyvinyl chloride and as an additive in plastics.

Угроза здоровью

The acute inhalation toxicity is of low order.Since it is a gas, the route of exposure isprimarily inhalation. The target organs arethe liver, central nervous system, respiratorysystem, and blood. Exposure to high concen trations can produce narcosis. A 30-minuteexposure to 30% vinyl chloride in air wasfatal to experimental animals. Chronic expo sure produced minor injury to the liver andkidneys. Such effects were noted at a 7-hourexposure daily to 200 ppm for 6 months.
Vinyl chloride is an animal and humancarcinogen. Rats subjected to 12 months’inhalation developed tumors of the lungs,skin, and bones. Occupational exposure tothis compound demonstrated an increasedincidence of liver cancer. Tabershaw andGaffey (1974) conducted epidemiologicalstudies on workers who had at least 1 year ofoccupational exposure to vinyl chloride. Thestudy indicated that cancers of the digestivesystem, respiratory system, and brain, as wellas lymphomas, were greater among peoplewho had the greatest estimated exposure tovinyl chloride.

Пожароопасность

Flammable gas; heavier than air, density 2.2 (air=D 1), flame propagation and flash back fire hazard if the container is placed near a source of ignition; autoignition tem perature 472°C (882°F); polymerization may occur at elevated temperatures, which may cause possible rupture of containers; fire extinguishing measure: stop the flow of gas; water may be used to keep fire-exposed containers cool. Vinyl chloride may decom pose under fire conditions, producing the toxic gases carbon monoxide and hydrogen chloride.
Vinyl chloride forms explosive mixtures with air in a wide range; the LEL and UEL values are 3.6% and 33.0% by volume in air, respectively. It may undergo oxidation by atmospheric oxygen, producing an unstable polyperoxide that may explode (MCA 1969). Such a reaction is catalyzed by a variety of contaminants.

Использование в материалах

Steel is recommended for all piping, storage tanks, and equipment used with vinyl chloride. However, at elevated temperatures, vinyl chloride in the presence of moisture speeds its corrosion. Stainless steel is also an acceptable material to use with vinyl chloride. Copper and copper alloys must not be used. Valves in vinyl chloride service must not contain copper or copper alloys. Acetylene may be present as an impurity in vinyl chloride and can form an explosive acetyl ide when exposed to copper.
Asbestos, Teflon, lead, and carbon are satisfactory gasket materials for fittings and connections.

Профиль безопасности

Confirmed human carcinogen producing liver and blood tumors. Moderately toxic by ingestion. Experimental teratogenic data. Experimental reproductive effects. Human reproductive effects by inhalation: changes in spermato- genesis. Human mutation data reported. A severe irritant to skin, eyes, and mucous membranes. Causes skin burns by rapid evaporation and consequent freezing. In high concentration it acts as an anesthetic. Chronic exposure has produced liver injury. Circulatory and bone changes in the fingertips have been reported in workers handling unpolymerized materials.A very dangerous fire hazard when exposed to heat, flame, or oxidzers. Large fires of ths material are practically inextinguishable. A severe explosion hazard in the form of vapor when exposed to heat or flame. Long-term exposure to air may result in formation of peroxides that can initiate explosive polymerization of the chloride. Can react vigorously with oxidizing materials. Can explode on contact with oxides of nitrogen. Obtain instructions for its use from the supplier before storing or handling ths material. To fight fire, stop flow of gas. When heated to decomposition it emits highly toxic fumes of Cl-. See also CHLORINATED HYDROCARBONS, ALIPHATIC.

Возможный контакт

Vinyl chloride is used as a vinyl monomer in the manufacture of polyvinyl chloride (vinyl chloride homopolymer) and other copolymer resins. It is also used as a chemical intermediate and as a solvent.

Канцерогенность

Vinyl chloride is known to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in humans.

Перевозки

UN1086 Vinyl chloride, stabilized, Hazard Class: 2.1; Labels: 2.1-Flammable gas. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written permission of the owner.

Несовместимости

Copper, oxidizers, aluminum, peroxides, iron, steel. Polymerizes in air, sunlight, heat, and on contact with a catalyst, strong oxidizers; and metals, such as aluminum and copper unless stabilized by inhibitors, such as phenol. Attacks iron and steel in presence of moisture.

Утилизация отходов

Return refillable compressed gas cylinders to supplier. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations governing storage, transportation, treatment, and waste disposal. Incineration, preferably after mixing with another combustible fuel. Care must be exercised to assured to assure complete combustion to prevent the formation of phosgene. An acid scrubber is necessary to remove the halo acids produced. A variety of techniques have been described for vinyl chloride recovery from PVC latexes.