General Description
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.
Reactivity Profile
VINYL CHLORIDE(75-01-4) 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.
Air & Water Reactions
Highly flammable. Forms polymeric peroxides that are explosive [Bretherick 1979. p. 164].
Health Hazard
INHALATION: high concentrations cause dizziness, anesthesia, lung irritation. SKIN: may cause frostbite; phenol inhibitor may be absorbed through skin if large amounts of liquid evaporate.
Potential Exposure
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.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately.
If this chemical has been inhaled, remove from exposure,
begin rescue breathing (using universal precautions, including
resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medical
attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit.
Shipping
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.
Incompatibilities
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.
Description
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).
Chemical Properties
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.
Waste Disposal
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.
Physical properties
Colorless, liquefied compressed gas with a faint, sweetish odor
Uses
In the plastics industry to manufacture of polyvinyl chloride; in organic syntheses. Has been used as refrigerant, spray can propellant.
Uses
Vinyl chloride is polymerized in various ways to polyvinyl chloride (PVC). It is also copolymerized with various other monomers to make a variety of useful resins.
Uses
Vinyl chloride is used as a monomer inthe manufacture of polyvinyl chloride resinsand plastics, as a refrigerant, and in organicsynthesis.
Definition
ChEBI: A monohaloethene that is ethene in which one of the hydrogens has been replaced by a chloro group.
Production Methods
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.
Production Methods
Vinyl Chloride is produced by alkaline dehydrochlorination of ethylene dichloride, or by thermal cracking of EDC, or 1,1-dichloroethane.
Hazard
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.
Fire Hazard
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.
Materials Uses
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.
Physiological effects
Vinyl chloride is toxic and carcinogenic.
ACGIH recommends a Threshold Limit ValueTime-Weighted Average (TLV-TWA) of 5
ppm (13 mg/m3) for vinyl chloride. The TLV-TWA is the time-weighted average concentration for a normal 8-hour workday and a 40-hour
workweek, to which nearly all workers may be
repeatedly exposed, day after day, without adverse effect.
OSHA lists an 8-hour Time-Weighted Average-Permissible Exposure Limit (TWA-PEL) of 1 ppm for vinyl chloride. TWA-PEL is the
exposure limit that shall not be exceeded by the
8-hour TWAin any 8-hour work shift of a
40-hour workweek. Additionally, there shall not
be exposure to concentrations greater than 5
ppm averaged over any period not exceeding 15
minutes. A complete standard describing control
of employee exposure to vinyl chloride as required by OSHA is given in 29 CFR 1910.1017.
Vinyl chloride acts as a general anesthetic in
concentrations over 500 ppm. It has been reported that acute exposures to vinyl chloride
concentrations above 1000 ppm slowly produce
mild disturbances such as drowsiness, blurred
vision, staggering gait, and tingling and numbness in the feet and hands.
The occurrence of acro-osteolysis and hepatic
angiosarcoma have been associated with vinyl
chloride exposure. Liver changes including hepatomegaly, liver function abnormalities, and
parenchymal damage have been reported.
Vinyl chloride can irritate or damage the eyes
on contact. Liquid vinyl chloride also irritates the
skin and can freeze the skin on prolonged contact.
Carcinogenicity
Vinyl chloride is known to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in humans.
Source
Vinyl chloride in soil and/or groundwater may form from the biotransformation of 1,1,1-
trichloroethane (Lesage et al., 1990), trichloroethylene, 1,2-dichloroethylene (Smith and Dragun,
1984; Wilson et al., 1986), and from the chemical reduction of trichloroethylene by zero-valent
iron (Orth and Gillham, 1996).
Drinking water standard (final): MCLG: zero; MCL: 2 μg/L (U.S. EPA, 2000).
Environmental Fate
Biological. Under anaerobic or aerobic conditions, degradation to carbon dioxide was reported
in experimental systems containing mixed or pure cultures (Vogel et al., 1987). The anaerobic
degradation of vinyl chloride dissolved in groundwater by static microcosms was enhanced by the
presence of nutrients (methane, methanol, ammonium phosphate, phenol). Methane and ethylene
were reported as the biodegradation end products (Barrio-Lage et al., 1990). When vinyl chloride
(1 mM) was incubated with resting cells of Pseudomonas sp (0.1 g/L) in a 0.1 M phosphate buffer
at pH 7.4, hydroxylation of the C-Cl bond occurred yielding acetaldehyde and chloride ions.
Oxidation at both the methyl and carbonyl carbons produced acetic acid and hydroxyacetaldehyde,
which underwent oxidation to give glycolic acid (hydroxyacetic acid). The acid was oxidized to
carbon dioxide (Castro et al., 1992).
Surface Water. In natural surface waters, vinyl chloride was resistant to biological and chemical degradation (Hill et al., 1976).
Groundwater. Under aerobic conditions, >99% vinyl chloride degraded in shallow groundwater
after 108 d and 65% was completely mineralized (Davis and Carpenter, 1990).
Photolytic. Irradiation of vinyl chloride in the presence of nitrogen dioxide for 160 min
produced formic acid, HCl, carbon monoxide, formaldehyde, ozone, and trace amounts of formyl
chloride and nitric acid. In the presence of ozone, however, vinyl chloride photooxidized to carbon
monoxide, formaldehyde, formic acid, and small amounts of HCl (Gay et al., 1976). Reported
photooxidation products in the troposphere include hydrogen chloride and/or formyl chloride
(U.S. EPA, 1985). In the presence of moisture, formyl chloride will decompose to carbon
monoxide and HCl (Morrison and Boyd, 1971). Vinyl chloride reacts rapidly with OH radicals in
the atmosphere. Based on a reaction rate of 6.6 x 10-12 cm3/molecule?sec, the estimated half-life for
this reaction at 299 K is 1.5 d (Perry et al., 1977). Vinyl chloride reacts also with ozone and NO3
in the gas-phase. Sanhueza et al. (1976) reported a rate constant of 6.5 x 10-21 cm3/molecule?sec
for the reaction with OH radicals in air at 295 K. Atkinson et al. (1988) reported a rate constant of
4.45 x 10-16 cm3/molecule?sec for the reaction with NO3 radicals in air at 298 K.
Chemical/Physical. In a laboratory experiment, it was observed that the leaching of a vinyl
chloride monomer from a polyvinyl chloride pipe into water reacted with chlorine to form
chloroacetaldehyde, chloroacetic acid, and other unidentified compounds (Ando and Sayato,
1984).
storage
Vinyl chloride should be used in a
well-ventilated area, preferably using a hood
with forced ventilation. Some authorities believe that the odor of vinyl chloride does not
provide adequate warning of its presence in
concentrations sufficient to produce dizziness
and unconsciousness, so special caution is urged
against leaks and poor ventilation.
Precautions required for the safe handling of
all flammable gas must be observed with vinyl
chloride. Adequate electrical grounding of all
lines and equipment, and ditching or diking in
storage tank areas to control the liquid in the
event of vessel rupture are among recommended
precautions. Ditching is preferable because the material should not be retained at a location
directly beneath or surrounding the storage
tanks. Installations must be designed to comply
with requirements for unfired pressure vessels
and all state, provincial, and local regulations.
Personnel handling vinyl chloride should
wear safety shoes, chemical safety goggles or a
full face shield, and rubber gloves. An effective
educational and training program must be instituted to inform the workers of the hazards involved in handling and using vinyl chloride and
the first aid measures to be followed in the
event of an emergency. For specific OSHA requirements, refer to 29 CFR 1910.1017.
For respiratory protection, SCBA, air-line
cartridge-type respirators, and U.S. Bureau of
Mines or NIOSH approved canister-type, cartridge-type respirators should be available in
emergencies. Instant-acting safety showers and
eyewash fountains should be conveniently located near the site ofthe operation.
Store and use cylinders of vinyl chloride in
well-ventilated areas away from heat and all
sources of ignition such as flames and sparks.
Do not use vinyl chloride around sparking motors or other equipment that is not explosion-proof equipment. Do not store reserve
cylinder stocks of vinyl chloride with cylinders
containing oxygen, chlorine, or other highly
oxidizing or combustible materials.
Toxicity evaluation
The mechanisms of toxicity for noncancer effects of VC have
not been completely determined.
It is hypothesized that VC is metabolized to the
reactive metabolites 2-chloroethylene oxide and, subsequently,
2-chloroacetaldehyde via mixed-function oxidases (MFOs),
whose activity is primarily concentrated in the liver. The presence
of the reactive 2-chloroacetaldehyde results in protein adduction,
which interferes with normal cellular function, resulting in cytotoxicity.
This is consistent with the progression of effects from
hypertrophy to fatty changes, hyperplasia, and necrosis. Indications
of binding to proteins such as immunoglobulin G (IgG) in
occupationally exposed individuals show immune responses
including B-cell proliferation, hyperimmunoglobulinemia, and
complement activation and increased circulating immune
complexes. It has been hypothesized that cardiac arrhythmia
reported after VC exposure may result from sensitization of the
heart to circulatory catecholamines, as occurs with other halogenated
hydrocarbons.
VC is a known human and animal carcinogen including both
increased incidence of hepatic angiosarcomas and hepatotoxicity.
It is thought that the mechanism for these liver effects is that
VC is metabolized by MFO to form an epoxide intermediate,
2-chloroethylene oxide, which rearranges to form 2-chloroacetaldehyde.
These reactive metabolites are transported from
parenchymal cells to the nonparenchymal cells forming four
primary DNA adducts which produce base–pair transitions
during transcription and DNA cross-links. Such mutations can
result in the mutation of ras oncogenes and the p53 tumor
suppressor gene which are found in VC-exposed individuals.
The metabolism of VC to highly reactive metabolites, the
observance of DNA adduction in mechanistic studies, and the
observed carcinogenicity resulting from a single, high-level
inhalation exposure in animals suggest that the primary
mechanism of VC carcinogenicity involves direct DNA interactions
rather than secondary responses to cytotoxicity.
Toxics Screening Level
The initial risk screening level (IRSL) for VINYL CHLORIDE is 0.11 μg/m3 (annual averaging time).
GRADES AVAILABLE
Vinyl chloride is available for commercial and
industrial use in various grades having much the
same composition from one producer to another. It typically has a minimum purity of 99.9
mole percent in the liquid phase.
