Vinyl chloride is a colorless, flammable gas with a sweet odor that is used to make polyvinyl chloride (PVC) plastics and polymers. It has a chemical formula of C2H3Cl and molecular weight of 62.5 g/mol. Exposure can occur through factory emissions, evaporation from waste sites, or off-gassing from new plastic products. Vinyl chloride is carcinogenic and toxic, especially to the liver, kidneys, and central nervous system. A 2004 explosion at a Formosa Plastics plant in Texas released vinyl chloride, ignited an explosion, and caused fires that burned for days after the accident.
2. Chemical composition and reactivity
• The chemical formula
for vinyl chloride is
C2H3Cl
• molecular weight =
62.5 g/mol
• The half-life of vinyl
chloride in air is a
few hours.
3. Physical Properties of Vinyl Chloride
• colorless gas with a mild, sweet odor
• slightly soluble in water
• extremely flammable
• vapor pressure = 2,600 mm Hg at 25 °C
• has a log octanol/water partition
coefficient (log Kow) of 1.36. (1)
4. Major Sources: Plastics and Vinyl
Used to make
polyvinyl chloride
(PVC)
pipes, wire and cable coatings,
packaging materials, furniture and
automobile upholstery, wall
coverings, house ware, automotive
parts, etc.
Carboxyl-Modified Vinyl Chloride
(VAMA)
Used as a coating for various
substrates, especially
metals, cellulosics, and certain
plastics.
5.
6. Exposure (generally very low)
from the discharge of exhaust gases from factories that
manufacture or process vinyl chloride, or evaporation from
areas where chemical wastes are stored.
Air inside new cars may contain vinyl chloride at higher
levels because vinyl chloride may outgas into the air from the
new plastic parts
Drinking water may contain vinyl chloride released from
contact with polyvinyl pipes.
Vinyl chloride is a microbial degradation product of
trichloroethylene in groundwater
Tobacco smoke also contains vinyl chloride.
7. Major Human Heath Risks
Carcinogen especially to the liver and kidney
Teratogen
Damages the
Central Nervous System
"vinyl chloride disease"
Causes irritation to the eyes
and respiratory tract
high exposure has caused loss of
consciousness, lung and kidney
irritation, and inhibition of blood
clotting in humans and cardiac
arrhythmias in animals.
8. Formosa Plastics Vinyl Chloride Explosion
“On April 23, 2004, five workers were fatally injured and two others were
seriously injured….The explosion followed a release of highly flammable
vinyl chloride, which ignited. The explosion forced a community evacuation
and lighted fires that burned for several days at the plant.”
-Accident Description by the Chemical Safety Board
(video with more on this example on the CSB’s website)
