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Industry
Companies in the U.S. began limited VCM
manufacturing in the 1920s. Commercial production of VCM began in the 1930s.
Throughout the sixties, seventies, eighties and nineties, the VCM and PVC
industry enjoyed immense growth and prosperity.
VCM is manufactured by the relatively simple
process of heating ethylene dichloride (EDC) to around 700°F in the presence of
oxygen. VCM is manufactured in a relatively small number of plants that are
almost entirely located along the gulf coast in Texas and Louisiana. VCM is
used almost exclusively in the manufacture of various types of polyvinyl
chloride (PVC) resins at PVC resin plants located across the United States, but
again, primarily in Texas and Louisiana using, again, a relatively simple
manufacturing process called polymerization.
VCM is charged to large polymerization reactors
that are often referred to as "polys" or PVC "kettles."
Since the polymerization process never consumes all of the available VCM,
varying amounts of VCM remain trapped in every form of PVC resin and in every
finished product fabricated from PVC resins. As a result, this residual vinyl
chloride monomer (RVCM) is present in varying quantities in all raw PVC resin
and in all finished PVC products until it is liberated into the atmosphere by
"off-gassing" or migrates into food, drink, or other substances
stored in containers made of PVC as well as various types of food wraps, etc.
The potential adverse health effects associated with consumer product exposures
are predictable but, because of the relatively low levels involved and the
ubiquity of such exposures, difficult or impossible to demonstrate empirically
in human beings. However, given animal studies and biological considerations,
RVCM almost certainly poses a significant risk to human beings even at
exceedingly low levels, notwithstanding industry propaganda to the contrary.
However, the potential health risks posed by PVC products is not at all limited
even to the millions of workers involved in fabricating PVC products but extends
to everyone who is exposed to vinyl products, meaning virtually everyone.
From the PVC plant, raw PVC resin is bagged and
shipped to a large number, perhaps hundreds, of compounding facilities where
the raw PVC resin is compounded with other chemicals. Most resin, however, is
shipped by rail and tank truck to thousands of PVC fabrication plants where
fabrication workers melt or mold the PVC resin and process it to make consumer
goods. In the course of product fabrication, millions of American workers are
occupationally exposed to significant levels of vinyl chloride, although the
vinyl industry would have us believe that only those workers directly involved
in the manufacture of VCM or PVC resin are at risk for occupational diseases
caused by vinyl chloride exposure. Even
the limited studies that have been conducted demonstrate a clear occupational
health hazard for these "downstream" vinyl workers involved in
melting, molding, extruding, and calendaring PVC into "thousands of useful
finished PVC products."
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