Product Safety Assessment: Vinyl Chloride Monomer
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Physical Hazard Information
- Occupational exposure is dependent upon the conditions under which VCM is used. VCM is manufactured in closed systems. Using a closed process reduces environmental releases and lowers worker exposure to VCM. Workplace exposure is tightly controlled in the U.S. and other European countries.3 See Exposure Potential
- Capacity – Global capacity for VCM was about 76 billion pounds (35 million metric tons) in 2005. The Dow Chemical Company and its consolidated subsidiaries (“Dow”) are one of the largest producers of VCM in the world. Dow has VCM manufacturing facilities in Freeport, Texas, Plaquemine, Louisiana, and Schkopau, Germany. A VCM manufacturing facility located in Fort Saskatchewan, Alberta, Canada, was shut down in 2006. Dow has roughly 5.1 billion pounds (2.4 million metric tons) of VCM capacity at the remaining facilities6
- Process7 – VCM is produced by Dow by cracking ethylene dichloride (EDC). EDC is produced by the chlorination of ethylene through one of two processes: direct chlorination or oxychlorination. The direct chlorination process reacts ethylene with chlorine, while oxychlorination reacts ethylene with dry hydrogen chloride and oxygen, to produce EDC, as shown in the process diagram.
VCM is a colorless, flammable, and highly volatile gas at room temperature. Its boiling point is 7.9ºF (-13.4ºC). Under pressure, as it is often stored, it is a liquid. VCM has a very high evaporation rate.8
Nearly all VCM is converted into PVC or vinyl copolymers. PVC is among the largest volume plastics produced around the world.9,10 PVC is used in:
- Construction - for siding, water distribution, irrigation and sewer pipe, wire and cable insulation, electrical conduit, floor and wall coverings, window frames, gutters and downspouts, single-ply roofing, landfill liners, piping used in food processing, chemical processing and other manufacturing, fire-sprinkler piping and fencing11
- Medical - for blood and intravenous bags, kidney dialysis and blood transfusions, cardiac catheters, endotracheal tubes, artificial heart valves and many others12
- Automotive - for body side moldings, windshield system components, interior upholstery, under-the-hood wiring, under-the-car abrasion coatings, floor mats, adhesives, sealants, and other components such as dashboards and arm rests13
- Electronics - for air conditioners, floppy disks, components, housings, keyboards, phone systems, computers, power tools, electrical cords, refrigerators, fiber optics, washers14
- Toys - for rigid and flexible parts
- Packaging - for flexible food wrap, shrink wrap, jar lids and can linings; and for rigid blister and clamshell packaging, and bottles to store household, personal care products, and automotive lubricants15
VCM is used in the production of PVC which is then used to manufacture a number of industrial and consumer products. Based on the uses for VCM, the public could be exposed through:
- Workplace exposure – Exposure can occur either in a VCM manufacturing facility or in the various industrial or manufacturing facilities that use VCM. Industry uses closed systems to produce PVC. This reduces environmental releases and lowers worker exposure to VCM. Manufacturers also use a combination of engineering controls and work practices to minimize exposure to VCM.16 Each manufacturing facility should have a thorough training program for employees, appropriate work processes and safety equipment in place to limit VCM exposure. In the U.S., there is an Occupational Safety and Health Administration (OSHA) standard, 29 CFR 1910.1017, in place that states requirements, including personal protective equipment, medical surveillance, and training. See Health Information, Regulatory Information and the Safety Data Sheet ( SDS ) for more detailed information.
- Consumer exposure to products containing VCM – Dow does not sell VCM for direct consumer use, but it is used as a raw material to make PVC, which is used in many consumer applications. Residual or unreacted quantities of monomers, including VCM, in PVC are analyzed and tightly controlled to maintain levels below regulatory limits.17 See Health Information.
- Environmental releases – In the event of a spill, the focus is on containing the spill to prevent contamination of soil, surface or ground water. Respiratory protection is necessary for cleaning up spills and leaks. VCM may be fatal if inhaled and it is extremely flammable. Eliminate all sources of ignition immediately. Keep upwind of spill and warn public of downwind explosion hazard. Vapors may travel a long distance and ignition and/or flashback may occur. Consult the relevant SDS for more information about protective equipment and procedures. See Environmental, Health and Physical Hazard Information.
- Large release – Industrial spills or releases are infrequent and are generally contained. If a large spill does occur, the material should be captured, collected and re-processed, or disposed of according to applicable governmental requirements. VCM is stored and produced in a closed system. A positive pressure, self-contained breathing apparatus (SCBA) with a full-face mask approved by NIOSH is recommended for emergency work. Eliminate all sources of ignition immediately. Use only explosion-proof equipment; ground and bond all containers and handling equipment. The public should be warned of down-wind vapor explosion hazards. Vapors are heavier than air and may travel a long distance and accumulate in low lying areas. Keep vapors out of sewers. Immediately withdraw all personnel from the area in case of rising sounds from venting safety device or discolorations of the container. Elevated temperatures can cause hazardous polymerization. Follow emergency procedures carefully. See Environmental, Health and Physical Hazard Information.
Using VCM improperly can lead to exposure. Brief exposure (minutes) to easily attainable vapor concentrations of VCM may cause serious adverse effects, even death. Symptoms of excessive exposure may be anesthetic or narcotic effects, dizziness, drowsiness or central nervous system effects.
Because VCM is a vapor at room temperature, the primary route of exposure is by inhalation. Ingestion is unlikely. VCM is rapidly absorbed following inhalation or oral exposure, and is bioactivated by the liver. VCM has caused cancer in humans and in laboratory animals – in particular, the liver. Repeated exposures can also affect the kidneys and lungs, and produce changes in bone, skin and the vascular system, particularly in the extremities of the body.
Human and animal studies show no effects on reproduction or birth defects except at levels toxic to the mother. VCM levels that were toxic to the mother were also toxic to the fetus in lab animals.
VCM stored under pressure or at low temperatures can be a liquid. Skin and eye contact with liquid or gaseous VCM can cause frostbite.
For specific health information, review the SDS.
Environmental releases of VCM are almost exclusively to the air because of the high vapor pressure. VCM has a low bioaccumulation potential because it biodegrades in the atmosphere with a half-life of 23 hours.20 VCM is practically non-toxic to fish on an acute basis.21
Atmospheric, groundwater, drinking water and environmental monitoring have shown VCM levels in the parts per million to parts per billion range, with most readings below the detection limit.22
For specific environmental information, review the SDS.
VCM is an extremely flammable vapor and liquid. Vapors are heavier than air and may travel a long distance and accumulate in low lying areas. Ignition and/or flash back may occur.
When VCM is stored in closed containers, a flammable atmosphere can develop. Flammable mixtures of VCM are readily ignited even by static discharge. Electrically ground and bond all equipment.
Alcohol resistant foams are preferred as preferred extinguishing media. Water may not be effective in extinguishing fire, and direct water streams may spread fire.
Emergency personnel and firefighters should wear positive-pressure self-contained breathing apparatus (SCBA) and protective fire fighting clothing. The smoke may contain VCM, hydrogen chloride, carbon monoxide, carbon dioxide and, in trace amounts, phosgene.
Although VCM is stable under recommended storage conditions, hazardous polymerization can occur at elevated temperatures. Polymerization can be catalyzed by air, free radical initiators, moisture, oxygen and sunlight.
Incompatible materials include:
- Air, moist air and oxygen
- Strong oxidizers
- Metals like aluminum, aluminum alloys and copper
Thermal decomposition products of VCM depend upon temperature, air supply and the presence of other materials. Avoid temperatures above 752ºF (400ºC). Decomposition products can include hydrogen chloride and trace amounts of phosgene.
Additional physical property information for VCM is available on the SDS.
Regulations may exist that govern the manufacture, sale, transportation, use and/or disposal of VCM. These regulations may vary by city, state, country or geographic region. Information may be found by consulting the relevant Safety Data Sheet or Contact Us.
In particular, the U.S. OSHA standard, 29 CFR 1910.1017, outlines occupational requirements, including personal protective equipment, medical surveillance, and training.
- Safety Data Sheet ( http://www.dow.com/webapps/msds/msdssearch.aspx )
- The Vinyl Institute ( http://www.vinylinfo.org )
- OECD SIDS Initial Assessment Report for SIAM 13 ( http://www.chem.unep.ch/irptc/sids/OECDSIDS/VINYLCHL.pdf )
- VCM Safety & Handling Evaluation Guideline (Dow Form No. 102-00512-0605)
- Toxicological Profile for Vinyl Chloride, U.S. Department of Health and Human Services Public Health Service, Agency for Toxic Substances and Disease Registry http://www.atsdr.cdc.gov/toxprofiles/tp20.html )
For more information about VCM, contact Dow’s Customer Information Group.
Last updated: January 12, 2007
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|1||OECD SIDS Initial Assessment Report for SIAM 13, ( www.chem.unep.ch/irptc/sids/OECDSIDS/VINYLCHL.pdf ), United Nations Environment Programme (UNEP), November 6-9, 2001, page 5.|
|2||Vinyl Chloride Monomer Material Safety Data Sheet, No. 12614, August 11, 2006, page 4.|
|3||OECD SIDS Initial Assessment Report for SIAM 13, ( www.chem.unep.ch/irptc/sids/OECDSIDS/VINYLCHL.pdf ), United Nations Environment Programme (UNEP), November 6-9, 2001, page 3.|
|4||VCM Safety & Handling Evaluation Guideline, The Dow Chemical Company, Form No. 102-00512-0605.|
|5||Vinyl Chloride Monomer Material Safety Data Sheet, No. 12614, August 11, 2006, page 1.|
|6||Chemical Economics Handbook Report Vinyl Chloride Monomer (VCM), SRI Consulting, July 2006, pages 4, 10, 11, and 20.|
|7||Toxicological Profile for Vinyl Chloride, U.S. Department of Health and Human Services Public Health Service, Agency for Toxic Substances and Disease Registry, Atlanta, GA, November 2, 2006, page 163.|
|8||Vinyl Chloride Monomer Material Safety Data Sheet, No. 12614, August 11, 2006, pages 1-4.|
|9||The Vinyl Institute; www.vinylinfo.org/aboutvi/vi_commitment2.html|
|10||OECD SIDS Initial Assessment Report for SIAM 13, ( www.chem.unep.ch/irptc/sids/OECDSIDS/VINYLCHL.pdf ), United Nations Environment Programme (UNEP), November 6-9, 2001, page 6.|
|11||The Vinyl Institute; www.vinylinfo.org/infiniteuses/construction/construction.html|
|12||The Vinyl Institute; www.vinylinfo.org/infiniteuses/medical/medical.html|
|13||The Vinyl Institute; www.vinylinfo.org/infiniteuses/automotive/automotive.html|
|14||The Vinyl Institute; www.vinylinfo.org/infiniteuses/electronic/electronic.html|
|15||The Vinyl Institute; www.vinylinfo.org/packaging.html|
|16||The Vinyl Institute; www.vinylinfo.org/aboutvi/vi_commitment2.html|
|17||Why Vinyl is a Leading Material for the Toy Industry brochure, The Vinyl Institute, www.vinylinfo.org/publicationscenter/toy.pdf|
|18||Vinyl Chloride Monomer Material Safety Data Sheet, No. 12614, August 11, 2006, pages 1-2.|
|19||OECD SIDS Initial Assessment Report for SIAM 13, ( www.chem.unep.ch/irptc/sids/OECDSIDS/VINYLCHL.pdf ), United Nations Environment Programme (UNEP), November 6-9, 2001, page 3.|
|20||Vinyl Chloride Monomer Material Safety Data Sheet, No. 12614, August 11, 2006, pages 5-6.|
|21||Vinyl Chloride Monomer Material Safety Data Sheet, No. 12614, August 11, 2006, pages 3, 5-6.|
|22||OECD SIDS Initial Assessment Report for SIAM 13, ( www.chem.unep.ch/irptc/sids/OECDSIDS/VINYLCHL.pdf ), United Nations Environment Programme (UNEP), November 6-9, 2001, pages 4 and 8.|
|23||Vinyl Chloride Monomer Material Safety Data Sheet, No. 12614, August 11, 2006, pages 1-5.|