Vinyl chloride is primarily used to make polyvinyl chloride, better known as PVC, one of the most widely produced plastics in the world. Global production reached roughly 47 million tonnes in 2022, and nearly all of it goes toward manufacturing PVC products that show up in construction, healthcare, consumer goods, and packaging. On its own, vinyl chloride is a colorless gas with a faintly sweet odor. It becomes useful only after being chemically linked into long chains to form the rigid or flexible plastic we encounter daily.
How Vinyl Chloride Becomes PVC
Vinyl chloride starts as two common industrial chemicals: ethylene (derived from oil or natural gas) and chlorine. In the most common method, called direct chlorination, ethylene reacts with chlorine gas to form an intermediate compound. That intermediate is then heated until it breaks apart, releasing vinyl chloride and hydrochloric acid as a byproduct. A second process, called oxychlorination, recycles that leftover hydrochloric acid by combining it with more ethylene and oxygen to produce additional vinyl chloride. Together, these two reactions make the manufacturing loop relatively efficient.
Once produced, vinyl chloride molecules are polymerized, meaning they’re bonded together into long molecular chains, creating PVC resin. Manufacturers then mix in various additives to make the final plastic either rigid or soft, depending on the intended product.
Construction and Building Materials
Construction is the single largest destination for PVC. The rigid form of the plastic is extruded into pipes of various diameters used to carry drinking water to buildings, route sewage and wastewater away, and handle drainage and venting inside structures. PVC pipe is also a standard choice for HVAC ductwork, air conditioning lines, and exhaust ventilation systems because it resists corrosion and holds up in moist environments.
Outside the plumbing system, PVC shows up as vinyl siding on houses, window frames, and door frames. These products are popular because they don’t rot, resist mold and algae growth, and require little maintenance compared to wood. Vinyl flooring, fencing, and rain gutters round out the list of common construction applications. By some industry estimates, building and construction products account for more than half of all PVC produced worldwide.
Medical and Healthcare Products
Flexible, medical-grade PVC is used to make IV tubing, blood bags, dialysis tubing, catheters, and respiratory equipment like oxygen masks and breathing tubes. PVC works well in healthcare settings because it can be sterilized, it’s transparent enough for visual monitoring of fluid flow, and it’s inexpensive to produce in single-use form. The flexibility comes from plasticizers blended into the resin during manufacturing, which allow otherwise rigid PVC to bend and conform to the body.
Consumer and Household Goods
PVC turns up in a surprisingly wide range of everyday products. Shower curtains, upholstery, raincoats, and garden hoses are all common examples. Credit cards and ID cards are typically made from PVC sheets. Children’s toys, binders, backpacks, and other school supplies often contain PVC as well. Electrical cable insulation is another major use: the plastic’s natural resistance to fire and its insulating properties make it a standard sheathing material for wiring in homes and commercial buildings.
Packaging is a smaller but notable market. PVC film wraps food trays, and rigid PVC forms the clear clamshell packaging used for electronics and retail products.
Health Risks of Vinyl Chloride Exposure
While PVC products themselves are stable under normal conditions, vinyl chloride in its raw gas form is a known human carcinogen. Workers at production facilities face the greatest risk, primarily through inhaling the gas. Long-term occupational exposure is linked to a rare liver cancer called hepatic angiosarcoma, along with increased risk of other liver cancers, brain and lung cancers, lymphoma, and leukemia. The National Cancer Institute identifies vinyl chloride as a confirmed cancer-causing substance.
Because of these risks, OSHA limits workplace exposure to no more than 1 part per million averaged over an eight-hour shift, with a ceiling of 5 ppm over any 15-minute period. The action level that triggers employer monitoring and medical surveillance is even lower, at 0.5 ppm.
What Happens When It Enters the Environment
Vinyl chloride doesn’t persist in the open air for long. Sunlight-driven reactions break it down with a half-life of roughly one to two days under normal conditions. In areas with smog and higher concentrations of nitrogen oxides, that half-life can drop to just a few hours.
In soil, the gas tends to evaporate quickly. Dry soil at a shallow depth can lose half its vinyl chloride in about 12 hours through a combination of evaporation and breakdown by soil microbes. Under aerobic conditions, about 25% degrades within a week, and more than 99% is gone within about four months. The bigger concern is groundwater. Vinyl chloride dissolves in water and can leach through soil before it has a chance to evaporate, potentially contaminating underground water supplies. Once trapped in groundwater with limited oxygen, it degrades much more slowly, which is why vinyl chloride contamination at industrial sites and chemical spills can remain a problem for years.
This groundwater risk is exactly what drew national attention during events like the 2023 train derailment in East Palestine, Ohio, where large quantities of vinyl chloride were released and burned. For communities near such incidents, the primary concern is whether the chemical reached local water sources before it could break down naturally.