The vinyl industry claims it is greening its products, but the manufacture, use and disposal of PVC still poses significant environmental and health issues.
POLYVINYL CHLORIDE, OR PVC, is ubiquitous in the building industry. Versatile and cheap, it’s found in nearly every part of the building, from roofing membrane, siding and floor coverings to electrical wiring and plumbing.
The vinyl industry has been attempting to clean up its act, with claims of new, less toxic formulations, reduced emissions during production and increased recycling rates. In light of these claims, architecture firm Perkins+Will, in cooperation with the non-profit Healthy Building Network, compiled a report called Healthy Environments: What’s New (and What’s Not) With PVC. Published in November 2015, the purpose of the study was to present information on the environmental and health hazards of PVC, and to determine if the vinyl industry’s claims have rendered the material safe enough to remove it from the Precautionary List, a group of 25 chemicals for which Perkins+Will says there are preferred alternatives.
The report acknowledges that the industry has taken steps to reduce the toxicity of vinyl. Harmful additives, such as lead-based stabilizers and phthalate plasticizers, are being replaced by more benign chemicals. But the report concludes that, despite these improvements, the fundamental hazards of PVC remain, and that healthier alternatives exist for many PVC products (see chart). Here are some highlights from the report:
A Problematic Life Cycle
PVC is a chlorinated plastic that poses environmental and health concerns in all phases of its life cycle. Here are some of the biggest concerns:
Mercury Pollution. PVC is made by reacting chlorine with ethylene. In the past, chlorine was extracted from salt water using mercury cells, which released mercury, a persistent pollutant, into the environment. Although this technology is being phased out, it is still widely used in China—the source of many vinyl building products.
Dioxin Emissions. The manufacture of PVC releases dioxins, a potent and persistent carcinogen. The Vinyl Institute claims the industry has reduced dioxin emissions by 82 percent since 2000; however, an analysis of data reported to the EPA from the industry shows that neither rates of production nor dioxin emissions have not changed substantially in the last 15 years.
Vinyl Chloride Monomer (VCM). This potent human carcinogen is the precursor to polyvinyl chloride resins. In 2014 alone, vinyl chloride monomer and PVC manufacturers released 531,203 pounds of VCM into the air.
Use in Building
Additives. PVC products require additives to improve their stability and flexibility. In the past, these have included toxic lead or cadmium stabilizers and phthalate plasticizers. The additives are not tightly bound to the PVC resin; over time, they are released out of the plastic, where it can either be ingested or absorbed directly by the skin. The industry is replacing these harmful chemicals with “organotin” stabilizers and non-pthalate plasticizers; however, other potentially harmful additives such as halogenated flame retardants and antimicrobial compounds are still being used.
Toxic Emissions from Fires. When burned, PVC “creates carcinogenic dioxins, a mist of corrosive hydrochloric acid, and thick smoke.” This toxic brew threatens occupants, first responders and anyone else who might be exposed during a building fire.
End of Life
Upon disposal, PVC products pose a hazard to workers, people living near landfills and incinerators and the environment. When incinerated, PVC releases chlorine and forms dioxins; therefore, landfilling is a better alternative. However, accidental landfill fires are fairly common, and the EPA Dioxin Inventory estimates that they fires may represent a significant source of dioxin emissions.
Recycling Vinyl: A Long Way to Go
Finally, the report notes that only about one percent of PVC is currently recycled. Ironically, incorporating recycled vinyl in new vinyl products potentially introduces some of the hazardous substances the industry is trying to avoid. Lead, cadmium, triclosan and phthalates are among the hazardous substances found in older vinyl products. Several flooring companies are addressing this problem by limiting the sources of recycled PVC.
The majority of PVC products that do get recycled are sent to China, where they are commingled into one waste stream, and where untrained, unprotected and low-wage workers sift through the scrap by hand. Some PVC products are burned in open pits to separate valuable metals from the plastic.