What is dioxin? Is the vinyl industry a source of dioxin emissions?
The general term “dioxin” is used to refer to a family of chemicals which includes polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Dioxin is an unintended byproduct of incomplete combustion in the presence of chlorine. The identified sources of dioxin include incineration, forest fires, metals melting and certain industrial processes involving chlorine and other organic compounds. Research has shown dioxin to be toxic and carcinogenic to animals, and the International Agency for Research on Cancer(IARC) has classified one PCDD called “2,3,7,8-TCDD” as a known human carcinogen.(7) The U.S. Environmental Protection Agency (EPA) is in the process of conducting a complete review of current dioxin science, termed “dioxin reassessment.” When the EPA embarked on this reassessment in 1991, the vinyl industry offered to voluntarily study its own emissions of dioxin, according to EPA protocols and under the guidance of an independent third party panel of scie
