http://www.cfsan.fda.gov/~lrd/dioxinqa.html
Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration
Dioxins refers to a group of chemical compounds that share certain chemical structures and biological characteristics. Dioxins are formed as a result of combustion processes such as commercial or municipal waste incineration and from burning fuels (like wood, coal or oil). This document answers questions about dioxins, including food safety and risk assessment.