Polychlorinated dibenzofurans (
PCDFs) are a family of
organic compounds with one or several of the hydrogens in the dibenzofuran structure replaced by chlorines. For example, 2,3,7,8-tetrachlorodibenzofuran (TCDF) has
chlorine atoms substituted for each of the hydrogens on the number 2, 3, 7, and 8 carbons (see structure in the upper left corner of the second image). Polychlorinated dibenzofurans are much more
toxic than the parent compounds, with properties and chemical structures similar to
polychlorinated dibenzodioxins. These groups together are often inaccurately called
dioxins. They are known
teratogens,
mutagens, and suspected human
carcinogens. PCDFs tend to co-occur with
polychlorinated dibenzodioxins (PCDDs). PCDFs can be formed by
pyrolysis or incineration at temperatures below 1200 °C of chlorine containing products, such as
PVC,
PCBs, and other
organochlorides, or of non-chlorine containing products in the presence of chlorine donors. Dibenzofurans are known
persistent organic pollutants (POP), classified among the
dirty dozen in the
Stockholm Convention on Persistent Organic Pollutants.