Polychlorinated dibenzofurans


More thorough treatise of all groups with similar actions and binding to aryl hydrocarbon reeceptor is given in Dioxins and dioxin-like compounds.
Polychlorinated dibenzofurans 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 has chlorine atoms substituted for each of the hydrogens on the number 2, 3, 7, and 8 carbons. Polychlorinated dibenzofurans with chlorines at least in positions 2,3,7 and 8 are much more toxic than the parent compound dibenzofurane, with properties and chemical structures similar to polychlorinated dibenzodioxins. These groups together are often inaccurately called dioxins. They are known developmental toxicants, and suspected human carcinogens. PCDFs tend to co-occur with polychlorinated dibenzodioxins. 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, classified among the dirty dozen in the Stockholm Convention on Persistent Organic Pollutants.

Safety, toxicity, regulation

Occupational exposure to PCDFs may occur through inhalation and contact with the skin, although intake even in workers at waste incineration plants are not particularly high. For general population the most important source is food of animal origin like with other dioxin-like compounds. The most relevant congener is 2,3,4,7,8-pentachlorodibenzofuran which is more toxic and based on relative toxicity more prevalent than other PCDFs.

Further resources