More thorough treatise of all groups with similar actions and binding to aryl hydrocarbon receptor is given in Dioxins and dioxin-like compounds. 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 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 Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of long-lived polyhalogenated compound, polyhalogenated organic compounds that are primarily anthropogenic, and contribute toxic, Persistent organic pollutant, persistent org ...

. These groups together are often inaccurately called

dioxin Dioxin may refer to: * 1,2-Dioxin or 1,4-Dioxin, two unsaturated heterocyclic 6-membered rings where two carbon atoms have been replaced by oxygen atoms, giving the molecular formula C4H4O2 *Dibenzo-1,4-dioxin, the parent compound also known as ...

s. They are known developmental toxicants, and suspected human carcinogens. PCDFs tend to co-occur with

polychlorinated dibenzodioxin Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of long-lived polyhalogenated organic compounds that are primarily anthropogenic, and contribute toxic, persistent organic pollution in the environment. They are commonly ...

s (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 Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed on 22 May 2001 in Stockholm and effective from 17 May 2004, that aims to eliminate or restrict the production and use of persistent organic ...

Congeners

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.Tuomisto J (2019). Dioxins and dioxin-like compounds: toxicity in humans and animals, sources, and behaviour in the environment. WikiJournal of Medicine 6 (1): 8. doi:10.15347/wjm/2019.008. ISSN 2002-4436.Congener-Specific Levels of Dioxins and Dibenzofurans in U.S. Food and Estimated Daily Dioxin Toxic Equivalent Intake. The National Institute of Environmental Health Sciences (NIEHS). The most relevant congener is 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PCDF) which is more toxic and based on relative toxicity more prevalent than other PCDFs.

References

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Further resources

Synopsis on dioxins and PCBs

Chemical Profile: DIBENZOFURANS (CHLORINATED)

Chloroarenes Incineration Immunotoxins Dibenzofurans Persistent organic pollutants under the Convention on Long-Range Transboundary Air Pollution Persistent organic pollutants under the Stockholm Convention

Congeners

Safety, toxicity, regulation

See also

References

Further resources