Octachlorodibenzodioxin

Octachlorodibenzodioxin
Names
	Preferred IUPAC name Octachlorooxanthrene
	Other names OCDD, Octachlorodibenzo-p-dioxin
Identifiers
CAS Number	3268-87-9 ;
3D model (JSmol)	Interactive image;
ChemSpider	17598 ;
ECHA InfoCard	100.223.031
PubChem CID	18636;
UNII	YW59P10266 ;
CompTox Dashboard (EPA)	DTXSID4025799 ;
	SMILES ClC1=C2C(OC(C(Cl)=C(Cl)C(Cl)=C3Cl)=C3O2)=C(Cl)C(Cl)=C1Cl;
Properties
Chemical formula	C12Cl8O2
Molar mass	459.75 g/mol
Related compounds
Related Polychlorinated dibenzodioxins	Tetrachlorodibenzodioxin
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Octachlorodibenzodioxin (can be abbreviated as OCDD or OctaCDD) is one of polychlorinated dibenzodioxins (PCDDs).

Its toxicity is similar to TCDD, but it is about 3000 times weaker.^[1]

It is one of the dominant dioxin congeners in smoke emissions, but because it is much less soluble than e.g. TCDD, it is not bioaccumulated as effectively and it is toxicologically less important than the most prevalent dioxins.
(for details see Dioxins and dioxin-like compounds).

Chlorinated pesticides can also contain impurities of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and their precursors. "Precursor formation of PCDD/Fs can also be mediated by ultraviolet light (UV)" from sun (OCDD mostly). Changes in congeners ratio after UV exposition suggest that pesticide sources of dioxines-like after sunlight exposure "may not be recognized based on matching source fingerprints established from manufacturing impurities. These changes also provide preliminary insights into the possible formation routes and types of precursors involved".^[2]

References

^ M. Van den Berg, L.S. Birnbaum, M. Denison, M. De Vito, W. Farland, M. Feeley, H. Fiedler, H. Hakansson, A. Hanberg, L. Haws, M. Rose, S. Safe, D. Schrenk, C. Tohyama, A. Tritscher, J. Tuomisto, M. Tysklind, N. Walker, R.E. Peterson, The 2005 World Health Organization reevaluation of human and mammalian toxic equivalency factors for dioxins and dioxin-like compounds, Toxicol. Sci. 93 (2006) 223–241.
^ Holt, E., Weber, R., Stevenson, G., & Gaus, C. (2012) Formation of dioxins during exposure of pesticide formulations to sunlight. Chemosphere, 88(3), 364-370.

[1] M. Van den Berg, L.S. Birnbaum, M. Denison, M. De Vito, W. Farland, M. Feeley, H. Fiedler, H. Hakansson, A. Hanberg, L. Haws, M. Rose, S. Safe, D. Schrenk, C. Tohyama, A. Tritscher, J. Tuomisto, M. Tysklind, N. Walker, R.E. Peterson, The 2005 World Health Organization reevaluation of human and mammalian toxic equivalency factors for dioxins and dioxin-like compounds, Toxicol. Sci. 93 (2006) 223–241.

[2] Holt, E., Weber, R., Stevenson, G., & Gaus, C. (2012) Formation of dioxins during exposure of pesticide formulations to sunlight. Chemosphere, 88(3), 364-370.

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