2,3,7,8-Tetrachlorodibenzofuran

2,3,7,8-Tetrachlorodibenzofuran
Names
	Preferred IUPAC name 2,3,7,8-Tetrachlorodibenzo[b,d]furan
	Other names 2,3,7,8-Tetrachlorodibenzofuran; 2,3,7,8-Tetrapolychlorinated dibenzofuran;
Identifiers
CAS Number	51207-31-9 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL136710;
ChemSpider	36507;
ECHA InfoCard	100.223.045
KEGG	C18104;
PubChem CID	39929;
CompTox Dashboard (EPA)	DTXSID3052147 ;
	InChI InChI=1S/C12H4Cl4O/c13-7-1-5-6-2-8(14)10(16)4-12(6)17-11(5)3-9(7)15/h1-4H Key: KSMVNVHUTQZITP-UHFFFAOYSA-N;
	SMILES ClC1=C(Cl)C=C2C(OC3=CC(Cl)=C(Cl)C=C23)=C1;
Properties
Chemical formula	C12H4Cl4O
Molar mass	305.96 g·mol−1
Appearance	Colorless Crystals
Melting point	227 °C (441 °F; 500 K)
Solubility in water	6.92×10−7 mg/mL at 26 °C (79 °F; 299 K)
Hazards
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	5–10 μg/kg (guinea pig, iv); >1 mg/kg (rat, iv); >6 mg/kg (mouse, iv); 1 mg/kg (monkey, iv);
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

2,3,7,8-Tetrachlorodibenzofuran (TCDF) is a polychlorinated dibenzofuran with a chemical formula of C₁₂H₄Cl₄O. TCDF is part of the chlorinated dibenzofuran (CDF) family that contains between 1 and 8 chlorine atoms attached to the parent dibenzofuran ring system. The CDF family includes 135 compounds, of which only a few have been studied.

TCDF was discovered in the mid-20th century along with other CDFs. It was found to be an unwanted by-product in the manufacturing of chlorinated compounds; it is not commercially used or produced itself. TCDF is directly released into the environment via emissions of waste incineration, fires of transformers with PCB oil, vehicle exhausts using leaded fuel, and bleaching of industrial products.

TCDF and other CDFs are known to have a lasting impact on the environment. It can exist as both a gas and as particles in the atmosphere, which results in deposition in the soil. It has an estimated half-life of around 60 days in the environment. The molecule can easily accumulate in the food chain, leading to potential human exposure. TCDF is listed as a hazardous air pollutant in the Clean Air Act of the 1990s. Monitoring programs are established to keep track of the levels on TCDF in various environmental compartments to avoid damaging ecosystems.