| Compound Name |
2,3,7,8-Tetrachlorodibenzo-P-dioxin |
| Stockholm Annex code | III, IV |
| Key |
Annex I to the regulation are subject to prohibition (with specific exemptions) on manufacturing, placing on the market and use; Annex II to the regulation are subject to restriction on manufacturing, placing on the market and use; Annex III to the regulation are subject to release reduction provisions; and Annex IV to the regulation are subject to waste management provisions. Note that for some substances listed in Annex I, specific exemptions on the prohibition of their use, manufacturing and placing on the market may apply. |
| Classification |
Intentional |
| Category |
Listed under Annex C |
| Year of Listing Decision |
2001 |
| Persistence |
Blood serum from Ranch Hand veterans revealed that TCDD has a half-life of about 7 years |
| Specific exemptions associated with its use |
Production: None |
| Acceptable purposes associated with its use |
It was used as a herbicide |
| Conventions on POPs |
Stockholm Convention Convention on Long-Range Transboundary Air Pollution Rotterdam Convention Basel Convention |
| Name |
2,3,7,8-Tetrachlorodibenzo-P-dioxin |
| Synonyms |
Polychlorinated dibenzo-p-dioxins Dioxin (herbicide contaminant) Tetradioxin 2,3,7,8-Tetrachlorodibenzo-p-dioxin Tetrachlorodibenzodioxin Dibenzo[b,e][1,4]dioxin, 2,3,7,8-tetrachloro- 2,3,7,8-tetraclorodibenzo[b,e][1,4]dioxin 2,3,7,8-Tetrachlorodibenzo-1,4-dioxin Dioxin p-Dioxin Dibenzo-p-dioxin, 2,3,7,8-tetrachloro- Dibenzo[b,e][1,4]dioxin, 2,3,7,8-tetrachloro- |
| Structure | Cl)OC3=CC(=C(C=C3O2)Cl)Cl.png)
Molecular Formula:
C12H4Cl4O2
|
| CAS Number | 1746-01-6 |
| European Community (EC) Number | 217-122-7 |
| European Chemicals Agency (ECHA) | 217-122-7 |
| PubChem ID | 15625 |
| DSSTOX Substance ID | DTXSID2021315 |
| KEGG | C07557 |
| ChemSpider |
35060 35228 |
| Similarity threshold | Name of Related Compound | DSSTox Substance ID | CAS Number | Molecular weight | Molecular formula |
|---|---|---|---|---|---|
| 1.0 | 2,3-Dichlorodibenzo-4-dioxin | DTXSID50183650 | 29446-15-9 | 253 g/mol | C12H6Cl2O2 |
| 1.0 | 2,3,7-Trichlorodibenzo-p-dioxin | DTXSID7074878 | 33857-28-2 | 287 g/mol | C12H5Cl3O2 |
| 1.0 | Dibenzo(b,e)(1,4)dioxin, 2,3,7,8-tetra(chloro-37Cl)- | DTXSID40234721 | 85508-50-5 | 328 g/mol | C12H4Cl4O2 |
| 1.0 | Dibenzo(b,e)(1,4)dioxin-13C12, 2,3,7,8-tetrachloro- | DTXSID60227332 | 76523-40-5 | 333 g/mol | C12H4Cl4O2 |
| 0.97 | 2-Chlorodibenzo-4-dioxin | DTXSID90192488 | 39227-54-8 | 218 g/mol | C12H7ClO2 |
| 0.97 | 2,7-Dichlorodibenzo-p-dioxin | DTXSID1020435 | 33857-26-0 | 253 g/mol | C12H6Cl2O2 |
| 0.97 | 2,8-Dichlorooxanthrene | DTXSID70872019 | 38964-22-6 | 253 g/mol | C12H6Cl2O2 |
| 0.97 | 8-Hydroxy-2,3-dichlorodibenzo-p-dioxin | DTXSID50243228 | 97741-80-5 | 269 g/mol | C12H6Cl2O3 |
| 0.97 | Dibenzo(b,e)(1,4)dioxin, 2,3-dichloro-7-methoxy- | DTXSID00219817 | 69557-80-8 | 283 g/mol | C13H8Cl2O3 |
| 0.97 | Phenol, 4,5-dichloro-2-(3,4-dichlorophenoxy)- | DTXSID90476912 | 56858-69-6 | 323 g/mol | C12H6Cl4O2 |
| Description | Reference | Article Link |
|---|---|---|
| Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of polyhalogenated organic compounds that are significant environmental pollutants. They are commonly but inaccurately referred to as dioxins for simplicity, because every PCDD molecule contains a dibenzo-1,4-dioxin skeletal structure, with 1,4-dioxin as the central ring. Members of the PCDD family bioaccumulate in humans and wildlife because of their lipophilic properties, and may cause developmental disturbances and cancer. Dioxins occur as by-products in the manufacture of some organochlorides, in the incineration of chlorine-containing substances such as polyvinyl chloride (PVC), in the chlorine bleaching of paper, and from natural sources such as volcanoes and forest fires. | Wikipedia:Polychlorinated dibenzodioxins. Accessed 14 October 2020 | Link |
| The toxic potencies of the individual polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) congeners (“dioxins”) differ considerably. The congeners that are of toxicological importance are substituted in each of the 2-, 3-, 7-, and 8-positions. Thus,among the 210 theoretically possible congeners, only 17 are of toxicological concern. They have a toxicological profile similar to that of the most toxic congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The toxic responses include dermal toxicity, immunotoxicity, carcinogenicity, and reproductive and developmental toxicity. The toxicity is mediated via the arylhydrocarbon receptor (AhR) present in most tissues of animals and humans. Among the 209 theoretically possible polychlorinated biphenyl (PCB) congeners 12 non-ortho and mono-ortho substituted PCB show toxicological properties similar to 2,3,7,8-TCDD and are therefore termed dioxin-like PCB. Dioxins and PCB are lipophilic compounds. They are very resistant towards chemical and biological degradation processes and therefore persist in the environment, accumulate in food chains, and consequently end up in fatty tissues of animals and humans. | Larsen. 2006. Risk assessments of polychlorinated dibenzop-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in food | Link |
| Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are chlorinated tricyclic aromatic compounds and are emitted into the environment as unwanted by-products of anthropogenic processes. PCDD/Fs have been globally distributed and are found in all environmental media. They are chemically stable, have low solubilities in water, and have been shown to accumulate in the foodchain. Seventeen of the 210 PCDD/Fs (those with chlorines substituted in the 2,3,7,8 positions) are thought to pose a risk to human health risk due to their toxicity, carcinogenic potential and potential effects on animal reproductive and immunological systems. In terms of health effects and risk assessments, those PCDD/Fs not substituted in the 2,3,7,8 positions can be ignored. The most toxic isomer is 2,3,7,8-TCDD, and as a consequence most toxicological studies have concentrated on this. Animal studies on the toxic affect of 2,3,7,8-TCDD have shown that this isomer is fatal to certain species (e.g. the guinea pig) at very low levels. | Flecther and McKay. 1993. Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in the aquatic environment - A literature review | Link |
| The polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are two series of tricyclic aromatic compounds. PCDDs and PCDFs can loosely be described as chlorodibenzo derivatives of the basic chemical structures p-dioxin and furan, respectively. The number of chlorine atoms can vary between one and eight and there are many positional isomers with 75 PCDDs and 135 PCDFs, in the latter case, the large number is due to the asymmetry of the basic dibenzofuran molecule. The most extensively studied isomer is 2,3,7,8-TCDD. This isomer has a melting point of about 305°C and a boiling point of 421°C. 2,3,7,8-TCDD is lipophilic and is almost insoluble in water. The vapour pressure is very low and therefore it tends not to volatilize readily. | Skene et al., 1989. Polychlorinated Dibenzo- p-dioxins and Polychlorinated Dibenzofurans: The Risks to Human Health. A Review | Link |
| Dioxins include polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and part of polychlorinated biphenyls (PCBs). Only the compounds that are chlorinated at the 2,3,7 and 8 positions have characteristic dioxin toxicity. PCDDs, PCDFs and PCBs accumulate in the food chain due to their high lipophilicity, high stability, and low vapor pressure. They are not metabolized easily; however their hydroxylated metabolites are detected in feces. They cause a wide range of endocrine disrupting effects in experimental animals, wildlife, and humans. Endocrine related effects of PCDDs, PCDFs and PCBs on thyroid hormones, neurodevelopment and reproductive development were referenced. In addition, some studies of contamination of foods, bioaccumulation, dietary exposure assessment, as well as challenges of scientific research in these compounds were reviewed. | Fernández-González et al., 2013. A critical review about the human exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) through foods | Link |