2,3,7,8-Tetrachlorodibenzodioxin

See also: Dioxins and dioxin-like compounds

2,3,7,8-Tetrachlorodibenzodioxin
Names
Preferred IUPAC name
2,3,7,8-Tetrachlorooxanthrene
Other names
2,3,7,8-Tetrachlorodibenzo[b,e][1,4]dioxine
Tetradioxin
Tetrachlorodibenzodioxin
Tetrachlorodibenzo-p-dioxin
Identifiers
3D model (JSmol)
Abbreviations TCDD; TCDBD
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.015.566 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C12H4Cl4O2/c13-5-1-9-10(2-6(5)14)18-12-4-8(16)7(15)3-11(12)17-9/h1-4H checkY
    Key: HGUFODBRKLSHSI-UHFFFAOYSA-N checkY
  • InChI=1/C12H4Cl4O2/c13-5-1-9-10(2-6(5)14)18-12-4-8(16)7(15)3-11(12)17-9/h1-4H
    Key: HGUFODBRKLSHSI-UHFFFAOYAA
  • ClC1=C(Cl)C=C2OC(C=C(C(Cl)=C3)Cl)=C3OC2=C1
Properties
C12H4Cl4O2
Molar mass 321.96 g·mol−1
Appearance Colorless to white crystalline solid[1]
Density 1.8 g/cm3
Melting point 305 °C (581 °F; 578 K)
0.2 μg/L[2]
log P 6.8
Vapor pressure 1.5 × 10−9 mmHg
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Potent carcinogen and persistent organic pollutant.[1]
GHS labelling:
GHS02: Flammable GHS06: Toxic GHS08: Health hazard GHS09: Environmental hazard
Danger
H225, H304, H315, H336, H361, H373, H401, H410
P201, P202, P210, P233, P240, P241, P242, P243, P260, P264, P271, P273, P280, P301+P310, P303+P361+P353, P304+P340+P312, P308+P313, P331, P332+P313, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
4
1
0
Flash point 164.2 °C (327.6 °F; 437.3 K)
NIOSH (US health exposure limits):
PEL (Permissible)
 none[1]
REL (Recommended)
 Ca[1]
IDLH (Immediate danger)
 N.D.[1]
Safety data sheet (SDS) MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a polychlorinated dibenzo-p-dioxin (sometimes shortened, though inaccurately, to simply 'dioxin')[3] with the chemical formula C12H4Cl4O2. Pure TCDD is a colorless solid with no distinguishable odor at room temperature. It is usually formed as an unwanted product in burning processes of organic materials or as a side product in organic synthesis.

TCDD is the most potent compound (congener) of its series (polychlorinated dibenzodioxins, known as PCDDs or simply dioxins) and became known as a contaminant in Agent Orange, an herbicide used in the Vietnam War.[4] TCDD was released into the environment in the Seveso disaster.[5] It is a persistent organic pollutant.

  1. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0594". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ Shiu WY; et al. (1988). "Physical-chemical properties of chlorinated dibenzo-p-dioxins". Environ Sci Technol. 22 (6): 651–658. Bibcode:1988EnST...22..651S. doi:10.1021/es00171a006. S2CID 53459209.
  3. ^ Tuomisto, Jouko (2019) Dioxins and dioxin-like compounds: toxicity in humans and animals, sources, and behaviour in the environment. WikiJournal of Medicine 6(1): 8 | https://doi.org/10.15347/wjm/2019.008
  4. ^ Schecter A, Birnbaum L, Ryan JJ, Constable JD (2006). "Dioxins: an overview". Environ. Res. 101 (3): 419–28. Bibcode:2006ER....101..419S. doi:10.1016/j.envres.2005.12.003. PMID 16445906.
  5. ^ M.H. Sweeney; P. Mocarelli (2000). "Human health effects after exposure to 2,3,7,8- TCDD". Food Addit. Contam. 17 (4): 303–316. doi:10.1080/026520300283379. PMID 10912244. S2CID 11814994.