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General Description

  • Synonyms: Dioxin; Dioxine; TCDBD; TCDD; 2,3,7,8-TCDD
  • OSHA IMIS Code Number: 2326
  • Chemical Abstracts Service (CAS) Registry Number: 1746-01-6
  • NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: HP3500000
  • NIOSH Pocket Guide to Chemical Hazards, 2,3,7,8-Tetrachloro-dibenzo-p-Dioxin: chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

  • National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): Appendix A - NIOSH Potential Occupational Carcinogens

Health Factors

  • Carcinogenic Classification:
  • Potential Symptoms: Eye irritation; allergic dermatitis, chloracne; porphyria; headache; weakness; gastrointestinal disturbance; possible reproductive, teratogenic effects. In animals: liver, kidney damage; hemorrhage; endometriosis; developmental neurotoxicity; immunosuppression; endocrine disturbances, reproductive problems; [potential occupational carcinogen].
  • Health Effects: Known human carcinogen (HE2); Chronic toxicity---Chloracne, hyperlipidemia (HE3); Irritation-Eyes, nose, throat, skin---Moderate (HE15)
  • Affected Organs: Eyes, skin, liver, kidneys, reproductive system
  • Notes:
    1. The body burden LOAEL for chloracne has been estimated to be 160 ng/kg. A 2001 follow-up study of 12 workers who acquired TCDD-induced chloracne in the late 1960s indicated that two still had it.
    2. Up to 30 years or more following occupational exposure, high incidences of hyperlipidemia (cholesterol, triglycerides), ischaemic heart disease (atherosclerosis, thicker carotid wall and plaques, hypertension), and neuropsychological complaints (e.g., memory) have been reported.
    3. TCDD binds to the aryl hydrocarbon receptor (AhR) and, due to a very slow elimination in humans (half-life >7 years), this can lead to chronic activation of AhR-driven gene expression, including induction of several drug-metabolizing enzymes (e.g., CYP1A1, CYP1A2, CYP1B1, glutathione S-transferase, UDP-glucuronosyltransferase), which may bind TCDD (e.g., CYP 1A2) but do not metabolize it.
  • Literature Basis:
    • NIOSH Pocket Guide to Chemical Hazards: 2,3,7,8-Tetrachlorodibenzo-p-Dioxin.
    • International Chemical Safety Cards (WHO/IPCS/ILO): 2,3,7,8-Tetrachlorodibenzo-p-dioxin.
    • Cole, P., Trichopoulos, D., Pastides, H., Starr, T. and Mandel, J.S.: Dioxin and cancer: a critical review. Regul. Toxicol. Pharmacol. 38(3): 378-388, 2003.
    • Greene, J.F., Hays, S. and Paustenbach, D.: Basis for a proposed reference dose (RfD) for dioxin of 1-10 pg/kg-day: a weight of evidence evaluation of the human and animal studies. J. Toxicol. Environ. Health B Crit. Rev. 6(2): 115-159, 2003.
    • Inouye, K., Shinkyo, R., Takita, T., Ohta, M. and Sakaki, T.: Metabolism of polychlorinated dibenzo-p-dioxins (PCDDs) by human cytochrome P450-dependent monooxygenase systems. J. Agric. Food Chem. 50(19): 5496-5502, 2002.
    • Kakeyama, M. and Tohyama, C.: Developmental neurotoxicity of dioxin and its related compounds. Ind. Health 41(3): 215-230, 2003.
    • Miller, K.P., Borgeest, C., Greenfeld, C., Tomic, D. and Flaws, J.A.: In utero effects of chemicals on reproductive tissues in females. Toxicol. Appl. Pharmacol. 198(2): 111-131, 2004.
    • Pelclová, D., et al.: Lipid metabolism and neuropsychological follow-up study of workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Int. Arch. Occup. Environ. Health 75(Suppl.): S60-S66, 2002.
    • Pohanish, R.P. (editor): Tetrachlorodibenzo-p-dioxin. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 2158-2160.
    • Takemoto, K., Nakajima, M., Fujiki, Y., Katoh, Miki, Gonzalez, F.J. and Yokoi, T.: Role of the aryl hydrocarbon receptor and Cyp 1b1 in the antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Arch. Toxicol. 78(6): 309-315, 2004.
    • Uno, S., et al.: Cyp1a1(-/-) male mice: protection against high-dose TCDD-induced lethality and wasting syndrome, and resistance to intrahypatocyte lipid accumulation and uroporphyria. Toxicol. Appl. Pharmacol. 196(3): 410-421, 2004.
  • Date Last Revised: 08/13/2004

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):
  • Call the Salt Lake Technical Center (SLTC) for sampling procedure.
Bulk Method:
  • Limit the amount of bulk submitted to one gram or one mL.

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