# NIOSH Pocket Guide to Chemical Hazards
2,3,7,8-Tetrachloro-dibenzo-p-dioxin | CAS 1746-01-6
C12H4Cl4O2 | RTECS HP3500000
Synonyms & Trade Names Dioxin; Dioxine; TCDBD; TCDD; 2,3,7,8-TCDD [Note: Formed during past production of 2,4,5-trichlorophenol, 2,4,5-T & 2(2,4,5-trichlorophenoxy)propionic acid.] | DOT ID & Guide
Exposure Limits | NIOSH REL: Ca See Appendix A
OSHA PEL: none
IDLH Ca [N.D.] | Conversion
Physical Description Colorless to white, crystalline solid. [Note: Exposure may occur through contact at previously contaminated worksites.]
MW: 322.0 | BP: Decomposes | MLT: 581°F | Sol: 0.00000002%
VP(77°F): 0.000002 mmHg | IP: ? |  | Sp.Gr: ?
Fl.P: ? | UEL: ? | LEL: ? |
Incompatibilities & Reactivities UV light (decomposes)
Measurement Methods None available
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated/Daily Remove: When wet or contaminated Change: Daily Provide: Eyewash, Quick drench | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap flush immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister having a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes; allergic dermatitis, chloracne; porphyria; gastrointestinal disturbance; possible reproductive, teratogenic effects; in animals: liver, kidney damage; hemorrhage; [potential occupational carcinogen]
Target Organs Eyes, skin, liver, kidneys, reproductive system Cancer Site [in animals: tumors at many sites]
See also: INTRODUCTION