2,3,7,8-Tetrachloro-dibenzo-p-dioxin

  • Dioxin
  • Dioxine
  • 2,3,7,8-TCDD
  • 2,3,7,8-Tetrachlorodibenzo[b,e][1,4]dioxin
Formula
C12H4Cl4O2
Structure
Description
White crystals or tan crystalline powder.
Uses
Research chemical.

Registry Numbers and Inventories.
CAS
1746-01-6
EC (EINECS/ELINCS)
217-122-7
RTECS
HP3500000
RTECS class
Tumorigen; Mutagen; Reproductive Effector; Human Data; Primary Irritant
Merck
12,9252
Beilstein/Gmelin
271116
Beilstein Reference
5-19-02-00041
EPA OPP
600000

Properties.
Formula
C12H4Cl4O2
Formula mass
321.97
Boiling point, °C
420
Vapor pressure, mmHg
8.3E-7 (25 C)
Solubility in water
0.2 ug/L
Partition coefficient, pKow
6.95
Heat of vaporization
64.5 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
For workers engaged in the decontamination process after an accident, it is recommended that they wear complete throw away equipment to protect the skin and prevent exposure to dust and vapors from the contaminated materials. NIOSH approved respiration should be used if any procedure that may produce inhalation of airborne contaminated material cannot be avoided.
Respirators
Use NIOSH/MSHA approved respirator appropriate for exposure of concern.
Small spills/leaks
If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then dampen the solid spill material with toluene, then using absorbent paper transfer the dampened material to a suitable container. Use absorbent paper dampened with toluene to pick up any remaining material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent-wash all contaminated surfaces with toluene followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.
Stability
Changed chemically when exposed in isooctane or n-octanol to UV light tetrachlorodibenzo-p-dioxin is stable under ordinary conditions of storage. 2,3,7,8-Tcdd is considered relatively stable toward heat, acids, and alkalies.
Incompatibilities
Uv light (decomposes)
Decomposition
2,3,7,8-tetrachlorodibenzo-p-dioxin begins to decompose at 500 C and virtually complete decomposition occurs within 21 seconds at a temp of 800 C.

Fire.
Flash Point,°C
164
Fire fighting
Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher.
Fire potential
This material is nonflammable

Health.
Exposure limit(s)
NIOSH REL: Ca See Appendix A
Carcinogin
I-1, N-1, CP65
Exposure effects
Peripheral neuropathy, with sensory impairment and lower extremity weakness, central neuropathy, mental status changes, headache and dizziness occur after exposure. Mild exposure may result in asymptomatic EMG alterations. Dioxins have not been proven to produce adverse reproductive effects in humans. However, low birthweights, ectodermal dysplasia, and growth and neurological deficits have been associated with dioxin exposure. Data on spontaneous abortions, decreased sperm quality and feminizing alterations of sex hormones have been mixed. TCDD accumulates in breast milk, and neurolgical deficits and increases in T4 and TSH have been associated with lactational exposure. TCDD is considered an animal teratogen.
   Ingestion
Right-upper-quadrant pain, anorexia, nausea and vomiting may be early symptoms. Pancreatitis occurred in one case of industrial exposure.
   Inhalation
Dyspnea may be noted.
   Skin
The initial dermal reaction is extensive inflammation of exposed areas with photosensitivity, followed by development of chloracne.
   Eyes
Inflammation of the eye, irritation and burning may be noted.

First aid
 
   Ingestion
If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. MMEDIATELY transport the victim to a hospital.
   Inhalation
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used.
   Skin
IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.
   Eyes
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Transport.