Tetroquinone

  • 2,3,5,6-Tetrahydroxy-2,5-cyclohexadiene-1,4-dione
  • 2,3,5,6-Tetrahydroxy-1,4-benzoquinone
  • 2,3,5,6-Tetrahydroxy-p-benzoquinone
  • Tetrahydroxy-p-quinone
  • Terasin
  • Kelox
Formula
C6H4O6
Structure
Description
Black solid. Penetrating odor.
Uses
Disodium salt is used as an indicator in the volumetric determination of sulfate by means of barium chloride solution.

Registry Numbers and Inventories.
CAS
319-89-1
EC (EINECS/ELINCS)
206-275-5
Merck
12,9385
Beilstein/Gmelin
1371548
Beilstein Reference
4-08-00-03604
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C6H4O6
Formula mass
172.09
Melting point, °C
280
Boiling point, °C
453
Decomposition point, °C
300
Vapor density (air=1)
5.9
Solubility in water
Very soluble
pKa/pKb
2.52 (pKa)
Partition coefficient, pKow
-5.06

Hazards and Protection.
Storage
Keep container closed when not in use. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Oxidizing agents.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Extinguishing media: Use agent most appropriate to extinguish fire. In case of fire use water spray, dry chemical, carbon dioxide, or appropriate foam.
Health
1
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure effects
   Ingestion
May cause gastrointestinal irritation with nausea, vomiting and diarrhea. The toxicological properties of this substance have not been fully investigated.
   Inhalation
Dust is irritating to the respiratory tract. May cause respiratory tract irritation. The toxicological properties of this substance have not been fully investigated.
   Skin
May cause skin irritation. The toxicological properties of this material have not been fully investigated.
   Eyes
May cause eye irritation. The toxicological properties of this material have not been fully investigated.

First aid
 
   Ingestion
Never give anything by mouth to an unconscious person. Do NOT induce vomiting. If conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water. Get medical aid if irritation or symptoms occur.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid if cough or other symptoms appear.
   Skin
Get medical aid if irritation develops or persists. Wash clothing before reuse. Flush skin with plenty of soap and water.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.