2,4-Dihydroxyazobenzene

  • Benzeneazoresorcinol
  • 4-(Phenylazo)resorcinol
  • C.I. 11920
  • Sudan Orange G
  • Fat Orange A
  • 1,3-Benzenediol, 4-(phenylazo)-
Formula
C12H10N2O2
Structure
Description
Orange-brown powder. Slight odor.
Uses
Food coloring.

Registry Numbers and Inventories.
CAS
2051-85-6
EC (EINECS/ELINCS)
218-131-9
RTECS
CZ9027500
RTECS class
Other
Beilstein/Gmelin
958430
Beilstein Reference
4-16-00-00264
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C12H10N2O2
Formula mass
214.22
Melting point, °C
170
Boiling point, °C
371
Solubility in water
Insoluble
Partition coefficient, pKow
3.69

Hazards and Protection.
Storage
Store in a cool, dry place. Store in a tightly closed container.
Handling
Avoid breathing dust, vapor, mist, or gas. Avoid contact with skin and eyes.
Protection
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.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents, strong bases.
Decomposition
Nitrogen oxides, carbon monoxide, carbon dioxide.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Extinguishing media: Use extinguishing media most appropriate for the surrounding fire.

Health.
Exposure effects
   Ingestion
Harmful if swallowed.
   Inhalation
May cause respiratory tract irritation. May be harmful if inhaled.
   Skin
May cause skin irritation. May be harmful if absorbed through the skin.
   Eyes
May cause eye irritation.

First aid
 
   Ingestion
Get medical aid. Wash mouth out with water.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
   Skin
Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.