1,2,3-Trimethylbenzene

  • Hemimellitene
Formula
C9H12
Structure
Description
Clear, colorless liquid with a distinctive, aromatic odor.

Registry Numbers and Inventories.
CAS
526-73-8
EC (EINECS/ELINCS)
208-394-8
RTECS
DC3300000
RTECS class
Mutagen
UN (DOT)
1993
Beilstein/Gmelin
1903410
Beilstein Reference
4-05-00-01007
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C9H12
Formula mass
120.21
Melting point, °C
-25
Boiling point, °C
175
Vapor pressure, mmHg
1
Vapor density (air=1)
4.15
Critical temperature
392
Critical pressure
33.98
Density
0.9101 g/cm3 (0 C)
Solubility in water
Slightly soluble
Surface tension
31.27 g/s2 (20 C)
Refractive index
1.5093 (19.5 C)

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Keep container closed when not in use. Flammables-area.
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
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Make no contact with the spilled material. ELIMINATE all ignition sources and ground all equipment. Stop leak if you can do it without risk. A vapor suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean non-sparking tools to collect absorbed material.
Stability
No data.
Incompatibilities
Keep away from nitric acid and oxidizers.
Decomposition
Oxides of carbon.

Fire.
Flash Point,°C
51
Autoignition, °C
470
Upper exp. limit, %
5.2
Lower exp. limit, %
0.9
Fire fighting
Use of water spray when fighting fire may be inefficient. Small Fires: Dry chemical, carbon dioxide, water spray or alcohol-resistant foam. Large Fires: Water spray, fog or alcohol-resistant foam. Use water spray or fog; do not use straight streams.
Fire potential
HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
Hazards
Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
0
 
Flammability
2
 
 
Reactivity
0
 

Health.
Exposure limit(s)
NIOSH REL: TWA 25 ppm (125 mg/m3)
Exposure effects
The toxological properties of this substance have not been fully investigated.
   Ingestion
May cause irritation.
   Inhalation
Vapors may cause dizziness or suffocation. May cause irritation or burns.
   Skin
May cause irritation or burns.
   Eyes
See Skin.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult.
   Skin
Remove and isolate contaminated clothing and shoes. Wash skin with soap and water. Flush with running water for at least 20 minutes
   Eyes
Flush with running water for at least 20 minutes.

Transport.
UN number
1993
Response guide
Hazard class
3
Packing Group
I; II; III
 
USCG CHRIS Code
TMD
 
32 Aromatic hydrocarbons
IMO Chemical Code
17
IMO Pollution Category
A
IMO Hazard code
P