1,3,5-Trimethylbenzene

  • Mesitylene
Formula
C9H12
Structure
Description
Clear, colorless liquid with distinctive aromatic odor.
Uses
Dyestuff intermediate, solvent, paintermediate thinner.

Registry Numbers and Inventories.
CAS
108-67-8
EC (EINECS/ELINCS)
203-604-4
EC Index Number
601-025-00-5
EC Class
Flammable; Irritant; Dangerous for the Environment
R 10 37 51/53
RTECS
OX6825000
RTECS class
Mutagen; Human Data; Primary Irritant
UN (DOT)
2325
Merck
13,5934
Beilstein/Gmelin
906806
Beilstein Reference
4.05-00-01016
Swiss Giftliste 1
G-2396
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
120.20
Melting point, °C
-45
Boiling point, °C
165
Vapor pressure, mmHg
2.3 (25 C)
Vapor density (air=1)
4.1
Saturation Concentration
l.0% at 20 C; 0.24% at 20 C (calculated)
Critical temperature
364
Critical pressure
32.0
Density
0.8637 g/cm3 (20 C)
Solubility in water
20 mg/L
Viscosity
6.92 cp (20 C)
Surface tension
28.83 g/s2 at 20 C
Refractive index
1.49541 (20 C)
Dielectric constant
2.2 (20 C)
Partition coefficient, pKow
3.60
Heat of vaporization
47.7 kJ/mol
Heat of combustion
-5241 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Flammables-area.
B3
Handling
Wash thoroughly after handling. Use only in a well ventilated area. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Avoid contact with heat, sparks and flame. Avoid ingestion and inhalation. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
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
Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Remove all sources of ignition. Use a spark-proof tool. Provide ventilation. A vapor suppressing foam may be used to reduce vapors.
Disposal code
1
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents.
Decomposition
Carbon monoxide, carbon dioxide.

Fire.
Flash Point,°C
44
Autoignition, °C
560
Upper exp. limit, %
6
Lower exp. limit, %
1
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Will burn if involved in a fire. Can release vapors that form explosive mixtures at temperatures above the flashpoint. Use water spray to keep fire-exposed containers cool. Containers may explode in the heat of a fire. Extinguishing media: For small fires, use dry chemical, carbon dioxide, water spray or alcohol-resistant foam. For large fires, use water spray, fog, or alcohol-resistant foam. Use water spray to cool fire-exposed containers. Water may be ineffective. Do NOT use straight streams of water.
Fire potential
HIGHLY FLAMMABLE.
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. May polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
0
 
Flammability
2
 
 
Reactivity
0
 

Health.
Exposure limit(s)
TLV: 25 ppm; 125 mg/m3 (ACGIH 1993-1994). NIOSH REL: TWA 25 ppm (125 mg/m3)
Poison_Class
4
Exposure effects
Prolonged or repeated skin contact may cause irritation. Chronic inhalation may cause effects similar to those of acute inhalation.
   Ingestion
May cause irritation of the digestive tract.
   Inhalation
Causes respiratory tract irritation. May cause anemia. May cause drowsiness, unconsciousness, and central nervous system depression. Vapors may cause dizziness or suffocation. May cause asthma-like symptoms and sleepiness.
   Skin
May cause skin irritation. Excessive drying of the skin may result form repeated or prolonged contact.
   Eyes
Causes eye irritation.

First aid
 
   Ingestion
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid.
   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 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.
UN number
2325
Response guide
Hazard class
3
Packing Group
III
 
USCG CHRIS Code
TMB
 
32 Aromatic hydrocarbons
HS Code
2902 90 80
 
Std. Transport #
4912685
 
IMO Chemical Code
17
IMO Pollution Category
A
IMO Hazard code
P