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TRIMETHYL BENZENE (MIXED ISOMERS)
ICSC: 1389
Peer-Review Status: 03.06.2002 Validated
Benzene, trimethyl (isomers)
Methylxylene 
CAS #: 25551-13-7 RTECS #: DC3220000
UN #: 1993
EINECS #: 247-099-9
 		    Formula: C9H12
Molecular mass: 120.2

TYPES OF
HAZARD /
EXPOSURE 		ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Flammable.  NO open flames, NO sparks and NO smoking.  Use alcohol-resistant foam, dry powder, carbon dioxide. 
EXPLOSION Above 44°C explosive vapour/air mixtures may be formed.  Above 44°C use a closed system, ventilation and explosion-proof electrical equipment. Prevent build-up of electrostatic charges (e.g., by grounding).  In case of fire: keep drums, etc., cool by spraying with water. 
 
EXPOSURE   PREVENT GENERATION OF MISTS!   
Inhalation Confusion. Cough. Dizziness. Drowsiness. Headache. Sore throat. Vomiting.  Use ventilation, local exhaust or breathing protection.  Fresh air, rest. Refer for medical attention. 
Skin Redness. Dry skin.  Protective gloves.  Remove contaminated clothes. Rinse skin with plenty of water or shower. 
Eyes Redness. Pain.  Wear safety spectacles.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion See Inhalation.  Do not eat, drink, or smoke during work.  Rinse mouth. Do NOT induce vomiting. Refer for medical attention . 

SPILLAGE DISPOSAL
 		PACKAGING & LABELLING
Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Do NOT wash away into sewer.  See Notes. 
EC Classification
 
UN Classification
UN Hazard Class: 3; UN Pack Group: III 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-30GF1-III.
NFPA Code: H0; F2; R0.  		Fireproof. Separated from strong oxidants. Well closed. Keep in a well-ventilated room. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. 

Physical dangers
 

Chemical dangers
Decomposes on burning. This produces toxic and irritating fumes. Reacts violently with strong oxidants. This generates fire and explosion hazard. 

Occupational exposure limits
TLV: 25ppm as TWA; (ACGIH 2008). 

Routes of exposure
The substance can be absorbed into the body by inhalation. 

Inhalation risk
A harmful contamination of the air will be reached rather slowly on evaporation of this substance at 20°C; on spraying or dispersing, however, much faster. 

Effects of short-term exposure
The substance is irritating to the eyes, skin and respiratory tract. If this liquid is swallowed, aspiration into the lungs may result in chemical pneumonitis. The substance may cause effects on the central nervous system. 

Effects of long-term or repeated exposure
The liquid defats the skin. Repeated or prolonged inhalation may cause effects on the lungs. This may result in chronic bronchitis. The substance may have effects on the blood and central nervous system. See Notes. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: 165-176°C
Melting point: -25 - 45°C
Relative density (water = 1): 0.86-0.89
Solubility in water: very poor
Vapour pressure, kPa at 20°C: 0.18 - 0.25
Relative vapour density (air = 1): 4.1
Flash point: 44-53°C c.c.
Auto-ignition temperature: 470-550°C
Octanol/water partition coefficient as log Pow: 3.4/3.8   		The substance is harmful to aquatic organisms. Bioaccumulation of this chemical may occur in fish. 

NOTES
Use of alcoholic beverages enhances the harmful effect.
Depending on the degree of exposure, periodic medical examination is indicated.
Card has been partly updated in April 2005. See section Occupational Exposure Limits.
See ICSC 1155 1,3,5-Trimethylbenzene (Mesitylene); ICSC 1362 1,2,3-Trimethylbenzene (Hemimellitene); ICSC 1433 1,2,4-Trimethylbenzene (Pseudocumene).1,3,5-Trimethylbenzene (Mesitylene) is classified as a marine pollutant.
Card has been partially updated in February 2009: see Occupational Exposure Limits. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety 		WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
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    See Also:
       Toxicological Abbreviations