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MESITYL OXIDEICSC: 0814
4-Methyl-3-penten-2-one
Methyl isobutenyl ketone
April 2017
CAS #: 141-79-7
UN #: 1229
EC Number: 205-502-5

  ACUTE HAZARDS PREVENTION FIRE FIGHTING
FIRE & EXPLOSION Flammable.  Above 25°C explosive vapour/air mixtures may be formed.  NO open flames, NO sparks and NO smoking.  Above 25°C use a closed system, ventilation and explosion-proof electrical equipment.  Use alcohol-resistant foam, powder, carbon dioxide.  In case of fire: keep drums, etc., cool by spraying with water. 

 STRICT HYGIENE!  
  SYMPTOMS PREVENTION FIRST AID
Inhalation Cough. Sore throat. Shortness of breath. Headache. Dizziness. Drowsiness. Unconsciousness. Respiratory and cardiac arrest.  Use ventilation, local exhaust or breathing protection.  Fresh air, rest. Artificial respiration may be needed. Refer immediately for medical attention. 
Skin Dry skin. Redness. Pain.  Protective gloves. Protective clothing.  Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention . 
Eyes Redness. Pain.  Wear face shield or eye protection in combination with breathing protection.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Abdominal cramps. Further see Inhalation.  Do not eat, drink, or smoke during work.  Rinse mouth. Do NOT induce vomiting. Refer immediately for medical attention. 

SPILLAGE DISPOSAL CLASSIFICATION & LABELLING
Personal protection: self-contained breathing apparatus. Ventilation. Do NOT let this chemical enter the environment. Collect leaking liquid in sealable containers. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. 

According to UN GHS Criteria

flam;flameskull;toxiccancer;health haz
DANGER
Flammable liquid and vapour
Harmful if swallowed
Toxic if inhaled
Causes skin and eye irritation
May cause respiratory irritation
May cause damage to organs through prolonged or repeated exposure
May be harmful if swallowed and enters airways
Harmful to aquatic life 

Transportation
UN Classification
UN Hazard Class: 3; UN Pack Group: III 

STORAGE
Fireproof. Separated from strong oxidants and acids. Do NOT store or transport in containers made from plastic or copper. Cool. Keep in the dark. Store in an area without drain or sewer access. 
PACKAGING
 
MESITYL OXIDE ICSC: 0814
PHYSICAL & CHEMICAL INFORMATION

Physical State; Appearance
COLOURLESS VISCOUS LIQUID WITH CHARACTERISTIC ODOUR. DARKENS ON STANDING. 

Physical dangers
No data. 

Chemical dangers
The substance can presumably form explosive peroxides. Reacts violently with strong oxidants and acids. Attacks many plastics and copper. 

Formula: C6H10O / (CH3)2C=CH-COCH3
Molecular mass: 98.1
Boiling point: 130°C
Melting point: -41.5°C
See Notes.
Density: 0.87 g/cm³
Solubility in water, g/100ml at 20°C: 3.0 (moderate)
Vapour pressure, kPa at 20°C: 1.2
Relative vapour density (air = 1): 3.4
Relative density of the vapour/air-mixture at 20°C (air = 1): 1.03
Flash point: 25°C c.c.
Auto-ignition temperature: 340°C
Explosive limits, vol% in air: 1.4-10.1
Octanol/water partition coefficient as log Pow: 1.7
Viscosity: 0.75 mm²/s at 20°C 


EXPOSURE & HEALTH EFFECTS

Routes of exposure
The substance can be absorbed into the body by inhalation of its vapour and by ingestion. 

Effects of short-term exposure
The substance is irritating to the eyes, skin and respiratory tract. Exposure far above the OEL could cause unconsciousness. If swallowed the substance may cause vomiting and could result in aspiration pneumonitis. 

Inhalation risk
A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20°C. 

Effects of long-term or repeated exposure
The substance defats the skin, which may cause dryness or cracking. The substance may have effects on the liver, kidneys and lungs. 


OCCUPATIONAL EXPOSURE LIMITS
TLV: 15 ppm as TWA; 25 ppm as STEL.
MAK: 8.1 mg/m3, 2 ppm; peak limitation category: I(2); skin absorption (H); pregnancy risk group: D 

ENVIRONMENT
The substance is harmful to aquatic organisms. 

NOTES
Other melting points: -59°C.
Use of alcoholic beverages enhances the harmful effect.
Depending on the degree of exposure, periodic medical examination is indicated.
Check for peroxides prior to distillation; eliminate if found.
Do NOT take working clothes home. 

ADDITIONAL INFORMATION
  EC Classification
Symbol: Xn; R: 10-20/21/22; S: (2)-25 

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    See Also:
       Toxicological Abbreviations