Mesityl oxide

  • 4-Methyl-3-penten-2-one
  • Isopropylideneacetone
  • Methyl isobutenyl ketone
  • 4-Methylpent-3-en-2-one
Formula (CH3)2CCHCOCH3
Structure
Description Colorless to yellow oily liquid, peppermint- like odor. Lachrymator.
Uses Solvent for nitrocellulose, many gums & resins, particularly vinyl resins, in lacquers, varnishes & enamels. Extractant of trace amounts of copper(II).

Registry Numbers and Inventories.
CAS 141-79-7
EC (EINECS/ELINCS) 205-502-5
EC Index Number 606-009-00-1
EC Class Flammable; Harmful
EC Risk Phrase R 10 20/21/22
EC Safety Phrase S 25
RTECS SB4200000
RTECS class Human Data; Primary Irritant
UN (DOT) 1229
Merck 13,5935
Beilstein/Gmelin 1361550
Beilstein Reference 4-01-00-03471
EPA OPP 52401
Swiss Giftliste 1 G-2397
Canada DSL/NDSL DSL
US TSCA Listed
Austrailia AICS Listed
New Zealand Listed
Japan ENCS (MITI) Listed
Korea ECL Listed

Odor Threshold Odor threshold 0.068 mg/m3
Properties.
Formula C6H10O
Formula mass 98.15
Melting point, °C -59
Boiling point, °C 127
Vapor pressure, mmHg 8.8 (25 C)
Vapor density (air=1) 3.38
Saturation Concentration 1.1% at 20 C
Evaporization number 8.4 (Butyl acetate = 1)
Critical temperature 332
Critical pressure 39.48
Density 0.8653 g/cm3
Solubility in water 28.9 g/L (20 C)
Viscosity 0.88 cp (25 C)
Surface tension 27.12 g/s2 (24 C)
Refractive index 1.4425 (20 C)
Dipole moment 2.84 D
Dielectric constant 15.6 (0 C)
Partition coefficient, pKow 1.12
Heat of vaporization 42.70 kJ/mol
Heat of combustion -3569 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. Keep from contact with oxidizing materials. Store in a cool, dry, well-ventilated area away from incompatible substances. Flammables-area.
WHMIS B3 D2B
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. Isolate area and deny entry. Provide ventilation. A vapor suppressing foam may be used to reduce vapors.
Disposal code 1
Stability Stable under normal temperatures and pressures.
Incompatibilities 2-Aminoethanol, strong oxidizing agents, chlorosulfonic acid, ethylene diamine, nitric acid, oleum, sulfuric acid.
Decomposition Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C 30
Autoignition, °C 344
Upper exp. limit, % 7.2
Lower exp. limit, % 1.4
Fire fighting Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Use water spray to keep fire-exposed containers cool. Water may be ineffective. Extinguishing media: For small fires, use water spray, dry chemical, carbon dioxide or chemical foam. Use water spray to cool fire-exposed containers. Water may be ineffective. For large fires, use water spray, fog or alcohol-resistant foam. Do NOT use straight streams of water.
Fire potential Flammable liquid and vapor.
Hazards Vapor is heavier than air and may travel a considerable distance to a source of ignition and flash back. Containers may explode in the heat of a fire.
Combustion products Combustion may produce irritants and toxic gases.
NFPA Health 2
  Flammability 3  
  Reactivity 1  

Health.
Exposure limit(s) NIOSH REL: TWA 10 ppm (40 mg/m3) OSHA PEL: TWA 25 ppm (100 mg/m3) 1400 ppm [10%LEL]
Poison_Class 3
Exposure effects Prolonged or repeated inhalation may cause lung damage and/or central nervous system disturbances. Prolonged or repeated skin contact may cause dermatitis. May cause liver and kidney damage.
   Ingestion May cause irritation of the digestive tract. May cause gastrointestinal irritation with nausea, vomiting and diarrhea. May cause liver and kidney damage. May cause central nervous system depression, characterized by excitement, followed by headache, dizziness, drowsiness, and nausea. Advanced stages may cause collapse, unconsciousness, coma and possible death due to respiratory failure. May be harmful if swallowed. Ingestion of large amounts may cause CNS depression.
   Inhalation Causes respiratory tract irritation. May cause liver and kidney damage. May cause lung damage. Causes narcotic effects including headache, dizziness, weakness, unconsciousness, and possible death. Aspiration may lead to pulmonary edema. Vapors may cause dizziness or suffocation. May cause burning sensation in the chest.
   Skin May cause severe skin irritation. Prolonged and/or repeated contact may cause irritation and/or dermatitis. Substance is rapidly absorbed through the skin. May cause irritation and dermatitis. May cause cyanosis of the extremities.
   Eyes Causes severe eye irritation. Vapors may cause eye irritation. May cause corneal opacity as in addition to corneal scarring and necrosis. May cause chemical conjunctivitis and corneal damage.

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

Transport.
UN number 1229
Response guide 129
Hazard class 3
Packing Group III  
USCG CHRIS Code MSO  
USCG Compatatibility Group 18 Ketones
HS Code 2914 19 90  
Std. Transport # 4909223  
IMO Chemical Code 17
IMO Pollution Category D
IMO Hazard code S