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
R 10 20/21/22
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

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)
Odor Threshold Odor threshold 0.068 mg/m3
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.
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.
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
Hazard class
3
Packing Group
III
 
USCG CHRIS Code
MSO
 
HS Code
2914 19 90
 
Std. Transport #
4909223
 
IMO Chemical Code
17
IMO Pollution Category
D
IMO Hazard code
S