2-Butanone

Synonyms & Trade Names
Ethyl methyl ketone, MEK, Methyl acetone, Methyl ethyl ketone
CAS No.
78-93-3
RTECS No.
DOT ID & Guide
1193 127
Formula
CH₃COCH₂CH₃
Conversion
1 ppm = 2.95 mg/m3
IDLH
3000 ppm
See: 78933
Exposure Limits
NIOSH REL
TWA 200 ppm (590 mg/m3) ST 300 ppm (885 mg/m3)
OSHA PEL
TWA 200 ppm (590 mg/m3) See Appendix G
Measurement Methods
NIOSH 2500 , 2555 , 3800;
OSHA 16 , 84 , 1004
See: NMAM or OSHA Methods
Physical Description
Colorless liquid with a moderately sharp, fragrant, mint- or acetone-like odor.
Molecular Weight
72.1
Boiling Point
175°F
Freezing Point
-123°F
Solubility
28%
Vapor Pressure
78 mmHg
Ionization Potential
9.54 eV
Specific Gravity
0.81
Flash Point
16°F
Upper Explosive Limit
(200°F): 11.4%
Lower Explosive Limit
(200°F): 1.4%
Class IB Flammable Liquid: Fl.P. below 73°F and BP at or above 100°F.
Incompatibilities & Reactivities
Strong oxidizers, amines, ammonia, inorganic acids, caustics, isocyanates, pyridines
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
irritation eyes, skin, nose; headache; dizziness; vomiting; dermatitis
Target Organs
Eyes, skin, respiratory system, central nervous system
Personal Protection/Sanitation
(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet (flammable)
Change:No recommendation
Provide:Eyewash
First Aid
(See procedures)
Eye:Irrigate immediately
Skin:Water wash immediately
Breathing:Fresh air
Swallow:Medical attention immediately
Respirator Recommendations

NIOSH/OSHA

Up to 3000 ppm:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode£
(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)£
(APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 0179   MEDICAL TESTS: 0133
Page last reviewed: October 30, 2019