NIOSH Pocket Guide to Chemical Hazards

2-Butanone CAS 78-93-3
CH3COCH2CH3 RTECS EL6475000
Synonyms & Trade Names
Ethyl methyl ketone, MEK, Methyl acetone, Methyl ethyl ketone
DOT ID & Guide
1193 127
1232 127
Exposure
Limits
NIOSH REL: TWA 200 ppm (590 mg/m3) ST 300 ppm (885 mg/m3)
OSHA PEL: TWA 200 ppm (590 mg/m3)
IDLH 3000 ppm Conversion 1 ppm = 2.95 mg/m3
Physical Description
Colorless liquid with a moderately sharp, fragrant, mint- or acetone-like odor.
MW: 72.1
BP: 175°F
FRZ: -123°F
Sol: 28%
VP: 78 mmHg
IP: 9.54 eV

Sp.Gr: 0.81
Fl.P: 16°F
UEL(200°F): 11.4%
LEL(200°F): 1.4%

Class IB Flammable Liquid: Fl.P. below 73F and BP at or above 100F.
Incompatibilities & Reactivities
Strong oxidizers, amines, ammonia, inorganic acids, caustics, isocyanates, pyridines
Measurement Methods
NIOSH 2500, 3800; OSHA 16, 84
Personal Protection & Sanitation
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
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
See also: INTRODUCTION