NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

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

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 See: 78933
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, 2555, 3800; OSHA 16, 84, 1004
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
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
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   See ICSC CARD: 0179   See MEDICAL TESTS: 0133