NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Isobutane

CAS
75-28-5

CH3CH(CH3)2

RTECS
TZ4300000
Synonyms & Trade Names

2-Methylpropane [Note: Also see specific listing for n-Butane.]
DOT ID & Guide
1075 / 115
1969 / 115

Exposure
Limits

NIOSH REL: TWA 800 ppm (1900 mg/m3)
OSHA PEL: none
IDLH
N.D. See: IDLH INDEX
Conversion
1 ppm = 2.38 mg/m3
Physical Description
Colorless gas with a gasoline-like or natural gas odor. [Note: Shipped as a liquefied compressed gas. A liquid below 11°F.]
MW: 58.1
BP: 11°F
FRZ: -255°F
Sol: Slight
VP(70°F): 3.1 atm
IP: 10.74 eV
RGasD: 2.06

Fl.P: NA (Gas)
UEL: 8.4%
LEL: 1.6%

Flammable Gas
Incompatibilities & Reactivities

Strong oxidizers (e.g., nitrates & perchlorates), chlorine, fluorine, (nickel carbonyl + oxygen)
Measurement Methods
None available
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Frostbite
Eyes: Frostbite
Wash skin: No recommendation
Remove: When wet (flammable)
Change: No recommendation
Provide: Frostbite wash
First Aid
(See procedures)
Eye: Frostbite
Skin: Frostbite
Breathing: Respiratory support

Respirator Recommendations
Not available.
Important additional information about respirator selection
Exposure Routes
inhalation, skin and/or eye contact (liquid)
Symptoms
Drowsiness, narcosis, asphyxia; liquid: frostbite
Target Organs
central nervous system
See also: INTRODUCTION   See ICSC CARD: 0901