ISOBUTANE

Chemical Identification
Chemical Identification
CAS # 75-28-5
Formula

C₄H₁₀

Synonyms

2-methylpropane

Physical Properties
Physical Properties
Physical description Colorless gas with a gasoline-like or natural gas odor.
Boiling point 10.8°F Molecular weight 58.12
Freezing point/melting point -216.9°F Vapor pressure 3.1 atm at 70°F
Flash point -117°F Vapor density 2.06
Specific gravity 0.557 Ionization potential 10.74 eV
Lower explosive limit (LEL) 1.6% Upper explosive limit (UEL) 8.4%
NFPA health rating 0 NFPA fire rating 4
NFPA reactivity rating 0 NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.)
Sampling group
Sampler/Sampling media
Sampling time*
Sampling volume (TWA)*
Sampling flow rate (TWA)*
Sampling volume (STEL/Peak/C)*
Sampling flow rate (STEL/Peak/C)*
Analytical method instruments
Method reference
Notes
Special requirements

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Wipe Method
Sampler/Sampling media
Bulk Method
Bulk Method
On-Site Screening Techniques
On-Site Screening Techniques
Device Detector tube Detector tube Detector tube
Model/Type Gastec 103 Gastec 104 Matheson-Kitagawa 8014-113SB
Sampling information
(see manufacturer instructions)
0.5-3 strokes, approx 0.02-1.7% range, uncertainty 16% 1 stroke, approx 10-3080 ppm range, uncertainty 16% 1 stroke, approx 25-1200 ppm range
Exposure Limits
Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA REL-TWA

800 ppm (1900 mg/m³)

TLV-TWA PEL-TWA
PEL-STEL REL-STEL TLV-STEL

1000 ppm [2012]

PEL-STEL
PEL-C REL-C TLV-C PEL-C
Skin notation

NA

Skin notation

N

Skin notation

N

Skin notation

NA

Notes:

Not established

Notes: Notes:

(EX) Explosion hazard: the substance is a flammable asphyxiant or excursions above the TLV could approach 10% of the LEL

Notes:

Not established

Health factors:  See NIH-NLM PubChem. IDLH
Carcinogenic classifications: Not listed Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Isobutane

NIOSH: Pocket Guide to Chemical Hazards - Isobutane

Literature References

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Butane, isomers. See annual publication for most recent information.
  • Fuke, C., et al.: A fatal case considered to be due to cardiac arrhythmia associated with butane inhalation. Leg. Med. (Tokyo) 4(2): 134-138, 2002.
  • Galvin, J.B. and Bond, G.: Isobutane CAS# 75-28-5. J. Toxicol. Environ. Health, Part A 58(1-2): 3-22, 1999.
  • Pohanish, R.P. (editor): Butanes. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 386-388.
  • Rohrig, T.P.: Sudden death due to butane inhalation. Am. J. Forensic Med. Pathol. 18(3): 299-302, 1997.
  • Tsukamoto, S., Chiba, S., Muto, T., Ishikawa, T. and Shimamura, M.: Study on the metabolism of volatile hydrocarbons in mice-propane, n-butane, and iso-butane. J. Toxicol. Sci. 10(4): 323-332, 1985.

Last Updated Date : 12/31/2020