Agent Name

Isobutane

CAS Number

75-28-5

Formula

C4-H10

Major Category

Solvents

Synonyms

1,1-Dimethylethane; 2-Methylpropane; Propane, 2-methyl-; R 600a; Trimethylmethane; [ChemIDplus]

Category

Aliphatics, Saturated (<C12)

Description

Colorless gas with a slight gasoline or natural gas odor; [HSDB]

Sources/Uses

Used as a fuel, a refrigerant, a propellant, and a gasoline additive; Used to calibrate instruments and to make other organic chemicals; [CHEMINFO] Used as an aerosol propellant and fuel source; [ACGIH]

Comments

In mice causes CNS depression at 15% for 60 minutes or 23% for 26 minutes; In dogs causes anesthesia at 45% for10 minutes. [HSDB] In rats, the LC50 (15 minutes) was 57%, "although the lack of oxygen likely contributed to the deaths of these animals." TLV Basis is CNS impairment; Volunteers exposed to 500 ppm 8 hours/day, 5 days/week for 2 weeks had no significant adverse effects; [ACGIH: Butane, isomers] Isobutane is in the list of "Some volatile substances which may be abused by inhalation" published on the web site of the U.N. International Drug Control Programme, indicating its potential to cause narcosis in workers. [Reference #1] See "n-Butane" and "Cyclobutane."

Reference Link

Volatile Substance Abuse

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data

STEL (ACGIH)

1000 ppm

MAK

1000 ppm

Vapor Pressure

2610 mm Hg

Lethal Concentration

LC50 (rat) = 570,000 ppm/15 min

Explanatory Notes

"Explosion Hazard." [TLVs and BEIs]

Adverse Effects
Neurotoxin

CNS Solvent Syndrome

Other Poison

Simple Asphyxiant

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

Search ChemIDplus

Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent: