Isobutane is a colorless gas with a faint petroleum-like odor.
Chemical intermediate for alkylate gasoline, component to control volatility of gasoline, chemical intermediate for propylene oxide, tert-butyl alcohol.
Registry Numbers and Inventories.
EC Index Number
Extremely flammable; Carcinogenic Category 1; Mutagenic Category 2
Swiss Giftliste 1
Japan ENCS (MITI)
Melting point, °C
Boiling point, °C
Vapor pressure, mmHg
2580 (25 C)
Vapor density (air=1)
0.559 g/cm3 (20 C)
Solubility in water
0.238 cp @ -10C
14.1 g/s2 @ -10 C
Partition coefficient, pKow
Heat of fusion
Heat of vaporization
Heat of combustion
Hazards and Protection.
Handle in accordance with all current regulations and standards. Subject to storage regulations: U.S. OSHA 29 CFR 1910.101. Grounding and bonding required.
Containers of this material may be hazardous when emptied. Since emptied containers retain product residues (vapor, liquid, and/or solid), all hazard precautions given in the data sheet must be observed.
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
Wear positive pressure self-contained breathing apparatus (SCBA).
Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.
Incompatible with the following: Strong oxidizers (e.g., nitrates & perchlorates), chlorine, fluorine, (nickel carbonyl + oxygen).
The gas mixes well with air, explosive mixtures are easily formed. Toxic fumes are formed when this material is heated.
Upper exp. limit, %
Lower exp. limit, %
Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.
Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Containers may explode when heated. Ruptured cylinders may rocket.
MAK: 1000 ppm; 2350 mg/m3 (STEL); IV (MAK 1991) NIOSH REL: TWA 800 ppm (1900 mg/m3)
Rapid breathing and rapid heart rate are common. In severe cases abnormally low blood pressure, apnea, and cardiac arrest develop. Various disturbances including headache, dizziness, mood disturbances, numbness of the extremities, sleepiness, mental confusion, poor judgement and coordination, and memory loss may occur. Prolonged or severe hypoxia results in unconsciousness. Prolonged asphyxia may produce CNS injury. Hemiparesis has been reported with volatile substance abuse. Cerebral edema with brainstem herniation may occur. Seizures have been reported following intentional inhalation.
Nausea, vomiting, and gastrointestinal hemorrhage may develop.
Hyperventilation may develop.
Dermal exposure may cause frostbite injury. Severe tissue burns have been reported.
Decreases in night vision, visual acuity, and visual fields (tunnel vision) may occur. Frothy mucous may be seen.
Seek medical assistance.
Administer 100% humidified supplemental oxygen with assisted ventilation as required. If hypoxia has been severe or prolonged, carefully evaluate for neurologic sequelae and provide supportive treatment as indicated.
Rewarming and a variety of topical treatments are indicated for frostbite injury. See main section for more information.
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.