Isobutane

  • 2-Methylpropane
Formula
C4H10
Structure
Description
Isobutane is a colorless gas with a faint petroleum-like odor.
Uses
Chemical intermediate for alkylate gasoline, component to control volatility of gasoline, chemical intermediate for propylene oxide, tert-butyl alcohol.

Registry Numbers and Inventories.
CAS
75-28-5
EC (EINECS/ELINCS)
200-857-2
EC Index Number
601-004-01-8
EC Class
Extremely flammable; Carcinogenic Category 1; Mutagenic Category 2
RTECS
TZ4300000
RTECS class
Other
UN (DOT)
1969
Beilstein/Gmelin
1730720
Beilstein Reference
4-01-00-00282
EPA OPP
97101
Swiss Giftliste 1
G-1699
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C4H10
Formula mass
58.14
Melting point, °C
-255.3
Boiling point, °C
-11.7
Vapor pressure, mmHg
2580 (25 C)
Vapor density (air=1)
1
Critical temperature
134.69
Critical pressure
35.82
Density
0.559 g/cm3 (20 C)
Solubility in water
Slightly soluble
Viscosity
0.238 cp @ -10C
Surface tension
14.1 g/s2 @ -10 C
Refractive index
1.3518 (-25C)
Partition coefficient, pKow
2.76
Heat of fusion
2.57 kJ/mol
Heat of vaporization
21.3 kJ/mol
Heat of combustion
-3061 kJ/mol

Hazards and Protection.
Storage
Handle in accordance with all current regulations and standards. Subject to storage regulations: U.S. OSHA 29 CFR 1910.101. Grounding and bonding required.
A B1
Handling
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.
Protection
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
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.
Stability
Stable.
Incompatibilities
Incompatible with the following: Strong oxidizers (e.g., nitrates & perchlorates), chlorine, fluorine, (nickel carbonyl + oxygen).
Decomposition
The gas mixes well with air, explosive mixtures are easily formed. Toxic fumes are formed when this material is heated.

Fire.
Flash Point,°C
-107
Autoignition, °C
460
Upper exp. limit, %
8.4
Lower exp. limit, %
1.8
Fire fighting
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.
Fire potential
EXTREMELY FLAMMABLE.
Hazards
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.
Health
0
 
Flammability
4
 
 
Reactivity
0
 

Health.
Exposure limit(s)
MAK: 1000 ppm; 2350 mg/m3 (STEL); IV (MAK 1991) NIOSH REL: TWA 800 ppm (1900 mg/m3)
Poison_Class
-
Exposure effects
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.
   Ingestion
Nausea, vomiting, and gastrointestinal hemorrhage may develop.
   Inhalation
Hyperventilation may develop.
   Skin
Dermal exposure may cause frostbite injury. Severe tissue burns have been reported.
   Eyes
Decreases in night vision, visual acuity, and visual fields (tunnel vision) may occur. Frothy mucous may be seen.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
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.
   Skin
Rewarming and a variety of topical treatments are indicated for frostbite injury. See main section for more information.
   Eyes
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.

Transport.
UN number
1969
Response guide
Hazard class
2.1
USCG CHRIS Code
IBT
 
Std. Transport #
4905747 4905429 4905750
 
IMO Gas Code
B