Propane

  • Dimethylmethane
  • Propyl hydride
  • Petroleum gas
  • PRP
Formula
CH3CH2CH3
Structure
Description
Colorless gas. Unodorized propane has a slightly sweet odor. If an odorant has been added it will have a strong unpleasant odor.
Uses
Component of liquid petroleum gas for commercial and industrial usage, feedstock in thermal cracking processes used to manufacture ethylene and propylene, refrigerant in chemical refining and gas processing operations, fuel in welding and cutting operations.

Registry Numbers and Inventories.
CAS
74-98-6
EC (EINECS/ELINCS)
200-827-9
EC Index Number
601-003-00-5
EC Class
Extremely flammable
RTECS
TX2275000
RTECS class
Agricultural Chemical and Pesticide
UN (DOT)
1978
Merck
12,7982
Beilstein/Gmelin
1730718
Beilstein Reference
4-01-00-00176
Swiss Giftliste 1
G-2784
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C3H8
Formula mass
44.1
Melting point, °C
-188
Boiling point, °C
-42
Vapor pressure, mmHg
7270 (25 C)
Vapor density (air=1)
0.117
Evaporization number
Gas
Odor Threshold Odor threshold 36,000 mg/m3
Critical temperature
96.81
Critical pressure
42.01
Density
0.515 g/cm3 (10 C) (liquid)
Solubility in water
100 mg/L (20 C)
Viscosity
0.2 cp (-40 C)
Surface tension
15.15 g/s2 (-40 C)
Refractive index
1.3407 (-42 C)
Dipole moment
0.08 D
Dielectric constant
1.61 (0 C)
Partition coefficient, pKow
2.36
Thermal expansion
0.003/K at 15 C
Heat of fusion
2.6 kJ/mol
Heat of vaporization
19.7 kJ/mol
Heat of combustion
-2206 kJ/mol

Hazards and Protection.
Storage
Specific requirements are listed in NFPA 58. Cylinder storage locations should be well-protected, well-ventilated, dry, and separated from combustible materials Cylinders should never knowingly be allowed to reach a temperature exceeding 52C. Cylinders of propane should be separated from oxygen cylinders or other oxidizers by a minimum distance of 20 ft., or by a barrier of non-combustible material at least 5 ft. high having a fire resistance rating of at least hour. Full and empty cylinders should be segregated. Use a first-in, first-out inventory system to prevent full containers from being stored for long periods of time. Cylinders should be stored upright with valve protection cap in place and firmly secured to prevent falling or being knocked over. Protect cylinders from physical damage; do not drag, roll, slide or drop. Use a suitable hand truck for cylinder movement.
A B1
Handling
Propane is heavier than air and may collect in low areas that are without proper ventilation. Leak check system with leak detection solution, never with flame. If user experiences difficulty operating cylinder valve, discontinue use and contact supplier. Never insert an object (e.g., wrench, screwdriver, pry bar, etc.) into valve cap openings. Doing so may damage valve, causing a leak to occur. Use an adjustable strap wrench to remove over-tight or rusted caps. Non-sparking tools should be used. Never strike an arc on a compressed gas cylinder or make a cylinder a part of an electrical circuit. Electrically bond and ground cylinder when transferring liquid product
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
Evacuate the immediate area. Eliminate any possible sources of ignition, and provide maximum explosion-proof ventilation. Shut off source of propane, if possible. If leaking from cylinder, or valve, contact your supplier. Never enter a confined space or other area where the concentration is greater than 10% of the lower flammable limit which is 0.22%.
Stability
Stable at normal temperratures and pressures.
Incompatibilities
Incompatible with strong oxidizing agents.
Decomposition
At 650 C decomposes to ethylene and ethane.

Fire.
Flash Point,°C
-104
Autoignition, °C
432
Upper exp. limit, %
9.5
Lower exp. limit, %
2.1
Fire fighting
Evacuate all personnel from danger area. Immediately cool container with water spray from maximum distance, taking care not to extinguish flames. If flames are accidentally extinguished, explosive re-ignition may occur. Stop flow of gas if without risk while continuing cooling water spray. Extinguish using CO2, dry chemical, water spray or fog for surrounding area. Do not extinguish until propane source is shut off.
Fire potential
Very flammable, combustion imminent.
Hazards
Containers may explode. Vapor is heavier than air and may travel a long distance to a source of ignition and flash back.
Health
1
 
Flammability
4
 
 
Reactivity
0
 

Health.
Exposure limit(s)
OSHA PEL: TWA 1000 ppm (1800 mg/m3) NIOSH REL: TWA 1000 ppm (1800 mg/m3) NIOSH IDLH: 2100 ppm LEL
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
Unlikely route of exposure.
   Inhalation
Simple asphyxiant. It should be noted that before suffocation could occur, the lower flammability limit of propane in air would be exceeded; possibly causing both an oxygen-deficient and explosive atmosphere. Exposure to concentrations (> 10%) may cause dizziness. Exposure to atmospheres containing 8-10% or less oxygen will bring about unconsciousness without warning, and so quickly that the individuals cannot help or protect themselves. Lack of sufficient oxygen may cause serious injury or death.
   Skin
ontact with liquid or cold vapor can cause frostbite.
   Eyes
Contact with liquid or cold vapor can cause freezing of tissue.

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
1978
Response guide
Hazard class
2.1
USCG CHRIS Code
PRP
 
Std. Transport #
4905781 4905776
 
IMO Gas Code
B