Characteristics & Hazards of Propane

Propane LPG (liquefied petroleum gas) is found in the same geological formations as crude oil and natural gas. About 30% of propane is refined from crude oil while 70% is processed from natural gas. Propane is odorless, tasteless, and colorless in its natural state. A sulfuric odorant (mercaptan) is added to give the gas a foul smell that is easily recognizable and helps us with finding leaks.

Propane belongs to the family of hydrocarbons that are made solely of hydrogen and carbon atoms. Propane has three carbons and eight hydrogens (C 3 H 8 ), where natural gas is mostly C 1 H 4 (methane), and gasoline is a mix of C 8 H 18 (octane) and others. Propane in its liquid state is roughly half the weight of water. Propane in gaseous or vapor state has a specific gravity of 1.6 compared to 1.0 for air (or .6 for natural gas and helium). Because Propane gas is heavier than air it will settle in low areas moving along a ditch line or collect in ground level dwellings.

Propane has a boiling point of -44℉ - below that temperature is a clear liquid with no pressure. At normal temperatures, propane is stored as a liquid in special tanks with 100-200 psi of pressure. When pressure is released, the liquid propane boils or vaporizes into a gas that can be converted to heat water, homes, and commercial spaces.

Hazards of Propane

Propane vapor is flammable at concentration of 2-10% gas in air – it’s also heavier than air so leaks can gather in low places in and along pipelines, utility conduits, ditches, basements, crawl spaces, and any low area. If vapor concentrations are within the 2-10% flammable limit, a heat or ignition source can cause a fire or explosion. Leaks can be ignited and travel back to the source of the initial leak.

Propane in its liquid form can cause severe cold burns to the skin because it vaporizes extremely fast. This can lead to frostbite on the skin wherever vapor touches it. This vaporization can also cause equipment to cool considerably and lead to cold burns on the skin.

As with the burning of any fuel, a faulty appliance can sometimes have improper combustion that releases carbon monoxide. If leaked into a room instead of venting out, carbon monoxide inhalation can lead to headaches, dizziness, lightheadedness, passing out or, in extreme cases, death.

Propane is non-toxic, however, it has a possible inhalation hazard if released into a confined space because it displaces oxygen in the air and can asphyxiate.

Examples of potential gas leaks include, but are not limited to:

• The smell of gas lasts more than an instant when igniting stove top burners.
• Presence of foul odor persists, or you cannot find the source of a foul order (i.e. sewer, garbage, dead animals, etc.).
• Hissing noises near gas appliances, piping, storage tanks, or cylinders.