In 1910, a motor car owner walked into the Pittsburgh office of chemist, Dr. Walter Snelling with a complaint. The car owner claimed the one gallon of gasoline he purchased at the pump was only half a gallon by the time he drove home.

The car owner complained that the government should look into why consumers were being cheated because the gasoline evaporated at a rapid and expensive rate.

Dr. Snelling however, took a scientific approach and discovered the evaporating gases were not gasoline at all. They were propane, butane and other hydrocarbons. Using coils from an old water heater and miscellaneous pieces of lab equipment, Dr. Snelling built a still which separated the gasoline into its liquid and gaseous components.

• By 1912, propane gas was used for cooking in homes.
• The first propane powered car appeared in 1913.
• By 1915, propane was used for torch cutting metal.
• In 1920, propane was marketed for flame cutting and further cooking applications.

Today, there are over 1000 different uses for the clean energy of propane. It is the worlds's most versatile energy.

The Compressed Gas Association (CGA) was established in the 1930's and proposed a set of recommendations to the National Fire Protection Association (NFPA). In 1932, the first pamphlet of standards was adopted for publication.

Today, all aspects of the propane industry are subject to stringent standards in an effort to ensure workplace, consumer and public safety.

Propane comes out of the same well as natural gas and crude oil. These products are called "hydrocarbons" because they contain hydrogen and carbon.

At a fractionation plant or refinery, the substances are "cleaned up", heated, cooled and separated. The chemical formula for propane is C3H8.

Propane is shipped throughout North America by pipelines, trucks and tank cars (rail).

The great characteristic of propane is that it can exist as a liquid or a gas.

It is stored and transported as a liquid, but can be used as either a liquid or a gas. A small amount of propane liquid produces a lot of propane gas (called vapour) and that reduces the size of storage containers required. It also enables propane to be stored and transported economically.

Just to look at propane, it would be difficult to tell it from water and like water, propane can exist as a liquid or a gas.

In its natural state, propane is a clear, odourless, colourless, non-toxic liquid. As it changes from a liquid to a gas, it appears as bubbles.

In its natural state, propane is odourless.

As a safety precaution, an odourant called Ethyl Mercaptan is added so any presence of propane may be easily detected. And while most of us are able to detect even the slightest propane odor, some people are unable to.

Propane is stored under pressure, in specially designed tanks. Depending on the application, the cylinder or tank may be constructed of steel, aluminum or stainless.

Regardless of material, each propane cylinder and tank is designed and manufactured in accordance with stringent requirements. This applies to the cylinder on a barbecue, the tank in your backyard, or the tank on a propane delivery truck.

Propane is 270 times more compact as a liquid than as a gas. If you reverse that, propane will expand 270 times if it changes from a liquid to a gas.

One liter of liquid propane will expand to 270 liters of vapour.

When does water become steam (or a gas)? When it boils. The same holds true with propane. Propane becomes a gas when it boils.

Propane remains in a liquid state as long as it is kept under pressure. But as soon as propane is exposed to normal atmospheric conditions (the outside air) it will boil. When propane boils it changes to a gas.

Propane boils at -44 Fahrenheit or -42 Celsius.

For propane to burn, there must be just the right mixture of oxygen and propane:

• If there is too much propane (too rich), it won't burn.
• If there is too little propane (too lean), it won't burn.

Propane will only burn when the mixture of propane and oxygen is within the range of flammability:

Lower Flammability Limit 2.4%

Upper Flammability Limit 9.5%

Example: a mixture of 2.4% propane and 97.6% oxygen through 9.5% propane and 90.5% oxygen will burn.

A flame will not burn inside a propane tank. The mixture is 100% propane too rich to support combustion.

Range of Flammability:

Propane 2.4% to 9.5%
Natural Gas 4.0% to 14.0%
Acetylene 2.5% to 81.0%

Propane vapour will burn in any mixture within its range of flammability, but combustion may not always be efficient. As a result, most gas appliance burners are designed and adjusted to burn an ideal gas/oxygen mixture. This mixture is commonly referred to as the "Ideal Combustion Ratio".

Even with an ideal mixture of propane and oxygen, there must be a source of ignition for combustion to take place. Propane will not burn on its own.

Ignition sources are usually expressed as the minimum temperature needed for a mixture of propane and oxygen to ignite.

Ignition temperature of propane: approximately 920 F

That may seem high, but compared to a common sulfur match, it isn't:

Ignition temperature of a sulfur match: as high as 3,000 F

A common ignition source for propane is another flame, such as the flame of a pilot, match or electronic igniter. There are others. Many develop enough heat to ignite a combustible mixture of propane and oxygen, including sparks from electric connections, including switches; engines; vehicle exhaust; a lit cigarette; even the static electricity generated by a nylon jacket.

That is why sources of ignition are not permitted around a propane installation.

During combustion, propane generates heat, which is measured in British Thermal Units (BTU's) or kilopascals.

In addition to heat, there are certain products of complete combustion: carbon dioxide (CO2), water (H20) and nitrogen (N).

Example: Burning 1 cubic foot of propane produces:

3 cubic feet of CO2
4 cubic feet of H2O
18.5 cubic feet of N

There is a direct relationship between temperature and pressure:

• If the outdoor temperature is 10 degrees, the propane inside a cylinder or tank will also be 10 degrees.
• As the temperature outside the tank increases, so does the temperature inside the tank.
• As the temperature rises, so does the pressure inside the tank.

Propane cylinders and tanks are never filled to 100% capacity. Sufficient space must be left in the container for the liquid to expand. As the temperature of liquid propane increases, it expands and takes up more space inside the tank, forcing the vapour into a smaller, tighter space.

The radiator on a vehicle is a similar example most of us can relate to: on a hot day, or after an extended drive on a hot day, the liquid in a rad expands, forcing vapour into less space and the pressure increases. In extreme cases, the expanding liquid may expand, consume all available vapour space and the rad will bubble over.

Propane is safe energy.

In fact, the National Fire Protection Agency declares gas the safest way to heat your home: safest by a 4 to 1 margin.

Here are the odds a member of the general public will be involved in one of the following incidents:

Individual Risk to Specific Fatal Incidents*

Motor Vehicle Accident: 1 in 4,700
Air Plane Crash (as a passenger): 1 in 140,000
Struck by Lightning: 1 in 1,375,000
Struck by Tornado: 1 in 2,450,000
Dam Failure/Rupture: 1 in 6,300,000
Air Plane Crash (as a person on the ground): 1 in 37,000,000
Propane Storage or Transportation Incident: 1 in 37,000,000

(*Source. U.S. Department of Energy, LPG Land Transportation and Storage Safety)

Propane, one of the cleanest burning fuels available, is the clear choice for our environment. Propane burns cleaner than gasoline and othe fossil fuels. It emits lower levels of carbon dioxide and particulates; it also doesn't produce sulfur dioxide, a primary cause of the greenhouse effect. Propane is non-toxic and vaporizes quickly, so it won't contaminate soil or groundwater.

Propane is also a natural by-product of the gas refining process and in plentiful supply - there's enough propane to meet America's needs in the 21st century. Most of the propane used in the United States is produced right here. All these factors make propane one of the most versatile fuels you can find.