SAFETY SOLUTIONS: Liquefied Petroleum Gas Safety

Many industries use liquefied petroleum gas (LPG) to operate their machinery, heat their places of employment or use it for their industrial truck operations or other industrial use. LPG is also used by many people in their homes for their BBQ or for running appliances.

What is LPG?

Liquefied petroleum gas is a colourless odourless liquid, which readily evaporates into a gas. Normally an odorant has been added to it to help detect leaks. LPG (either Butane or Propane) is generally stored and distributed as a liquid and it is widely used for process and space heating, cooking and automotive propulsion. It is classified as highly flammable and if it contains more than 0.1% Butadiene, it is also classified as a carcinogen and mutagen. LPG is non-corrosive but can dissolve lubricants, certain plastics or synthetic rubbers.

What are the dangers of LPG?

LPG may leak as a gas or a liquid. If the liquid leaks it will quickly evaporate and form a relatively large cloud of gas, which will drop to the ground, as it is heavier than air. LPG vapours can run for long distances along the ground and can collect in drains or basements. When the gas meets a source of ignition it can burn or explode. Cylinders can explode if involved in a fire and LPG can cause cold burns to the skin and it can asphyxiate at high concentrations.

How do you work safely with LPG?

Identify the LPG cylinders used in your workplace. These may be propane, acetylene, butane, or propane/butane mixture. If you use this article for a safety meeting topic, then bring a cylinder of the most-used LPG to the discussion area. If cylinders are not available or difficult to bring, you can use photographs as visual aids. Identify, and bring with you, the material safety data sheets (MSDSs) for all LP gases used by your company. Check the areas where LPG cylinders are stored for your location, and note any problems in the storage area.

A variety of industries use LPG cylinders for many applications. Storage and handling of these cylinders depends upon the type, size and use. A few storage and handling requirements apply to all these cylinders. Of primary interest is the flammability of LPG at temperatures between 0 and 120°F. This safety topic will discuss the storage and handling of portable cylinders smaller than 100-pound gross weight.

Most liquefied petroleum gases used in industry are not classified as toxic. The greatest hazard in working with these cylinders is the risk of fire or explosion.

Common uses for LPG include: acetylene for welding and cutting is dissolved in acetone to reduce the chances of auto-polymerization. This allows high-volume storage of acetylene at low pressures; propane for lift truck motor fuel is normally mounted horizontally in a specially designed bracket. Specific training is required to avoid mis-mounting the cylinder; propane used for other motor fuels may be attached for use of the liquid or the gas portion of the fuel. Cylinders designed for use of liquid fuel and those designed for using the fuel as a gas must be stored separately; propane/butane mixtures for utility and construction site heaters are in 20-pound cylinders that commonly have no specific brackets. These must be secured in an upright position to avoid tipping over.

Review with the group the types of LPG cylinders used. Ask where the LPG cylinders are stored in your workplace, and add any storage areas not mentioned by the group.

Review the reasons the cylinders are stored in these areas. Go over the fire protection, security and inspection of the areas. NFPA recommends a fire extinguisher of 18 pounds of agent or more for cylinder storage areas. For security, always lock cages or storage rooms with controlled keys.

Ask the group where is it not safe to store LPG cylinders. Add that NFPA says they should not be stored on roofs, in ways of exit, under or on stairways, in areas of public access or near sources of ignition.

Ask the group how they get an LPG cylinder when they need one. Recognize the correct answers and review the procedures, including:

• Who has access?
• How to transport the cylinder to the point of use.
• Always check the cylinder for leaks (by odor), and have the safety pressure release valve at the vapour space of the cylinder (as marked on the cylinder). It must be secured against dropping or rolling, and must never be carried by holding onto the valve or connecting port.

Ask the group what you should check for when connecting a cylinder. Possible answers include:

• Oil, grease, dirt or corrosion on the connections.
• Damaged connections or connecting hoses.
• Damaged mounting brackets.
• An odor after the cylinder is attached. If the odor persists, the connection is leaking.

Ask the group what you should do if the connection is leaking when a fresh cylinder is being attached.

• For minor leaks, back off the connection and reseat the connectors.
• For a large leak, or if the second attempt fails, remove the cylinder, mark it as defective and try another.
• Observe caution to avoid freezing the skin from contact with the gas or liquid.

Go over the storage areas with the group. Note the reasons the storage areas are located as they are. Review the answers given in the discussion, and reinforce the most important points, such as: inspection of the cylinder before use, care in transporting the cylinder, testing for leaks when attaching a fresh cylinder, and avoiding sources of ignition in the storage area and when connecting a cylinder.

Address any concerns expressed by the group, and follow up the meeting with answers that are not immediately available.

Group Actions

Ask the group to inspect the cylinders (or photographs) used as training aids, and take down any comments or questions they may have. Have the group review any MSDSs you brought to the meeting.

Ask the group to look over the storage area when they are nearby, and think through the next time they might need to change a cylinder.

Have the members of the group who do not normally change cylinders observe others as they perform the task correctly.

Always check a cylinder for leaks (by odor), and have the safety pressure release valve at the vapour space of the cylinder (as marked on the cylinder). It must be secured against dropping or rolling, and must never be carried by holding onto the valve or connecting port.

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