Natural gas is a naturally occurring compound made up predominantly of methane. It is lighter than air and in most circumstances will rise through the soil near a leak and escape harmlessly into the atmosphere. It is non toxic, but, if present in sufficient quantities, may displace air and cause asphyxiation.

Natural gas is by nature colourless and odourless. A stenching chemical is added at trace levels to assist in identifying leaks. This odour commonly smells like a combination of rotting eggs and cabbage.

If you smell a gas leak it is recommended that you take immediate action;

If inside your house

• Leave the premises, opening doors and windows and if possible, extinguish any open flames as you go.
• Do not unplug or plug in any electrical appliances, or switch any lights on or off. This may cause a spark that could start a gas fire.
• Do not smoke or light matches near your home and be mindful that operating some flashlights may also cause a spark.
• If safe to do so, isolate the gas at your meter and the electricity at your meter, if it is externally located.
• From a safe location, for example from a neighbour's phone, call 1800 808 526 for assistance.
• Do not re-enter your home until a gas company representative has inspected the premises, made any necessary repairs, and deemed it safe.

If the gas leak is outside your house

• It may be much more difficult to detect by smell.
• Indications of a possible outdoor gas leak include a hissing sound, dirt or water being blown into the air, bubbles on the surface of puddles of water, patches of dead grass or vegetation near a gas pipeline.

If any of these are detected, avoid the area and from a safe location, for example a neighbour's phone, call 1800 808 526 for assistance.

To help prevent gas leaks, it is important to make sure your gas appliances are properly installed and vented, kept clean and in good working order. Annual inspections by a qualified technician are also recommended. To reduce a chance of fire, be sure to keep all combustible materials away from space heaters, water heaters and cookers.