Gas is a safe and efficient source of energy when used properly. Gas appliances and installations incorporate in their designs safety features to protect people and property from malfunctions (usually with appliances). However, without proper installation and use, the potential exists for the appliance not to function correctly.

All gases will diffuse in air.  Gases that are lighter than air, such as natural gas rise, mix with air and disappears quite quickly.  Gases that are heavier than air, such as LP Gas tend to collect at the lowest point.  If LP Gas builds up on the ground or in a confined space, the gas disappears slower as air may be mixing in smaller amounts.

For escaping gas to be a fire or explosion hazard, there must be gas (fuel) and air (oxygen) in the correct proportions and an ignition source.

What to do if you can smell gas

Smells of gas in a building are not normal and steps must be taken to eliminate a hazard or potential hazard that could arise from leaking gas.  Gas suppliers' instructions should always be followed. However, the steps below offer general information on making the situation safe.

1. Turn off the supply of gas to the building at the meter or cylinder.  Turning off the gas at the meter may not stop the leak, as it may be coming from a nearby gas main or service.
2. If you consider it necessary, evacuate the building.
3. Eliminate ignition sources by extinguishing any naked flames, preventing smoking, preventing striking of matches and lighters and by not touching any electrical switches.
4. If lights are on, leave them on.
5. Ventilate the building by opening all the doors and windows.
6. Notify the gas supplier.  
7. Do not enter the gas-affected area.

Odorant

All hydrocarbon gases have odour (smells) added before distribution to the customer.  The amount of odorant is specified in the Gas Standards (Gas Supply and System Safety) Regulations 2000.  Some of the compounds used to odorise gas are different but their smell is similar.  A common ingredient of odorants is Ethyl Mercaptan and it is very smelly.