LPG, in its natural state, is an odourless gas, but because of the potential danger associated with gas leaks, to make it detectable for safety reasons, a strong-smelling substance, ethyl mercaptan, is added to act as a warning to users.
Ethyl mercaptan is a clear liquid with a distinctive sulphur-like odour. It’s added to LPG at the refineries to give the fuel a strong and unpleasant stench, often described as similar to rotten eggs or rotting cabbage. The foul smell makes it easier to detect leakages that may otherwise go unnoticed.
The reason: It’s a safety measure. Often a smell of gas can be an early warning sign of a potentially dangerous gas leak, and whilst LPG, when used correctly, is a very safe gas, it’s vital to be able to identify a leak as LPG is a highly flammable fuel. And it's equally important to know what to do if you suspect a leak.
The risks
There are several potentially serious hazards associated with LPG leaks:
- Health: Whilst exposure to low levels of gas is not harmful, long-term exposure can affect your health and can even lead to asphyxia and breathing difficulties. In extreme cases, high levels of exposure can be fatal. Gas leaks can cause headaches, dizziness, nausea and fatigue, eye irritation and skin blisters. The reason for this is because gas leaks actually change the amount of oxygen available, so as you breathe less oxygen in, you’ll start to experience symptoms.
- Fire and explosion: LPG vapour is highly flammable when mixed with air. A small spark or an open flame can ignite the gas and lead to a fire or even an explosion if the gas is confined. LPG vapour is heavier than air and therefore will accumulate at ground level or in drains, and if not dispersed, can remain there for some time.
- Environmental impact: Whilst LPG is less potent than methane or carbon dioxide, it is a greenhouse gas and leaks still have an environmental impact. And because LPG is heavier than air and settles to the ground, it can potentially contaminate soil.
- Property damage: Escaped gas can lead to explosions and fire outbreaks which can cause damage to property.
What to do if you smell gas
If you do smell gas, stay calm and do not panic. Do not take any risks – the most important thing to do is keep yourself and your family safe, but you do need to take immediate action.
Call your supplier’s emergency service number, and ring 999 immediately, advising the emergency services that there is LPG on the premises.
Evacuate everyone from the area. Extinguish any naked flames immediately. Shut off the LPG Emergency Control Valve (ECV) on the external wall of your property if it is safe to do so, thus isolating the tank.
For indoor leaks make sure all electrical equipment is turned off. Open all windows and doors to ventilate the building.
For outdoor leaks, establish an exclusion zone around the incident and stay upwind of any escaping LPG.
If you’re feeling unwell, call your GP or visit your local hospital immediately and let them know you’ve been exposed to a gas leak.
What NOT to do if you smell gas
- Do not switch lights on or off, or use household appliances
- Do not smoke, vape, light a match or use any sort of naked flame
- Do not keep doors closed
- Do not use mobile phones or any other electrical devices that could cause a spark
- Do not try to repair the leak yourself
Other signs of a gas leak
Whilst the most common sign of a gas leak is being able to smell gas, other things to look out for are:
- Visible damage to gas pipes or connections
- Dying plants in your home or near to your LPG tank. Check the surrounding area for patches of yellow grass or dying flowers as this might be a sign of a leak coming from underground pipes
- Air bubbles in standing water. Again, this could be a sign of a leak from underground pipes
- A hissing sound near your gas line or appliance. Generally the louder the hissing, the more gas will be leaking
- Physical symptoms such as those described above. If you’re feeling unwell and think you may have been exposed, contact your GP or visit your nearest hospital to be checked over
- An unusually high gas bill
Prevention Tips
Familiarise yourself with your LPG tank. Find out where the safety shut-off valve is, so if you do have a leak, you know where to shut off the supply.
There’s no substitute for regular maintenance which is not just essential for safety. A regular boiler service will keep you gas safe at home, and also will keep your system running at its most efficient, and help protect the lifespan of your system.
Your LPG supplier will be responsible for the routine maintenance of your LPG tank. This will include regular tank inspections, testing, maintenance and any repairs needed due to wear and tear.
A gas safety check should be carried out annually by a Gas Safe registered engineer. You can find a local Gas Safe registered engineer by typing your postcode into the ‘Find an Engineer’ search tool on the Gas Safe Register website, or call us on 01423 772 789 and we will be able to recommend an engineer in your area.
Your engineer will test your gas appliances to make sure they are safe, that there’s adequate and permanent air supply that’s suitable for the appliances installed, that all safety devices are functioning properly, and check your installation is in good condition by visually inspecting and testing pipework. Your engineer will also check for carbon monoxide, a highly poisonous gas, often called the ‘silent killer’ as it can’t be seen, tasted or smelt.
Install a gas detector in your home to provide early warning of leaks, and a carbon monoxide detector too.
Remember, LPG leaks are rare, and LPG is a very safe and efficient fuel when used correctly and equipment is regularly maintained. We hope this information will help you spot the common signs of a gas leak if you’re unfortunate enough to experience one, but do remember, they are rare. Please also remember that if you have any questions or concerns, we’re just at the end of the phone and you can call us anytime on 01423 772 789.