Recognising and Responding to a Gas Leak
Gas leaks are among the most serious household hazards. Both natural gas and LPG are highly flammable, and prolonged exposure to even low concentrations can cause health problems or create explosion risks. The good news: with the right knowledge, gas leaks are almost always detectable before they become dangerous.
Warning Signs of a Gas Leak
1. The Smell of Rotten Eggs or Sulphur
This is the most well-known indicator. Natural gas and LPG are both odorless in their natural state, but suppliers add a chemical odorant (mercaptan) that produces a distinctive rotten egg or sulphur smell. If you detect this anywhere in your home, treat it as a gas leak immediately.
2. A Hissing or Whistling Sound
A hissing sound near a gas appliance, pipe, or connection point often indicates gas escaping under pressure. This is especially concerning if it occurs near a flexible hose, regulator, or appliance connection.
3. Dead or Discoloured Plants
If a patch of your garden suddenly dies or grass turns yellow-brown for no apparent reason, underground gas from a leaking service pipe may be the cause. Gas displaces oxygen in the soil, starving plant roots.
4. Bubbles in Standing Water
In puddles or wet soil near your gas line, escaping gas can cause bubbling. This is most visible after rain.
5. Physical Symptoms
Low-level gas exposure can cause:
- Headaches or dizziness
- Nausea
- Fatigue or confusion
- Eye and throat irritation
If multiple people in your household experience these symptoms simultaneously — especially indoors — gas or carbon monoxide exposure may be the cause.
Immediate Steps If You Suspect a Gas Leak
- Do not operate any electrical switches — no light switches, no appliance buttons, no fans. A spark can ignite gas.
- Do not use your mobile phone indoors — take it outside before calling anyone.
- Extinguish all open flames — candles, pilot lights, cigarettes.
- Open windows and doors to ventilate the area as you leave.
- Turn off the gas at the meter or cylinder valve if it is safe and accessible.
- Evacuate everyone from the building, including pets.
- Call your gas emergency number from outside or away from the building.
- Do not re-enter until emergency services or a qualified technician has given the all-clear.
How to Test for a Gas Leak Yourself (Minor Suspected Leaks)
If you smell a very faint odour near a connection point and want to do a preliminary check before calling for help:
- Mix a small amount of dish soap with water
- Apply it to the connection, hose, or valve with a brush or cloth
- If bubbles form, there is a leak at that point
- Never use a flame to check for a gas leak
Even if you locate and confirm a small leak this way, do not attempt to repair it yourself. Turn off the supply and call a licensed gas fitter.
Installing Gas Detectors
A gas detector or gas alarm is one of the most cost-effective safety investments you can make. There are two main types:
| Type | Detects | Best For |
|---|---|---|
| Combustible gas detector | Methane, propane, LPG | Kitchen, utility rooms |
| Carbon monoxide detector | CO (incomplete combustion) | Bedrooms, living areas |
Install gas detectors near floor level for LPG (it's heavier than air) and near ceiling level for natural gas (it's lighter than air). Test your detectors monthly and replace them per the manufacturer's guidelines.
Preventing Gas Leaks
- Have all gas appliances and pipework inspected annually by a licensed professional
- Replace flexible hoses every 5 years or as recommended
- Never use damaged or corroded cylinders or regulators
- Ensure adequate ventilation in rooms with gas appliances
- Know where your main gas shut-off valve is located
Gas safety is not something to leave to chance. Regular maintenance and a prepared household are your best defences.