Gas Emergency Procedures Flashcards

What is the national gas emergency telephone number in Great Britain?

Answer: 0800 111 999

0800 111 999 is the National Gas Emergency Service number, operated by Cadent (and other gas network operators). It is available 24 hours a day, 7 days a week, and is free to call.

What is the correct immediate action if a gas smell is detected in a property?

Answer: Do not operate any switches, open windows and doors, turn off the gas at the meter if safe, get everyone out, and call 0800 111 999

On detecting a gas smell: do not operate any electrical switches (which can ignite gas), ventilate by opening windows and doors, turn off the gas at the emergency control valve (meter) if safe, evacuate, and call 0800 111 999 from outside.

Why must electrical switches NOT be operated when a gas escape is suspected?

Answer: Electrical switches create sparks that can ignite the gas-air mixture, causing an explosion or fire

Even low-energy electrical switches create small sparks when opened or closed. If gas has accumulated to within its flammable range (5-15% in air for natural gas), this spark can ignite the mixture, causing a fire or explosion.

At what concentration in air does natural gas become explosive?

Answer: Between 5% and 15% gas in air (the Lower Explosive Limit and Upper Explosive Limit)

Natural gas (methane) has a flammable range of 5% to 15% by volume in air. Below 5% (LEL) there is insufficient gas to ignite; above 15% (UEL) there is insufficient air. Within this range, any ignition source can cause explosion.

What is an 'Emergency Control Valve' (ECV) in a domestic gas installation?

Answer: The isolation valve at or near the gas meter that can shut off the entire gas supply to the property in an emergency

The Emergency Control Valve (ECV) is located at or near the gas meter and allows the entire gas supply to the property to be isolated quickly in an emergency. All occupants and engineers should know its location.

After a gas escape has been confirmed and the supply turned off, when may the gas supply be restored?

Answer: Only after the source of the escape has been identified and repaired by a Gas Safe Registered engineer, and a tightness test confirms the installation is gas-tight

Gas must not be restored until the escape source has been identified and repaired by a Gas Safe Registered engineer, and a tightness test confirms the installation is secure. Restoring gas without these steps risks further escape.