A gas escape during utility construction work is an emergency that requires immediate action. Natural gas is flammable and explosive when mixed with air at concentrations between 5% and 15%. Gas can migrate through soil, enter buildings, and accumulate in confined spaces creating an explosion risk over a wide area. Every operative working near gas infrastructure must know the emergency procedure for a gas escape and be able to act within seconds of detecting the smell of gas or a gas alarm.
Key Hazards
Explosion from accumulated gas finding an ignition source in a confined area
Asphyxiation from gas displacing oxygen in below-ground chambers and excavations
Fire from ignited gas escaping from a damaged or leaking main connection
Gas migrating into nearby buildings through soil creating a remote explosion risk
Control Measures
Evacuate everyone from the immediate area upwind of the suspected gas escape location.
Extinguish all naked flames and prohibit smoking within the evacuation area immediately.
Do not operate any electrical switches, mobile phones, or vehicles near the gas escape.
Call the National Gas Emergency Service on 0800 111 999 and provide the exact location.
Establish a cordon at a safe distance and prevent anyone from entering the exclusion zone.
Warn occupants of nearby buildings and advise them to open windows and avoid ignition sources.
Do not attempt to repair or stop the gas escape yourself under any circumstances.
Remain at the cordon to brief the gas emergency engineer on arrival and direct them to the location.
Record the details of the incident for the site report and notify the principal contractor.
Emergency / Rescue
If you smell gas or your gas detector alarms, evacuate upwind immediately. Remove all ignition sources. Call the National Gas Emergency Service on 0800 111 999. Call 999 if anyone is injured or a building is at risk.
Remember
Natural gas is explosive at concentrations between 5% and 15% in air — evacuation is immediate.
Do not operate electrical switches, phones, or vehicles near a gas escape as they can cause ignition.
Call 0800 111 999 immediately and provide the exact location of the suspected gas escape.
Gas migrates through soil and can enter buildings far from the original escape point.
Never attempt to repair a gas leak yourself — wait for the gas emergency engineer to arrive.
Evacuate upwind because gas is lighter than air but can concentrate in low-lying and enclosed areas.
Applicable Legislation: Gas Safety (Installation and Use) Regulations 1998 · Health and Safety at Work etc. Act 1974 · Pipeline Safety Regulations 1996 · Dangerous Substances and Explosive Atmospheres Regulations 2002