When the Gas Smell Is Strong, Leave First — Shutoff Is Secondary
Claim: When you smell a strong or persistent gas odour inside a building, the correct first action is immediate evacuation — not locating the shutoff valve. Shutoff at the meter is the right action only when the smell is mild, the source is external, or you can safely reach the meter without entering or re-entering the gas-filled space.
Mechanism
Natural gas is explosive in concentrations of approximately 5–15% in air (the flammable range). At the concentrations that produce a strong indoor odour, a single ignition source — a light switch, a phone, a pilot light, a doorbell, a static spark — can trigger an explosion. The time it takes to find and operate the meter shutoff valve is time spent inside a potentially explosive atmosphere.
FortisBC’s emergency protocol reflects this priority order:
- Stop what you’re doing.
- Don’t operate any electrical switch, phone, or ignition source — including turning off lights.
- Leave the building, leaving the door open behind you.
- Once outside and at a safe distance, call 1-800-663-9911 or 911.
- Only if you can safely reach the meter without entering the building: shut off the gas.
The shutoff step is in fifth position, not first, because it is optional from a life-safety standpoint — the fire department and FortisBC can shut off the meter when they arrive. You cannot be replaced.
When shutoff IS appropriate first
- A very faint smell near a specific appliance (not a whole-room smell) — you can turn off the individual appliance valve and ventilate before calling FortisBC
- An earthquake has passed with no smell detected — a precautionary shutoff to allow FortisBC inspection before resuming use is appropriate (not an emergency shutdown, a planned one)
- The meter is clearly outside and away from the smell source, and you can operate the valve without entering the building
The switch/phone rule
This is the counterintuitive detail most people don’t know: do not turn OFF light switches or use your phone inside a gas-filled space. Electrical switches create a small arc when operated; phones emit RF energy. Either can be an ignition source in a flammable gas concentration. Leave switches where they are. Exit, then use your phone outside.
Scope
This applies to natural gas and propane. It does not change the general rule about keeping a wrench at the meter and knowing the shutoff location — preparedness still matters; this rule just clarifies that preparedness does not mean “reach for the valve first.”
Idea Compass
North: Where this comes from
- gas-meter-shutoff (Home Systems) — the component note this decision rule is embedded in
- FortisBC emergency protocol for gas leaks and odours — the direct source for the priority ordering
- Basic combustion chemistry — the 5–15% flammable range defines when switching a light becomes a hazard
East: Tensions / failure
- Gas Shutoff Is a Quarter-Turn — Perpendicular Means Closed (Home Systems) — the tension: knowing how to shut off gas is valuable, but the instinct to use that knowledge first in a strong-smell situation is dangerous
- The “do something” instinct — in emergencies, action feels safer than evacuation; this is the instinct the rule is designed to override
South: Where this leads
- Do Not Turn Gas Back On Yourself — FortisBC Must Inspect After Any Shutoff (Home Systems) — the rule that closes the loop: if you do shut off, the restoration step is not yours
- emergency-shutoffs (Home Systems) — the broader emergency-shutoff note cross-references this gas-specific priority ordering
West: What’s similar
- Fire evacuation protocol — the same priority inversion: do not pause to collect belongings, do not use elevators, exit first then account and call. The “gas smell” protocol is the same shape as fire evacuation, not as a system-shutdown checklist.