Gas Smell — B2B Emergency Guide | Montréal Combustion

A gas smell in a mechanical room, boiler room or commercial utility space is a potentially critical situation: a build-up of natural gas in the air can create a fire or explosion risk. The priority is never diagnosis — it is the safety of people. This guide outlines the right course of action in a B2B context; it does not replace your building’s emergency protocol or the instructions of emergency services.

What should you do immediately when you smell gas?

Follow your facility’s evacuation protocol. The recognized principles are: evacuate the area and the building depending on severity, keep access routes clear, and call from a safe location, outside or well away from the source. Contact your natural gas distributor (Énergir in Québec) on its emergency line, 911 if the situation requires it, then a qualified team such as our emergency repair service to secure and inspect the installation. If a gas shut-off valve is safely accessible and your procedure allows it, closing it can limit the supply — without ever entering a gas-charged atmosphere.

Which actions are dangerous and must be avoided?

Any spark source can ignite combustion. Do not operate any electrical switch, do not turn lights on or off, and do not use a phone, motor, lighter or tool in the affected area. Do not try to locate the leak with a flame and do not restart the gas burner to “test” it. A rotten-egg smell comes from the odorant added to natural gas: take it seriously even when faint. Precise detection and repair are the job of qualified personnel with suitable instruments.

When should you call a professional?

After any gas alert, the installation should only return to service once verified by authorized personnel: tightness testing of lines and fittings, inspection of the gas heating and combustion system, and validation of safety devices before restart. Montréal Combustion serves Greater Montréal, the North Shore and the South Shore for B2B gas installations: structured diagnostics, return to compliance and safe return to service. 450-473-0909.

Frequently Asked Questions

Can I look for the leak myself to confirm the gas smell?

No. Never search for a leak with a flame and don't use any device that could create a spark. Evacuate the area, warn occupants and leave leak detection to qualified personnel with proper equipment.

Should I shut off the gas at the main valve?

Only if the shut-off valve is safely accessible and your building protocol calls for it. Do not enter an area heavily charged with gas to reach a valve. When in doubt, evacuate first and let the distributor or emergency services intervene.

Is a faint gas smell really an emergency?

Any persistent gas smell should be treated as a hazard. Natural gas is odorized precisely so it can be detected early. Even faint, report it, evacuate if it intensifies, and have the installation checked before any return to service.