Smell of Gas or Burning: Response Decision Tree

Why this matters

A gas smell or a burning smell is the one category of call where diagnosis comes second and getting people out comes first. Natural gas and propane explode. An electrical fire spreads inside walls where you cannot see it. The wrong move here is not a callback, it is a casualty. The discipline is simple to state and hard to hold under pressure: act on the hazard, then think about the cause. This tree is the order you follow when your nose tells you something is wrong.

Start here: what does it smell like

Sort the smell into one of three buckets in the first few seconds. They get different first moves.

• Rotten eggs, sulfur, or skunk - treat as a gas leak (natural gas and propane are odorized to smell this way).
• Hot, acrid, "electrical," melting-plastic, or fishy - treat as an overheating electrical fault.
• Smoky, scorched, or actively burning - treat as a fire.

When in doubt, escalate to the worst plausible case. You can always stand down later.

If it smells like gas

Stop diagnosing. Do this in order:

1. Get everyone out of the structure, including yourself. Take the occupants with you.
2. Touch nothing electrical. Do not flip a light switch, do not unplug anything, do not use a doorbell, do not start a vehicle in an attached garage. A spark in a gas-air mixture is the ignition source.
3. Do not use your phone inside the building. Call from outside, well away.
4. Do not light anything and do not look for the leak with a flame.
5. If you can reach a manual shutoff on your way out without delay, and only the readings or hiss tell you which, you may close the gas at the meter or tank. Never go back in for it.
6. From a safe distance, call the gas utility's emergency line and 911. Let them clear the building before anyone re-enters.

Only after the utility confirms it is safe do you investigate a fitting, a pilot, or an appliance connector.

If it smells like overheating electrical

Burning plastic, an "ozone" or fishy odor, or hot insulation means a circuit is failing.

1. Locate the source by smell and heat, but do not put hands on energized parts.
2. De-energize at the breaker for that circuit, or kill the main if you cannot isolate it. Removing power removes the heat source.
3. If you see flame or heavy smoke, do not open the panel or the device. Treat it as a fire (next section).
4. Once power is off and the area has cooled, then you assess the scorched component, the loose lug, or the failed connection.

A warm breaker or a discolored outlet is a finding to act on, not a part to keep running.

If something is actively burning

1. Get people out and call 911 first. Do not delay the call to fight a small fire.
2. A fire small enough to fight is one you can put out in seconds with a rated extinguisher while keeping a clear exit behind you. Energized electrical fires need a Class C rated extinguisher; never water on a live circuit.
3. Kill power to the area if the panel is safe to reach.
4. If the fire is in a wall, a ceiling, or an appliance you cannot fully see into, back out and let the fire department open it. Hidden fire travels.
5. After the fire department clears the scene, the equipment is evidence and a teardown, not a same-visit repair.

Re-entry and documentation

Re-enter only after the utility or fire department says the air is clear and the hazard is controlled. Then:

• Photograph the failed component before you touch it.
• Red-tag or lock out the appliance or circuit so no one re-energizes it.
• Write down what you smelled, what you did, and who you called, in that order. This protects the customer and you.

The judgment to bank: a smell of gas or burning is never a "let me just check one thing" moment. People out, hazard off, utility called - then diagnose.

References

• OSHA General Duty Clause and emergency-evacuation guidance (29 CFR 1910)
• NFPA 54 (National Fuel Gas Code) and NFPA 70 (National Electrical Code) for fuel-gas and electrical safety basics
• Local gas utility emergency-response procedures
• See related: Is This Safe to Leave Running, and Red Tag vs Warn vs Proceed on Unsafe Equipment