Suspected Gas Leak: Leave First, Call From Outside
Leave the building immediately with everyone including pets. Do not switch anything on or off, use a phone indoors, or look for the leak. Call the gas utility's emergency line from outside; they respond immediately and free of charge. Do not re-enter until they say it is safe.
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Why this one is different
Every other guide on this site tells you to assess the situation before acting. This one does not. A gas leak's failure mode is an explosion, the ignition source can be something as ordinary as a light switch or a doorbell, and there is no version of investigating it yourself that improves your position.
Natural gas is odorless; utilities add mercaptan specifically so leaks are detectable by smell. That rotten egg smell is a deliberately engineered warning. Treat it as one.
What to do, in order
Leave immediately
Get everyone out, including pets. Leave doors open behind you if that is quick, but do not delay to do it.
Touch nothing electrical
Do not flip switches on or off, do not unplug anything, do not use the phone indoors, do not press a garage door opener. Any of these can spark.
Do not start a vehicle in an attached garage
The ignition is a spark source in a space that may be holding gas.
Call from a safe distance
From outside and well away, call your gas utility's emergency number. Call 911 as well if anyone has symptoms or the smell is strong.
Wait outside
Do not re-enter for any reason, including to retrieve belongings or turn off appliances, until the utility clears the building.
Signs beyond the smell
Smell is the primary indicator but not the only one, and some people have a reduced ability to detect mercaptan.
- A hissing or whistling sound near a gas line, meter, or appliance
- Dead or dying vegetation in a strip over a buried gas line, with healthy growth around it
- Bubbles rising through standing water or wet ground over a line
- Dirt or dust blowing up from the ground with no wind
- Headache, dizziness, nausea, or fatigue that improves when you go outside
Carbon monoxide is a separate hazard
Carbon monoxide is not a gas leak. It is a product of incomplete combustion in an appliance, most often from a blocked vent, a cracked heat exchanger, or a malfunctioning burner, and unlike natural gas it has no odor at all.
The symptoms overlap with flu: headache, nausea, confusion, fatigue. If a CO alarm sounds, treat it exactly like a gas leak: leave and call 911 from outside. Every home with gas appliances should have working CO alarms on every level, and they expire, typically after seven to ten years.
Frequently asked questions
Should I call a plumber or the gas utility?
The utility, always, and from outside. They respond to gas odor calls immediately and at no charge, and their job is to shut off supply and confirm the building is safe. A plumber cannot do that and is the wrong first call. Once the utility has made it safe, a licensed technician handles the repair.
Can I just shut off the gas myself at the meter?
If you can reach the meter from outside safely and you have a wrench, turning the valve perpendicular to the pipe shuts it off, and utilities generally accept this. What you should not do is go back inside for a tool or to reach an interior valve. Do not turn the gas back on yourself afterward; that must be done by the utility with appliance relighting and leak testing.
How much does the utility charge for a gas leak call?
Nothing. Gas utilities respond to suspected leak reports free of charge as a matter of public safety, and they would far rather come out to a false alarm than to an explosion. There is no financial reason to hesitate, and hesitating is the actual risk.
What if I only smell it faintly and I'm not sure?
Call anyway, from outside. Faint intermittent gas odor is exactly the profile of a small leak that will grow, and the utility treats it as a legitimate call. Being wrong costs you a visit that is free. Being right and waiting costs considerably more.
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Common questions
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