What to Do If You Smell Gas in Your Home (2026)

Natural gas has no smell on its own. What you smell is mercaptan, a sulfur chemical added so a leak announces itself as rotten eggs. If that odor is strong in your home, the right sequence is simple: get everyone out, avoid anything that can spark, and call for help from outside. Leave the detective work to the utility.

The short answer: if you smell gas, do not hunt for the source. Get people and pets out through the nearest exit without touching switches, unplugging things, or using phones inside. Once outside and upwind, call 911 and your gas utility emergency line. Shut the meter valve only if you know exactly where it is, can reach it without staying inside, and the odor points to the meter or one appliance. Never try to relight pilots yourself.

That line is the whole plan. Everything below is how to make it work when your brain wants to do the opposite.

Why you smell it at all

Utilities add mercaptan at about 1 part per million because methane is invisible and odorless. At that level most noses catch it well before gas reaches a flammable mix, which gives you time to leave. The smell can fade if you stay in it, if you have a cold, or if you are older, and some leaks in walls or soil lose odor outdoors. Treat any sulfur smell near a gas appliance, meter, or pipe as a leak until a tech clears it.

This is different from carbon monoxide. CO is the odorless byproduct of incomplete burning, a furnace or generator or grill that did not vent right. A Kidde Battery-Powered Carbon Monoxide Detector will alarm for CO but it will not alarm for raw natural gas, and a combustible gas detector will not alarm for CO. If you heat with gas, you want both. The CO alarm belongs on every floor outside sleeping areas, the gas risk is handled by smell, a detector if you choose one, and the shutoff habit below.

For the quake-triggered version of this decision, see when and how to shut off gas after an earthquake, which covers the quarter-turn, when NOT to shut off, and why a needless shutoff can leave you waiting days for a relight.

The first 60 seconds: leave and do not spark

Gas needs an ignition source, not just a flame. A light switch, a garage door opener, a phone ringing in a pocket, static from a sweater can be enough at the right mix.

1. Get everyone out now. Use the nearest exterior door. Do not open windows to ventilate on your way out if it means lingering. Grab no bags. If you must pass an appliance with an open flame, do not stop to blow it out.
2. Do not create sparks inside. That means no flipping switches, no unplugging appliances, no starting a car in an attached garage, no using a phone, flashlight, or lighter until you are outside. If the odor is strong, leave doors and windows as they are on your way out.
3. Count at the meeting point. The spot your family already chose for fire or gas, usually the mailbox or the tree at the far end of the driveway, from your family emergency plan. Pets too.
4. Call from outside and upwind. 911 first if the odor is strong, anyone feels dizzy or nauseated, or the building is shared. Then your gas utility emergency number, which is on your bill and often on a sticker at the meter. Give the address, where you smell it, and that you have evacuated.

If you are in an apartment or condo, pull the building alarm only if your lease or manager says to, knock as you go, and tell neighbors to leave without using elevators. Many buildings share a gas manifold, so cutting one unit does not isolate the building. Let the utility make that call.

Should you shut the meter yourself?

The valve at the meter is a flat rectangular bar on the pipe before the dial. Along the pipe is on, across the pipe is off, one quarter turn with a fitted wrench. In a calm moment that is ten seconds. During a leak it is a judgment call.

Shut it if all three are true: you know exactly where the meter is, you can reach it without going back inside or staying inside longer, and the odor clearly points to the meter, the line to the house, or a single appliance valve. A Prime-Line PH 17106 Gas Shut-Off Wrench zip tied to the meter pipe or hung at eye height next to it means you are not hunting a toolbox in the dark, and its single-piece head will not slip and round the bar the way pliers do.

Do not shut it if: the odor is strong throughout the house, you would have to search for the meter, the meter is behind debris or in a basement you must reenter, or you feel lightheaded. Get out instead and let the crew isolate the building. In apartments, treat the building main as the utility's job unless only your unit smells and your own appliance valve stops it. Never go looking for a shutoff in a crawl space that smells like gas.

What to do once you are outside

Stay out. Do not go back for phones, pets you missed, or to open more windows. From upwind, after you have called:

• Tell the dispatcher whether the smell is inside only, outside only, or both, whether you hear hissing at the meter or an appliance, and whether anyone has headache, dizziness, nausea, or a headache that clears outside. Those details help them prioritize.
• Block the doorway with a chair or tape if neighbors might walk in, and flag the utility crew to the meter when they arrive. Point out where you smelled it strongest.
• If you did shut the meter, leave it off. Tag it with a note so no one turns it back on.

Who to call and what happens next

You will usually talk to two parties. The fire department checks the building and the air, the gas utility locates the leak and decides whether to lock the meter. Both carry combustible gas detectors that read far below what your nose needs. Let them.

Do not confuse the call tree with a CO alarm. If a Kidde Battery-Powered Carbon Monoxide Detector is sounding but you do not smell gas, treat it as carbon monoxide: get out, call 911 from outside, do not ventilate by opening a garage door with an electric opener or by running a fan. If you smell rotten eggs and no CO alarm is sounding, treat it as a gas leak anyway and follow the gas sequence above.

Relight rules

Once any valve is shut, whether you shut it or the utility did, only the utility or a licensed tech restores gas. They purge air from the line, check each appliance for leaks, and relight pilots in order. Doing it yourself can push gas into a room you already cleared or leave a slow leak at a joint you disturbed. Expect to wait. After a widespread event where many homes shut off unnecessarily, relights run days for exactly this reason, which is why the quake guide says leave it on unless you have evidence.

While gas is off, the house still needs light and water. A headlamp beats a candle, and a stored water jug covers the day without hot water. Details for that in-place routine are in what to do when the power grid goes down and the water shutoff playbook.

Common mistakes

• Hunting for the leak with matches, lighters, or soapy water while still inside. If you are still inside and smell gas, searching is the wrong task. Leave first.
• Flipping a switch to turn on a vent fan. The spark at the switch is the hazard.
• Using a phone, flashlight, or garage opener inside. Use them only from outside.
• Rounding the meter bar with pliers. A fitted wrench costs about 11 dollars and lives on the pipe. An adjustable jaw slips when your hands shake.
• Going back in for a pet or a phone. Call from a neighbor's line. Let a masked crew go back with meters.
• Assuming the CO alarm will warn for gas. It will not. Smell and a combustible gas detector are different layers.

Build the habit before you need it

Walk out tonight with no leak present and find the meter. Note whether it is on the street wall, in a utility closet, or in a basement. Fit the Prime-Line PH 17106 Gas Shut-Off Wrench on the bar, picture the quarter turn to crosswise, then hang the wrench back on the pipe and go inside. Show the other adults in the house the same 60 second rehearsal and where the two emergency numbers live on your phone favorites. Put a Kidde Battery-Powered Carbon Monoxide Detector on each floor per the manual, test monthly, and replace on schedule. That is the whole skill, and it works for any Tuesday night, not just after a quake.

Quick recommendations

• Know the odor: mercaptan added to odorless gas smells like rotten eggs at very low levels, which is the early warning to leave.
• Leave without sparks: no switches, no phones inside, no starting a car in an attached garage.
• Call from outside: 911 and your gas utility emergency line, from upwind.
• Meter valve last: a Prime-Line PH 17106 Gas Shut-Off Wrench lives on the pipe for the ten seconds that matter, but only use it without lingering.
• CO is separate: a Kidde Battery-Powered Carbon Monoxide Detector guards against odorless carbon monoxide, not raw gas; keep both layers if you have gas appliances.

Sources: Pipeline and Hazardous Materials Safety Administration leak guidance, Ready.gov utility shutoff, major gas utility emergency instructions 2024 to 2026, National Fire Protection Association gas leak response. Check your local utility card for its exact emergency number and valve shape, since details vary by region.