Running a generator safely during an outage
Never indoors — not even the garage
Portable generators produce carbon monoxide (CO), an odorless, invisible gas that kills in minutes in enclosed spaces. The CPSC links more than 100 US deaths every year to portable generators, and warns never to run one inside a home or garage — even with doors and windows open. Basements and enclosed porches trap the exhaust the same way.
20 feet from the house
CPSC guidance: run the generator at least 20 feet from your home, exhaust pointed away from windows, doors, and vents — yours and your neighbors'. Battery-powered CO alarms on every level of the home are the backstop.
Keep it dry
Electric shock and electrocution are another danger the CPSC names, especially when a generator runs in wet conditions. If you must use one when it's wet outside, the CPSC says to operate it under an open, canopy-like structure on a dry surface where water can't reach it or puddle or drain under it, and to dry your hands before touching it. Sheltering it never means running it indoors or near an opening to the house, the CPSC adds: that brings back the carbon-monoxide danger.
No backfeeding — ever
Plugging a generator into a wall outlet ("backfeeding") energizes lines that crews and neighbors believe are dead. The CPSC calls it extremely dangerous: it puts utility workers and neighbors served by the same transformer at risk of electrocution. Power anything wired into the house only through a transfer switch installed by a qualified electrician, per OSHA, or plug appliances directly into the generator with heavy-duty outdoor cords.
Cool before refueling
Turn the generator off and let it cool before refueling: the CPSC warns that gasoline spilled on hot engine parts could ignite. Store fuel outside living areas in properly labeled, non-glass safety containers, away from fuel-burning appliances such as a gas water heater in a garage.
Recognize CO poisoning — and what to do
The CPSC lists the symptoms of carbon-monoxide poisoning as headache, dizziness, weakness, nausea, vomiting, sleepiness and confusion, and its questions and answers say the first signs of low-to-moderate poisoning are similar to the flu, but without the fever. Higher exposures cause loss of consciousness — and because you cannot see or smell CO, you can be exposed without knowing it. If an alarm sounds or symptoms appear: get everyone to fresh air immediately and call 911. Don't go back inside, not even to open windows, until emergency responders say you can.
CO alarms: the non-negotiable backstop
Install battery-operated CO alarms (or plug-ins with battery backup) on every level of the home and outside sleeping areas, and test them monthly, per the CPSC; replace each one at the replacement age its manufacturer recommends. If you ever run a generator, the alarm is what catches the mistake you didn't know you made — exhaust drifting to a window you forgot about, a breeze change, a neighbor's vent.
Buy the safer machine if you're buying
The CPSC recommends looking for a portable generator with a CO shut-off safety feature, designed to shut the generator off automatically when high levels of CO build up around it. The CPSC estimates these models significantly reduce deaths from CO poisoning — a reduction, not an exemption: the 20-foot rule still applies.
Cords and loads
Plug appliances in with heavy-duty, outdoor-rated extension cords whose wattage rating exceeds the total of everything plugged into them, free of cuts and with all three prongs, per the CPSC. Add up the watts of what you'll run and stay under the generator's rating, as its manual gives it: Ready.gov's outage sheet says to plan which things you need to plug in first, because you may not be able to power all appliances at one time.
Between outages
Look after the machine before you need it: OSHA's generator fact sheet lists, among its safe work practices, maintaining and operating a portable generator in accordance with the manufacturer's use and safety instructions, so run and service it on the maker's schedule and treat its fuel the way the manual says. Store fuel in labeled safety containers outside living areas, per the CPSC. Keep the manual with the machine — the next user may not be you.
Placement in a real yard
Twenty feet is the radius; the details are wind and openings. Point the exhaust away from every door, window, and vent — yours and your neighbors' (CO doesn't respect property lines, and attached homes share walls and airspace). Keep it out from under awnings, carports, and overhangs, off dry leaves, and reachable by cords that don't cross standing water. If the safe spot changes with the wind, move the generator, not the rule.
If you don't own one: the CO risk can still be yours
Attached homes, townhouses, and close-set houses share air. If a neighbor runs a generator, your battery CO alarms are your protection — another reason every level of every home should have one, generator owner or not.
Know how long you actually need it
Fuel planning depends on outage length. Our live tracker shows the utility's posted restoration time when one is available, and our independent estimate when the data supports one — it follows the outage's own recovery and leans on past outages there while that trend is thin. Check it before a fuel run.
- CPSC — Carbon Monoxide Information Center (generators and CO)
- CPSC — Portable generator hazards (safety alert, PDF)
- CPSC — Carbon monoxide questions and answers
- CPSC — Winter storm carbon monoxide safety tips (Dec. 2025)
- CPSC — Generators with a CO shut-off feature (July 2024)
- OSHA — Grounding requirements for portable generators (fact sheet, PDF)
- Ready.gov — Power outages
- Ready.gov — Be prepared for a power outage (FEMA info sheet, PDF)