Generator Safety: Avoiding Carbon Monoxide Poisoning During a Power Outage

Portable generator running outdoors away from the house with extension cord

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Quick answer: Never run a generator inside a house, garage, basement, or any enclosed/partially enclosed space — even with doors open. Place it at least 20 feet from windows, doors, and vents, pointed away from the home, and install battery-powered CO detectors inside regardless.

Important: Carbon monoxide is colorless and odorless. Generator-related CO poisoning kills dozens of Americans every year, almost always after storms and outages, and almost always from running a generator too close to or inside living spaces.

The 20-Foot Rule

Generators must run outdoors, at least 20 feet from any window, door, or vent, with the exhaust pointed away from the house. A garage with the door open is not safe — CO still accumulates and drifts indoors.

Gear that helps here:

Signs of Carbon Monoxide Poisoning

  • Headache, dizziness, weakness
  • Nausea, vomiting, confusion
  • Chest pain, shortness of breath
  • Loss of consciousness (in severe cases)

If anyone shows these symptoms while a generator is running nearby, get them to fresh air immediately and call 911 — don’t wait to see if symptoms pass.

Other Generator Safety Basics

  • Let the generator cool before refueling — hot engine + spilled gasoline is a fire risk.
  • Never connect a generator directly to household wiring without a properly installed transfer switch — this can backfeed the grid and electrocute utility workers.
  • Keep it dry — operate under an open canopy, never in rain, to avoid electrocution risk.

Common Mistakes

  • Running a generator in a garage ‘just for a little while’ with the door cracked open.
  • Placing the generator near a window or vent, even outdoors.
  • Skipping a battery-powered CO detector because ‘the generator is outside.’
  • Backfeeding a home’s electrical panel without a transfer switch.

    • Frequently Asked Questions

    Can carbon monoxide from a generator outside still get into my house?

    Yes — CO can seep in through windows, doors, vents, and even small gaps if the generator is too close to the structure, which is why the 20-foot minimum distance matters.

    Do CO detectors need electricity to work?

    Battery-powered CO detectors are specifically recommended for outage situations, since plug-in-only detectors are useless exactly when you need them most — during a power outage.

    How much CO does it take to be dangerous?

    Even moderate concentrations become dangerous with prolonged exposure; CO poisoning can occur within minutes at high concentrations, which is why enclosed-space generator use is never acceptable, even briefly.

    Is a dual-fuel or solar generator safer regarding CO?

    Battery/solar power stations produce zero CO and can run indoors safely, making them the safer choice for indoor backup power for smaller loads, though they carry less total wattage than a fuel generator for whole-home needs.