The invisible killer
CPSC data shows that portable generators kill dozens of Americans every year from carbon monoxide poisoning, with many deaths occurring in garages with the door open. An open garage door does not provide adequate ventilation. CO is odorless, colorless, and can reach lethal concentrations in minutes.
The only safe location for a portable generator is outdoors, at least 20 feet from any window, door, or vent, with the exhaust pointed away from the building. This distance prevents CO from being drawn into the home through open windows or HVAC intakes.
Install battery-powered CO alarms on every level of the home and near every sleeping area. These are your last line of defense if CO enters the house despite correct generator placement.
Why you cannot plug a generator into a wall outlet
Backfeeding means connecting a generator to household wiring through an outlet, typically using a homemade double-male extension cord (sometimes called a "suicide cord"). This practice is illegal and potentially lethal.
Even with the main breaker turned off, a mistake or breaker failure can send generator electricity back through the home's transformer and onto utility power lines at dramatically increased voltage. Line workers restoring power after a storm can be electrocuted by a single backfed home miles away.
The only safe way to connect a generator to home wiring is through a transfer switch installed by a licensed electrician. A transfer switch physically isolates the home from the grid before connecting the generator.
The practical side
Never refuel a running or hot generator. Shut it down and let it cool for at least 5 minutes before adding fuel. Gasoline spilled on a hot engine or exhaust can ignite.
Store fuel in approved containers in a well-ventilated area away from the generator and any ignition source. Gasoline degrades over 3 to 6 months; add a fuel stabilizer if storing longer.
Run the generator under load for 30 minutes every month to keep the carburetor clear and the battery charged. A generator that sits unused for a year may not start when you need it.
- Placement: outdoors, 20+ feet from any window, door, or vent
- An open garage door is NOT adequate ventilation
- Never backfeed through a wall outlet. Use a transfer switch only
- Let the generator cool before refueling. Never refuel while running
- Install CO alarms on every level and near sleeping areas
- Run monthly under load to maintain reliability
- Generator Safety — CPSC generator safety guidance and fatality data.
- Portable Generator Safety — NFPA generator placement and fuel safety.