1. Carbon monoxide: outdoors and far away
Generator exhaust contains carbon monoxide (CO), a gas you cannot see or smell. It can reach deadly levels within minutes in an enclosed or partly enclosed space.
- Run the generator outdoors only. Never in a house, basement, crawl space, garage, shed or carport, even with doors and windows open.
- Keep it at least 20 feet (6 metres) from the house. This is the distance given by both the US Consumer Product Safety Commission and Health Canada.
- Point the exhaust away from doors, windows and vents, including your neighbours'.
- Fit battery-powered or battery-backup CO alarms on every level of the home and outside sleeping areas. Test them before storm season.
Headache, dizziness, nausea and tiredness are early signs of CO poisoning. If anyone feels unwell, get everyone into fresh air at once and call emergency services.
2. Backfeeding: never use a wall outlet
Plugging a generator into a household outlet sends power backwards through your panel and out to the utility lines. The transformer on the pole steps that up to thousands of volts, which can kill a line worker or a neighbour. It can also destroy the generator when grid power returns.
There are two safe ways to connect:
- Extension cords run directly from the generator to each appliance.
- A transfer switch or panel interlock, installed by a licensed electrician, with a proper inlet box. This lets you power hard-wired equipment such as a furnace.
3. Extension cords
- Use cords marked for outdoor use that are rated for the load. A thin indoor cord on a fridge or heater can overheat.
- Longer runs need thicker wire. Follow the cord chart in your generator's manual.
- Check cords for cuts and bent or missing ground pins. Run them where they will not be pinched in a door or sit in standing water.
- Do not overload a single cord with a power strip full of appliances.
4. Rain, snow and electric shock
A generator must stay dry, but it also must stay outdoors. Use an open-sided canopy or a purpose-made generator tent that keeps rain off while letting exhaust escape freely. Stand it on a dry, level surface. Dry your hands before touching it.
5. Refuelling and fuel storage
- Switch the generator off and let it cool before refuelling. Gasoline spilled on a hot engine can ignite.
- Store fuel in approved containers, outside living areas and away from any appliance with a flame or pilot light.
- Check your local limit on how much fuel may be stored at home.
A setup checklist
| Check | Why |
|---|---|
| 20 ft (6 m) or more from the house | Keeps CO out of the home |
| Exhaust pointing away from openings | Wind can carry exhaust indoors |
| CO alarms tested | The only warning you will get |
| Dry, level ground with a cover overhead | Prevents shock and tipping |
| Outdoor-rated cords, undamaged | Prevents overheating and fire |
| Nothing plugged into a wall outlet | Prevents backfeeding |
| Fuel stored away from the generator | Prevents fire |
What about power stations?
Battery power stations produce no exhaust, so they can be used indoors. They still need care: keep them dry, do not block their cooling vents, and stay within their output rating.
Sources
- US Consumer Product Safety Commission: carbon monoxide and generator safety
- Health Canada: preventing carbon monoxide exposure
- Ready.gov: Power Outages
Related
Reviewed October 2026 by Lee Palmer. This guide is general information, not professional advice. Suggest a correction.