Portable generators can keep essential equipment running during an outage, but their engines produce carbon monoxide (CO): a poisonous gas that has no smell, taste or colour. A running generator does not become safe merely because a garage door, window or shed door is open.
The safest first decision
Never run a portable generator inside a home, garage, basement, shed, camper or other enclosed or partly enclosed space. The US Consumer Product Safety Commission says to use a generator outside only, at least 20 feet from the home, with its exhaust directed away from the building. Canadian households should also follow the generator manufacturer's instructions and local fire, electrical and building requirements; this article does not replace those rules.
Check the location before the power fails
- Choose a dry outdoor operating position that follows the manufacturer's weather instructions.
- Measure the distance from doors, windows and vents rather than estimating it in the dark.
- Point the exhaust away from the home and away from neighbouring buildings or occupied outdoor areas.
- Check that no air intake, open window or door can draw exhaust back inside.
- Do not move the generator into a garage, porch enclosure or shed because of rain; use only a weather solution allowed by its manufacturer.
CPSC's 20-foot direction is specific US federal safety guidance. Health Canada warns that outdoor fuel-burning equipment can expose people when used in homes, garages, sheds, campers and other poorly ventilated areas, including outdoor locations near an air intake. When requirements differ, follow the stricter applicable instruction.
CO alarms are a second layer, not permission for unsafe placement
CPSC recommends battery-operated CO alarms, or alarms with battery backup, on every level of the home and outside sleeping areas. Interconnected alarms are preferable because one alarm can trigger the others. Alarm placement and replacement requirements may differ by province, state, municipality, building type and product model, so also check the alarm instructions and local fire authority.
Test alarms according to the manufacturer's schedule before storm season or planned generator use. Record each unit's manufacture date, replacement date, power source and end-of-life signal. A successful test-button check does not prove that a generator is safely located.
If a CO alarm sounds
Leave immediately for fresh air and contact emergency services from outside. Do not stay inside to search for the source, silence the alarm or open more windows. Do not re-enter simply because the alarm stops; wait for emergency responders or the responsible authority to say it is safe.
Symptoms are not a reliable early-warning system
CPSC lists headache, dizziness, weakness, nausea, vomiting, sleepiness and confusion among possible CO-poisoning symptoms. People can be affected before recognizing the danger. If CO exposure is suspected, get outside immediately and seek emergency help. This guide cannot diagnose or treat exposure.
Connection and fuel checks
- Never connect a generator directly to household wiring unless a qualified professional has installed an approved transfer system that meets local requirements.
- Follow the generator manual for grounding, load limits, extension cords, refuelling and cool-down time.
- Store fuel only in approved containers and in a location permitted by local fire rules.
- Keep the generator, cords and fuel away from children and from ignition sources.
- Arrange qualified inspection or service if the generator is damaged, behaves unusually or has been recalled.
A five-minute outage card
Write the approved generator location, setup sequence, emergency number, fuel type and the appliances that may be powered on a paper card stored with the equipment. Add a reminder that every person and pet leaves immediately if a CO alarm sounds. This reduces improvisation during darkness, severe weather or a stressful outage.
US and Canada jurisdiction limits
The 20-foot placement statement and US mortality statistics on the CPSC page apply to US guidance and data. Health Canada's source and exposure guidance applies nationally, while installation, alarm and electrical rules can be provincial, territorial or municipal. Verify the rules for the property's location and the exact generator model before use.