Carbon Monoxide Risks During Power Outages

Power outages significantly increase the risk of carbon monoxide poisoning. When electricity fails, people turn to generators, portable gas heaters, camping stoves, and other combustion devices for light, warmth, and cooking — often inside buildings with reduced ventilation. CO poisoning deaths spike dramatically during and after major power outages and winter storms.

In the United States alone, the CDC reports that CO poisoning is responsible for hundreds of deaths during power outages each year — with the majority caused by generator use inside homes, garages, or near open windows. Understanding why outages increase CO risk, and how to manage each risk source, can prevent entirely preventable deaths.

Why Power Outages Increase CO Risk

Factor	How It Increases CO Risk
Generators used indoors or in garages	Single biggest cause of outage-related CO deaths
Portable gas heaters brought inside	Combustion in reduced-ventilation spaces
Camping stoves used for warmth or cooking indoors	Not designed for indoor use; high CO output
Charcoal grills brought inside	Rapid lethal CO buildup
Central heating turns off → alternative heating sought	Transition to higher-risk combustion sources
Windows and doors kept closed for warmth	Reduced ventilation while combustion is increased
CO detectors may also lose power	Battery backup is essential

The common thread across all these risks is that combustion devices generate CO and normal electrical equipment does not — so any shift from electrical to combustion creates CO risk.

Generators — The Highest-Risk Device

Portable petrol or diesel generators produce extremely high concentrations of CO from their exhaust:

Fatal CO concentrations can be reached within minutes in enclosed spaces.

A generator in a garage with the door open has killed people — CO flows back into the house through gaps around the interior door. A generator on a covered porch has killed people — the enclosure concentrates exhaust.

Correct Generator Use

Requirement	Detail
Minimum distance from any building	7 metres (20 feet) from doors, windows, and vents
Exhaust direction	Pointed away from the building and neighbour's buildings
Garage use	Never — even with the garage door open
Covered porch, carport, partial shelter	Never — insufficient ventilation
Open window or vent facing the generator	Check before starting; exhaust can enter through any opening
CO detector inside the building	Required when operating a generator outdoors
Never refuel while running	Fire risk and continued CO exposure

⚠️ There is no safe location for a generator indoors, in a garage, in a tent, or under a covered structure. "Cracking a window" does not make it safe. The only safe generator operation is fully outdoors, at least 7 metres from all openings, with exhaust directed away from all structures. Battery CO detectors should be used in every room of the home when running an outdoor generator.

CO Detector Battery Backup

If power is out, CO detectors with mains-only power will not function. Before a potential outage event:

• Confirm your CO detectors have battery backup
• Replace batteries annually regardless
• Consider purchasing battery-only CO detectors as backups for extended outages

Portable Gas Heaters During Outages

When central heating fails in a power outage, portable bottled gas heaters (propane, butane, LPG) are a common response. These require careful management:

1. Only use in a room with active ventilation — a window open at least 5cm is the minimum; a trickle vent alone is insufficient for a burning heater
2. Never sleep with a portable heater running — turn it off before sleeping; use extra bedding instead
3. Run only in short cycles — heat the room, turn it off, retain warmth with insulation
4. CO detector must be functional in the room — battery-powered
5. Size the heater appropriately — a large heater in a small room accumulates CO more quickly than a small heater in a large room
6. Catalytic heaters produce less CO than radiant burners — if you can choose, catalytic is preferable

Camping Stoves for Cooking During Outages

Using a camping stove for cooking is common in extended outages. This carries risk that can be managed:

Safer approach:

1. Open doors and windows when cooking — treat it as outdoor cooking
2. Keep cooking brief — do not use the stove for extended simmering
3. Never use for heating — cooking output is brief and ventilated; heating runs continuously and is not

Never do:

• Use a camping stove as a heater
• Use in a small room (bathroom, bedroom) for warmth
• Use charcoal-fuelled camping equipment indoors — this includes Asian-style tabletop charcoal grills

Cold Rooms During an Outage — Safe Warmth Alternatives

The pressure to use risky heating during an outage comes from the genuine discomfort and danger of cold. Safe warm alternatives:

Method	Effectiveness	CO Risk
Extra clothing (wool, thermal base layers)	High	None
Sleeping bags rated for low temperatures	High	None
Multiple duvets / blankets	High	None
Warm drinks (if gas hob available with ventilation)	Moderate	Low
Body heat — stay in one room with all household members	High	None
Insulating windows and door gaps with towels, curtains	Moderate	None
Hot water bottles (using gas hob briefly)	Moderate	Low
Moving in with neighbours or to shelter	High	None

Hypothermia risk from a cold home is real, but it takes hours to develop. Lethal CO concentrations from a generator or charcoal can develop in minutes. Choose the low-risk warming option first.

Preparing Your CO Detection for Outages

Before an anticipated outage event (storm warning, infrastructure instability):

1. Test all CO detectors — press and hold the test button
2. Replace batteries in all detectors even if not expired
3. Purchase additional battery CO detectors if you plan to use a generator
4. Place CO detectors in every room where a combustion device may be used
5. Brief all household members on what to do when an alarm sounds — this must be planned before the outage, not during it

Responding to CO Alarm During an Outage

A CO alarm during a power outage creates an additional hazard — the building is already compromised. The response is the same regardless:

1. Evacuate immediately — do not stop to collect belongings
2. Leave doors open to ventilate the building
3. Call 999 / 911 from outside — describe the power outage and CO alarm
4. Do not return until cleared by emergency services and gas network
5. Do not turn off the generator or enter the garage if that is the source — CO in a closed space will affect you within seconds

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Quick Reference

Device	Safe Indoors?	Key Rule
Petrol/diesel generator	Never	7m from all openings; outdoors only
Portable gas heater	Only with ventilation	Never while sleeping
Camping stove	Cooking only, with ventilation	Never for heating
Charcoal grill	Never indoors	Fatal; no exceptions
Electric heaters	Yes	No CO risk
CO detector during outage	Battery backup required	Test before expected outage
Warm alternatives	Clothing, bedding, one room	Safe; should be first choice