Carbon monoxide during power outages

The invisible killer

Carbon monoxide (CO) is a gas produced by incomplete combustion of any carbon-based fuel: natural gas, propane, gasoline, kerosene, charcoal, or wood. It has no color, no odor, and no taste. You cannot detect it without an alarm.

CDC reports that more than 400 Americans die from unintentional, non-fire CO poisoning each year. More than 20,000 visit the emergency room. More than 4,000 are hospitalized. The risk spikes during power outages, when households turn to generators, camp stoves, and improvised heating.

CO binds to hemoglobin roughly 200 times more readily than oxygen does. At dangerous concentrations, the body cannot get enough oxygen to the brain, heart, or other organs. Death can occur within minutes in enclosed spaces with a running generator or charcoal grill.

How it happens during power outages

Generators. CPSC estimates that roughly 100 people die each year from CO poisoning caused by portable generators alone. Most deaths occur in residences. The top cause: running a generator in a garage, basement, or crawlspace. Opening a garage door or cracking a window does not provide enough ventilation to prevent lethal CO buildup.

Camp stoves and charcoal grills. Both are designed for outdoor use only. A propane camp stove with a window cracked, or a charcoal grill in an open garage, can produce fatal CO levels within an hour.

Gas ovens used for heat. A gas oven left running with the door open produces CO continuously. The kitchen may feel warmer, but the CO builds silently. This is one of the most common and most preventable CO poisoning scenarios during winter outages.

Unvented kerosene and propane heaters. Indoor-rated kerosene heaters exist but require active ventilation, a partially open window, and constant attention. Outdoor-only propane heaters brought inside are lethal.

Blocked vents. Even properly installed gas furnaces and water heaters can produce CO if their exhaust vents are blocked by snow, ice, or debris during a storm. CPSC recommends clearing snow from all outdoor vents during winter storms.

The rules that save lives

Generators: outside only, 20 feet from the house. CPSC's rule is explicit: operate portable generators outside only, at least 20 feet away from any window, door, or vent. Direct the exhaust away from the home. A porch or carport is not far enough.

No combustion appliances indoors for heat. Camp stoves, charcoal grills, outdoor propane heaters, and gas ovens are not heating devices. None of them belong inside your home during an outage, under any circumstance.

CO alarms on every level. Battery-operated or battery-backup CO alarms should be installed on every level of the home and outside every sleeping area. CPSC found that a working CO alarm was present in only about 8% of fatal CO incidents involving engine-driven tools. Test alarms monthly. Replace batteries at least annually.

Safe indoor heating alternatives. A properly vented wood fireplace with a clear chimney, or a UL-listed indoor kerosene heater with a cracked window, are the safest emergency heat sources. A battery-powered CO alarm should be running in the same room whenever any fuel is burning indoors.

Recognize it before it is too late

Early CO symptoms mimic the flu: headache, dizziness, nausea, weakness, confusion. The critical difference is that CO symptoms affect everyone in the household at the same time. If multiple people feel sick and there is a fuel-burning source running, suspect CO first.

If the CO alarm sounds: get everyone outside immediately. Do not stop to open windows. Do not try to find the source. Call 911 from outside. Do not re-enter the building until emergency responders clear it.

If someone is unconscious or unresponsive: move them to fresh air if you can do so safely. Call 911. Begin CPR if they are not breathing. CO poisoning can cause lasting brain and heart damage even in people who survive.