Generator CO Safety Check

Portable generators are the single leading product cause of carbon monoxide deaths in the United States. Between 85 and 100 people die each year from generator-related CO poisoning, and hundreds more are hospitalized. Most of these deaths occur during power outages, when generators are placed too close to the home or operated in garages, basements, or other enclosed spaces.

The core rule is simple: place your generator at least 20 feet from any door, window, or vent, with the exhaust pointed away from the building. But power outage situations create pressure to cut corners, the generator feels too far away, the extension cord is not long enough, or rain and cold push people to move it closer to shelter. That is when the risk spikes.

This 2-minute safety check evaluates your generator setup and power outage habits across six areas: generator placement, enclosure risk, CO safety features, CO detector status, alternative heat sources, and vehicle idling. Based on your answers, you will get a clear safety assessment and a prioritized action list.

Nothing above is law, and that is worth stating plainly on a page that hands you a number. We hold carbon monoxide law for all 51 US jurisdictions and searched every record: the 20 feet appears in none of them, and a generator is named at all in only seven. The rules that do exist attach the alarm to a building, which is exactly the thing a portable generator sits outside of. The one place in the fifty-one that puts a detector on the generator's user instead is Reno, Nevada, and it got there by regulating food trucks: a mobile vendor running an ancillary power source has to carry a carbon monoxide detector in the unit. Carbon monoxide appears in Reno's code exactly once, and that is it. The reasoning transfers to a driveway better than the drafting suggests, because a vendor and a homeowner during an outage are in the same position - an engine running a few feet from an enclosed space somebody is standing in, and no building alarm anywhere near it.

Critical warning: If you are currently running a generator inside your home, garage, basement, or any enclosed or partially enclosed space, turn it off immediately, open all doors and windows, and move everyone outside. Call 911 if anyone feels dizzy, has a headache, or is nauseous.

In 2 Minutes

• One portable generator produces as much CO as hundreds of idling cars, concentrations can reach lethal levels in minutes in an enclosed space.
• The CPSC recommends at least 20 feet between a generator and any door, window, or vent, with exhaust directed away from the building.
• A garage is never safe for generator operation, even with the door fully open, CO accumulates faster than it disperses.
• CO-sensing shutoff generators exist and the two standards behind them are not equal. CPSC staff modelled 511 deaths and found generators meeting UL 2201 would avert nearly 100 per cent of them, while generators meeting only PGMA G300 would avert about 87 per cent, leaving 69. UL 2201 shuts the engine down at 150 ppm on a 10-minute rolling average or 400 ppm instantly; G300 allows twice that, 400 ppm and 800 ppm. Look for UL 2201.
• Generators are not the only power outage CO risk, charcoal grills, camp stoves, kerosene heaters, and cars idling in attached garages also produce deadly CO levels indoors.
• A working CO detector near sleeping areas is your last line of defense if CO enters the home despite precautions.

What This Check Covers

• How far your generator is placed from the building and whether exhaust is directed away.
• Whether you have ever operated a generator in a garage, basement, porch, or carport.
• Whether your generator has a CO-sensing automatic shutoff feature.
• Whether you have working CO detectors near sleeping areas during power outages.
• Whether you use any other CO-producing equipment indoors during outages.
• Whether vehicles are ever left running in an attached garage.

Start the Check

How to Interpret Your Result

This check evaluates your generator setup and power outage habits against CPSC, CDC, and NFPA safety guidelines.

• Setup Looks Safe: Your generator placement and power outage habits align with CPSC, CDC, and NFPA safety recommendations. Your generator is positioned at a safe distance, you have working CO detectors, and you avoid indoor use of CO-producing equipment.
• Risks Identified: No immediately life-threatening practices were found, but one or more habits increase your CO exposure risk, especially during prolonged outages or adverse weather. Specific corrections are provided below.
• Serious Hazard: Your current setup or habits include practices directly associated with CO poisoning deaths. Immediate changes are required, specific hazards and corrections are detailed below.

Sources & References

1. City of Reno, Nevada, Reno Municipal Code, mobile vendor ancillary power source . The only rule in our 51-jurisdiction survey that requires a carbon monoxide detector to travel with the generator rather than sit in a building. Carbon monoxide appears once in Reno's code and this is it, found by a full-code read on our municipal survey; the index answered on the same pass with 449 hits for "building" and 562 for "alarm", so the single hit is a finding rather than a search that failed.
2. U.S. Consumer Product Safety Commission (CPSC), Generators and Engine-Driven Tools . "NEVER use portable generators indoors or in garages, basements, or sheds. They should always be used outside well away from windows, doors, vents, or any other opening." The 20-foot figure is on the CO Information Center, not on this page.
3. CPSC, Carbon Monoxide Information Center . "More than 200 people in the United States die every year from accidental non-fire related CO poisoning associated with consumer products. More than 100 of those deaths are linked to portable generators", one generator producing "the same amount of carbon monoxide as hundreds of cars", and the 20-foot rule: "Use generators outside only, at least 20 feet away from homes with exhaust facing away."
4. Centers for Disease Control and Prevention (CDC), Generator Safety Fact Sheet . A one-page fact sheet, downloadable in nine languages. Its own words: "Only use generators outside, more than 20 feet away from your home, doors, and windows." It gives no annual death count beyond "hundreds of people every year".
5. U.S. Environmental Protection Agency (EPA), Power Outages and Indoor Air Quality . Covers generators, cooking, heating, and lighting CO risks during power outages.
6. American Red Cross, Safe Generator Use . Backfeeding, which is the hazard nobody else here covers: "Never try to power the house wiring by plugging the generator into a wall outlet." Developed with CDC, NFPA and CPSC, named on the page. It gives no distance.
7. Ready.gov (FEMA/DHS), Power Outages . "20 feet away from windows, doors and attached garages", the one source here that names attached garages in the same breath as the distance.
8. OSHA, Carbon Monoxide Poisoning, Portable Generators . OSHA's worker card. The clearance figure is the one a homeowner will not find elsewhere: "Make sure the generator has 3 to 4 feet of clear space on all sides and above it."
9. UL Solutions, Safety Standard for Portable Generators, 88 FR 24336 (20 April 2023) . CPSC's own rulemaking, and the readable source for what UL 2201 actually requires: a weighted CO emission rate limit of 150 g/h and shutoff at "150 parts per million by volume (ppmv) of CO during a 10-minute rolling average" or "an instantaneous reading of 400 ppmv". It also gives PGMA G300's weaker figures, 400 ppmv rolling and 800 ppmv instantaneous, and CPSC's staff estimate that UL 2201 would avert nearly 100 per cent of 511 modelled deaths against about 87 per cent for G300.
10. NFPA, Generator Safety Tip Sheet . NFPA's generator tip sheet. The landing page carries only the framing, "portable generators emit carbon monoxide (CO), a poisonous, deadly gas"; the tips themselves are in the downloadable sheet.
11. PIRG Education Fund, Portable Generators Kill About 100 People Each Year . "About 100 people have died each year from carbon monoxide poisoning associated with portable generators." Advocacy analysis, and useful for its finding that manufacturer manuals still print clearances as small as 5 feet against CPSC's 20-foot minimum.