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May 29, 2024

Dangerous Assumptions About Carbon Monoxide Putting Americans at Risk

Woman testing carbon monoxide alarm

By: Sayon Deb

“We can prevent the next death,” Daniel Krier, Minnesota state fire marshal, said after a carbon monoxide leak killed two people and a pet and sent one other person to the hospital in Princeton Township, Minn. in February 2024. 

Krier is among countless officials and advocates urging consumers to heed the call to use carbon monoxide detectors and alarms for protection from poisoning by the colorless, odorless gas that can be emitted by heating equipment or other gas-burning appliances commonly used in homes and other buildings. Without proper ventilation, CO poisoning can occur and trigger symptoms ranging from headache and fatigue to death—sending more than 100,000 people to the ER every year in the U.S.

Unfortunately, UL Standards & Engagement’s latest study, Understanding the Silent Threat: Early Detection and Prevention of Carbon Monoxide Poisoning, shows that a lack of detection options in homes and the false perception that protections exist in public spaces are consequences of a dangerous assumption that CO poisoning won’t happen to them. 

One-third of U.S. homes don’t have CO detection 

Man cooking on gas range with female seated behind himOne-third (36%) of U.S. adults – 86.2 million individuals – have no means of detecting CO leaks in their homes. Confusion about what qualifies as CO detection complicates the issue. Nearly three in ten (29%) U.S. consumers — more than an estimated 69 million Americans — say they do not need (17%) or are unsure (12%) if they need a CO alarm in the home if smoke alarms are present.

This confusion, or the choice to not use CO detectors, continues to have deadly consequences. When siblings Roy Modzeleski, Cindy Hammond, and Linda Munroe lost their parents and younger brother to carbon monoxide poisoning last December, they became unexpected advocates for alarms. “We want everybody to be aware," Linda said. "Get them. Save people's lives.” 

Potentially deadly awareness gap among generator owners 

Portable generators are a significant cause of unintentional CO poisoning. An estimated 29 million Americans own a portable generator, most often to temporarily restore power when extreme weather causes outages. Despite portable generators outsized role in carbon monoxide deaths, ULSE’s survey found that 62% said they do not feel that they or their household are at risk of CO exposure or poisoning from their generator. 

Running portable generators inside a home or closed space like a garage or RV is extremely hazardous and has claimed the lives of occupants or resulted in hospitalization. These devices should be operated at least 20 feet away from the dwelling and consumers should review the safety information provided by the manufacturer. But as these products are often bought in anticipation of a storm, many rushed consumers are not taking the time to learn about safe operation: 34% are not researching in advance of the purchase and 26% did not look up or receive information after purchase. 

Assuming CO protection exists in all public places

Woman reclining on bed in hotel roomMany Americans are unconcerned about CO in public settings like churches, daycares, restaurants, and hotels. UL Standards & Engagement’s research found that half of Americans do not worry about exposure to CO in public spaces because they trust that CO alarms are installed. Nearly half (46%) of travelers do not worry about CO exposure when staying in hotels and rental properties because they assume CO alarms are installed, and another 44% say they believe every state has laws that require alarms. In fact, codes and other regulations can vary in different states and jurisdictions. 

Lax or inconsistent requirements for CO detection systems in these public spaces has proven fatal. In 2013, Daryl and Shirley Jenkins succumbed to carbon monoxide poisoning in a hotel room in Boone, North Carolina. Tragically, the cause of death hadn’t been identified when a few weeks later, an 11-year-old boy died, and his mother suffered long-term physical effects as a result of CO poisoning in the same room. The high levels of CO were emitted by a corroded pool heater exhaust system below their room. The hotel did not have carbon monoxide detection devices installed, therefore the victims were never alerted to the need to evacuate. The Jenkins’ daughter, Kris Hauschildt, founded the Jenkins Foundation in her parents’ memory. The nonprofit organization works to prevent deaths and injuries through education and advocacy. Hauschildt also serves on the ULSE technical committee which maintains UL 2034, Single and Multiple Station Carbon Monoxide Alarms. She proposed an update to the standard which expanded its scope to cover more spaces, like motels, restaurants, and other places that may not have alarms installed. The proposal was unanimously approved by the technical committee and is now part of UL 2034. 

Product safety is critical

Safety standards are published for the products and systems which emit CO. These standards set requirements to help protect consumers from the inherent hazards as well as other operating aspects. Using products which have been certified as conforming to applicable safety standards are a significant step in preventing CO poisoning and support greater safety- particularly when consumers adhere to safety best practices. 

Safer products in the marketplace make a significant impact toward preventing CO poisonings, but consumers must also play a role in mitigating the risks. The consumer awareness gap and attitudes around CO hazards and detection indicated by the survey demonstrate the need for enhanced and expanded education initiatives. These initiatives must also drive the adoption of detection in homes and public settings because they can alert inhabitants to elevated levels of CO in the event of an appliance malfunction, ventilation blockage, or other problems. 

Preventing CO poisonings requires overcoming the dangerous assumption that carbon monoxide poisoning “won’t happen to me.” It is a very real threat which can and does happen—and can and must be prevented. 

Mitigating the risk of CO poisoning through safety standards

UL Standards & Engagement has more than 75 standards in its catalog that address carbon monoxide safety in various environments. These include detectors and alarm systems and fuel-burning products such as home heating and cooking appliances and portable generators. Some of these standards are summarized below:

  • UL 2034, Single and Multiple Station Carbon Monoxide Alarms, features performance requirements to ensure fixed and portable alarms are functional and reliable in detecting dangerous levels of carbon monoxide. The standard requires alarms to report before CO reaches levels that cause a loss of ability to react. 
  • UL 2201, Carbon Monoxide (CO) Emission Rate of Portable Generators, is the first standard for portable generators to address the mitigation of carbon monoxide emissions. Conformance to the standard requires a portable generator to limit the active CO emissions produced while running and to be equipped with a sensor that will shut the unit off if it detects a high output or accumulation of carbon monoxide. A U.S. Consumer Product Safety Commission report determined that nearly 100% of CO poisoning deaths studied would have been averted had the portable generator in use conformed to UL 2201. 
  • ANSI/CAN/UL 1008M, Transfer Switch Equipment, Meter-Mounted, provides requirements for equipment that enables homeowners to safely connect portable generator power to a home at the meter base outdoors, greatly reducing the likelihood of individuals running generators indoors in the event of a power outage.

Consumers should look for the mark of an independent testing laboratory certifying that these and other related devices and components conform to these or other applicable standards, and be aware of counterfeits, damage, or malfunctions which can render safety protections ineffective.


Sayon Deb is director of insights at UL Standards & Engagement and the author of the report, Understanding the Silent Threat: Early Detection and Prevention of Carbon Monoxide Poisoning."