Residential carbon monoxide detector failure rates in the United States.

There are more than 38 million residential carbon monoxide detectors installed in the United States. We tested 30 detectors in use and found that more than half failed to function properly, alarming too early or too late. Forty percent of detectors failed to alarm in hazardous concentrations, despite outward indications that they were operating as intended. Public health professionals should consider community education concerning detector use and should work with stakeholders to improve the reliability and accuracy of these devices.