What is the acceptable carbon monoxide (CO) reading for a residence?

The acceptable carbon monoxide (CO) reading for a residence is 9 parts per million (ppm). This level is regarded as safe and is primarily informed by guidelines set by health organizations, including the Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC). These organizations indicate that low concentrations of CO, like 9 ppm, have minimal short-term health effects.

Monitoring and managing CO levels in residential areas is crucial, as higher concentrations can lead to serious health risks. Readings above 9 ppm often indicate the need for further inspection or intervention, as they could signify unsafe conditions. While there are other readings provided in the options that may seem nominal, they exceed the threshold considered safe for long-term exposure. Therefore, 9 ppm is established as the optimal guideline for ensuring the health and safety of individuals in a residential setting.