What FEco level is typically associated with a non-smoker?

The typical level of exhaled carbon monoxide (FEco) associated with a non-smoker is under 10 ppm (parts per million). This range reflects the absence of significant tobacco smoke exposure, as non-smokers generally have lower carbon monoxide levels in their breath. Smoking introduces carbon monoxide into the bloodstream, leading to higher FEco levels. Therefore, a reading below 10 ppm is considered an indicator of a person's non-smoking status or low exposure to carbon monoxide from other sources. Thus, under 10 ppm is a standard benchmark for assessing smoking status in patients.