Health risks due to low concentrations of carbon monoxide

Inhaling carbon monoxide, for instance due to a malfunctioning central heating system in the home, may be harmful to health. That goes not only for high concentrations, as is often presumed, it goes for low concentrations as well. The World Health Organization (WHO) recommends to avoid prolonged exposure to low concentrations of carbon monoxide. When exposed during eight hours, the average carbon monoxide concentration in air should not exceed 9 ppm (parts per million), according to WHO. The guideline value is 6 ppm when exposure lasts twenty four hours.  

Carbon monoxide alarms on the market in the Netherlands, do not detect concentrations below 10 ppm and they only give an acoustic alarm at and above 50 ppm. The Health Council of the Netherlands recommends furthering that carbon monoxide alarms be adjusted to the WHO values. In addition, the Health Council advises to pay greater attention to the risks of exposure to low concentrations of carbon monoxide in the information given to the public, emergency services and installation companies.