The presence of CO in an automobile park suggests that other dangerous fumes (e.g. benzene) also are current. As a result of this, the German authorities have decreased the limits for CO in car parking services from a hundred ppm to 50-sixty ppm, depending upon the federal condition in question. https://collinjapcp.blog5star.com/37088280/helping-the-others-realize-the-advantages-of-car-park-ventilation