The presence of CO in a car park signifies that other dangerous fumes (e.g. benzene) are also existing. As a result of this, the German authorities have lessened the bounds for CO in auto parking services from one hundred ppm to 50-sixty ppm, according to the federal state in dilemma. https://lorenzocwmbo.bloggerswise.com/44135024/helping-the-others-realize-the-advantages-of-car-park-ventilation