The existence of CO in a vehicle park signifies that other hazardous fumes (e.g. benzene) are current. Due to this, the German authorities have decreased the bounds for CO in automobile parking services from one hundred ppm to 50-60 ppm, with regards to the federal condition in issue. Odor Command: https://basementventilation24566.webbuzzfeed.com/37038936/basement-ventilation-fundamentals-explained