In accordance with the relevant provisions of the Air Pollution Prevention and Control Law of the People's Republic of China,the Ministry of Ecology and Environment in collaboration with the National Health Commission formulated the List of Toxic and Hazardous Air Pollutants(2018)(hereinafter referred to as the Air List).Based on the Inventory of Priority Controlled Substances (First Batch),the Water List selects 11 categories of chemical substances that can be controlled and discharged into the air environment:six volatile organic compounds, including dichloromethane, formaldehyde,chloroform,trichloroethylene, tetrachloroethylene, and acetaldehyde,five heavy metals substances including cadmium and cadmium compounds,chromium and its compounds,mercury and mercury compounds, lead and lead compounds, and arsenic and arsenic compounds.