Legal analysis: the emission standard of air pollutants is the limit standard for the quantity or concentration of pollutants discharged into the atmosphere in order to control the emission of pollutants and make the air quality meet the environmental quality standards. Particulate matter 20 mg/m3 (daily average), 30 mg/m3 (time average); HCl 50mg/m3 (daily average) and 60mg/m3 (hourly average); SO2 80 mg/m3 (daily average), 100 mg/m3 (time average).

Legal basis: Article 15 of the Environmental Protection Law of People's Republic of China (PRC), and the competent department of environmental protection of the State Council formulates national environmental quality standards. The people's governments of provinces, autonomous regions and municipalities directly under the Central Government may formulate local environmental quality standards for projects not specified in the national environmental quality standards; For projects that have been stipulated in the national environmental quality standards, local environmental quality standards that are stricter than the national environmental quality standards can be formulated. Local environmental quality standards shall be reported to the competent department of environmental protection of the State Council for the record. The state encourages the development of environmental benchmark research.