A 1977 amendment to section 111 directed EPA to take a new approach to setting NSPSs for three pollutants from combustion of fossil fuels-sulfur dioxide, nitrogen dioxide, and particulates.

• 1977年修正案第111条规定环境保护局要采用新方法解决《新污染源运行标准》的3类污染物问题。 3类污染物都来自矿物燃料，即二氧化硫、二氧化氮和颗粒物。