Resolution CONAMA No. 491 establishing air quality standards.

This Resolution establishes air quality standards. The resolution defines air quality standards for various atmospheric pollutants, including particulate matter, sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide, and lead. The air quality standards will be implemented in four stages, with intermediate standards being adopted before the final standards are reached. The resolution also includes definitions of terms such as “atmospheric pollutant” and “air quality standard,” as well as provisions for monitoring air quality and implementing measures to control emissions taking into account the Atmospheric Emissions Control Plans and the Air Quality Assessment Reports, prepared by the state and district environmental bodies. It will be up to the competent environmental agency to establish criteria applicable to environmental licensing, observing the air quality standard adopted locally. The state and district environmental agencies must prepare, within 3 years from the entry into force of this Resolution, an Atmospheric Emissions Control Plan that must be defined by its own regulations. The Atmospheric Emissions Control Plan must consider the Quality Standards defined in this Resolution, as well as the guidelines contained in PRONAR.