In response to a lawsuit from states, the U.S. Environmental Protection Agency proposed new air quality standards Friday that would slash the amount of fine-particle soot allowed from smokestacks, wood-burning stoves and diesel vehicles.

The EPA said 99% of U.S. counties, because of prior anti-pollution efforts, could meet the proposed rules by 2020 without taking additional steps. Environmental and public health groups hailed the rules but critics, including the oil and gas industry, said they could force costly pollution-abatement upgrades and harm economic growth.