soot

The U.S. Environmental Protection Agency (EPA) in February issued a final rule imposing tighter restrictions on fine particulate matter (PM2.5) or soot.  The final rule, issued on Feb. 7, strengthens the nation’s National Ambient Air Quality Standards (NAAQS) by lowering the level of the primary (health-based) annual PM2.5 standard from 12.0 micrograms per cubic meter […]

In a significant but controversial final action, the Environmental Protection Agency (EPA) on Dec. 7 retained its existing National Ambient Air Quality Standards (NAAQS) for both fine and coarse particulate matter (PM2.5 and PM10). While the EPA said the decision came “after careful review and consideration of the most recent available scientific evidence and technical […]