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…
soot
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…