Expect Tighter Particulate Matter Standards
Particulate matter (PM) is a hot button issue poised to raise business costs and litigation. The U.S. Environmental Protection Agency (EPA) was recently due to issue final PM standard revisions. EPA last year proposed stronger National Ambient Air Quality Standards (NAAQSs) for fine PM (2.5 micrometers or less in diameter (PM2.5)) and the 24-hour PM2.5 standard. However, EPA sought to keep annual PM2.5 NAAQS of 15 µg/m3. EPA’s proposal was inconsistent with a Clean Air Scientific Advisory Committee (CASAC) recommendation to reduce standards to a 13 to 14 µg/m3 range. How EPA decides to proceed and which standards it selects are closely watched topics.