CASAC Reaches Consensus On Range For Tightening EPA Ozone NAAQS

摘要

EPA's Clean Air Scientific Advisory Committee (CASAC) has after several delays reached consensus that the agency should tighten its ozone national ambient air quality standard (NAAQS) from 75 parts per billion (ppb) to a range between 60-70 ppb, with the caveat that public health protections are higher at the lower end of the range. Members of a CASAC panel reviewing EPA's documents for its latest five-year review of the ozone standard are also reiterating their past support for creating a novel secondary standard to protect the environment. The overall 60-70 ppb range for the primary health-based standard is the same that CASAC has endorsed in the past, though the U.S. Court of Appeals for the District of Columbia Circuit has said that the agency is not compelled under the Clean Air Act to adhere to the panel's recommendations. CASAC weeks ago agreed on setting the lower end of the standard at 60 ppb, but panelists had to date been unable to agree on the upper limit.