CASAC Backs Stricter Ozone NAAQS Amid Debate On Background Levels

摘要

EPA's Clean Air Scientific Advisory Committee (CASAC) is preparing to restate its support for a stricter 8-hour ozone national ambient air quality standard (NAAQS) within the agency's proposed range, even as debate lingers about whether high levels of background ozone could render a more stringent standard unworkable. On a conference call March 23, CASAC's ozone NAAQS review panel met to finalize changes to a draft letter it will shortly send to EPA Administrator Lisa Jackson, offering its opinion on EPA's proposal to revise the Bush EPA's ozone NAAQS issued in 2008 of 75 parts per billion (ppb). The Obama EPA has proposed tightening the standard to a level within a range of 60 to 70 ppb - the same range CASAC endorsed before the 2008 standard was set.