On October 1, 2015, after years of delay punctuated by litigation and political maneuvering, the U.S. Environmental Protection Agency issued revised national ambient air quality standards for ground-level ozone. Last set at 75 parts per billion (ppb) in 2008, the new standard of 70 ppb has already elicited promises of legal challenges from industry and environmental advocates. High levels of ozone are linked to respiratory illness, especially among children and the elderly. Environmental and public health advocates had succeeded in obtaining a court order setting the October deadline, but many have expressed disappointment that the new standard does not go far enough to adequately protect public health. Industry groups, on the other hand, have decried the rule as unnecessary and claim it will cripple the economy in any place deemed out of compliance with the new standard. On October 15, 2015, the Environmental Law Institute convened a panel of attorneys who either worked on promulgating the rule or advocated for clients during its development. Here we present a transcript of the discussion, which has been edited for style, clarity, and space considerations.