Yesterday, 22 members of the House of Representatives wrote to EPA Administrator Stephen Johnson urging him to tighten the national standard for ozone, a.k.a. smog. In June, EPA proposed a range of 0.070 parts per million (ppm) to 0.075 ppm for the new standard. The current standard is 0.084 ppm. While any standard within EPA's proposed range would be an improvement, it may not be good enough. As the congressmen point out: The EPA's panel of expert science advisors, the Clean Air Scientific Advisory Committee (CASAC), unanimously found that the smog standard "needs to be substantially reduced to protect human health, particularly in sensitive subpopulations." . . . CASAC called for [a] standard of .060 to .070 ppm. Experts on lung health, including the American Thoracic Society and the American Lung Association, are calling for a standard of .060 ppm given the strength of the scientific evidence. The congressmen's point is important because the Clean Air Act requires EPA to periodically revise the standard in order to protect public health and to make decisions that "reflect the latest scientific knowledge." The bipartisan group (16 Democrats and six Republicans) concludes by asking Johnson to adopt a standard within CASAC's recommended range. Unfortunately, the congressmen miss another key aspect of the Clean Air Act. The Act prohibits EPA from considering monetary costs or benefits when setting the standard. EPA must set the standard solely based on public health considerations. Later, when EPA provides the regulated community with guidance on how to use pollution reduction methods to meet the standard, economics are considered. Nonetheless, the letter makes an economic argument: "It is interesting to note that studies have shown that there are large economic benefits to lowering the air pollution burden on public health and the environment." Even when a tighter ozone standard would be an economic boon, EPA cannot consider the monetary benefits. An economically beneficial regulation may be good policy, but it is inappropriate to argue the point here, based on the language in the Clean Air Act. The debate over EPA's revision to the ozone standard must be one of science and public health, not economics.