Any day now, the Environmental Protection Agency will decide whether to lower the maximum legal level for ozone, a pollutant that’s the main component of smog. The EPA rarely issues a new rule without controversy, but this one is already setting records for hyperbole from furious Republicans and industry groups.

On Friday, Senators David Vitter and James Inhofe wrote to the White House that the proposed rule “will represent one of the costliest rules every issued by EPA and will serve as one of the most devastating regulations.” Last week, the GOP-led House Energy and Commerce Committee claimed that studies “suggest EPA’s coming ozone changes could amount to the most expensive rule ever imposed by the agency.” The American Petroleum Institute labeled the proposal “the costliest regulations ever,” while the National Association of Manufacturers says it will be the “most expensive regulation the U.S. government has ever issued,” estimating that the rule would cost  $270 billion a year and put “millions of jobs at risk.” 

Costliest regulations, ever? That's a big claim, but even if it were true, we wouldn't know it yet: The rule hasn't been announced yet, so we don't know the details. The EPA has a court-ordered December 1 deadline to decide if it will lower the current standard to somewhere between 60-70 parts per billion or keep it as it is at 75 parts per billion. The current standard “fails to adequately protect public health,” says the American Lung Association. The EPA’s scientists, environmentalists, and public health groups have long argued in favor of an aggressive standard as low as 60. About 45 percent of the American population now live in areas that don't meet current standards.

A Congressional Research Service report on ozone found NAM's study used the strictest assumptions to generate the highest dollar value. Referring to the ozone rule as "NAAQS,” the report states, "At the moment, no one knows what a revised NAAQS would cost... But even after a proposal is signed, cost estimates will be little better than guesses." That's because the regulation has a long, decentralized implementation period, and the technological strides between now and when it's enacted are unpredictable. In the agency's words, "Technological advances over time will tend to increase the economic feasibility of reducing emissions, and will tend to reduce the costs of reducing emissions." 

But there is a tiny bit of truth to the right's overreaction. Unlike the EPA’s carbon rules for power plants, this one would require action from a broader range of industries at the source of the pollution. This explains the outcry: Ozone comes from utilities, car exhaust, gas vapors and chemical solvents, so the rule impacts factories, automobile manufacturers, and the power plant sector. It doesn't impose direct regulations on the industry, but it could mean areas that are out of the accepted level of pollution mean the state have to submit a plan to the EPA on bringing areas in compliance. 

For instance, California has more ozone-polluted cities than other states, as the map below shows:

ozone
EPA.gov

The ozone standard has been particularly controversial in the Obama Administration. The Clean Air Act requires that standards for ground-level ozone, sulfur dioxide, nitrogen oxide, and other pollutants be reviewed every five years. A 1997 review set it at 80 parts per billion. When the Bush Administration finally reviewed it in 2008, it decided on the weak standard of 75 parts per billion. Environmentalists sued, but Obama delayed his own administration’s new proposal to tighten the standard to 65 parts per billion in 2011. Obama’s decision to punt was seen as rebuke of the EPA’s own science, with the White House hoping it would improve his chances at reelection. It certainly would have made its way into Mitt Romney's campaign stump speech as an example of Obama's war on the economy. Republicans will surely make the same claim once the new proposal is public.