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Winter/Spring 2006 Vol. 6 No. 1

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©Stephanie Carter Setting Standards for Vehicle Emissions

California has become synonymous with strict environmental standards, some of which can be traced to a 1952 discovery by a scientist at the California Institute of Technology who found that nitrogen oxides and hydrocarbons emitted by vehicle engines and fuels interact in the presence of ultraviolet radiation to form ozone, a key component of smog. That finding, along with studies showing how unhealthy smog could be for humans, sparked the movement to regulate vehicle emissions. By the early 1960s, California had established the nation's first standards to control such emissions.

In 1967, Congress recognized California's leadership in regulating emissions -- and the fact that it had 10 million vehicles and some of the worst pollution in the country -- by exempting the state from a section of the newly passed Clean Air Act which dictated that federal emissions standards pre-empt state standards. California could set its own standards for vehicles as long as they were as protective in the aggregate as federal standards. A decade later Congress went a step further when it allowed other states to adopt California standards in lieu of federal regulations.

A new report from the National Research Council says that over the years California has enacted more aggressive emissions standards, just as Congress intended, which also had the added benefit of driving innovations in emission-control technology. And it did so by following standard-setting practices and procedures similar to EPA's. The report warns, however, that the ability for California to set tighter standards -- and for other states to follow its lead -- is still needed. Even now, California has some of the worst air quality conditions in the country, and along with other states, needs tougher vehicle emissions rules in order to meet EPA's overall air quality standards.

The report says that EPA could help by streamlining the process for granting a waiver, which must be obtained by California each time it sets a new emission standard. Currently, EPA only grants waivers to California, but the report says that the agency also should play a role in other states' adoption of California standards. The committee that wrote the report could not agree on whether EPA's participation should include a waiver process for other states, but it did say that the agency's opinion could help prevent or settle legal disputes that arise when automakers claim difficulty complying with California standards when they are adopted elsewhere. For example, cars made to meet California's emission standards may not achieve a similar standard or operate efficiently in another state because of colder weather or different fuel composition.   -- Bill Kearney

State and Federal Standards for Mobile Source Emissions. Committee on State Practices in Setting Mobile Source Emissions Standards, Board on Environmental Studies and Toxicology, Division on Earth and Life Studies (2006, approx. 310 pp.; ISBN 0-309-10151-4; available from the National Academies Press, tel. 1-800-624-6242; $30.00 plus $4.50 shipping for single copies).

The committee was chaired by David Allen, Melvin Gertz Regents Professor in Chemical Engineering, and director, Center for Energy and Environmental Resources, University of Texas, Austin. The study was funded by the U.S. Environmental Protection Agency.

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Copyright 2006 by the National Academy of Sciences