The
U.S. Environmental Protection Agency (EPA) is proposing to tighten the
one-hour standard for measuring emissions of nitrogen dioxide (NO2),
but not change the annual standard. The long-term exposure would remain
at a maximum of 53 parts per million (0.053 ppm) while an acceptable
short-term exposure limit would be between 80 and 100 ppm (0.08 – 0.10
ppm).
The EPA believes NO2 exposure has been linked to
respiratory problems. The primary man-made sources for NO2 are motor
vehicles, coal-burning power plants and factories. In addition to
reducing the one-hour standard, the EPA will require additional
measuring devices be installed near city roadways where higher levels
may be found.
According to the EPA, ambient concentrations of
nitrogen dioxide dropped 41 percent between 1980 and 2006. All areas of
the country currently meet the existing primary annual air quality
standard, according to EPA. The EPA is not proposing any additional
actions at this time, such as further reducing auto emissions of
nitrogen oxide.
For more information on this topic or other matters of legislation that might affect the automotive aftermarket, visit SEMA online.