EPA Proposes Hourly Air Quality Standard For Nitrogen Dioxide, Retains Annual Limit

摘要

The Environmental Protection Agency proposed on June 29 the first ever one-hour air quality standard for nitrogen dioxide, while retaining the existing annual standard for the pollutant and expanding its monitoring network.rnEPA's proposed rule, which will be published in the Federal Register, would amend 40 C.F.R. Parts 50, 53, and 58 to create the first ever primary one-hour national ambient air quality standard for nitrogen dioxide at a level between 0.080 part per million and 0.10 ppm. The agency proposed retaining the current annual primary standard of 0.053 ppm, which is an annual average. The secondary annual standard currently also is set at 0.053 ppm.