February 17 Draft AQ Handbook - California Air Resources …

On review of all of the evidence, the State of California Air Resources Board (ARB) staff recommended a standard of 0.09 ppm averaged over 1-hour. The decision to maintain a one-hour averaging time was made for “historical reasons” (1). In July, 1997, the U.S. Environmental Protection Agency promulgated an 8-hour standard of 0.08 ppm (157 ... ................
................