Review of Ozone Standards: April 2005 Board Meeting Summary

This page reviewed November 24, 2009.

On April 28, 2005, the California Air Resources Board (ARB) approved the nation's most health protective ozone standard with special consideration for children's health. The Board's actions included:
  • Establish a new 8-hour-average standard for Ozone at 0.070 ppm, not to be exceeded.

  • Retain the current 1-hour-average standard for ozone at 0.09 ppm, not to be exceeded.

  • Retain the current monitoring method for Ozone, which uses the ultraviolet (UV) photometry method, for compliance with the state Ambient Air Quality Standard for Ozone.
At the April 28 hearing, the staff presented a modified health benefits analysis, using a different methodology than the analysis presented in the Staff Report released on March 11, 2005. The modifications were developed in response to public comments received on the Staff Report. The health benefits analysis was included to inform people in practical terms of the potential health benefits from attaining the California ozone standards. Also included in the modified analysis was an analysis of the incremental benefits of attaining the federal and California ozone standards, also in response to public comments. The Board requested staff to modify the staff report to incorporate the health benefits analysis modifications presented and to make that text available to the public.
The next step in this process will involve a 15-day notice of public availability of modified text from the staff report, which will incorporate clarifications of the methodology used to quantify the health benefits of attaining the new Ozone standards. The modifications are indicated in underline/strikeout type. In addition, typographical errors in the titles to several references will also be corrected.
Following the 15-day review and comment period, the Executive Officer approves the modified text and the standards will be adopted. Staff will prepare the Final Statement of Reasons or "FSOR" for final submittal to the Office of Administrative Law. We anticipate that the adopted standards will go into effect in January 2006. For a full list of the regulatory documents, please go to our web site at

For more information on review of the ozone ambient air quality standard, please contact
Dr. Deborah Drechsler at (916) 323-1526 or email at

Ambient Air Quality Standards Review
Ozone Standards Review