California Air Resources Board

The Health and Safety Code (H&SC) section 39607(e) requires the California Air Resources Board (CARB) to establish and periodically review area designation criteria. These designation criteria provide the basis for CARB to designate areas of California as attainment, nonattainment, or unclassified for the State standards.

In addition, H&SC section 39608 requires CARB to use the designation criteria to designate areas of California and to annually review those area designations. CARB makes area designations for ten pollutants: ozone, suspended particulate matter (PM₁₀ and PM_2.5), carbon monoxide, nitrogen dioxide, sulfur dioxide, sulfates, lead, hydrogen sulfide, and visibility reducing particles.  CARB made the first area designations for State ambient air quality standards (State standards) in 1989.  H&SC 39608 also requires CARB to conduct an annual review of the area designations and update them as appropriate.  These updates are based on the three most recent calendar years of complete and validated air quality data.

Information regarding the statutory requirements, as well as maps of current area designations, can be found through the Resources tab on the left.