Meeting Air Quality Standards

In February 2021, the California Air Resources Board took action at a public hearing to change Santa Barbara County’s designation from attainment to nonattainment for the State ozone standards. This change was based on data measured at multiple locations in the County for the 3-year period from 2017 to 2019, and it is expected to be finalized by the California Office of Administrative Law (OAL) later in 2021.  View the District’s comment letter.

Air quality standards define clean air. They tell us how much of a substance can be in the air without causing harm, based on proven scientific and medical research. Both the federal and state governments set air quality standards. In most cases, California’s standards are more protective of health. The Attainment Designation tells us whether our air meets these health standards.

Federal standards have been established for seven pollutants:

  1. ozone,
  2. nitrogen dioxide,
  3. sulfur dioxide,
  4. carbon monoxide,
  5. respirable particulate matter less than 10 microns in diameter (PM10),
  6. fine particulate matter less than 2.5 microns in diameter (PM2.5), and
  7. lead.

California state standards exist for all of these, plus four more:

  1. sulfates,
  2. hydrogen sulfide,
  3. vinyl chloride (chloroethene), and
  4. visibility reducing particles.

These are the only pollutants – out of hundreds in our air – for which standards have been set. There is not enough known about the health effects of other pollutants to set air quality standards. View the State and Federal Ambient Air Quality Standards.

Santa Barbara County was designated unclassifiable/attainment for the 2015 revised federal 8-hour ozone standard on April 30, 2018 and attainment for the state ozone standard. The County is also unclassifiable/attainment for the federal PM2.5 standard and unclassified for the state PM2.5 standard. However, the County is currently nonattainment for the state PM10 standard.


To view exceedances of the standards, see Days Exceeding Ozone and Particulate Standards.

To view historical statistics on ozone and particle pollution levels in Santa Barbara County and other areas of the state, visit the California Air Resources Board air quality data base.

Santa Barbara County Attainment & Nonattainment Classification Summary

Averaging Time
California Standards
National Standards
ConcentrationAttainment StatusConcentrationAttainment Status
8 hour0.070 ppmA0.070 ppmU/A
1 hour0.09 ppm
(180 µg/m3)
Carbon Monoxide8 hour9.0 ppm
(10 mg/m3)
A9.0 ppm
(10 m/m3)
1 hour20.0 ppm
(23 mg/m3)
A35.0 ppm
(40 µg/m3)
Nitrogen Dioxide
annual average0.030 ppm
(56 µg/m3)
A53 ppbU/A
1 hour0.18 ppm
(338 µg/m3)
A100 ppbU/A
Sulfur Dioxide
annual averageRevoked
24 hour0.04 ppm
(105 µg/m3)
1 hour0.25 ppm
(655 µg/m3)
A75 ppb*
Particulate Matter (PM10)
annual arithmetic mean20 µg/m3NRevokedA
24 hour50 µg/m3N150 µg/m3A
Particulate Matter – Fine (PM2.5)annual arithmetic mean12µg/m3U12.0 µg/m3U/A
24 hour35 µg/m3U/A
Sulfates24 hour25 µg/m3A
calendar quarter1.5 µg/m3A
30 day average1.5 µg/m3A
Rolling 3-month average0.15 µg/m3U
Hydrogen Sulfide
1 hour0.03 ppm
(42 µg/m3)
Vinyl Chloride (chloroethene)
24 hour0.010 ppm
(26 µg/m3)
Visibility Reducing Particles
8 hour
(1000 to 1800 PST)

A = Attainment;  N = Nonattainment;  U = Unclassified;  U/A = Unclassifiable/Attainment;   — = No Standard

   mg/m3 = milligrams per cubic meter;  µg/m3 = micrograms per cubic meter;  ppm = parts per million;  ppb = parts per billion;


*  EPA has not yet made final designations on attainment status.  For more information, see EPA’s website.