National Ambient Air Quality Standards (NAAQS)

National Ambient Air Quality Standards (NAAQS) are concentration limits for six common pollutants set by the U.S. Environmental Protection Agency (EPA) under the Clean Air Act to protect public health and welfare: 

• Carbon Monoxide (CO)
• Lead (Pb)
• Nitrogen Dioxide (NO₂) (part of nitrogen oxides)
• Ozone (O₃) (ground-level)
• Particulate Matter (PM) (including PM₂.₅ and PM₁₀)
• Sulfur Dioxide (SO₂) (part of sulfur oxides) 

In addition, California adds four additional pollutants:

• Sulfates
• Hydrogen Sulfide
• Vinyl Chloride (chloroethene)
• Visibility Reducing Particles 

Districts that meet all the standards are said to be in "attainment."  NoSoCo Air is in attainment for the federal and state ambient air quality standards.

Hot Spots

California's AB 2588 Air Toxics "Hot Spots" Information and Assessment Act is a state program requiring industrial facilities to report their routine air toxic emissions, assess associated public health risks, notify nearby residents of significant risks, and ultimately reduce those emissions.  Air Districts, including NoSoCo Air provide an annual report that summarizes and discusses the risk of permitted facilities.

<2025 Report>