Criteria air pollutants are a group of six common air pollutants regulated by the EPA. The EPA developed National Ambient Air Quality Standards (NAAQS) for these pollutants to protect public health and the environment. The six Criteria Pollutants are Ozone (O₃), Particulate Matter (PM_2.5 and PM₁₀), Carbon Monoxide (CO), Nitrogen Dioxide (NO₂), Sulfur Dioxide (SO₂) and Lead (Pb).

The Las Vegas Valley (Hydrographic Area 212) is a moderate nonattainment area for the 2015 O₃ NAAQS and an attainment area subject to a maintenance plan for the CO and PM₁₀ NAAQS. Hydrographic Areas 164A, 164B, 165, 166, 167, 212, 213, 214, 216, 217, and 218 (excluding the Moapa River Indian Reservation and the Fort Mohave Indian Reservation) are attainment areas subject to a maintenance plan for the 1997 O₃ NAAQS. Clark County is in attainment/unclassifiable for the PM_2.5, SO₂, Pb, NO₂ and 2008 O₃ NAAQS.

A detailed map of the designated areas within Clark County can be downloaded here.