Current Regulations: Winter (Oct. - March) ethanol mandate (min. 3.5 wt% oxygen content) in Clark County (Las Vegas; see Clark County Air Quality Regulations, Section 53), and (Oct. - Jan.) oxygenated gasoline (min. 2.7 wt%) program in Washoe County (Reno; see Washoe County District Health Department, Air Quality Management Division, regulation 040.095).

MTBE in gasoline was phased out in Washoe County on the same date as California (see Washoe County District Board of Health regulations governing air quality management at Section 040.095, last amended 10/25/00); after the effective date in California, the MTBE cap is 0.3 vol%.

On April 22, 1999, Clark County adopted winter (Nov. - March) gasoline standards, adding CA sulfur limits (40 ppm flat or 30 ppm avg./80 ppm cap) and aromatics limits (25 vol% limit or 22 vol% avg./30 vol% cap) to existing max. 9.0 psi RVP and 10 vol% ethanol winter (Oct. - Mar.) standards. See Clark County Air Quality Regulations, Section 54. The Clark County Board of Commissioners adopted Ordinance 3809 suspending the CBG Rule, effective 9/29/09.

On November 24, 2004, EPA announced enforcement discretion (temporarily until midnight on November 29) for gasoline in Clark County provided that the gasoline meets CaRFG3 or AZ Cleaner-Burning Gasoline standards.

Effective January 11, 2005, EPA announced enforcement discretion to permit the use of alternative gasoline in Clark County until midnight on January 18. The alternative gasoline should be CaRFG3. If CaRFG3 is not available, then conventional gasoline (including AZ Cleaner-Burning Gasoline) may be used.

Gasoline sulfur standards: 800 ppm cap for central and northeast Nevada, 300 ppm cap for southern and western Nevada. See Nevada Administrative Code 590.065(5). Effective January 1, 2004, these gasoline sulfur standards are superseded by more stringent national, federal gasoline sulfur regulations.

Nevada Administrative Code NAC 590.050 includes ASTM D 975-01a for diesel, and 590.061 and 590.065 include ASTM D 4814-01a for gasoline. These are enforced by the Nevada Department of Agriculture, Division of Measurement Standards, Bureau of Petroleum Technology.

Summer Federal Phase II RVP: Max. 7.8 psi RVP gasoline is required in the Washoe County (Reno) former 1 hr. ozone nonattainment area. Max. 9.0 psi RVP gasoline is required elsewhere. The summer maximum RVP limitation shall be 1 psi higher for conventional gasoline blends containing 10 vol% ethanol per Clean Air Act section 211(h)(4). 

Last updated August 2010