Evaporative Emission Controls for On-Road Motor Vehicles

This page last reviewed August 6, 2010


The ARB administers a program for reducing evaporative emissions from on-road motor vehicles, including motorcycles. These reductions are accomplished using specific emission standards and test procedures. The current Low Emission Vehicle II evaporative (or "LEV II Evap") emission standards and test procedures were formally adopted in August 1999, as part of the second phase of ARB's Low Emission Vehicle (or "LEV II") regulations. The program also includes emission standards and test procedures for reducing motor vehicle refueling emissions ("On-Board Refueling Vapor Recovery" or "ORVR"). The current ORVR regulations were also adopted in August 1999 under the LEV II amendments. Authority for controlling on-road motor vehicle evaporative and ORVR emissions is established in sections 1976 and 1978, title 13, California Code of Regulations (CCR), respectively.

What's New...

On January 14, 2010, the California Office of Administrative Law approved ARB's proposed changes to the motor vehicle evaporative and refueling emission test procedures that pertain to plug-in hybrid electric vehicles. Further information about these proposed changes, as well as the regulatory process involved, is available on the Zero Emission Vehicle Program webpage under Hybrid Electric Vehicle Test Procedures.

Current Regulations and Test Procedures

Evap & ORVR Emission Warranty Changes

Minor changes to the LEV II Evap and ORVR test procedures were included as part of the amendments to California's emission warranty information reporting and recall regulations that were adopted by ARB on March 22, 2007, and became effective on January 4, 2008.

Evap "Streamlining" Changes

On June 22, 2006, ARB adopted minor technical amendments for "streamlining" the LEV II Evap and ORVR test procedures, without changing the stringency of the existing emission standards. The amendments became effective on February 17, 2007.

LEV II Evap Background

The "LEV II" and "Compliance Assurance Program" (or "CAP2000") amendments were formally adopted by ARB on August 5, 1999; approved by the California OAL on October 28, 1999; and, became operative on November 27, 1999.


Where Can I Get More Information?

For more information, please contact Leela Rao, Emission Research Section, at (626) 350-6469.