Effects of Low-Purge Vehicle Applications and Ethanol-Containing Fuels on Evaporative Emissions Canister Performance

The California Air Resources Board (CARB) LEV II regulations require less than 500 mg of vehicle evaporative emissions which, typically requires canister emissions of less than 200 mg. PZEV regulations require less than 350 mg vehicle emissions and zero emissions (< 54 mg) from the fuel system.

Activated carbon canister emissions of less than 20 mg are typically required in order to meet PZEV regulations. LEV II canister emissions levels can typically be achieved through a combination of canister design, sufficient purge volumes, use of the appropriate activated carbon or combination of carbons, and in some cases an activated carbon honeycomb.