Out-Of-State Fuel and Colorado Vapor Pressure Requirements for the Winter/Spring Season

Fuel distributors, retailers or any other parties purchasing motor gasoline in states that
border Colorado need to be aware that gasoline fuel loaded outside of Colorado does not
always meet Colorado’s vapor pressure requirements and is not legal for either sale or use in
Colorado during the months in which the vapor pressure requirements do not align. To avoid
penalties for non-compliance, Colorado buyers must be mindful that other states’ fuel
requirements can be different from those in Colorado when ordering and purchasing fuel from
out-of-state sources.

Typically, gasoline available for sale in other states is formulated to meet the vapor pressure
specifications for those states. Due to Colorado adopting updated ASTM¹ gasoline fuel
standards into state regulations at the beginning of this year, the vapor pressure
requirements in some bordering states may no longer match those in Colorado during the
winter/spring months of December through April (see table below).

Maximum allowable vapor pressure (psi) of E10 gasoline - includes 1.0 psi waiver at retail²

^{Note: Values marked with an * do not match the Colorado standard.}

Facilities currently purchasing out-of-state motor gasoline need to coordinate with their
fuel suppliers during the months of December through April to order Colorado compliant
fuels.

Thank you for working together with the Division of Oil and Public Safety to achieve and
maintain regulatory compliance in Colorado.

¹ASTM International is an organization that develops and publishes standards for products, materials,
systems, and services to ensure their quality and safety.
²As of April 28, 2025, Nebraska no longer uses the 1.0 psi waiver, so their allowable vapor pressures do
not include that allowance.
³North of 34 degrees latitude.