CRS INSIGHT Prepared for Members and Committees of Congress
INSIGHTi
Year-Round Sale of E15
Updated February 6, 2025
E15—a fuel blend of up to 15% ethanol and 85% gasoline—generally cannot be sold during the summer driving season (June 1–September 15) because it does not meet the gasoline Reid Vapor Pressure (RVP) requirements, which limit fuel volatility under the Clean Air Act (CAA). The statute, however, allows the U.S. Environmental Protection Agency (EPA) Administrator to issue a temporary fuel waiver of these requirements (42 U.S.C. §7545(c)(4)(C)(ii)) under certain conditions. On April 19, 2024, EPA issued the first nationwide fuel waiver for the 2024 summer driving season, and on August 27, 2024, it issued its seventh consecutive (and final) nationwide fuel waiver for the 2024 summer driving season. The waiver allowed for “the continued sale of E15 during the summer driving season” to address “extreme and unusual fuel supply circumstances caused by a confluence of events including the ongoing war in Ukraine and conflict in the Middle East that are affecting all regions of the Nation.”
President Trump’s January 20, 2025, Executive Order (EO) 14156, “Declaring a National Energy Emergency,” included a provision about the year-round sale of E15 (see Section 2(b)). The EO states:
(b) Consistent with 42 U.S.C. 7545(c)(4)(C)(ii)(III), the Administrator of the Environmental Protection Agency, after consultation with, and concurrence by, the Secretary of Energy, shall consider issuing emergency fuel waivers to allow the year-round sale of E15 gasoline to meet any projected temporary shortfalls in the supply of gasoline across the Nation.
The statutory provision referenced in the EO is the third of three factors the EPA Administrator must consider when determining whether to issue a temporary fuel waiver: whether the waiver is “in the public interest.” The EO directs the EPA Administrator to consider issuing—but does not require the Administrator to issue—temporary fuel waivers that would allow for the year-round sale of E15 gasoline. In light of the statutory limit that requires waivers to be effective for a period of 20 calendar days or shorter, to achieve the year-round sale of E15 the EPA Administrator would have to issue a series of consecutive waivers as the Biden Administration did in 2024.
Some Members of Congress have proposed permanent year-round sale of E15 (S. 2707; 118th Congress). A provision for this was included in a short-term FY2025 spending bill introduced in the House in December 2024 (H.R. 10445; 118th Congress) but was removed from the FY2025 continuing resolution package that became law (P.L. 118-158). It is not clear what action, if any, the 119th Congress may take on the year-round sale of E15 or how EPA will implement E.O. 14156.
Congressional Research Service
https://crsreports.congress.gov
IN10979
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As Congress considers this issue, some states have undertaken a measure allotted to them under the CAA to achieve the same result (i.e., the year-round sale of E15). In April 2022, eight states petitioned EPA for a permanent waiver to sell E15 year-round (see 42 U.S.C. §7545(h)(5)). In February 2024, EPA, under the Biden Administration, issued a final rule to approve the permanent waiver for those eight states, effective April 28, 2025. It is not clear what action, if any, the Trump Administration may take pertaining to this rule. Congress could monitor the implementation of the final rule before taking action, if any.
Clean Air Act RVP Requirements
The CAA authorizes the EPA Administrator to regulate fuels and fuel additives. The CAA regulates (among other pollutants) precursors for ground-level ozone (a primary component of “smog”), which negatively impacts human health and welfare, among other environmental effects. One of the requirements intended to reduce smog is a limit on gasoline volatility because volatile organic compounds within gasoline evaporate more readily at higher temperatures (i.e., during the summer months) and can contribute to smog formation. RVP is a common metric of volatility—the lower the RVP, the less the substance will evaporate. RVP requirements in Section 211(h) of the CAA—which apply to the 48 contiguous states and the District of Columbia—generally prohibit the sale of gasoline with an RVP greater than 9 pounds per square inch (psi) during the high ozone season (i.e., the summer months). The National Renewable Energy Laboratory (NREL) has reported that the addition of 10% ethanol to gasoline increases the RVP of the blend by about 1 psi.
The act provides some exceptions, including a waiver—the “one-pound waiver”—stipulating that ethanol-gasoline fuel blends containing 10% ethanol (E10) are subject to an RVP limit that is 1 psi greater than what would otherwise apply given certain conditions (e.g., the 9.0 psi standard for certain areas would subject E10 to a 10.0 psi limit). Further, the act provides exclusions from the waiver such that, upon notification by a governor that the RVP limit granted for E10 will increase air pollutant emissions in that state, the Administrator must revert to the 9 psi limit for that area. In some areas of the country, generally based on nonattainment for ozone, more stringent RVP limits apply (e.g., 7.8 psi RVP for conventional gasoline), with the one-pound waiver added on. The waiver does not apply to reformulated gasoline (RFG); there is a 7.4 psi RVP standard for RFG. EPA reports about 25% of gasoline sold in the United States is RFG. EPA also reports the waiver “does not apply in areas where EPA has approved a regulation into a state implementation plan (SIP) that limits the applicability of the 1.0 psi allowance.” The regulations for gasoline RVP standards are available at 40 C.F.R. §1090.215.
Congressional Issues
NREL reported in 2012 that “the RVP impact of 15% ethanol is indistinguishable from that of 10% ethanol in gasoline for all volatility seasons and base hydrocarbon vapor pressures” and “there is no technical reason for treating E10 differently from E15…” However, the issue of selling E15 year-round involves other aspects that Congress may consider, including:
• How much consumer demand is there for E15?
• Who pays to install E15 fueling infrastructure (e.g., blender pumps)?
• Would the rural economy benefit from the year-round sale of E15?
• What impact might the additional sales of E15 have on the Renewable Fuel Standard (RFS) program?
• Would the additional use of ethanol for E15 raise environmental concerns?
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IN10979 · VERSION 13 · UPDATED
• Will California allow the sale of E15, possibly affecting E15 demand? California has not approved the use of E15 in its state.
This CRS product highlights some details of the year-round sale of E15 debate. The product is not a comprehensive analysis of the issue, and should not be interpreted as such. Congressional staff are encouraged to contact CRS if they have any questions.
Author Information
Kelsi Bracmort Specialist in Natural Resources and Energy Policy
Disclaimer
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