INSIGHTi

Year-Round Sale of E15
Updated April 23, 2024
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 announced
it would allow “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.” The waiver is
effective May 1, 2024. EPA states “[i]t is the Agency’s intention to issue new waivers effectively
extending (renewing) this waiver until such time as the extreme and unusual fuel supply circumstances
described in this action are no longer present.”
Some Members of Congress and legislative proposals (e.g., S. 2707) have called for permanent year-
round sale of E15. As Congress considers this issue, some states have undertaken a measure allotted to
them under the CAA to achieve the same result. 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 issued a
final rule to approve the permanent waiver for those eight states, effective April 28, 2025. One fuel
industry trade group asserts that the 2025 effective date would be “problematic” and “there must be a
reasonable transition to producing summer gas according to a different specification.” One biofuel
industry trade group appears satisfied with the final rule. In the interim, some have requested that the
Biden Administration issue temporary emergency fuel waivers for the 2024 summer driving season. Some
Members of Congress have made the same request. One fuel industry group reportedly argues that
Congress should take action on a national level to supersede state petitions and regional requirements.
Alternatively, 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. Among other pollutants,
the CAA regulates 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
Congressional Research Service
https://crsreports.congress.gov
IN10979
CRS INSIGHT
Prepared for Members and
Committees of Congress

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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 a 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
The sale of E15 has been a long-standing issue for Congress (see for example H.Amdt.156 to H.R. 1 in
the 112th Congress). Over the last few years, discussion has focused on the year-round sale of E15. 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)? In a 2022 report, the
U.S. Department of Agriculture (USDA) discussed the market conditions as well as some
of the challenges and opportunities for E15. There are federal and state programs that
support E15 infrastructure.
• What impact might the additional sales of E15 have on the Renewable Fuel Standard
(RFS) program? Some researchers examined this relationship in 2017 and 2018.
• Will the additional use of ethanol for E15 raise environmental concerns? In 2019, some
environmental organizations requested that EPA “limit the sale and use of E15 in a
manner that better protects our health and environment.”
• Will California’s nonuse of E15 affect E15 demand? California has not approved the use
of E15 in its state. In 2022, the California Air Resources Board (CARB) released an E15
evaluation status update.

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.

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Author Information

Kelsi Bracmort

Specialist in Natural Resources and Energy Policy




Disclaimer
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Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of
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IN10979 · VERSION 11 · UPDATED

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