EPA Approves Request from Tennessee
to Relax the Federal Summer Gasoline
Volatility Standard in Shelby County
(Memphis),Tennessee
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•	Tennessee previously requested that Shelby County be redesignated to attainment for
the 2008 ozone NAAQS. In that request, Tennessee took a conservative approach for
the maintenance plan demonstration by modeling 9.0 psi for the RVP requirements as
opposed to 7.8 psi. EPA Region 4 previously approved the redesignation request and
maintenance plan for the portion of Tennessee that is within the Memphis, Tennessee-
Mississippi-Arkansas (Memphis, TN-MS-AR) 2008 ozone nonattainment area on June
23, 2016 (81 FR 40816). Tennessee did not, at that time, request the relaxation of the
federal RVP requirements for Shelby County.
•	In April 2017, Tennessee requested a relaxation of the federal RVP requirements. This
necessitated a demonstration that relaxing the federal RVP requirement would not in-
terfere with maintenance of any NAAQS, including the 2008 and 2015 ozone NAAQS,
or any other applicable Clean Air Act (CAA) requirement. Therefore, in a July 7, 2017
rulemaking, EPA Region 4 approved Tennessee's non-interference demonstration for its
already approved maintenance plan for the 2008 ozone NAAQS (82 FR 31462).
•	Relaxing the volatility requirements for gasoline sold in the Memphis Area could be
beneficial because this action could improve the fungibility of gasoline in the area. Once
this rule becomes effective, the summertime gasoline sold in the Memphis Area can be
identical to the fuel sold in the rest of Tennessee. For motorists, the change in summer-
time gasoline volatility specifications should be virtually unnoticed.
Background
In 1987, EPA determined that gasoline nationwide had become increasingly volatile, causing an
increase in evaporative emissions from gasoline-powered vehicles and equipment. Evaporative
emissions from gasoline, referred to as volatile organic compounds (VOCs), are precursors to
the formation of tropospheric ozone and contribute to the nation's ground-level ozone problem.
Ground-level ozone causes health problems, including damaged lung tissue, reduced lung func-
tion, and lung sensitization to other pollutants.
The most common measure of fuel volatility is RVP. To provide for cleaner air and greater public
health protection, EPA enforces maximum limits on the RVP of gasoline sold during the summer
ozone season. Specifically, EPA's regulations at 40 CFR 80.27(a)(2) establish maximum RVP
standards of 9.0 psi or 7.8 psi depending on the state, the month, and the area's initial designa-
tion with respect to the ozone NAAQS.
For More Information
You can access the rule and related documents on the EPA's Office of Transportation and
Air Quality Web site at:
www.epa.gov/gasoline-standards/relaxation-summer-gasoline-volatility-standard-
shelby-county-memphis-tennessee
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For further information on this final rule, please contact:
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