Intermediate-Level Blends of Ethanol in
Gasoline, and the Ethanol “Blend Wall”

Brent D. Yacobucci
Specialist in Energy and Environmental Policy
October 18, 2010
Congressional Research Service
7-5700
www.crs.gov
R40445
CRS Report for Congress
P
repared for Members and Committees of Congress

Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

Summary
On March 6, 2009, Growth Energy (on behalf of 52 U.S. ethanol producers) applied to the
Environmental Protection Agency (EPA) for a waiver from the current Clean Air Act (CAA)
limitation on ethanol content in gasoline. Currently, ethanol content in gasoline is capped at 10%
(E10); the application requests an increase in the maximum concentration to 15% (E15).
On October 13, 2010, EPA issued a partial waiver for the use of E15 in model year (MY) 2007
and later passenger cars and light trucks. The agency also announced that it could expand the
waiver to MY2001-2006 cars and light trucks after it receives final testing data from the
Department of Energy (DOE)—a decision that could come as early as November 2010. At the
same time, EPA denied the waiver request for the use of E15 in MY2000 and older passenger
vehicles, as well as in motorcycles, heavy trucks, and non-road applications, citing a lack of
sufficient data to alleviate the agency’s concerns about potential emissions increases from these
engines. A broad waiver would allow the use of significantly more ethanol in gasoline than is
currently permitted under the CAA.
The current 10% limitation leads to an upper bound of roughly 14 billion to 15 billion gallons of
ethanol in all U.S. gasoline. This “blend wall” will likely limit the fuel industry’s ability to meet
an Energy Independence and Security Act (EISA, P.L. 110-140) requirement to use increasing
amounts of renewable fuels (including ethanol) in transportation. To meet the high volumes of
renewable fuels mandated by EISA, EPA recognized in a November 2009 letter to Growth Energy
that “it is clear that ethanol will need to be blended into gasoline at levels greater than the current
limit of 10 percent.” The partial waiver for newer vehicles—roughly one-third of the cars and
light trucks on the road in 2011—will allow the use of more ethanol going forward, assuming
other conditions are met. Expanding the waiver to MY2001 and later would cover an additional
one-third of vehicles and an even larger share of fuel consumption (as newer cars are driven more
miles than older cars).
To receive a waiver, the petitioner must establish to EPA that the increased ethanol content will
not “cause or contribute to a failure of any emission control device or system” to meet emissions
standards. EPA is to consider short- and long-term effects on evaporative and exhaust emissions
from various vehicles and engines, including cars, light trucks, and non-road engines.
In addition to the emissions concerns, other factors affecting consideration of the blend wall
include vehicle and engine warranties and the effects on infrastructure. Currently, no automaker
warrants its vehicles to use gasoline with higher than 10% ethanol. Small engine manufacturers
similarly limit the allowable level of ethanol. In addition, most gasoline distribution systems (e.g.,
gas pumps) are designed to dispense up to E10. While some of these vehicle and fuel distribution
systems may be able to operate effectively on E15 or higher, their warranties/certifications would
likely need to be modified. Further, many current state laws prohibit the use of blends higher than
E10. Questions have been raised whether fuel suppliers would even be willing to sell E15
alongside E10 if some of their customers may not use the higher blend.
As EPA’s waiver only applies to newer vehicles, a key question is how fuel pumps might be
labeled to keep owners from using E15 in older vehicles and other equipment. Along with the
waiver decision, EPA proposed new pump labeling rules to indicate which gasoline pumps
dispense E15. A 60-day comment period for the proposal will begin once the proposal is
published in the Federal Register.
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Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

Contents
Background ................................................................................................................................ 1
What Is the “Blend Wall”? .......................................................................................................... 5
Approval of New Fuels and Fuel Additives ................................................................................. 6
What Studies or Data Must Accompany a Section 211(f) Waiver Request? ............................ 7
What Actions Are Federal Agencies Such as the Department of Energy and EPA
Taking to Study the Compatibility of Higher Blends of Fuel in Non-flex Fuel
Vehicles? What Are the Timelines of These Studies, and Will They Be
Comprehensive Enough to Support a Section 211(f) Waiver Request? ................................ 8
What Are the Potential Outcomes of a Waiver Request? ........................................................ 9
What Entity Can Make a Request? ........................................................................................ 9
Other Than a Successful Section 211 Waiver Request, Are There Other Means to
Approve Higher Blends of Ethanol, Such as an Executive Order or Other
Administrative Action? .................................................................................................... 10
Growth Energy’s Waiver Application ........................................................................................ 10
Other Issues .............................................................................................................................. 11

Figures
Figure 1. Renewable Fuel Standard Under the Energy Independence and Security Act................. 2
Figure 2. Projected Ethanol Consumption in Gasoline at Selected Blend Levels vs.
Renewable Fuel Standard Mandates ......................................................................................... 3

Contacts
Author Contact Information ...................................................................................................... 12

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Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

Background
There is growing interest in the potential for ethanol to displace petroleum as a transportation
fuel.1 In 2008, the United States consumed roughly 9 billion gallons of fuel ethanol, representing
about 6% of all U.S. gasoline consumption (by volume).2 Fuel ethanol consumption has grown
from roughly 1 billion gallons per year in the early 1990s, largely as a result of federal policies
promoting its use, including tax incentives and mandates for the use of renewable fuels.3
Arguably the most significant incentive for ethanol’s use is the renewable fuel standard (RFS)
established in the Energy Policy Act of 20054 and expanded in the Energy Independence and
Security Act of 2007.5 The RFS mandates the use of 9.0 billion gallons of renewable fuel in 2008,
increasing steadily through 2022 (Figure 1). While the RFS is not an explicit ethanol mandate,
the vast majority of the requirement has been met using corn-based ethanol. Going forward, there
are limitations on the amount of corn-based ethanol that may be used to meet the mandate,
although it is likely that much of the additional mandate for “advanced biofuels”6 will be met
using ethanol derived from sugarcane and from cellulosic feedstocks such as perennial grasses,
fast-growing trees, and agricultural wastes.7 By 2022, EISA requires the use of 36 billion gallons
of renewable fuels, and much of this will likely be ethanol from a variety of feedstocks.

1 For more information on fuel ethanol, see CRS Report RL33290, Fuel Ethanol: Background and Public Policy Issues,
by Brent D. Yacobucci.
2 Renewable Fuels Association (RFA), Industry Statistics, http://www.ethanolrfa.org/industry/statistics/, accessed
September 10, 2008.
3 CRS Report R40110, Biofuels Incentives: A Summary of Federal Programs, by Brent D. Yacobucci
4 EPAct 2005, P.L. 109-58.
5 EISA, P.L. 110-140.
6 Biofuels produced from feedstocks other than corn starch and with 50% lower lifecycle greenhouse gas emissions
compared to gasoline.
7 For more information on the RFS, see CRS Report R40155, Renewable Fuel Standard (RFS): Overview and Issues,
by Randy Schnepf and Brent D. Yacobucci.
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Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

Figure 1. Renewable Fuel Standard Under the
Energy Independence and Security Act
40
35
30
25
llons
20
illion Ga
B
15
10
5
0
2008
2010
2012
2014
2016
2018
2020
2022
Unspecified
Advanced Biofuel

Source: CRS Analysis of P.L. 110-140.
However, there is a key obstacle to the use of so much ethanol in gasoline. Currently, although
some ethanol is sold as an alternative fuel (E85),8 most is sold as an additive in conventional and
reformulated gasoline. At present, the amount of ethanol that may be blended in gasoline is
limited to 10% by volume (E10) by guidance developed by the Environmental Protection Agency
(EPA) under the Clean Air Act (CAA), as well as by vehicle and engine warranties, and
certification procedures for fuel-dispensing equipment.
Under the RFS, assuming that most of the mandate is met using ethanol, gasoline blenders are
likely to hit a limit in the next few years. In 2012, the RFS will require over 15 billion gallons of
renewable fuel, while projected gasoline consumption in 2012 is slightly less than 150 billion
gallons.9 After 2012, the renewable fuel mandate will continue to increase. However, a limit of
10% ethanol means that ethanol for gasoline blending (not including E85) likely cannot exceed
14 billion gallons per year.10 This “blend wall” is the maximum possible volume of ethanol that

8 A blend of 85% ethanol and 15% gasoline. Ethanol-gasoline blends are designated with an “E” followed by a
number—the percentage ethanol concentration by volume. For example, a blend of 10% ethanol and 90% gasoline is
referred to as “E10.”
9 U.S. Energy Information Administration (EIA), Annual Energy Outlook 2010 Early Release, December 2009,
Reference Case Table 11.
10 If gasoline demand were to increase, the maximum amount of ethanol that could be blended into that gasoline would
increase proportionally. Likewise, if gasoline demand were to decrease, the maximum amount of ethanol that could be
(continued...)
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Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

can be blended into U.S. motor gasoline (see Figure 2). It is likely that the actual limit is lower,
since older fuel tanks and pumps at some retail stations may not be equipped to handle ethanol-
blended fuel.
Figure 2. Projected Ethanol Consumption in Gasoline at Selected Blend Levels vs.
Renewable Fuel Standard Mandates
40
25% Limit
35
30
25
15% Limit
llons
(Requested)
a
G
20
lion
10% Limit (Current)
Bil 15
10
5
0
2008
2010
2012
2014
2016
2018
2020
2022
RFS Mandate
10% Limit (Current)
15% Limit (Requested)
25% Limit

Source: RFS mandates from P.L. 110-140. Projected ethanol consumption at various limits from CRS analysis of
U.S. Energy Information Administration, Annual Energy Outlook 2010, DOE/EIA-0383(2010), Washington, DC,
May 11, 2010, Reference Case Table 11, http://www.eia.doe.gov/oiaf/aeo/aeoref_tab.html.
Notes: Although the RFS is not an explicit ethanol mandate, it has been widely interpreted as an effective
mandate given the current market and technology conditions. However, other biofuels are expected to play a
somewhat limited role, at least in the near future. For example, a share of the RFS mandate must be met using
biomass-based diesel fuels. That share is 0.65 billion gallons in 2009, rising to 1.0 billion gallons in 2012. After
2012, EPA is to set the mandated level.

(...continued)
blended would decrease proportionally.
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Because of this “blend wall,” there is interest, especially among ethanol producers, in increasing
the allowable concentration of ethanol in gasoline. Research is ongoing on intermediate-level
blends, including 15%, 20%, 30%, and 40% ethanol (E15, E20, E30, and E40, respectively).
On March 6, 2009, Growth Energy (on behalf of 52 U.S. ethanol producers) applied to EPA for a
waiver from the current CAA E10 limit.11 The application requested an increase in the maximum
concentration to 15% (E15). If granted, the waiver would allow the use of significantly more
ethanol in gasoline than is currently permitted.12 Under EISA, EPA had 270 days (December 1,
2009) to grant or deny the waiver. On In a November 2009 letter to Growth Energy, EPA noted
that “it is clear that ethanol will need to be blended into gasoline at levels greater than the current
limit of 10 percent”13 to meet the EISA mandates. In the letter, EPA noted that long-term testing
on newer vehicles has not been completed, but that the agency expected that model year 2001 and
newer vehicles “will likely be able to accommodate higher ethanol blends, such as E15.”14 On
October 13, EPA granted a partial waiver for MY2007 and later vehicles, and deferred a decision
on MY2001-2006 vehicles until it receives final testing data from the Department of Energy
(DOE)—perhaps by November 2010.15 At the same time, EPA denied the waiver for use of E15 in
MY2000 and older passenger vehicles, as well as for all heavy-duty vehicles, motorcycles,
marine engines, and non-road equipment.
EPA estimates that MY2007 and later vehicles will represent 29% of the cars and light trucks on
the road in 2011. Expanding the waiver to MY2001 and later would cover an additional 38% of
vehicles.
As part of the decision, EPA stated that it had “reasons for concern with use of E15 in nonroad
products, particularly with respect to long-term exhaust and evaporative emissions durability and
materials compatibility.”16 EPA denied this part of the waiver petition but stated that the agency
would revisit the issue if new data were submitted. In a July “Status Update” EPA stated that
Although we continue to evaluate all available information, it has become clear that
insufficient data have been submitted on the use of E-15 in older vehicles and non-road
engines (such as chainsaws and marine engines) to enable EPA to make a decision on a
waiver that would allow the use of E-15 for these engines.17
As noted by EPA, granting Growth Energy’s petition to increase gasoline ethanol content to 15%
addresses only one component of the blend wall. The other impediments—current state laws,

11 Growth Energy on Behalf of 52 United States Ethanol Manufacturers, Application for a Waiver Pursuant to Section
211(f)(4) of the Clean Air Act for E-15
, March 6, 2009.
12 Instead of the roughly 15-billion-gallon limit in 2012 discussed above, ethanol could represent up to roughly 22
billion gallons of gasoline content.
13 Gina McCarthy, Notice of a Receipt of a Clean Air Act Waiver Application to Increase the Allowable Ethanol
Content of Gasoline to 15 Percent; Letter to Petitioners
, U.S. Environmental Protection Agency, Office of Air and
Radiation, Washington, DC, November 30, 2009, p. 1, http://www.epa.gov/otaq/regs/fuels/additive/
lettertogrowthenergy11-30-09.pdf.
14 Ibid., p. 2.
15 U.S. Environmental Protection Agency, Partial Grant and Partial Denial of Clean Air Act Waiver Application
Submitted by Growth Energy to Increase the Allowable Ethanol Content of Gasoline to 15 Percent; Decision of the
Administrator, Washington, DC, October 13, 2010, http://www.epa.gov/otaq/regs/fuels/additive/e15/e15-waiver-
decision.pdf.
16 Ibid.
17 Ibid.
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vehicle and engine warranties, and distribution infrastructure—still need to be addressed before
ethanol use in gasoline is taken beyond 10%. Further, for EPA to allow the sale of E15, a fuel
supplier still needs to register the fuel with EPA and submit health effects testing for EPA to
review—a process that has not yet been started.
What Is the “Blend Wall”?
The “blend wall” is the upper limit to the total amount of ethanol that can be blended into U.S.
gasoline. Currently, gasoline ethanol content is limited to 10% by volume, and in 2008 gasoline
consumption was roughly 140 billion gallons.18 Therefore, the current blend wall is roughly 14
billion to 15 billion gallons of ethanol that could be blended into gasoline.19 The blend wall is
largely driven by four factors.
First, under the CAA it is unlawful to sell gasoline that contains additives at levels higher than
those approved by EPA. For ethanol, the current limit is 10% by volume. To allow a higher
percentage, a fuel manufacturer would need to petition EPA for a waiver. (See “Approval of New
Fuels and Fuel Additives.”)
Second, automakers currently warranty their vehicles to operate on ethanol/gasoline blends up to
10%. While there is data to suggest that newer vehicles could be operated reliably on higher
levels of ethanol without modification, no automaker has yet approved those higher blends for
use.20 Further, small engine manufacturers generally advise against using gasoline with more than
10% ethanol in machines such as lawnmowers, trimmers, and snowmobiles. Even if EPA were to
approve higher ethanol blends for sale, it is unclear whether vehicle and machine owners would
be willing to use the new fuel without explicit approval from the engine/vehicle manufacturer.21
Third, most existing infrastructure (e.g., underground gasoline storage tanks, fuel pumps) is
designed and certified to deliver blends up to E10. It is unclear whether it can tolerate higher
ethanol concentrations. Underwriters Laboratories (UL), an independent testing and certification
company, announced guidance supporting the use of ethanol blends up to a maximum of 15% in
existing fuel pumps currently certified to dispense E10.22 However, according to the same
announcement, UL stated that “under normal business conditions, E10 at the dispenser can vary

18 Beyond the blend wall, more ethanol could be used in transportation, as E85 in flexible fuel vehicles (FFVs)
specially designed for its use. However, there are far fewer FFVs than conventional vehicles, and most of these are
currently operated on gasoline. If all of the roughly 6 million to 7 million FFVs were operated on E85 all of the time,
that could represent an additional 5 billion to 6 billion gallons of ethanol use beyond the limits of the blend wall.
19 Technically, the blend wall is a number slightly higher than 10% of gasoline consumption. Ethanol has a lower
energy content than gasoline, thus one gallon of ethanol does not displace an entire gallon of gasoline. As the share of
ethanol in gasoline increases, the total volume must increase to provide an equivalent amount of energy. For example,
140 billion gallons of gasoline would have the equivalent energy to roughly 145 billion gallons of a 10% ethanol blend.
20 For example, in Brazil all gasoline contains between 20% and 25% ethanol. While specific vehicle requirements
differ between the United States and Brazil, especially emissions control standards, there is reason to believe that
somewhat higher blends could be used in the United States.
21 This was a key concern in the state of Minnesota. That state mandates that all gasoline in the state contain 10%
ethanol. That mandate is set to increase to 20% in 2013, but only if EPA approves the use of the fuel, and automakers
warranty their vehicles to operate on the fuel.
22 Underwriter’s Laboratories, Underwriter’s Laboratories Announces Support for Authorities Having Jurisdiction Who
Decide to Permit the Use of Existing UL Listed Gasoline Dispensers with Automotive Fuel Containing up to a
Maximum of 15% Ethanol
, Northbrook, IL, February 19, 2009.
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from about seven to 13 percent ethanol.”23 However, a similar variance is likely to exist for E15:
according to a UL representative, “it cannot ever be said that [E15] is exactly 15 percent.”24
Therefore, a higher maximum level, perhaps 18%, would be necessary to allow those pumps to be
certified to deliver E15.
Fourth, many state laws and regulations, including fire codes and other standards, limit ethanol in
gasoline to 10%. To allow E15, these state laws and regulations would also need to be amended.
While all of these components of the blend wall are relevant, this report focuses on the process
for addressing the first component, the current CAA restriction on ethanol concentration in
gasoline.
Approval of New Fuels and Fuel Additives
For a blend of gasoline and gasoline additives to be approved under Section 211(f)(1)(A) of the
CAA, it must be “substantially similar” to unleaded gasoline.25 EPA has defined “gasoline” to
have an upper limit of 2.7% oxygen content (by weight), effectively limiting the ethanol
concentration to roughly 7.5% (by volume).26 However, Section 211(f)(4) of the CAA (as
amended by EISA) allows manufacturers of fuels and fuel additives to apply for a waiver from
the “substantially similar” requirement if they can prove that the use of the fuel or additive will
not “cause or contribute to” a vehicle not meeting applicable emissions standards over its useful
life.
The EPA Administrator, upon application of any manufacturer of any fuel or fuel additive,
may waive the prohibitions established under paragraph (1) or (3) of this subsection or the
limitation specified in paragraph (2) of this subsection, if he determines that the applicant has
established that such fuel or fuel additive or a specified concentration thereof, and the
emission products of such fuel or fuel additive or specified concentration thereof, will not
cause or contribute to a failure of any emission control device or system (over the useful life
of the motor vehicle, motor vehicle engine, nonroad engine or nonroad vehicle in which such
device or system is used) to achieve compliance by the vehicle or engine with the emission
standards with respect to which it has been certified pursuant to Sections 206 and 213(a) of
this title. The Administrator shall take final action to grant or deny an application submitted
under this paragraph, after public notice and comment, within 270 days of the receipt of such
an application.27
EPA has twice granted waivers for 10% ethanol under Section 211(f). The first was granted in
1978 to Gas Plus, Inc. for blends of ethanol up to 10%.28 The second was in 1982 to Synco 76
Fuel Corp. for a blend of 10% ethanol plus a proprietary additive.29 To allow the use of E15 or

23 Ibid.
24 Christopher Jensen, “Laboratory Will Not Certify Pumps for Gas with 15 Percent Ethanol,” New York Times, May 8,
2009.
25 42 U.S.C. 7545(f)(1)(A).
26 EPA, “Regulation of Fuels and Fuel Additives; Definition of Substantially Similar,” Revised Interpretive Rule, Final
Action, February 11, 1991. 56 Federal Register 5332-5336.
27 42 U.S.C. 7545(f).
28 44 Federal Register 20777.
29 47 Federal Register 22404.
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E20, EPA would need to revise its definition of “substantially similar” to allow a higher oxygen
content, or a manufacturer would need to petition EPA for a waiver under Section 211(f), as
Growth Energy has done.
What Studies or Data Must Accompany a Section 211(f)
Waiver Request?

According to EPA, there are no specific guidelines for what data must accompany a waiver
application. However, based on communication between EPA’s Office of Transportation and Air
Quality (OTAQ) and the Minnesota Department of Agriculture,30 as well as a presentation made
by a member of OTAQ staff to the American Petroleum Institute Technology Committee,31 a
submission must
• include both evaporative and exhaust emissions;
• be comprehensive, assessing the emissions effects both short-term and over the
full useful life of the vehicle;32
• include tests on a variety of vehicles (e.g., new and used, car, truck, and
motorcycle), and the selection of vehicles should reflect their frequency on the
road; and
• assess the durability of vehicles and vehicle parts using the fuel, including
assessments of the compatibility of the new fuel (or blend level) with engine
materials, and the effects on operability and performance.
Because gasoline is also used in other engines (e.g., lawnmowers, snowmobiles, boats, etc.), the
long-term effects on emissions and engine durability for these engines must also be studied,
according to EPA. In the case of higher-level ethanol blends, this may be a key concern. While
newer automobiles have complex fuel systems, including computers that can measure and adjust
fuel/air ratios in real time, most small non-road engines have much simpler carburetor systems
with set fuel/air ratios. One potential problem is that ethanol contains oxygen:33 by increasing the
oxygen content in the fuel—increasing the ethanol content from 10% to 20% effectively doubles
the oxygen content—while keeping the amount of air coming into the engine constant, the engine
will run much leaner. This could cause the engine to misfire, and/or to run much hotter than
originally designed, especially in the case of air-cooled engines (e.g., lawnmowers).
After the waiver is granted, but before sale of the new fuel is permitted, the fuel must be
registered with EPA. That registration must include an assessment of the health effects of the fuel
(e.g., inhalation exposure studies).

30 Margo Oge, U.S. Environmental Protection Agency, Office of Transportation and Air Quality (OTAQ), Letter to
Gene Hugoson, Director, Minnesota Department of Agriculture, March 6, 2008.
31 Karl Simon, EPA, OTAQ, “Mid Level Ethanol Blend Experimental Framework—EPA Staff Recommendations,”
Presentation to the American Petroleum Institute Technology Committee Meeting, Chicago, June 4, 2008.
32 Full useful life for modern cars and light trucks is 150,000 miles. For motorcycles, full useful life is 20,000 miles.
EPA expects that the aging of the vehicles will occur under both controlled (e.g., dynamometer) and on-road
environmental (e.g., hot and cold weather) conditions.
33 In modern vehicles, additional oxygen is generally a benefit in that it promotes more complete combustion,
potentially reducing carbon monoxide and other pollutant emissions.
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What Actions Are Federal Agencies Such as the Department of
Energy and EPA Taking to Study the Compatibility of Higher
Blends of Fuel in Non-flex Fuel Vehicles? What Are the Timelines
of These Studies, and Will They Be Comprehensive Enough to
Support a Section 211(f) Waiver Request?

Preliminary research has been completed or is ongoing on many of the above data requirements.
Much of the preliminary research has been conducted by or for the state of Minnesota. Minnesota
has a state law requiring the use of E10 across the state. Assuming E20 is approved as a motor
fuel, the state will mandate its use starting in 2013. Therefore, Minnesota has headed much of the
research that led to the Growth Energy waiver application. According to the Minnesota
Department of Agriculture, some of the preliminary research has been completed or is ongoing on
materials compatibility and driveability.34
In a presentation to EPA’s Clean Air Act Advisory Committee’s Mobile Sources Technical
Review Committee, representatives of Chrysler and Honda highlighted key research areas in
assessing mid-level ethanol blends.35 For cars and trucks they categorized the research into seven
main topics: durability, tailpipe emissions, evaporative emissions, driveability, materials
compatibility, emissions inventory, and on-board diagnostic (OBD) integrity. For most of these
topics, they showed that fuel producers, automakers, EPA and/or DOE had completed
“preliminary, partial or screening” assessments, but that comprehensive testing had just started in
some areas, while other areas may still need to be addressed. According to their timeline, much of
the comprehensive research would not be completed before the end of 2009. Similar research
must be completed for non-road engines. However, their timeline showed that the planning for
that research was incomplete as of mid-2008.
In its November 30, 2009, letter to Growth Energy, EPA noted that durability testing is ongoing at
DOE. According to the letter, DOE is testing a total of 19 newer vehicles, has completed testing
of two of those vehicles, and expects “testing will be completed on an additional 12 vehicles by
the end of May 2010. As a result EPA expects to have a significant amount of the total data being
generated through this testing program available to us by mid-June.”36 The letter made no
comment on the status of testing for older vehicles or for non-road engines.
In its July 2010 update, EPA pushed back the expected completion date for testing of the newest
(model year 2007 and later) vehicles to the end of September. The completion of that testing led

34 Ralph Groschen, Minnesota Department of Agriculture, “What’s Happening With E20?,” Presentation to the Iowa
Renewable Fuels Summit, Des Moines, IA, January 31, 2008. In her letter to Gene Hugoson of the Minnesota
Department of Agriculture, OTAQ Director Oge stated that “the draft reports presented to us ... are a good first step in
beginning the evaluation of the effects of E20. We understand that you consider these test results to be preliminary and
not sufficient for a complete waiver application, and we agree with that determination.” Margo Oge, op. cit.
35 Reg Modlin, Chrysler Corporation, and Dave Rainey, Honda Motor Company, “Assessing Effects of Mid-Level
Ethanol Blends,” Presentation to the Mobile Sources Technical Review Subcommittee Meeting, Arlington, VA, May 8,
2008.
36 Gina McCarthy, Notice of a Receipt of a Clean Air Act Waiver Application to Increase the Allowable Ethanol
Content of Gasoline to 15 Percent; Letter to Petitioners
, U.S. Environmental Protection Agency, Office of Air and
Radiation, Washington, DC, November 30, 2009, pp. 1-2, http://www.epa.gov/otaq/regs/fuels/additive/
lettertogrowthenergy11-30-09.pdf.
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to EPA’s granting a partial waiver in October 2010. For vehicles between model years 2001 and
2006, EPA expects DOE to complete testing by late November. For older vehicles and non-road
engines, EPA stated that insufficient data have been submitted to alleviate concerns about
durability and evaporative emissions—thus EPA denied that part of the waiver.
What Are the Potential Outcomes of a Waiver Request?
Under CAA Section 211(f)(4), as amended by Section 251 of EISA, the Administrator must grant
or deny the waiver request within 270 days of receipt. Before being amended by EISA, the
language in Section 211(f)(4) stated that “if the Administrator has not acted to grant or deny an
application under this paragraph within one hundred and eighty days of receipt of such
application, the waiver authorized by this paragraph shall be treated as granted.” The amended
section no longer specifies the status of a waiver request if EPA neither grants nor denies the
request within 270 days, as is the case with Growth Energy’s current request.
A question that has been raised is whether EPA can grant a partial waiver. For example, some
contended that it is possible for EPA to quickly grant a waiver to allow E12 or E13, and take more
time to review Growth Energy’s application for E15. In press reports, Agriculture Secretary Tom
Vilsack supported this strategy.37 In a June 2010 letter, Archer Daniels Midland Company (ADM)
requested that EPA grant a waiver for E12 or determine that E12 is “substantially similar” to E10.
In its decision on the Growth Energy petition, EPA determined that there were insufficient data to
determine that E12 was substantially similar, that similar data concerns exist for older vehicles
and non-road engines, and that for newer vehicles E12 is subsumed in the waiver for E15.38
What Entity Can Make a Request?
According to CAA Section 211(f)(4), the EPA Administrator may waive the limitations “upon
application of any manufacturer of any fuel or fuel additive.” Therefore, presumably any gasoline
or ethanol producer may petition EPA for the waiver, provided they can demonstrate to EPA that
the new additive or (in this case) specified concentration of an existing additive will meet the
criteria set out in Section 211(f)(4).39 In the case of the current waiver application, Growth Energy
filed the application on behalf of 52 U.S. ethanol manufacturers,40 in partnership with the

37 Christopher Doering, “USDA Chief Backs Boost of Ethanol Blend in Gasoline,” Reuters, March 9, 2009.
38 U.S. Environmental Protection Agency, Partial Grant and Partial Denial of Clean Air Act Waiver Application
Submitted by Growth Energy to Increase the Allowable Ethanol Content of Gasoline to 15 Percent; Decision of the
Administrator, Washington, DC, October 13, 2010, http://www.epa.gov/otaq/regs/fuels/additive/e15/e15-waiver-
decision.pdf.
39 There has been some confusion over whether the petition would have to come from a gasoline producer (since the
waiver is for increased ethanol content in gasoline), but the language in Section 211(f)(4) states that the application
may come from “any manufacturer of any fuel or fuel additive.”
40 While the cover page of the application mentions 52 for the number of ethanol manufacturers represented, the text of
the application lists 54 companies: Absolute Energy, LLC; Agri-Energy LLC/Dakota Renewable; Amazing Energy,
LLC; Arizona Grain Inc.; Arkalon Energy, LLC; Big River Resources, LLC; Cardinal Ethanol, LLC; Castle Rock
Renewable Fuels, LLC; Conestoga Energy; DENCO; Didion Ethanol, East Kansas Agri Energy, LLC; Front Range
Energy LLC; Golden Grain Energy, LLC; Granite Falls Energy, LLC; Green Plains Renewable Energy, Inc.; Hawkeye
Renewables LLC, IBEC Ethanol; ICM; Kansas Ethanol, LLC; LifeLine Foods, Inc.; Little Sioux Corn Processors,
LLC; Marquis Energy, LLC; Nesika Energy, LLC; Patriot Renewable Fuels, LLC; Pinal Energy, Poet Biorefining—
Alexandria; Poet Biorefining—Ashton; Poet Biorefining—Big Stone; Poet Biorefining—Caro; Poet Biorefining—
Chancellor; Poet Biorefining—Coon Rapids; Poet Biorefining—Corning; Poet Biorefining—Emmetsburg; Poet
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Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

American Coalition for Ethanol, the Renewable Fuels Association, and the National Ethanol
Vehicle Coalition.
Other Than a Successful Section 211 Waiver Request, Are There
Other Means to Approve Higher Blends of Ethanol, Such as an
Executive Order or Other Administrative Action?

The provisions of Section 211 are explicit, and there seem to be few options outside of the
Section 211(f)(4) waiver process for E15 or other intermediate blends to be approved. While there
may be no administrative action that could permit the use of E15 other than an EPA waiver or a
determination that E15 is “substantially similar” to gasoline, there are potential legislative
options. These include
• amending the CAA to explicitly allow the use of E15 (or some other level of
ethanol);
• amending the CAA to provide expedited approval of higher levels of previously
approved fuel additives; and
• mandating the production and sale of flexible fuel vehicles (since intermediate
blends between E85 and E0—straight gasoline with no ethanol—are already
approved for use in these vehicles), and promoting (or mandating) the use of E85
fuel.
Growth Energy’s Waiver Application
As stated above, on March 6, 2009, Growth Energy petitioned EPA for a waiver to allow the use
of up to 15% ethanol in gasoline. Under the CAA, EPA had up to 270 days (December 1, 2009) to
approve or deny the waiver request, but on November 30, 2009, EPA sent a letter to Growth
Energy stating that not enough testing had been completed, and that it would continue to evaluate
the petition.41 On October 13, 2010, EPA granted a partial waiver for MY2007 and later passenger
vehicles; EPA denied the waiver for MY2000 and older vehicles, as well as for heavy-duty
vehicles, motorcycles, and non-road equipment; and deferred a decision on MY2001-2006
passenger vehicles.
In its application, Growth Energy stated that “recent and extensive research demonstrates that use
of higher ethanol blends will significantly benefit the environment by reducing greenhouse gas
emissions, reducing harmful tailpipe emissions, reducing smog, using less energy for an
equivalent amount of fuel, and protecting natural resources.”42 Growth Energy contended that

(...continued)
Biorefining—Glenville; Poet Biorefining—Gowrie; Poet Biorefining—Groton; Poet Biorefining—Hanlontown; Poet
Biorefining—Hudson; Poet Biorefining—Jewell; Poet Biorefining—Laddonia; Poet Biorefining—Lake Crystal; Poet
Biorefining—Leipsic; Poet Biorefining—Macon; Poet Biorefining—Mitchell; Poet Biorefining—Portland; Poet
Biorefining—Preston; POET Ethanol Products; Prairie Horizon Agri-Energy LLC; Quad County Corn Processors;
Renew Energy; Siouxland Ethanol LLC; Sire; and Western Plains Energy, LLC.
41 Gina McCarthy, op. cit., p. 2.
42 Growth Energy, op. cit., p. 2.
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Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

available data and multiple recent studies43 regarding the impact of various intermediate
blends [of ethanol] on emissions, materials compatibility, durability, and driveability, were
completed on extensive and representative test fleets, provide a reliable comparison to
certification conditions, and demonstrate that use of E-15 will not cause or contribute to
failure of any emission control device or system to meet its certification emissions
standards.44
Growth Energy cited a DOE study45 that found a statistically significant decrease in carbon
monoxide emissions using E15, and a marginally significant decrease in non-methane
hydrocarbon emissions.46 The same study also found a statistically significant increase in
acetaldehyde emissions, and a marginally significant increase in formaldehyde emissions.47 Both
formaldehyde and acetaldehyde are regulated as toxic air pollutants under Sections 202 and 211
of the CAA. However, the fact that emissions increased using the fuel is not enough for EPA to
deny the waiver: EPA would need to prove that that increase in emissions is enough to cause the
vehicle or engine to fall out of compliance with emissions standards. Growth Energy asserts that
the DOE study and other studies have found that the use of E15 results in emissions within
applicable limits.48 In its November 30 letter to Growth Energy, EPA stated that “we want to
make sure we have all necessary science to make the right decision,” including more long-term
testing data.49
On October 13, 2010, EPA granted a partial waiver for newer (MY2007 and later) passenger cars
and light trucks, deferred a decision on MY2001-2006 passenger vehicles, and denied the waiver
for older passenger vehicles as well as all other vehicles. In its October 13 decision, EPA
determined that there were insufficient data to alleviate concerns over potential emissions
increases from older passenger vehicles and non-road engines.
Other Issues
As stated above, the EPA waiver is not the only hurdle in enabling the use of intermediate-level
ethanol blends. With the waiver granted, a fuel supplier still must register the fuel with EPA under
the CAA, a process which includes an assessment of the health effects of the fuel.
A key non-vehicle issue is whether existing infrastructure can support ethanol blends above E10.
Like automobiles, while some existing gasoline tanks and pumps were designed and/or certified
to handle up to E10, none to date have been designed or certified to handle higher ethanol
blends.50 Even if the fuel is approved by EPA for use in motor vehicles, presumably fuel suppliers

43 Growth Energy cites seven studies completed by or for the U.S. Department of Energy, the American Coalition for
Ethanol, the State of Minnesota, the Coordinating Research Council, the Rochester Institute of Technology, the
Minnesota Center for Automotive Research, and Stockholm University.
44 Ibid., p 6.
45 U.S. Department of Energy, Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Non-Road
Engines
, Report 1, Oak Ridge, TN, October 2008.
46 Growth Energy, op. cit., p. 16.
47 Ibid.
48 Ibid., p. 18.
49 Gina McCarthy, op. cit., p. 1.
50 Potential concerns that have been raised include whether the higher ethanol concentration will corrode seals and
other components, and whether the higher concentration would lead to stress cracking of tanks and other metal
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Intermediate-Level Blends of Ethanol in Gasoline, and the Ethanol “Blend Wall”

and/or retailers would be unwilling to sell the fuel unless they are confident that it will not
damage their existing systems or lead to liability issues in the future. Otherwise, it seems doubtful
that fuel suppliers and retailers would voluntarily upgrade their systems to handle the new fuel.
Further, loan covenants and insurance policies would need to be modified to reflect the use of the
higher ethanol blend.
In addition to fuel supply concerns, for vehicle and machine owners to accept the new fuel,
engine and auto manufacturers would likely need to convince their customers that both new and
existing equipment would not be damaged by using the new fuel, and that its use would not void
vehicle and equipment warranties. This may be especially difficult for small-engine
manufacturers and users who are currently concerned about the effects on their engines from E10,
let alone higher blends of ethanol.
Finally, many state laws and regulations limit the use of ethanol in gasoline to 10%. These state
rules would also need to be updated to allow widespread use of E15.

Author Contact Information

Brent D. Yacobucci

Specialist in Energy and Environmental Policy
byacobucci@crs.loc.gov, 7-9662



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components.
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