Document ID: EPA-HQ-OAR-2018-0131-0001
Agency: epa
Document Type: Proposed Rule
Title: Registration of Isobutanol as a Gasoline Additive
Posted Date: 2018-03-29T04:00Z

[Federal Register Volume 83, Number 61 (Thursday, March 29, 2018)]
[Proposed Rules]
[Pages 13460-13463]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-06119]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 79

[EPA-HQ-OAR-2018-0131; FRL-9975-89-OAR]

Registration of Isobutanol as a Gasoline Additive: Opportunity 
for Public Comment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Request for information.

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SUMMARY: The Environmental Protection Agency (``EPA'' or ``the 
Agency'') is seeking public comment on any aspect of the use of 
isobutanol in gasoline. Butamax Advanced Biofuels, LLC (``Butamax''), a 
manufacturer of isobutanol, has submitted an application pursuant to 
the regulations titled ``Registration of Fuels and Fuel Additives'' for 
the registration of isobutanol as a gasoline additive at up to 16 
volume percent. Butamax has submitted information that would likely 
satisfy the applicable registration requirements. The Clean Air Act 
requires the EPA to register a fuel or fuel additive once all the 
applicable registration requirements have been met by the manufacturer. 
Due to the potential for the widespread introduction of isobutanol into 
commerce, we are taking steps to make the public aware of the 
likelihood of this registration. We are seeking public comment 
regarding any issues we should take into consideration for this 
registration and any supplemental actions we should consider under the 
Clean Air Act to further protect public health and welfare.

DATES: Comments must be received on or before April 30, 2018.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2018-0131, to the Federal eRulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or withdrawn. The 
EPA may publish any comment received to its public docket. Do not 
submit electronically any information you consider to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Multimedia submissions (audio, video, etc.) must 
be accompanied by a written comment. The written comment is considered 
the official comment and should include discussion of all points you 
wish to make. The EPA will in general not consider comments or comment 
contents located outside of the primary submission (i.e. on the web, 
cloud, or other file sharing system). For additional submission 
methods, the full EPA public comment policy, information about CBI or 
multimedia submissions, and general guidance on making effective 
comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: James W. Caldwell, Environmental 
Engineer, Compliance Division, Office of Transportation and Air 
Quality, Mail Code 6405A, U.S. Environmental Protection Agency, 1200 
Pennsylvania Avenue NW, Washington, DC 20460; Telephone: (202) 343-
9303; Fax: (202) 343-2802; Email address: [email protected].

SUPPLEMENTARY INFORMATION: The EPA is seeking public comment on any 
aspect of the use of isobutanol in gasoline. Butamax Advanced Biofuels, 
LLC (``Butamax''), a manufacturer of isobutanol, has submitted an 
application pursuant to the regulations at 40 CFR part 79, Registration 
of Fuels and Fuel Additives, for the registration of isobutanol, an 
alcohol, as a gasoline additive at up to 16 volume percent. Our review 
of the information Butamax has submitted leads us to believe that 
Butamax would likely satisfy the applicable registration requirements 
under 40 CFR part 79 (discussed in more detail below). Section 211(b) 
of the Clean Air Act (Clean Air Act, CAA or the Act) requires the EPA 
to register a fuel or fuel additive once all the applicable 
registration requirements have been met by the manufacturer. While the 
EPA does not have any specific concerns, due to the potential for the 
widespread introduction of isobutanol into commerce, we are taking 
steps to make the public aware of the likelihood of this registration 
and are seeking public comment regarding any issues we should take into 
consideration for this registration and/or any potential supplemental 
actions we should consider under the Clean Air Act to further protect 
public health and welfare.

I. Statutory and Regulatory Background

Section 211(a) and (b)--Fuels and Fuel Additives Designation and 
Registration

    Section 211(a) of the Act authorizes the Administrator to designate 
fuels and fuel additives (F/FAs) by regulations and, once designated, 
to register such F/FAs prior to introduction into commerce. To date, 
the Administrator has designated on-highway motor vehicle gasoline and 
gasoline additives and on-highway motor vehicle diesel and diesel 
additives for registration. The EPA codified the registration 
requirements under Sections 211(b) and 211(e) of the Act at 40 CFR part 
79. Registration requirements at 40 CFR part 79 include emissions 
speciation testing and a literature search of the associated emissions 
(Tier 1 testing) and animal testing of exposure to emissions for 
purposes of determining health effects (Tier 2 testing). Manufacturers 
with less than $50 million in total annual sales are considered small 
businesses, as specified in the regulations at 40 CFR 79.58(d). In 
certain cases, a small

[[Page 13461]]

business is exempt from some or all of these testing requirements. For 
any potential registrant with $50 million or more in total annual 
sales, Tier 1 and Tier 2 requirements must be met before registration.
    In addition, Sec. Sec.  79.11(i) and 79.21(h) respectively require 
that fuel and fuel additive manufacturers demonstrate that their fuels 
and fuel additives are substantially similar to those used in emissions 
certification or have a waiver as part of 40 CFR part 79 registration.
    The Tier 1 registration regulations at 40 CFR 79.52 require a 
characterization of the emission products that are generated by 
evaporation and combustion of a gasoline with, if applicable, an 
oxygenated additive such as isobutanol. Combustion testing must be 
conducted with and without after-treatment of exhaust emissions. A 
literature search for information on the potential toxicological 
environmental, and other public welfare effects is required for 
emission products, except that it is not required for those emission 
products that are the same as the emission products for baseline 
gasoline (represented in testing by a gasoline with no oxygenates such 
as ethanol or isobutanol). This is because a test group organized by 
the American Petroleum Institute (API) has tested baseline gasoline and 
also conducted the literature search for its emission products. The 
results of this testing and literature search were reported in the 1997 
API baseline gasoline Tier 1 literature review.
    The regulations at 40 CFR 79.53 specify the requisite health 
effects testing for compliance with Tier 2 as well as provisions for a 
manufacturer that opts to rely on existing health effects test data to 
satisfy these testing requirements. Additionally, the flexibility to 
modify Tier 2 requirements and to require Alternative Tier 2 testing 
can be found at 40 CFR 79.58(c). In 1998, EPA opted to modify the 
standard Tier 2 testing requirements for gasoline and various 
oxygenated gasoline blends and issued Alternative Tier 2 testing 
requirements to the API ``Section 211(b) Research Group.'' This was 
based on the EPA's determination that alternative test procedures would 
yield more useful data than standard Tier 2 testing. The primary 
difference between the testing for baseline gasoline and various 
oxygenated gasoline blends, under the Alternative Tier 2 and standard 
Tier 2 testing requirements, was that the Alternative Tier 2 testing 
focused on identifying and evaluating potential adverse health effects 
of evaporative emissions. It did not include examination of combustion 
emissions. At the time, the EPA explained the rationale for focusing on 
evaporative emissions and why the combustion emission studies would 
likely not produce meaningful information as being due to 
methodological complications caused by carbon monoxide (i.e., the 
carbon monoxide component of the combustion exhaust emissions may be 
lethal or otherwise compromise the health of the test animals). The EPA 
required specific testing for baseline gasoline and various oxygenated 
gasoline blends and these health studies have now been largely 
completed and approved.
    The regulations at 40 CFR 79.54 provide for additional testing 
under Tier 3 provisions if the Tier 1 and Alternative Tier 2 data or 
other data obtained by the Agency indicates that such testing is 
warranted. The EPA has yet to initiate a Tier 3 process for any fuel or 
fuel additive. If the EPA were to require Tier 3 testing, we would 
develop the testing protocol and requirements through a public process.

CAA Section 211(f)--Substantially Similar and Waivers

    Section 211(f)(1) of the Act makes it unlawful for any manufacturer 
of any fuel or fuel additive to first introduce into commerce, or to 
increase the concentration in use of, any fuel or fuel additive for use 
by any person in motor vehicles manufactured after model year 1974 
which is not substantially similar to any fuel or fuel additive 
utilized in the certification of any model year 1975, or subsequent 
model year, vehicle or engine under Section 206 of the Act. The EPA 
last issued an interpretive rule on the phrase ``substantially 
similar'' at 73 FR 22281 (April 25, 2008). Generally speaking, this 
interpretive rule describes the types of unleaded gasoline that are 
considered ``substantially similar'' to the unleaded gasoline utilized 
in the EPA's emissions certification program by placing limits on a 
gasoline's chemical composition and its physical properties, including 
the amount of alcohols and ethers (oxygenates) that may be added to 
gasoline. Gasoline and diesel fuels that are found to be 
``substantially similar'' to the EPA's certification fuels may be 
registered and introduced into commerce. The current ``substantially 
similar'' interpretive rule for unleaded gasoline allows oxygen content 
up to 2.7 percent oxygen by weight for certain ethers and alcohols, 
which equates to approximately 12 volume percent isobutanol.\1\ 
Gasoline-isobutanol blends containing up to 16 volume percent 
isobutanol would contain up to 3.7 percent oxygen by weight, which 
exceeds the allowable limit for oxygen content under the current 
``substantially similar'' interpretive rule, and would require a waiver 
under section 211(f)(4) of the Act.
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    \1\ See 56 FR 5352 (February 11, 1991).
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    Section 211(f)(4) of the Act provides that upon application of any 
fuel or fuel additive manufacturer, the Administrator may waive the 
prohibitions of CAA section 211(f)(1) if the Administrator determines 
that the applicant has established that such fuel or fuel additive, or 
a 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 to which it has 
been certified pursuant to Sections 206 and 213(a) of the Act. In other 
words, the Administrator may grant a waiver for a prohibited fuel or 
fuel additive if the applicant can demonstrate that the new fuel or 
fuel additive will not cause or contribute to engines, vehicles or 
equipment failing to meet their emissions standards over their useful 
lives. The statute requires that the Administrator shall take final 
action to grant or deny the application, after public notice and 
comment, within 270 days of receipt of the application.
    In addition, the regulations at Sec. Sec.  79.11(i) and 79.21(h) 
require that fuel and fuel additive manufacturers must demonstrate that 
their fuels and fuel additives, respectively, are substantially similar 
or have a waiver as described in section 211(f) of the Act.

CAA Section 211(c)--Rulemaking To Regulate Fuels

    Section 211(c)(1) of the Act allows the Administrator, by 
regulation, to ``control or prohibit the manufacture, introduction into 
commerce, offering for sale, or sale of any fuel or fuel additive for 
use in a motor vehicle, motor vehicle engine, or nonroad engine or 
nonroad vehicle (A) if, in the judgment of the Administrator, any fuel 
or fuel additive or any emission product of such fuel or fuel additive 
causes, or contributes, to air pollution or water pollution (including 
any degradation in the quality of groundwater) that may reasonably be 
anticipated to endanger the public health or welfare, or (B) if 
emission products of such fuel or fuel additive will impair to a 
significant degree the performance of any emission control device or 
system which is in general use, or which the Administrator

[[Page 13462]]

finds has been developed to a point where in a reasonable time it would 
be in general use were such regulation to be promulgated.'' Prior to 
doing so, the EPA must consider scientific and medical evidence as well 
as the costs of any control and setting regulations under Section 202 
of the Act. The EPA must also publish a finding that a control or 
prohibition will not result in the use of other substitute fuels or 
fuel additives that will also endanger public health or welfare.

II. Registration of Isobutanol

Isobutanol Background

    Isobutanol is a flammable colorless liquid that is used as a 
gasoline additive and as an industrial solvent. Isobutanol is composed 
of the chemical elements hydrogen, oxygen, and carbon and it can be 
made from petroleum or renewable biomass, such as corn, grasses, 
agricultural waste and other renewable sources. It can be used in 
internal combustion engines as an additive to gasoline and is 
registered under the 40 CFR part 79 as a gasoline additive for 
manufacturers that are exempt from the Tier 1 and Alternative Tier 2 
testing. A blend level of 16 percent for a non-exempt manufacturer 
would require a new registration that would include meeting Tier 1 and 
Alternative Tier 2 health effects testing requirements and a waiver 
under CAA section 211(f)(4). Biobutanol is the common name for 
isobutanol made from renewable sources.
    There has been an increased interest in the use of biobutanol as a 
direct result of the requirements for increased use of renewable fuel 
volumes, adopted in the Energy Information and Security Act of 2007. 
These provisions require an increase in the use of renewable fuels, 
with 36 billion gallons of renewable fuel to be used in the U.S. by 
2022. Parties required to meet these standards are interested in cost 
effective and practical ways to satisfy the standards and meet the 
performance needs of the vehicles and engines. Biobutanol is one 
potentially attractive option because of its higher energy density, 
lower blending vapor pressure, and lower heat of vaporization in 
comparison to other alcohols such as ethanol.

Current Isobutanol Registrations

    As previously discussed, regulations at 40 CFR 79.58(d) specify 
that a company with total annual sales of less than $50 million is a 
small business and is exempt in certain instances from applicable 
testing requirements. The EPA has registered isobutanol as a fuel 
additive for companies that qualified under this provision.
    Fuel and fuel additive manufacturers with total annual sales of $50 
million or greater do not qualify as small businesses, are prohibited 
from registering the use of isobutanol produced by small businesses, 
and instead must comply with all applicable registration requirements, 
including health effects testing. Gasoline manufacturers typically have 
sales greater than $50 million per year and would need to register 
isobutanol as an additive to their gasoline if they wanted to use it. 
Therefore, a gasoline manufacturer cannot rely on the registration of a 
small additive manufacturer as a means of complying with the 40 CFR 
part 79 registration requirements. Additionally, because no gasoline 
manufacturer has completed the 40 CFR part 79 registration 
requirements, including required health effects testing for isobutanol, 
the agency has yet to grant a registration request of isobutanol as an 
additive to gasoline by a gasoline manufacturer. This has resulted in 
limiting isobutanol to blending at terminals by parties that are not 
gasoline manufacturers. See the definition of fuel manufacturer at 40 
CFR 79.2(d). For this reason, among others, isobutanol has yet to be 
introduced into commerce in any significant volume.

Butamax--Isobutanol Registration

    Butamax Advanced Biofuels, LLC (Butamax) has applied for 
registration of the use of up to 16 percent by volume isobutanol as a 
fuel additive in motor-vehicle gasoline.\2\ As discussed above, fuels 
and fuel additives to motor-vehicle gasoline are required to be 
registered by the EPA under 40 CFR part 79 prior to introduction into 
commerce. As previously described, there are two main requirements for 
the fuel or fuel additive manufacturer. First, the fuel or fuel 
additive must be substantially similar to fuel additives used in 
emissions certification, or, if not, have a waiver under CAA section 
211(f)(4) (42 U.S.C. 7545(f)(4), 40 CFR 79.21(h)). A fuel containing a 
blend of gasoline and 16 percent isobutanol is not substantially 
similar to any EPA certification fuels so Butamax must operate via a 
waiver under CAA section 211(f)(4) prior to registration. The EPA 
allows manufacturers to use previously granted waivers if they can 
satisfy the waiver's terms and conditions. Of relevance here is the 
OCTAMIX waiver, which the EPA granted on February 8, 1988,\3\ and has 
since modified the waiver on October 28, 1988,\4\ June 7, 2012,\5\ and 
June 14, 2012.\6\ The waiver allows a variety of alcohols in gasoline, 
including isobutanol, at up to 3.7 percent oxygen by weight. For a 
gasoline with a typical density, this equates to a maximum of 16 
percent isobutanol by volume when no other oxygenates are present. 
Butamax has stated that it intends to produce the isobutanol fuel 
additive for use in accordance with the OCTAMIX waiver. Butamax must 
show that it will comply with all seven conditions in the OCTAMIX 
waiver to be able to rely on that waiver to satisfy the registration 
requirement at 40 CFR 79.21(h). The Agency has evaluated Butamax's 
March 25, 2011 submission regarding Butamax\TM\ Advanced Biofuels LLC 
and its application of the OCTAMIX Waiver for up to 16 volume percent 
isobutanol as a fuel additive if blended with gasoline and agrees with 
its evaluation that Butamax can meet all seven conditions specified in 
the OCTAMIX waiver.
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    \2\ Ethanol is allowed in gasoline at up to 15 percent by volume 
for certain vehicles. Isobutanol at 16 percent by volume would not 
have a vehicle restriction.
    \3\ See 53 FR 3636 (February 8, 1988).
    \4\ See 53 FR 43768 (October 28, 1988).
    \5\ See 77 FR 33733 (June 7, 2012).
    \6\ See 77 FR 35677 (June 14, 2012).
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    Second, a manufacturer must conduct Tier 1 and either Tier 2 or 
Alternative Tier 2 health-effects testing, unless the manufacturer is 
exempt under the small-business provisions specified at 40 CFR 
79.58(d). Butamax does not qualify as a small business and is not 
exempt from these testing requirements. Additionally, the regulations 
at 40 CFR 79.53(b) allow a manufacturer to rely on existing health 
effects test data that would provide ``reasonably comparable'' 
information in lieu of conducting health effects testing ``regarding 
the carcinogenicity, mutagenicity, neurotoxicity, teratogenicity, 
reproductive/fertility measures, and general toxicity effects of the 
emissions for a fuel or additive'' for registration. The Agency's 
current review leads it to believe that Butamax will likely meet the 
requisite health effects testing requirements for isobutanol at 16 
percent through its submittal of information on testing for the health 
effects end points identified under Alternative Tier 2 testing 
procedures for oxygenates.\7\ Similarly, the Agency also believes that 
Butamax will likely meet the other requirements for registration on EPA 
Form 3520-13,

[[Page 13463]]

Fuel Additive Manufacturer Notification.
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    \7\ Letter to Dr. Carol Henry, American Petroleum Institute, 
from Margo Oge, U.S. EPA, November 2, 1998.
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III. Recent Studies Regarding Isobutanol Blended Gasolines

    The OCTAMIX waiver evaluated a number of 1980s gasoline-fueled 
vehicles on the effects of gasoline-alcohol mixtures (applicable to 
isobutanol at up to 16 percent by volume) on those vehicles emissions 
controls. Since then, studies have been conducted to evaluate the 
potential effects of isobutanol on gasoline-fueled vehicles, engines, 
and fuel dispensing and storage equipment. Recent testing on the use of 
gasoline-isobutanol blended fuels illustrates that isobutanol-blended 
fuels generally do not significantly affect oxides of nitrogen 
(NOX), carbon monoxide (CO), or non-methane organic gas 
(NMOG) emissions. In a recent study, gasoline was splash blended with 
alcohols to produce four blends with a target value of 5.5 percent 
oxygen by weight including a gasoline-isobutanol blend of 21 volume 
percent isobutanol.\8\ The study found that the gasoline-isobutanol 
blended fuel did not significantly affect NOX, CO, or NMOG 
emissions.
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    \8\ Ratcliff, M. A.; Luecke, J.; Williams, A.; Christensen, E.; 
Yanowitz, J.; Reek, A.; and McCormick, R. L.; Impact of higher 
alcohols blended in gasoline on light-duty vehicle exhaust 
emissions. Environ. Sci. Technol., 2013, 47 (23), pp 13865-13872.
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    In a test of isobutanol exposure impacts on fueling infrastructure 
materials, the observed swell for elastomers for exposures to 16 
percent and 24 percent gasoline blends were similar to but slightly 
less than the oxygen equivalent ethanol fuels of E10 and E17. Samples 
of metals commonly found in fuel storage and dispensing systems were 
immersed in 16 percent and 24 percent isobutanol blends at 60 [deg]C 
for 28 days. In all cases, the annualized corrosion rates for 
isobutanol based on weight loss were negligible.\9\
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    \9\ Kass, M.; Theiss, T.; Janke, C.; Pawel, S.; et al; 
Compatibility study for plastic, elastomeric, and metallic fueling 
infrastructure materials exposed to aggressive formulations of 
isobutanol-blended gasoline. Oak Ridge National Laboratory, 2014.
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    Finally, in a 50-hour field emissions test of 175 horsepower and 
215 horsepower boating engines, 16.1 volume percent isobutanol (blended 
to 93 octane) showed similar total HC+NOX emissions compared 
to a non-oxygenated certification gasoline.\10\ In that same test, CO 
emissions were reduced using isobutanol vs. indolene which was expected 
as isobutanol is a partially oxidized fuel. The enleanment reported for 
16.1 percent isobutanol was in line with what is typical of E10 
relative to indolene. The study noted that no operability issues were 
observed while the marine engines were operated on the gasoline-
isobutanol blended fuels.\11\
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    \10\ Until changed in the Tier 3 rulemaking (see 79 FR 23414, 
April 28, 2014), certification gasoline did not contain ethanol, or 
any other oxygenates. However, the Tier 3 rulemaking now requires 
federal motor vehicle gasoline certification fuel to contain 10 
volume percent ethanol.
    \11\ Wasil, J. R.; McKnight, J.; Kolb, R.; Munz, D.; Adey, J.; 
and Goodwin, B.; In-use performance testing of butanol-extended fuel 
in recreational marine engines and vessels. SAE [Tech Pap.] 2012.
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    The Agency believes that based on the referenced studies on the 
potential effects of isobutanol on gasoline-fueled vehicles and engines 
and its engineering judgement, that modern motor vehicles and engines 
should continue to meet emissions standards and suffer no issues with 
driveability or operability on gasoline-isobutanol blended fuels up to 
16 volume percent. However, even though the information cited above 
concerning regulated emissions, retail fuel dispensing and storage 
equipment materials, and marine engines suggests that isobutanol 
blended into gasoline should not pose any significant issues, the 
narrowness of the size and scope of these studies does not address all 
potential effects isobutanol may have on gasoline-fueled vehicles and 
engines. Therefore, the Agency seeks comment on whether there is 
available information on other areas that should be addressed for 
gasoline-isobutanol blended fuels up to 16 volume percent. The Agency 
could use information gleaned from this public comment process to 
determine whether further controls might be necessary (potentially via 
rulemaking under section 211(c) of the Act) to help ensure the smooth 
introduction of isobutanol into the gasoline market or to help 
determine whether the Agency should impose certain conditions on the 
registration of isobutanol as a gasoline additive through 40 CFR part 
79.

IV. Conclusion

    The EPA will register isobutanol for Butamax in accordance with the 
regulations at 40 CFR part 79 once applicable requirements are met. 
Butamax has submitted the required information, including: (1) The 
speciation of exhaust and evaporative emissions for gasoline with 16 
percent isobutanol (Tier 1 testing), (2) a literature search for health 
information on the Tier 1 emissions found for that blend that were not 
found in the Tier 1 testing of gasoline without any oxygenate, and (3) 
the results of the Alternative Tier 2 health-effects testing for that 
blend (animal exposure to evaporative emissions). Butamax has also 
submitted information to demonstrate that it can comply with the 
requirements of the OCTAMIX waiver, which allows the blending of 
isobutanol into gasoline at up to 3.7 percent oxygen by weight, or 16 
percent isobutanol by volume.
    The EPA seeks comments and any information and data on the use of 
isobutanol in gasoline, including, but not limited to: (1) The need for 
additional health-effects testing under the Tier 3 provisions in the 
regulations, and (2) the need for additional regulatory controls for 16 
percent isobutanol in gasoline, beyond those for gasoline at 40 CFR 
parts 79 and 80, under the authority of CAA section 211(c).

    Dated: March 15, 2018.
Byron J. Bunker,
Director, Compliance Division, Office of Transportation and Air 
Quality, Office of Air and Radiation.
[FR Doc. 2018-06119 Filed 3-28-18; 8:45 am]
 BILLING CODE 6560-50-P