v>EPA
Office of Transportation EPA420-B-06-013
United States and Air Quality October 2006
Environmental Protection
Agency
RFG/Anti-Dumping
Questions and Answers
October 12, 2006
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EPA420-B-06-013
October 2006
RFG/Anti-Dumping Questions and Answers
October 12, 2006
Transportation and Regional Programs Division
Office of Transportation and Air Quality
U.S. Environmental Protection Agency
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RFG/ANTI-DUMPING QUESTIONS AND ANSWERS, OCTOBER 12, 2006
The following are responses to questions received by the Environmental Protection
Agency (EPA) concerning the manner in which the EPA intends to implement and assure
compliance with the reformulated gasoline and anti-dumping regulations at 40 CFR Part
80. This document was prepared by EPA's Office of Air and Radiation, Office of
Transportation and Air Quality, and Office of Enforcement and Compliance Assurance,
Office of Regulatory Enforcement, Air Enforcement Division.
Regulated parties may use this document to aid in achieving compliance with the
reformulated gasoline (RFG) and anti-dumping regulations. However, this document
does not in any way alter the requirements of these regulations. While the answers
provided in this document represent the Agency's interpretation and general plans for
implementation of the regulations at this time, some of the responses may change as
additional information becomes available or as the Agency further considers certain
issues.
This guidance document does not establish or change legal rights or obligations. It does
not establish binding rules or requirements and is not fully determinative of the issues
addressed. Agency decisions in any particular case will be made applying the law and
regulations on the basis of specific facts and actual action.
While we have attempted to include answers to all questions received, the necessity for
policy decisions and/or resource constraints may have prevented the inclusion of certain
questions. Questions not answered in this document will be answered in a subsequent
document. Questions that merely require a justification of the regulations, or that have
previously been answered or discussed either in a previous Question and Answer
document or the Preamble to the regulations have been omitted.
OXYGENATES
Question: May small amounts of oxygenates other than ethanol be present in gasoline-
ethanol blends that contain 10 volume percent ethanol, or gasoline blendstock that is
blended with 10 volume percent ethanol?
Answer: Section 21 l(f) of the Clean Air Act prohibits fuel or fuel additives to be used in
gasoline unless they are "substantially similar" to that used in the certification of motor
vehicles or motor vehicle engines. EPA has determined that an additive is substantially
similar if it contains only carbon, hydrogen, oxygen, nitrogen or sulfur at concentrations
under 0.25 volume percent (see 46FR38582 (July 28, 1981)). EPA has also determined
that conventional gasoline may contain up to 2.7 weight percent oxygen, regardless of the
number of different allowable oxygenates in the gasoline (see 56FR5352 (February 11,
1991)). However, conventional gasoline may contain up to 3.5 weight percent oxygen if
ethanol is the only oxygenate present in the gasoline (see 44FR20777 (March 29, 1979)).
Gasoline which contains 10 volume percent ethanol, where ethanol is the only oxygenate
in the gasoline, typically contains 3.5 weight percent oxygen.
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EPA has historically allowed blends of conventional gasoline and ethanol containing 10
volume percent ethanol to also contain up to 2 volume percent MTBE (see letter to Ben
Henneke, Jr., President, Energy Fuels Development Corporation from Richard D. Wilson,
Director, Office of Mobile Sources, dated December 15, 1986). Gasoline which contains
2 volume percent MTBE, where MTBE is the only oxygenate in the gasoline, typically
contains approximately 0.36 weight percent oxygen. EPA believes it is reasonable to
allow conventional gasoline that contains 10 volume percent ethanol to also contain small
amounts of oxygenates other than MTBE. However, if conventional gasoline contains
both 10 volume percent ethanol and small amounts of any other oxygenates, the
combination of all oxygenates other than ethanol may not increase the weight percent
oxygen in the conventional gasoline by more than a total of 0.36 weight percent.
EPA has also historically allowed blends of reformulated blendstock for oxygenate
blending (RBOB) and ethanol to contain up to 0.6 volume percent MTBE, ETBE,
TAME or t-butanol, or 0.2 volume percent methanol (see Reformulated Gasoline and
Antidumping Questions and Answers, October 3, 1994 and May 9, 1995). Gasoline
which contains 0.6 volume percent MTBE, where MTBE is the only oxygenate in the
gasoline, typically contains approximately 0.11 weight percent oxygen. EPA believes it
is reasonable to allow blends of RBOB and ethanol to also contain small amounts of
oxygenates other than MTBE, ETBE, TAME, t-butanol or methanol. However, if a blend
of RBOB and ethanol contains small amounts of any oxygenates other than MTBE,
ETBE, TAME, t-butanol or methanol, the combination of all oxygenates other than
ethanol may not increase the weight percent oxygen in the RBOB-ethanol blend by more
than a total of 0.11 weight percent.
TRANSMIX
Question: How will EPA determine if the endpoint of transmix-blended gasoline is in
violation of the 437 degree maximum specified in EPA regulations?
Answer: Transmix blenders are refiners who produce gasoline by blending relatively
small amounts (typically 0.25 volume percent) of transmix in gasoline. EPA has
provided regulatory flexibility that allows transmix blenders to produce gasoline without
having to meet all of the regulatory requirements for refiners, provided the endpoint of
the transmix-blended gasoline does not exceed 437 degrees Fahrenheit (see 40 CFR
80.84. Blending transmix into gasoline increases the endpoint of the gasoline, and can
potentially have a detrimental effect on emissions. In EPA's assessment of the effect of
transmix blending on emissions, EPA determined that the effect of transmix blending on
emissions would be negligible, provided the endpoint of the transmix-blended gasoline
did not exceed 437 degrees F.
Transmix is a mixture of gasoline and distillate fuels that pipelines generate from their
normal operations. Pipeline and terminal operators are able to blend transmix into
gasoline to efficiently dispose of the transmix, because the endpoint of the gasoline prior
to blending is typically less than the 437 degree F maximum specified in industry
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standards and EPA's regulations. Transmix blending affects emissions because of the
distillate fuel in the transmix. However, the amount of transmix that can be blended into
gasoline is significantly limited by the percentage of distillate fuel in the transmix.
Distillate fuels have much higher boiling points than gasoline, so transmix blenders must
limit the addition of transmix so that the endpoint of the transmix-blended gasoline does
not exceed 437 degrees F. Consequently, transmix which contains relatively high
percentages of distillate fuel must be blended into gasoline at relatively low amounts so
that the endpoint of the transmix-blended gasoline does not exceed 437 degrees F.
Conversely, transmix which contains a relatively high percentage of gasoline could be
blended into gasoline in relatively greater amounts without causing the endpoint of the
transmix-blended gasoline to exceed 437 degrees F, since the transmix itself is already
mostly composed of gasoline.
437 degrees F is the maximum allowable endpoint for gasoline specified in EPA's
regulatory standard for automotive spark-ignition engine fuel, ASTM D 4814-88.
Gasoline endpoint is measured using EPA regulatory method ASTM D 86-01, which
measures the percentage of a gasoline sample that evaporates, as a function of
temperature, as the sample is heated up under controlled conditions. Endpoint is the
temperature at which all the volatile portion of a gasoline sample is evaporated. ASTM
D 4814-88 specifies a maximum allowable endpoint of 437 degrees F in order to limit the
amount of higher-boiling point compounds that can be present in gasoline.
ASTM D 86-01 also provides values for reproducibility, a measure of overall variability,
of endpoint test results. Using the automated D 86-01 test method on gasoline with an
RVP greater than 9.5 psi, the reproducibility for endpoint is 16 degrees F. Using the
automated D 86-01 test method on gasoline with an RVP less than or equal to 9.5 psi, the
reproducibility for endpoint is 18.9 degrees F. From discussions with refiners, EPA
understands that in commercial practice, reproducibility is typically adjusted by a
multiplier of 0.59, calculated from ASTM D 3244 Standard Practice for Utilization of
Test Data to Determine Conformance with Specifications. Multiplying the above
reproducibilities by 0.59 results in adjusted reproducibilities of 9.4 degrees F for gasoline
with an RVP greater than 9.5 psi and 11.2 degrees F for gasoline with an RVP less than
or equal to 9.5 psi.
EPA typically allows test tolerances for fuel downstream of the refinery gate, but does
not allow any tolerances in test results for refiners. In the rulemaking that provided
regulatory flexibility to transmix blenders, EPA did not provide any allowances for
variability in endpoint tests. EPA is concerned that using the reproducibility in ASTM D
86-01, adjusted through ASTM D 3244, as a test tolerance would potentially result in
transmix being blended into gasoline in greater-than-anticipated percentages, and could
cause a non-negligible effect on emissions.
Although EPA believes the adjusted reproducibility is unacceptably large for EPA
regulatory use, we do believe that some recognition of variability in endpoint testing is
warranted. The RFG regulations at 80.65(e)(2)(i) provide allowances for differences in
test results between a refiner or importer and an independent laboratory. For the 90%
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distillation point (T90), the RFG regulations allow a difference in test results of up to 5
degrees F, as measured by ASTM D 86-01. Since gasoline endpoint and T90 measure
very similar gasoline properties, EPA believes it is similarly appropriate to also allow a 5
degree F tolerance in test results for gasoline endpoint. Thus, EPA will consider
transmix-blended gasoline to be compliant if an enforcement test result for gasoline
endpoint is no more than 5 degrees greater than the 437 degree F maximum specified in
the regulations.
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