[Code of Federal Regulations]
[Title 40, Volume 14]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR79.56]

[Page 509-518]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 79--REGISTRATION OF FUELS AND FUEL ADDITIVES--Table of Contents
 
            Subpart F--Testing Requirements for Registration
 
Sec. 79.56  Fuel and fuel additive grouping system.

    (a) Manufacturers of fuels and fuel additives are allowed to satisfy 
the testing requirements in Secs. 79.52, 79.53, and 79.54 and the 
associated reporting requirements in Sec. 79.59 on an individual or 
group basis, provided that such products meet the criteria in this 
section for enrollment in the same fuel/additive group. However, each 
manufacturer of a fuel or fuel additive must individually comply with 
the notification requirements of Sec. 79.59(b). Further, if a 
manufacturer elects to comply by participation in a group, each 
manufacturer continues to be individually subject to the information 
requirements of this subpart.
    (1) The use of the grouping provision to comply with Tier 1 and Tier 
2 testing requirements is voluntary. No manufacturer is prohibited from 
testing and submitting its own data for its own product registration, 
despite its qualification for membership in a particular group.
    (2) The only groups permitted are those established in this section.
    (b) Each manufacturer who chooses to enroll a fuel or fuel additive 
in a group of similar fuels and fuel additives as designated in this 
section may satisfy the registration requirements through a group 
submission of jointly-sponsored testing and analysis conducted on a 
product which is representative of all products in that group, provided 
that the group representative is chosen according to the specifications 
in this section.
    (1) The health effects information submitted by a group shall be 
considered applicable to all fuels and fuel additives in the group. A 
fuel or fuel additive manufacturer who has chosen to participate in a 
group may subsequently choose to perform testing of such fuel or fuel 
additive on an individual basis; however, until such independent 
registration information has been received and reviewed by EPA, the 
information initially submitted by the group on behalf of the 
manufacturer's fuel or fuel additive shall be considered applicable and 
valid for that fuel or fuel additive. It could therefore be used to 
support requirements for further testing under the provisions of Tier 3 
or to support regulatory decisions affecting that fuel or fuel additive.
    (2) Manufacturers are responsible for determining the appropriate 
groups for their products according to the criteria in this section and 
for enrolling their products into those groups under industry-sponsored 
or other independent brokering arrangements.
    (3) Manufacturers who enroll a fuel or fuel additive into a group 
shall share the applicable costs according to appropriate arrangements 
established by the group. The organization and administration of group 
functions and the development of cost-sharing arrangements are the 
responsibility of the participating manufacturers. If manufacturers are 
unable to agree on fair and equitable cost sharing arrangements and if 
such dispute is referred by one or more manufacturers to EPA for 
resolution, then the provisions in Sec. 79.56(c) (1) and (2) shall 
apply.
    (c) In complying with the registration requirements for a given fuel 
or fuel additive, notwithstanding the enrollment of such fuel or 
additive in a group, a manufacturer may make use of available 
information for any product which conforms to the same grouping criteria 
as the given product. If, for this purpose, a manufacturer wishes to 
rely upon the information previously submitted by another manufacturer 
(or group of manufacturers) for registration of a similar product (or 
group of products), then the previous submitter is entitled to 
reimbursement by the manufacturer for an appropriate portion of the 
applicable costs incurred to obtain and report such information. Such 
entitlement shall remain in effect

[[Page 510]]

for a period of fifteen years following the date on which the original 
information was submitted. Pursuant to Sec. 79.59(b)(4)(ii), the 
manufacturer who relies on previously-submitted registration data shall 
certify to EPA that the original submitter has been notified and that 
appropriate reimbursement arrangements have been made.
    (1) When private efforts have failed to resolve a dispute about a 
fair amount or method of cost-sharing or reimbursement for testing costs 
incurred under this subpart, then any party involved in that dispute may 
initiate a hearing by filing two signed copies of a request for a 
hearing with a regional office of the American Arbitration Association 
and mailing a copy of the request to EPA. A copy must also be sent to 
each person from whom the filing party seeks reimbursement or who seeks 
reimbursement from that party. The information and fees to be included 
in the request for hearing are specified in 40 CFR 791.20(b) and (c).
    (2) Additional procedures and requirements governing the hearing 
process are those specified in 40 CFR 791.22 through 791.50, 791.60, 
791.85, and 791.105, excluding 40 CFR 791.39(a)(3) and 791.48(d).
    (d) Basis for Classification. (1) Rather than segregating fuels and 
fuel additives into separate groups, the grouping system applies the 
same grouping criteria and creates a single set of groups applicable 
both to fuels and fuel additives.
    (2) Fuels shall be classified pursuant to Sec. 79.56(e) into 
categories and groups of similar fuels and fuel additives according to 
the components and characteristics of such fuels in their uncombusted 
state. The classification of a fuel product must take into account the 
components of all bulk fuel additives which are listed in the 
registration application or basic registration data submitted for the 
fuel product.
    (3) Fuel additives shall be classified pursuant to Sec. 79.56(e) 
into categories and groups of similar fuels and fuel additives according 
to the components and characteristics of the respective uncombusted 
additive/base fuel mixture pursuant to Sec. 79.51(h)(1).
    (4) In determining the category and group to which a fuel or fuel 
additive belongs, impurities present in trace amounts shall be ignored 
unless otherwise noted. Impurities are those substances which are 
present through contamination or which remain in the fuel or additive 
naturally after processing is completed.
    (5) Reference Standards. (i) American Society for Testing and 
Materials (ASTM) standard D 4814-93a, ``Standard Specification for 
Automotive Spark-Ignition Engine Fuel'', used to define the general 
characteristics of gasoline fuels (paragraph (e)(3)(i)(A)(3) of this 
section) and ASTM standard D 975-93, ``Standard Specification for Diesel 
Fuel Oils'', used to define the general characteristics of diesel fuels 
(paragraph (e)(3)(ii)(A)(3) of this section) have been incorporated by 
reference.
    (ii) This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from the American Society for Testing and 
Materials (ASTM), 1916 Race Street, Philadelphia, PA 19103. Copies may 
be inspected at U.S. EPA, OAR, 401 M Street SW., Washington, DC 20460 or 
at the Office of the Federal Register, 800 North Capitol Street NW., 
suite 700, Washington, DC.
    (e) Grouping Criteria. The grouping system is represented by a 
matrix of three fuel/additive categories within six specified fuel 
families (see table F94-7, Grouping System for Fuels and Fuel 
Additives). Each category may include one or more groups. Within each 
group, a representative may be designated based on the criteria in this 
section and joint registration information may be developed and 
submitted for member fuels and fuel additives.

[[Page 511]]



                                                Table F94-7--Grouping System for Fuels and Fuel Additives
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                        Conventional Fuel Families                                   Alternative Fuel Families
                                 -----------------------------------------------------------------------------------------------------------------------
            Category                                                                                              Methane (CNG, LNG)
                                     Gasoline  (A)        Diesel  (B)        Methanol (C)         Ethanol (D)             (E)         Propane (LPG)  (F)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline........................  One group           One group           Two groups: (1)     One group           One group           One group
                                   represented by      represented by      M100 group          (includes ethanol-  (includes both      represented by
                                   gasoline base       diesel base fuel.   (includes           gasoline            CNG and LNG),       LPG base fuel.
                                   fuel.                                   methanol-gasoline   formulations with   represented by
                                                                           formulations with   at least 50%        CNG base fuel.
                                                                           at least 96%        ethanol)
                                                                           methanol)           represented by
                                                                           represented by      E85 base fuel.
                                                                           M100 base fuel
                                                                           (2) M85 (includes
                                                                           methanol-gasoline
                                                                           formulations with
                                                                           50-95% methanol)
                                                                           represented by
                                                                           M85 base fuel.
Non-baseline....................  One group for each  One group for each  One group for each  One group for each  One group to        One group to
                                   gasoline-           oxygen-             individual non-     individual non-     include methane     include propane
                                   oxygenate blend     contributing        methanol, non-      ethanol, non-       formulations        formulations
                                   or each gasoline-   compound or class   gasoline            gasoline            exceeding the       exceeding the
                                   methanol/co-        of compounds; one   component and one   component and one   specified limit     specified limit
                                   solvent blend;      group for each      group for each      group for each      for non-methane     for butane and
                                   one group for       synthetic crude-    unique              unique              hydrocarbons.       higher
                                   each synthetic      derived fuel.       combination of      combination of                          hydrocarbons.
                                   crude-derived                           such components.    such components.
                                   fuel.
Atypical........................  One group for each  One group for each  One group for each  One group for each  One group for each  One group for each
                                   atypical element/   atypical element/   atypical element/   atypical element/   atypical element/   atypical element/
                                   characteristic,     characteristic,     characteristic,     characteristic,     characteristic,     characteristic,
                                   or unique           or unique           or unique           or unique           or unique           or unique
                                   combination of      combination of      combination of      combination of      combination of      combination of
                                   atypical elements/  atypical elements/  atypical elements/  atypical elements/  atypical elements/  atypical elements/
                                   characteristics.    characteristics.    characteristics.    characteristics.    characteristics.    characteristics.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (1) Fuel Families. Each of the following six fuel families (Table 
F94-7, columns A-F) includes fuels of the type referenced in the name of 
the family as well as bulk and aftermarket additives which are intended 
for use in those fuels. When applied to fuel additives, the criteria in 
these descriptions refer to the associated additive/base fuel mixture, 
pursuant to Sec. 79.51(h)(1). One or more base fuel formulations are 
specified for each fuel family pursuant to Sec. 79.55.
    (i) The Gasoline Family includes fuels composed of more than 50 
percent gasoline by volume and their associated fuel additives. The base 
fuel for this family is specified in Sec. 79.55(b).
    (ii) The Diesel Family includes fuels composed of more than 50 
percent diesel fuel by volume and their associated fuel additives. The 
Diesel fuel family includes both Diesel 1 and Diesel 2 
formulations. The base fuel for this family is specified in 
Sec. 79.55(c).
    (iii) The Methanol Family includes fuels composed of at least 50 
percent methanol by volume and their associated fuel additives. The M100 
and M85 base fuels are specified in Sec. 79.55(d).
    (iv) The Ethanol Family includes fuels composed of at least 50 
percent ethanol by volume and their associated fuel additives. The base 
fuel for this family is E85 as specified in Sec. 79.55(e).
    (v) The Methane Family includes compressed natural gas (CNG) and 
liquefied natural gas (LNG) fuels containing at least 50 mole percent 
methane and their associated fuel additives. The base fuel for the 
family is a CNG formulation specified in Sec. 79.55(f).

[[Page 512]]

    (vi) The Propane Family includes propane fuels containing at least 
50 percent propane by volume and their associated fuel additives. The 
base fuel for this family is a liquefied petroleum gas (LPG) as 
specified in Sec. 79.55(g).
    (vii) A manufacturer seeking registration for formulation(s) which 
do not fit the criteria for inclusion in any of the fuel families 
described in this section shall contact EPA at the address in 
Sec. 79.59(a)(1) for further guidance in classifying and testing such 
formulation(s).
    (2) Fuel/Additive Categories. Fuel/additive categories (Table F94-7, 
rows 1-3) are subdivisions of fuel families which represent the degree 
to which fuels and fuel additives in the family resemble the base 
fuel(s) designated for the family. Three general category types are 
defined in this section. When applied to fuel additives, the criteria in 
these descriptions refer to the associated additive/base fuel mixture, 
pursuant to Sec. 79.51(h)(1).
    (i) Baseline categories consist of fuels and fuel additives which 
contain no elements other than those permitted in the base fuel for the 
respective fuel family and conform to specified limitations on the 
amounts of certain components or characteristics applicable to that fuel 
family.
    (ii) Non-Baseline Categories consist of fuels and fuel additives 
which contain no elements other than those permitted in the base fuel 
for the respective fuel family, but which exceed one or more of the 
limitations for certain specified components or characteristics 
applicable to baseline formulations in that fuel family.
    (iii) Atypical Categories consist of fuels and fuel additives which 
contain elements or classes of compounds other than those permitted in 
the base fuel for the respective fuel family or which otherwise do not 
meet the criteria for either baseline or non-baseline formulations in 
that fuel family. A fuel or fuel additive product having both non-
baseline and atypical characteristics pursuant to Sec. 79.56(e)(3), 
shall be considered to be an atypical product.
    (3) This section defines the specific categories applicable to each 
fuel family. When applied to fuel additives, the criteria in these 
descriptions refer to the associated additive/base fuel mixture, 
pursuant to Sec. 79.51(h)(1).
    (i) Gasoline Categories. (A) The Baseline Gasoline category contains 
gasoline fuels and associated additives which satisfy all of the 
following criteria:
    (1) Contain no elements other than carbon, hydrogen, oxygen, 
nitrogen, and/or sulfur.
    (2) Contain less than 1.5 percent oxygen by weight.
    (3) Sulfur concentration is limited to 1000 ppm per the 
specifications cited in the following paragraph.
    (4) Possess the physical and chemical characteristics of unleaded 
gasoline as specified by ASTM standard D 4814-93a (incorporated by 
reference, pursuant to paragraph (d)(5) of this section), in at least 
one Seasonal and Geographical Volatility Class.
    (5) Derived only from conventional petroleum, heavy oil deposits, 
coal, tar sands, and/or oil sands.
    (B) The Non-Baseline Gasoline category is comprised of gasoline 
fuels and associated additives which conform to the specifications in 
paragraph (e)(3)(i)(A) of this section for the Baseline Gasoline 
category except that they contain 1.5 percent or more oxygen by weight 
and/or may be derived from sources other than those listed in paragraph 
(e)(3)(i)(A)(5) of this section.
    (C) The Atypical Gasoline category is comprised of gasoline fuels 
and associated additives which contain one or more elements other than 
carbon, hydrogen, oxygen, nitrogen, and sulfur.
    (ii) Diesel Categories. (A) The Baseline Diesel category is 
comprised of diesel fuels and associated additives which satisfy all of 
the following criteria:
    (1) Contain no elements other than carbon, hydrogen, oxygen, 
nitrogen, and/or sulfur. Pursuant to 40 CFR 80.29, highway diesel sold 
after October 1, 1993 shall contain 0.05 percent or less sulfur by 
weight;
    (2) Contain less than 1.0 percent oxygen by weight;
    (3) Diesel formulations containing more than 0.05 percent sulfur by 
weight are precluded by 40 CFR 80.29;
    (4) Possess the characteristics of diesel fuel as specified by ASTM 
standard D 975-93 (incorporated by reference,

[[Page 513]]

pursuant to paragraph (d)(5) of this section); and
    (5) Derived only from conventional petroleum, heavy oil deposits, 
coal, tar sands, and/or oil sands.
    (B) The Non-Baseline Diesel category is comprised of diesel fuels 
and associated additives which conform to the specifications in 
paragraph (e)(3)(ii)(A) of this section for the Baseline Diesel category 
except that they contain 1.0 percent or more oxygen by weight and/or may 
be derived from sources other than those listed in paragraph 
(e)(3)(ii)(A)(5) of this section.
    (C) The Atypical Diesel category is comprised of diesel fuels and 
associated additives which contain one or more elements other than 
carbon, hydrogen, oxygen, nitrogen, and sulfur.
    (iii) Methanol Categories. (A) The Baseline Methanol category is 
comprised of methanol fuels and associated additives which contain at 
least 50 percent methanol by volume, no more than 4.0 percent by volume 
of substances other than methanol and gasoline, and no elements other 
than carbon, hydrogen, oxygen, nitrogen, sulfur, and/or chlorine. 
Baseline methanol shall contain no more than 0.004 percent by weight of 
sulfur or 0.0001 percent by weight of chlorine.
    (B) The Non-Baseline Methanol category is comprised of fuel blends 
which contain at least 50 percent methanol by volume, more than 4.0 
percent by volume of a substance(s) other than methanol and gasoline, 
and meet the baseline limitations on elemental composition in paragraph 
(e)(3)(iii)(A) of this section.
    (C) The Atypical Methanol category consists of methanol fuels and 
associated additives which do not meet the criteria for either the 
Baseline or the Non-Baseline Methanol category.
    (iv) Ethanol Categories. (A) The Baseline Ethanol category is 
comprised of ethanol fuels and associated additives which contain at 
least 50 percent ethanol by volume, no more than five (5) percent by 
volume of substances other than ethanol and gasoline, and no elements 
other than carbon, hydrogen, oxygen, nitrogen, sulfur, chlorine, and 
copper. Baseline ethanol formulations shall contain no more than 0.004 
percent by weight of sulfur, 0.0004 percent by weight of chlorine, and/
or 0.07 mg/L of copper.
    (B) The Non-Baseline Ethanol category is comprised of fuel blends 
which contain at least 50 percent ethanol by volume, more than five (5) 
percent by volume of a substance(s) other than ethanol and gasoline, and 
meet the baseline limitations on elemental composition in paragraph 
(e)(3)(iv)(A) of this section.
    (C) The Atypical Ethanol category consists of ethanol fuels and 
associated additives which do not meet the criteria for either the 
Baseline or the Non-Baseline Ethanol categories.
    (v) Methane Categories. (A) The Baseline Methane category is 
comprised of methane fuels and associated additives (including at least 
an odorant additive) which contain no elements other than carbon, 
hydrogen, oxygen, nitrogen, and/or sulfur, and contain no more than 20 
mole percent non-methane hydrocarbons. Baseline methane formulations 
shall not contain more than 16 ppm by volume of sulfur, including any 
sulfur which may be contributed by the odorant additive.
    (B) The Non-Baseline Methane category consists of methane fuels and 
associated additives which conform to the specifications in paragraph 
(e)(3)(v)(A) of this section for the Baseline Methane category except 
that they exceed 20 mole percent non-methane hydrocarbons.
    (C) The Atypical Methane category consists of methane fuels and 
associated additives which contain one or more elements other than 
carbon, hydrogen, oxygen, nitrogen, and/or sulfur, or exceed 16 ppm by 
volume of sulfur.
    (vi) Propane Categories. (A) The Baseline Propane category is 
comprised of propane fuels and associated additives (including at least 
an odorant additive) which contain no elements other than carbon, 
hydrogen, oxygen, nitrogen, and/or sulfur, and contain no more than 20 
percent by volume non-propane hydrocarbons. Baseline Propane 
formulations shall not contain more than 123 ppm by weight of sulfur, 
including any sulfur which may be contributed by the odorant additive.
    (B) The Non-Baseline Propane category consists of propane fuels and 
associated additives which conform to

[[Page 514]]

the specifications in paragraph (e)(3)(vi)(A) of this section for the 
Baseline Propane category, except that they exceed the 20 percent by 
volume limit for butane and higher hydrocarbons.
    (C) The Atypical Propane category consists of propane fuels and 
associated additives which contain elements other than carbon, hydrogen, 
oxygen, nitrogen, and/or sulfur, or exceed 123 ppm by weight of sulfur.
    (4) Fuel/Additive Groups. Fuel/additive groups are subdivisions of 
the fuel/additive categories. One or more group(s) are defined within 
each category in each fuel family according to the presence of differing 
characteristics in the fuel or additive/base fuel mixture. For each 
group, one formulation (either a base fuel or a member fuel or additive 
product) is chosen to represent all the member products in the group in 
any tests required under this subpart. The section which follows 
describes the fuel/additive groups.
    (i) Baseline Groups. (A) The Baseline Gasoline category comprises a 
single group. The gasoline base fuel specified in Sec. 79.55(b) shall 
serve as the representative of this group.
    (B) The Baseline Diesel category comprises a single group. The 
diesel base fuel specified in Sec. 79.55(c) shall serve as the 
representative of this group.
    (C) The Baseline Methanol category includes two groups: M100 and 
M85. The M100 group consists of methanol-gasoline formulations 
containing at least 96 percent methanol by volume. These formulations 
must contain odorants and bitterants (limited in elemental composition 
to carbon, hydrogen, oxygen, nitrogen, sulfur, and chlorine) for 
prevention of purposeful or inadvertent consumption. The M100 base fuel 
specified in Sec. 79.55(d) shall serve as the representative for this 
group. The M85 group consists of methanol-gasoline formulations 
containing at least 50 percent by volume but less than 96 percent by 
volume methanol. The M85 base fuel specified in Sec. 79.55(d) shall 
serve as the representative of this group.
    (D) The Baseline Ethanol category comprises a single group. The E85 
base fuel specified in Sec. 79.55(e) shall serve as the representative 
of this group.
    (E) The Baseline Methane category comprises a single group. The CNG 
base fuel specified in Sec. 79.55(f) shall serve as the representative 
of this group.
    (F) The Baseline Propane category comprises a single group. The LPG 
base fuel specified in Sec. 79.55(g) shall serve as the representative 
of this group.
    (ii) Non-Baseline Groups--(A) Non-Baseline Gasoline. The Non-
Baseline gasoline fuels and associated additives shall sort into groups 
according to the following criteria:
    (1) For gasoline fuel and additive products which contain 1.5 
percent oxygen by weight or more, a separate non-baseline gasoline group 
shall be defined by each oxygenate compound or methanol/co-solvent blend 
listed as a component in the registration application or basic 
registration data of any such fuel or additive.
    (i) Examples of oxygenates occurring in non-baseline gasoline 
formulations include ethanol, methyl tertiary butyl ether (MTBE), ethyl 
tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), 
diisopropyl ether (DIPE), dimethyl ether (DME), tertiary amyl ethyl 
ether (TAEE), and any other compound(s) which increase the oxygen 
content of the gasoline formulation. A separate non-baseline gasoline 
group is defined for each such oxygenating compound.
    (ii) Each unique methanol and co-solvent combination (whether one, 
two, or more additional oxygenate compounds) used in a non-baseline fuel 
shall also define a separate group. An oxygenate compound used as a co-
solvent for methanol in a non-baseline gasoline formulation must be 
identified as such in its registration. If the oxygenate is not 
identified as a methanol co-solvent, then the compound shall be regarded 
by EPA as defining a separate non-baseline gasoline group. Examples of 
methanol/co-solvent combinations occurring in non-baseline gasoline 
formulations include methanol/isopropyl alcohol, methanol/butanol, and 
methanol with alcohols up to C8/octanol (Octamix).
    (iii) For each such group, the representative to be used in testing 
shall

[[Page 515]]

be a formulation consisting of the gasoline base fuel blended with the 
relevant oxygenate compound (or methanol/co-solvent combination) in an 
amount equivalent to the highest actual or recommended concentration-in-
use of the oxygenate (or methanol/co-solvent combination) recorded in 
the basic registration data of any member fuel or additive product. In 
the event that two or more products in the same group contain the same 
and highest amount of the oxygenate or methanol/co-solvent blend, then 
the representative shall be chosen at random for such candidate 
products.
    (2) An oxygenate compound or methanol/co-solvent combination to be 
blended with the gasoline base fuel for testing purposes shall be 
chemical-grade quality, at a minimum, and shall not contain a 
significant amount of other contaminating oxygenate compounds.
    (3) Separate non-baseline gasoline groups shall also be defined for 
gasoline formulations derived from each particular petroleum source not 
listed in paragraph (e)(3)(i)(A)(5) of this section.
    (i) Such groups may include, but are not limited to, those derived 
from shale, used oil, waste plastics, and other recycled chemical/
petrochemical products.
    (4) Pursuant to Sec. 79.51(i), non-baseline gasoline products may 
belong to more than one fuel/additive group.
    (B) Non-Baseline Diesel. The Non-Baseline diesel fuels and 
associated additives shall sort into groups according to the following 
criteria:
    (1) For diesel fuel and additive products which contain 1.0 percent 
or more oxygen by weight in the form of alcohol(s) and/or ether(s):
    (i) A separate non-baseline diesel group shall be defined by each 
individual alcohol or ether listed as a component in the registration 
application or basic registration data of any such fuel or additive.
    (ii) For each such group, the representative to be used in testing 
shall be a formulation consisting of the diesel base fuel blended with 
the relevant alcohol or ether in an amount equivalent to the highest 
actual or recommended concentration-in-use of the alcohol or ether 
recorded in the basic registration data of any member fuel or additive 
product.
    (2) A separate non-baseline diesel group is also defined for each of 
the following classes of oxygenating compounds: mixed nitroso-compounds; 
mixed nitro-compounds; mixed alkyl nitrates; mixed alkyl nitrites; 
peroxides; furans; mixed alkyl esters of plant and/or animal origin 
(biodiesel). For each such group, the representative to be used in 
testing shall be formulated as follows:
    (i) From the class of compounds which defines the group, a 
particular oxygenate compound shall be chosen from among all such 
compounds recorded in the registration application or basic registration 
data of any fuel or additive in the group.
    (ii) The selected compound shall be the one recorded in any member 
product's registration application with the highest actual or 
recommended maximum concentration-in-use.
    (iii) In the event that two or more oxygenate compounds in the 
relevant class have the highest recorded concentration-in-use, then the 
oxygenate compound to be used in the group representative shall be 
chosen at random from the qualifying candidate compounds.
    (iv) The compound thus selected shall be the group representative, 
and shall be used in testing at the following concentration:
    (A) For biodiesel groups, the representative shall be 100 percent 
biodiesel fuel.
    (B) Otherwise, the group representative shall be the selected 
compound mixed into diesel base fuel at the maximum recommended 
concentration-in-use.
    (3) Separate non-baseline diesel groups shall also be defined for 
diesel formulations derived from each particular petroleum source not 
listed in paragraph (e)(3)(i)(A)(5) of this section.
    (i) Such groups may include, but are not limited to, those derived 
from shale, used oil, waste plastics, and other recycled chemical/
petrochemical products.
    (ii) In any such group, the first product to be registered or to 
apply for

[[Page 516]]

EPA registration shall be the representative of that group. If two or 
more products are registered or apply for first registration 
simultaneously, then the representative shall be chosen by a random 
method from among such candidate products.
    (4) Pursuant to Sec. 79.51(i), non-baseline diesel products may 
belong to more than one fuel/additive group.
    (C) Non-Baseline Methanol. The Non-Baseline methanol formulations 
are sorted into groups based on the non-methanol, non-gasoline 
component(s) of the blended fuel. Each such component occurring 
separately and each unique combination of such components shall define a 
separate group.
    (1) The representative of each such non-baseline methanol group 
shall be the group member with the highest percent by volume of non-
methanol, non-gasoline component(s).
    (2) In case two or more such members have the same and highest 
concentration of non-methanol, non-gasoline component(s), the 
representative of the group shall be chosen at random from among such 
equivalent member products.
    (D) Non-Baseline Ethanol. The Non-Baseline ethanol formulations are 
sorted into groups based on the non-ethanol, non-gasoline component(s) 
of the blended fuel. Each such component occurring separately and each 
unique combination of such components shall define a separate group.
    (1) The representative of each such non-baseline ethanol group shall 
be the group member with the highest percent by volume of non-ethanol, 
non-gasoline component(s).
    (2) In case two or more such members have the same and highest 
concentration of non-ethanol, non-gasoline component(s), the 
representative of the group shall be chosen at random from among such 
equivalent member products.
    (E) Non-Baseline Methane. The Non-Baseline methane category consists 
of one group. The group representative shall be the member fuel or fuel/
additive formulation containing the highest concentration-in-use of non-
methane hydrocarbons. If two or more member products have the same and 
the highest concentration-in-use, then the representative shall be 
chosen at random from such products.
    (F) Non-Baseline Propane. The Non-Baseline propane category consists 
of one group. The group representative shall be the member fuel or fuel/
additive formulation containing the highest concentration-in-use of 
butane and higher hydrocarbons. If two or more products have the same 
and the highest concentration-in-use, then the representative shall be 
chosen at random from such products.
    (iii) Atypical groups. (A) As defined for each individual fuel 
family in Sec. 79.56(e)(3), fuels and additives meeting any one of the 
following criteria are considered atypical.
    (1) Gasoline Atypical fuels and additives contain one or more 
elements in addition to carbon, hydrogen, oxygen, nitrogen, and sulfur.
    (2) Diesel Atypical fuels and additives contain one or more element 
in addition to carbon, hydrogen, oxygen, nitrogen, and sulfur.
    (3) Methanol Atypical fuels and additives contain:
    (i) one or more element in addition to carbon, hydrogen, oxygen, 
nitrogen, sulfur, and chlorine, and/or
    (ii) sulfur in excess of 0.004 percent by weight, and/or
    (iii) chlorine in excess of 0.0001 percent by weight.
    (4) Ethanol Atypical fuels and additives contain:
    (i) one or more element in addition to carbon, hydrogen, oxygen, 
nitrogen, sulfur, chlorine, and copper, and/or
    (ii) sulfur in excess of 0.004 percent by weight, and/or
    (iii) contain chlorine (as chloride) in excess of 0.0004 percent by 
weight, and/or
    (iv) contain copper in excess of 0.07 mg/L.
    (5) Methane Atypical fuels and additives contain:
    (i) one or more element in addition to carbon, hydrogen, oxygen, 
nitrogen, and sulfur, and/or
    (ii) sulfur in excess of 16 ppm by volume.
    (6) Propane Atypical fuels and additives contain:
    (i) one or more element in addition to carbon, hydrogen, oxygen, 
nitrogen, and sulfur, and/or

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    (ii) sulfur in excess of 123 ppm by weight.
    (B) General rules for sorting these atypical fuels and additives 
into separate groups are as follows:
    (1) Pursuant to Sec. 79.51(j), a given atypical product may belong 
to more than one atypical group.
    (2) Fuels and additives in different fuel families may not be 
grouped together, even if they contain the same atypical element(s) or 
other atypical characteristic(s).
    (3) A fuel or additive containing one or more atypical elements 
attached to a polymer compound must be sorted into a separate group from 
atypical fuels or fuel additives containing the same atypical element(s) 
in non-polymer form. However, the occurrence of a polymer compound which 
does not contain an atypical element does not affect the grouping of a 
fuel or additive.
    (C) Specific rules for sorting each family's atypical fuels and 
additives into separate groups, and for choosing each such group's 
representative for testing, are as follows:
    (1) A separate group is created for each atypical element (or other 
atypical characteristic) occurring separately, i.e., in the absence of 
any other atypical element or characteristic, in one or more fuels and/
or additives within a given fuel family.
    (i) Consistent with the basic grouping guidelines provided in 
Sec. 79.56(d), a fuel product which is classified as atypical because 
its basic registration data or application lists a bulk additive 
containing an atypical characteristic, may be grouped with that additive 
and/or with other fuels and additives containing the same atypical 
characteristic.
    (ii) Within a group of products containing only one atypical element 
or characteristic, the fuel or additive/base fuel mixture with the 
highest concentration-in-use or recommended concentration-in-use of the 
atypical element or characteristic shall be the designated 
representative of that group. In the event that two or more fuels or 
additive/base fuel mixtures within the group contain the same and 
highest concentration of the single atypical element or characteristic, 
then the group representative shall be selected by a random method from 
among such candidate products.
    (2) A separate group is also created for each unique combination of 
atypical elements (and/or other specified atypical characteristics) 
occurring together in one or more fuels and/or additives within a given 
fuel family.
    (i) Consistent with the basic grouping guidelines provided in 
Sec. 79.56(d), a fuel which is classified as atypical because its basic 
registration data lists one bulk additive containing two or more 
atypical characteristics, may be grouped with that additive and/or with 
other fuels and/or additives containing the same combination of atypical 
characteristics. Grouping of fuels containing more than one atypical 
additive shall be guided by provisions of Sec. 79.51(j).
    (ii) Within a group of such products containing a unique combination 
of two or more atypical elements or characteristics, the designated 
representative shall be the product within the group which contains the 
highest total concentration of the atypical elements or characteristics.
    (iii) In the event that two or more products within a given atypical 
group contain the same and highest concentration of the same atypical 
elements or characteristics then, among such candidate products, the 
designated representative shall be the product which, first, has the 
highest total concentration of metals, followed in order by highest 
total concentration of halogens, highest total concentration of other 
atypical elements (including sulfur concentration, as applicable), 
highest total concentration of polymers containing atypical elements, 
and, lastly, highest total concentration of oxygen.
    (iv) If two or more products have the same and highest concentration 
of the variable identified in the preceding paragraph, then, among such 
products, the one with the greatest concentration of the next highest 
variable on the list shall be the group representative.
    (v) This decision-making process shall continue until a single 
product is determined to be the representative. If two or more products 
remain tied at

[[Page 518]]

the end of this process, then the representative shall be chosen by a 
random method from among such remaining products.

[59 FR 33093, June 27, 1994, as amended at 62 FR 12571, Mar. 17, 1997]