[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: 40CFR79.55]

[Page 506-509]
 
                   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. 79.55  Base fuel specifications.

    (a) General Characteristics. (1) The base fuel(s) in each fuel 
family shall serve as the group representative(s) for the baseline 
group(s) in each fuel family pursuant to Sec. 79.56. Also, as specified 
in Sec. 79.51(h)(1), for fuel additives undergoing testing, the 
designated base fuel for the respective fuel family shall serve as the 
substrate in which the additive shall be mixed prior to the generation 
of emissions.
    (2) Base fuels shall contain a limited complement of the additives 
which are essential for the fuel's production or distribution and/or for 
the successful operation of the test vehicle/engine throughout the 
mileage accumulation and emission generation periods. Such additives 
shall be used at the minimum effective concentration-in-use for the base 
fuel in question.

[[Page 507]]

    (3) Unless otherwise restricted, the presence of trace contaminants 
does not preclude the use of a fuel or fuel additive as a component of a 
base fuel formulation.
    (4) When an additive is the test subject, any additive normally 
contained in the base fuel which serves the same function as the subject 
additive shall be removed from the base fuel formulation. For example, 
if a corrosion inhibitor were the subject of testing and if this 
additive were to be tested in a base fuel which normally contained a 
corrosion inhibitor, this test additive would replace the corrosion 
inhibitor normally included as a component of the base fuel.
    (5) Additive components of the methanol, ethanol, methane, and 
propane base fuels in addition to any such additives included below 
shall be limited to those recommended by the manufacturers of the 
vehicles and/or engines used in testing such fuels. For this purpose, 
EPA will review requests from manufacturers (or their agents) to modify 
the additive specifications for the alternative fuels and, if necessary, 
EPA shall change these specifications based on consistency of those 
changes with the associated vehicle manufacturer's recommendations for 
the operation of the vehicle. EPA shall publish notice of any such 
changes to a base fuel and/or its base additive package specifications 
in the Federal Register.
    (b) Gasoline Base Fuel. (1) The gasoline base fuel is patterned 
after the reformulated gasoline summer baseline fuel as specified in CAA 
section 211(k)(10)(B)(i). The specifications and blending tolerances for 
the gasoline base fuel are listed in table F94-1. The additive types 
which shall be required and/or permissible in the gasoline base fuel are 
listed in table 1 as well.

               Table F94-1--Gasoline Base Fuel Properties
------------------------------------------------------------------------

------------------------------------------------------------------------
API Gravity..................................  57.40.3
Sulfur, ppm..................................  33925
Benzene, vol%................................  1.530.3
RVP, psi.....................................  8.70.3
Octane, (R+M)/2..............................  87.30.5
Distillation Parameters:
  10%,  deg.F................................  1285
  50%,  deg.F................................  2185
  90%,  deg.F................................  3305
Aromatics, vol%..............................  32.02.7
Olefins, vol%................................  9.22.5
Saturates, vol%..............................  58.82.0
Additive Types:
  Required...................................  Deposit Control
                                               Corrosion Inhibitor
                                               Demulsifier
                                               Anti-oxidant
                                               Metal Deactivator
  Permissible................................  Anti-static
------------------------------------------------------------------------

    (2) The additive components of the gasoline base fuel shall contain 
compounds comprised of no elements other than carbon, hydrogen, oxygen, 
nitrogen, and sulfur. Additives shall be used at the minimum 
concentration needed to perform effectively in the gasoline base fuel. 
In no case shall their concentration in the base fuel exceed the maximum 
concentration recommended by the additive manufacturer. The increment of 
sulfur contributed to the formulation by any additive shall not exceed 
15 parts per million sulfur by weight and shall not cause the gasoline 
base fuel to exceed the sulfur specifications in table F94-1 of this 
section.
    (c) Diesel Base Fuel. (1) The diesel base fuel shall be a 2 
diesel fuel having the properties and blending tolerances shown in table 
F94-2 of this section. The additive types which shall be permissible in 
diesel base fuel are presented in table F94-2 as well.

                Table F94-2--Diesel Base Fuel Properties
------------------------------------------------------------------------

------------------------------------------------------------------------
API Gravity..................................  331
Sulfur, wt%..................................  0.050.0025
Cetane Number................................  45.22
Cetane Index.................................  45.72
Distillation Parameters:
  10%,  deg.F................................  4335
  50%,  deg.F................................  5165
  90%,  deg.F................................  6065
Aromatics, vol%..............................  38.42.7
Olefins, vol%................................  1.50.4
Saturates, vol%..............................  60.12.0
Additive Types:
  Required...................................  Corrosion Inhibitor
                                               Demulsifier
                                               Anti-oxidant
                                               Metal Deactivator
  Permitted..................................  Anti-static
                                               Flow Improver
  Not Permitted..............................  Deposit Control
------------------------------------------------------------------------

    (2) The additive components of the diesel base fuel shall contain 
compounds comprised of no elements other than carbon, hydrogen, oxygen, 
nitrogen, and sulfur. Additives shall be used at the minimum 
concentration needed to perform effectively in the diesel

[[Page 508]]

base fuel. In no case shall their concentration in the base fuel exceed 
the maximum concentration recommended by the additive manufacturer. The 
increment of sulfur contributed to the base fuel by additives shall not 
cause the diesel base fuel to exceed the sulfur specifications in table 
F94-2 of this section.
    (d) Methanol Base Fuels. (1) The methanol base fuels shall contain 
no elements other than carbon, hydrogen, oxygen, nitrogen, sulfur, and 
chlorine.
    (2) The M100 base fuel shall consist of 100 percent by volume 
chemical grade methanol.
    (3) The M85 base fuel is to contain 85 percent by volume chemical 
grade methanol, blended with 15 percent by volume gasoline base fuel 
meeting the gasoline base fuel specifications outlined in paragraph 
(b)(1) of this section. Manufacturers shall ensure the methanol 
compatibility of lubricating oils as well as fuel additives used in the 
gasoline portion of the M85 base fuel.
    (4) The methanol base fuels shall meet the specifications listed in 
table F94-3.

               Table F94-3--Methanol Base Fuel Properties
------------------------------------------------------------------------

------------------------------------------------------------------------
M100:
    Chemical Grade MeOH, vol%..................................      100
    Chlorine (as chlorides), wt%, max..........................   0.0001
    Water, wt%, max............................................      0.5
    Sulfur, wt%, max...........................................    0.002
M85
    Chemical Grade MeOH, vol%,.................................       85
    Gasoline Base Fuel, vol%...................................       15
    Chlorine (as chlorides), wt%, max..........................   0.0001
    Water, wt%, max............................................      0.5
    Sulfur, wt%, max...........................................    0.004
------------------------------------------------------------------------

    (e) Ethanol Base Fuel. (1) The ethanol base fuel, E85, shall contain 
no elements other than carbon, hydrogen, oxygen, nitrogen, sulfur, 
chlorine, and copper.
    (2) The ethanol base fuel shall contain 85 percent by volume 
chemical grade ethanol, blended with 15 percent by volume gasoline base 
fuel that meets the specifications listed in paragraph (b)(1) of this 
section. Additives used in the gasoline component of E85 shall be 
ethanol-compatible.
    (3) The ethanol base fuel shall meet the specifications listed in 
table F94-4.

                Table F94-4--Ethanol Base Fuel Properties
------------------------------------------------------------------------

------------------------------------------------------------------------
E85:
    Chemical Grade EtOH, vol%, min.............................       85
    Gasoline Base Fuel, vol%...................................       15
    Chlorine (as chloride), wt%, max...........................   0.0004
    Copper, mg/L, max..........................................     0.07
    Water, wt%, max............................................      0.5
    Sulfur, wt%, max...........................................    0.004
------------------------------------------------------------------------

    (f) Methane Base Fuel. (1) The methane base fuel is a gaseous motor 
vehicle fuel marketed commercially as compressed natural gas (CNG), 
whose primary constituent is methane.
    (2) The methane base fuel shall contain no elements other than 
carbon, hydrogen, oxygen, nitrogen, and sulfur. The fuel shall contain 
an odorant additive for leak detection purposes. The added odorant shall 
be used at a level such that, at ambient conditions, the fuel must have 
a distinctive odor potent enough for its presence to be detected down to 
a concentration in air of not over \1/5\ (one-fifth) of the lower limit 
of flammability. After addition of the odorant, the methane base fuel 
shall contain no more than 16 ppm sulfur by volume.
    (3) The methane base fuel shall meet the specifications listed in 
table F94-5.

              Table F94-5--Methane Base Fuel Specifications
------------------------------------------------------------------------

------------------------------------------------------------------------
Methane, mole%, min.............................................    89.0
Ethane, mole%, max..............................................     4.5
Propane and higher HC, mole%, max...............................     2.3
C6 and higher HC, mole%, max....................................     0.2
Oxygen, mole%, max..............................................     0.6
Sulfur (including odorant additive) ppmv, max...................      16
Inert gases:
  Sum of CO2 and N2, mole%, max.................................     4.0
------------------------------------------------------------------------

    (g) Propane Base Fuel. (1) The propane base fuel is a gaseous motor 
vehicle fuel, marketed commercially as liquified petroleum gas (LPG), 
whose primary constituent is propane.
    (2) The propane base fuel may contain no elements other than carbon, 
hydrogen, oxygen, nitrogen, and sulfur. The fuel shall contain an 
odorant additive for leak detection purposes. The added odorant shall be 
used at a level such that at ambient conditions the fuel must have a 
distinctive odor potent enough for its presence to be detected down to a 
concentration in air of not over \1/5\ (one-fifth) of the lower limit of 
flammability. After addition of

[[Page 509]]

the odorant, the propane base fuel shall contain no more than 120 ppm 
sulfur by weight.
    (3) The propane base fuel shall meet the specifications listed in 
table F94-6.

             Table F94--6--Propane Base Fuel Specifications
------------------------------------------------------------------------

------------------------------------------------------------------------
Vapor pressure at 100-F, psig, max..............................     208
Evaporative temperature, 95%,  deg.F, max.......................     -37
Propane, vol%, min..............................................    92.5
Propylene, vol%, max............................................     5.0
Butane and heavier, vol%, max...................................     2.5
Residue-evaporation of 100mL, max, mL...........................    0.05
Sulfur (including odorant additive) ppmw, max...................     123
------------------------------------------------------------------------