[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: 40CFR79.57]
[Page 518-526]
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. 79.57 Emission generation.
This section specifies the equipment and procedures that must be
used in generating the emissions which are to be subjected to the
characterization procedures and/or the biological tests specified in
Secs. 79.52(b) and 79.53 of these regulations. When applicable, they may
also be required in conjunction with testing under Secs. 79.54 and
79.58(c). Additional requirements concerning emission generation,
delivery, dilution, quality control, and safety practices are outlined
in Sec. 79.61.
(a) Vehicle and engine selection criteria. (1) All vehicles and
engines used to generate emissions for testing a fuel or additive/fuel
mixture must be new (i.e., never before titled) and placed into the
program with less than 500 miles on the odometer or 12 hours on the
engine chronometer. The vehicles and engines shall be unaltered from the
specifications of the original equipment manufacturer.
(2) The vehicle/engine type, vehicle/engine class, and vehicle/
engine subclass designated to generate emissions for a given fuel or
additive shall be the same type, class, and subclass which, over the
previous three years, has consumed the most gallons of fuel in the fuel
family applicable to the given fuel or additive. No distinction shall be
made between light-duty vehicles and light-duty trucks for purposes of
this classification.
(3) Within this vehicle/engine type, class, and subclass, the
specific vehicles and engines acceptable for emission generation are
those that represent the most common fuel metering system and the most
common of the most important emission control system devices or
characteristics with respect to emission reduction performance for the
model year in which testing begins. These vehicles will be determined
through a survey of the previous model year's vehicle/engine sales
within the given subclass. These characteristics shall include, but need
not be limited to, aftertreatment device(s), fuel aspiration, air
injection, exhaust gas recirculation, and feedback type.
(4) Within the applicable subclass, the five highest selling
vehicle/engine models that contain the most common such equipment and
characteristics shall be determined. Any of these five models of the
current model year (at the time testing begins) may be selected for
emission generation.
(i) If one or more of the five models is not available for the
current model year, the choice of model for emission generation shall be
limited to those remaining among the five.
(ii) If fewer than five models of the given vehicle/engine type are
available for the current model year, all such models shall be eligible.
(5) When the fuel or fuel additive undergoing testing is not
commonly used or intended to be used in the vehicle/engine types
prescribed by this selection procedure, or when rebuilding or alteration
is required to obtain a suitable vehicle/engine for emission generation,
the manufacturer may submit a request to EPA for a modification in test
procedure requirements. Any such request must include objective test
results which support the claim that a more appropriate vehicle/engine
type is needed as well as a suggested substitute vehicle/engine type.
The vehicle/engine selection in this case shall be approved by EPA prior
to the start of testing.
(6) Once a particular model has been chosen on which to test a fuel
or additive product, all mileage accumulation and generation of
emissions for characterization and biological testing of such product
shall be conducted on that same model.
(i) If the initial test vehicle/engine fails or must be replaced for
any reason, emission generation shall continue with a second vehicle/
engine which is identical to, or resembles to the greatest extent
possible, the initial test vehicle/engine. If more than one replacement
vehicle/engine is necessary, all such vehicles/engines shall be
identical, or resemble to the greatest extent possible, the initial test
vehicle/engine.
(ii) Manufacturers are encouraged to obtain, at the start of a test
program,
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more than one emission generation vehicle/engine of the identical model,
to ensure the availability of back-up emission generator(s). All backup
vehicles/engines must be conditioned and must have their emissions fully
characterized, as done for the initial test vehicle/engine, prior to
their use as emission generators for biological testing. Alternating
between such vehicles/engines regularly during the course of testing is
permissible and advisable, particularly to allow regular maintenance on
such vehicles/engines during prolonged health effects testing.
(b) Vehicle/engine operation and maintenance. (1) For the purpose of
generating combustion emissions from a fuel or additive/base fuel
mixture for which the relevant class is light duty, either a light-duty
vehicle shall be operated on a chassis dynamometer or a light-duty
engine shall be operated on an engine dynamometer. When the relevant
class is heavy duty, the emissions shall be generated on a heavy-duty
engine operated on an engine dynamometer. In both cases, the vehicle or
engine model shall be selected as described in paragraph (a) of this
section and shall have all applicable fuel and emission control systems
intact.
(2) Except as provided in Sec. 79.51(h)(2)(iii), the fuel or
additive/base fuel mixture being tested shall be used at all times
during operation of the test vehicle or engine. No other fuels or
additives shall be used in the test vehicle or engine once mileage
accumulation has begun until emission generation for emission
characterization and biological testing purposes is completed.
(i) A vehicle or engine may be used to generate emissions for the
testing of more than one fuel or additive, provided that all such fuels
and additives belong to the same fuel family pursuant to
Sec. 79.56(e)(i), and that, once a vehicle or engine has been used to
generate emissions for an atypical fuel or additive (pursuant to
Sec. 79.56(e)(2)(iii)), it shall not be used in the testing of any other
fuel or additive. Paragraphs (a) (2) and (3) of this section shall apply
only to the first fuel or additive tested.
(ii) Prior to being used to generate emissions for testing an
additional fuel or additive, a vehicle or engine which has previously
been used for testing a different fuel or additive shall undergo an
effective intermediate preconditioning cycle to remove the previously
used fuel and its emissions from the vehicle's fuel and exhaust systems
and from the combustion emission and evaporative emission control
systems, if any.
(iii) Such preconditioning shall include, at a minimum, the
following steps:
(A) The canister (if any) shall be removed from the vehicle and
purged with 300 deg.F nitrogen at 20 liters per minute until the
incremental weight loss of the canister is less than 1 gram in 30
minutes. This typically takes 3-4 hours and removes 100 to 120 grams of
adsorbed gasoline vapors.
(B) The fuel tank shall be drained and filled to capacity with the
new test fuel or additive/fuel mixture.
(C) The vehicle or engine shall be operated until at least 95% of
the fuel tank capacity is consumed.
(D) The purged canister shall be returned to the vehicle.
(E) The fuel tank shall be drained and filled to 40% capacity with
test fuel.
(F) Two-hour fuel tank heat builds from 72-120 deg.F shall be
performed repeatedly as necessary to achieve canister breakthrough. The
fuel tank must be drained and filled prior to each heat build.
(3) Scheduled and unscheduled vehicle/engine maintenance. (i) During
emission generation, vehicles and engines must be maintained in good
condition by following the recommendations of the original equipment
manufacturer (OEM) for scheduled service and parts replacement, with
repairs performed only as necessary. Modifications, adjustments, and
maintenance procedures contrary to procedures found in 40 CFR part 86
for the maintenance of test vehicles/engines or performed solely for the
purpose of emissions improvement are not allowed.
(ii) If unscheduled maintenance becomes necessary, the vehicle or
engine must be repaired to OEM specifications, using OEM or OEM-approved
parts. In addition, the tester is required to measure the basic
emissions
[[Page 520]]
pursuant to Sec. 79.52(b)(2)(i) after the unscheduled maintenance and
before resuming testing to ensure that the post-maintenance emissions
shall be within 20 percent of pre-maintenance emissions levels. If the
basic emissions cannot be brought within 20 percent of their previous
levels, then the manufacturer shall restart the emissions
characterization and health testing of its products combustion emissions
using a new vehicle/engine.
(c) Mileage accumulation. (1) A vehicle/engine break-in period is
required prior to generating emissions for characterization and/or
biological testing under this subpart. The required mileage accumulation
may be accomplished on a test track, on the street, on a dynamometer, or
using any other conventionally accepted method.
(2) Vehicles to be used in the evaluation of baseline and non-
baseline fuels and fuel additives shall accumulate 4,000 miles prior to
emission testing. Engines to be used in the evaluation of baseline and
non-baseline fuels and fuel additives shall accumulate 125 hours of
operation on an engine dynamometer prior to emission testing.
(3) When the test formulation is classified as an atypical fuel or
fuel additive formulation (pursuant to definitions in
Sec. 79.56(e)(4)(iii)), the following additional mileage accumulation
requirements apply:
(i) The test vehicle/engine must be operated for a minimum of 4,000
vehicle miles or 125 hours of engine operation.
(ii) Thereafter, at intervals determined by the tester, all emission
fractions (i.e., vapor, semi-volatile, and particulate) shall be sampled
and analyzed for the presence and amount of the atypical element(s) and/
or other atypical constituents. Pursuant to paragraph (d) of this
section, the sampled emissions must be generated in the absence of an
intact aftertreatment device. Immediately before the samples are taken,
a brief warmup period (at least ten miles or the engine equivalent) is
required.
(iii) Mileage accumulation shall continue until either 50 percent or
more of the mass of each atypical element (or other atypical
constituent) entering the engine can be measured in the exhaust
emissions (all fractions combined), or the vehicle/engine has
accumulated mileage (or hours) equivalent to 40 percent of the average
useful life of the applicable vehicle/engine class (pursuant to
regulations in 40 CFR part 86). For example, the maximum mileage
required for light-duty vehicles is 40 percent of 100,000 miles (i.e.,
40,000 miles), while the maximum time of operation for heavy-duty
engines is the equivalent of 40 percent of 290,000 miles (i.e., the
equivalent in engine hours of 116,000 miles).
(iv) When either condition in paragraph (c)(3)(iii) of this section
has been reached, additional emission characterization and biological
testing of the emissions may begin.
(d) Use of exhaust aftertreatment devices. (1) If the selected test
vehicle/engine, as certified by EPA, does not come equipped with an
emissions aftertreatment device (such as a catalyst or particulate
trap), such device shall not be used in the context of this program.
(2) Except as provided in paragraph (d)(3) of this section for
certain specialized additives, the following provisions apply when the
test vehicle/engine, as certified by EPA, comes equipped with an
emissions aftertreatment device.
(i) For mileage accumulation:
(A) When the test formulation does not contain any atypical elements
(pursuant to definitions in Sec. 79.56(e)(4)(iii)), an intact
aftertreatment device must be used during mileage accumulation.
(B) When the test formulation does contain atypical elements, then
the manufacturer may choose to accumulate the required mileage using a
vehicle/engine equipped with either an intact aftertreatment device or
with a non-functional aftertreatment device (e.g., a blank catalyst
without its catalytic wash coat). In either case, sampling and analysis
of emissions for measurement of the mass of the atypical element(s) (as
described in Sec. 79.57(c)(3)) must be done on emissions generated with
a non-functional (blank) aftertreatment device.
(1) If the manufacturer chooses to accumulate mileage without a
functional aftertreatment device, and if the manufacturer wishes to do
this outside of a laboratory/test track setting, then a
[[Page 521]]
memorandum of exemption for product testing must be obtained by applying
to the Director of the Field Operations and Support Division (see
Sec. 79.59(a)(1)).
(2) [Reserved]
(ii) For Tier 1 (Sec. 79.52), the total set of requirements for the
characterization of combustion emissions (Sec. 79.52(b)) must be
completed two times, once using emissions generated with the
aftertreatment device intact and a second time with the aftertreatment
device rendered nonfunctional or replaced with a non-functional
aftertreatment device as described in paragraph (d)(2)(i)(B) of this
section.
(iii) For Tier 2 (Sec. 79.53), the standard requirements for
biological testing of combustion emissions shall be conducted using
emissions generated with a non-functioning aftertreatment device as
described in paragraph (d)(2)(i)(B) of this section.
(iv) For alternative Tier 2 requirements (Sec. 79.58(c)) or Tier 3
requirements (Sec. 79.54) which may be prescribed by EPA, the use of
functional or nonfunctional aftertreatment devices shall be specified by
EPA as part of the test guidelines.
(v) In the case where an intact aftertreatment device is not in
place, all other manufacturer-specified combustion characteristics
(e.g., back pressure, residence time, and mixing characteristics) of the
altered vehicle/engine shall be retained to the greatest extent
possible.
(3) Notwithstanding paragraphs (d)(1) and (d)(2) of this section,
when the subject of testing is a fuel additive specifically intended to
enhance the effectiveness of exhaust aftertreatment devices, the related
aftertreatment device may be used on the emission generation vehicle/
engine during all mileage accumulation and testing.
(e) Generation of combustion emissions--(1) Generating combustion
emissions for emission characterization. (i) Combustion emissions shall
be generated according to the exhaust emission portion of the Federal
Test Procedure (FTP) for the certification of new motor vehicles, found
in 40 CFR part 86, subpart B for light-duty vehicles/engines, and
subparts D, M and N for heavy-duty vehicles/engines. The Urban
Dynamometer Driving Schedule (UDDS), pursuant to 40 CFR part 86,
appendix I(a), shall apply to light-duty vehicles/engines and the Engine
Dynamometer Driving Schedule (EDS), pursuant to 40 CFR part 86, appendix
I(f)(2), shall apply to heavy-duty vehicles/engines. The motoring
portion of the heavy-duty test cycle may be eliminated, at the
manufacturer's option, for the generation of emissions.
(A) For light-duty engines operated on an engine dynamometer, the
tester shall determine the speed-torque equivalencies (``trace'') for
its test engine from valid FTP testing performed on a chassis
dynamometer, using a test vehicle with an engine identical to that being
tested. The test engine must then be operated under these speed and
torque specifications to simulate the FTP cycle.
(B) Special procedures not included in the FTP may be necessary in
order to characterize emissions from fuels and fuel additives containing
atypical elements or to collect some types of emissions (e.g.,
particulate emissions from light-duty vehicles/engines, semi-volatile
emissions from both light-duty and heavy-duty vehicles/engines). Such
alterations to the FTP are acceptable.
(C) For Tier 2 testing, the engines shall operate on repeated bags 2
and 3 of the UDDS or back to back repeats of the heavy-duty transient
cycle of the EDS.
(ii) Pursuant to Sec. 79.52(b)(1)(i) and Sec. 79.57(d)(2)(ii),
emission generation and characterization must be repeated three times
when the selected vehicle/engine is normally operated without an
emissions aftertreatment device and six times when the selected vehicle/
engine is normally operated with an emissions aftertreatment device. In
the latter case, the emission generation and characterization process
shall be repeated three times with the intact aftertreatment device in
place and three times with a non-functioning (blank) aftertreatment
device in place.
(iii) From both light-duty and heavy-duty vehicles/engines, samples
of vapor phase, semi-volatile phase, and particulate phase emissions
shall be collected, except that semi-volatile phase, and particulate
emissions need not be sampled for fuels and additives in the
[[Page 522]]
methane and propane families (pursuant to Sec. 79.56(e)(1)(v) and (vi)).
The number and type of samples to be collected and separately analyzed
during one emission generation/characterization process are as follows:
(A) In the case of combustion emissions generated from light-duty
vehicles/engines, the samples consist of three bags of vapor emissions
(one from each segment of the light-duty exhaust emission cycle) plus
one sample of particulate-phase emissions and one sample of semi-
volatile-phase emissions (collected over all segments of the exhaust
emission cycle). If the mass of particulate emissions or semi-volatile
emissions obtained during one driving cycle is not sufficient for
characterization, up to three driving cycles may be performed and the
extracted fractions combined prior to chemical analysis. Particulate-
phase emissions shall not be combined with semi-volatile-phase
emissions. The test laboratory should focus on the characterization of
the limit of detection for particulates and semi-volatile emissions.
(B) In the case of combustion emissions generated from heavy-duty
engines, the samples consist of one sample of each emission phase
(vapor, particulate, and semi-volatile) collected over the entire cold-
start cycle and a second sample of each such phase collected over the
entire hot-start cycle (see 40 CFR 86.334 through 86.342).
(iv) Emission collection and storage. (A) Vapor phase emissions
shall be collected and stored in Tedlar bags for subsequent chemical
analysis. Storage conditions are specified in Sec. 79.52(b)(2).
(B) Particulate phase emissions shall be collected on a particulate
filter (or more than one, if required) using methods described in 40 CFR
86.1301 through 86.1344. These methods, ordinarily applied only to
heavy-duty emissions, are to be adapted and used for collection of
particulates from light-duty vehicles/engines, as well. The particulate
matter may be stored on the filter in a sealed container, or the soluble
organic fraction may be extracted and stored in a separate sealed
container. Both the particulate and the extract shall be shielded from
ultraviolet light and stored at -20 deg.C or less. Particulate
emissions shall be tested no later than six months from the date they
were generated.
(C) Semi-volatile emissions shall be collected immediately
downstream from the particulate collection filters using porous polymer
resin beds, or their equivalent, designed for their capture. The soluble
organic fraction of semi-volatile emissions shall be extracted
immediately and tested within six months of being generated. The extract
shall be stored in a sealed container which is shielded from ultraviolet
light and stored at -20 deg.C or less.
(D) Particulate and semi-volatile phase emission collection,
handling and extraction methods shall not alter the composition of the
collected material, to the extent possible.
(v) Additional requirements for combustion emission sampling,
storage, and characterization are specified in Sec. 79.52(b).
(2) Generating whole combustion emissions for biological testing.
(i) Biological tests requiring whole combustion emissions shall be
conducted using emissions generated from the test vehicle or engine
operated in accordance with general FTP requirements.
(ii) Light-duty test vehicles/engines shall be repeatedly operated
over the Urban Dynamometer Driving Schedule (UDDS) (or equivalent engine
dynamometer trace, per paragraph (e)(1)(i)(A) of this section) and
heavy-duty test engines shall be repeatedly operated over the Engine
Dynamometer Schedule (EDS) (see 40 CFR part 86, appendix I).
(A) The tolerances of the driving cycle shall be two times those of
the Federal Test Procedure and must be met 95 percent of the time.
(B) The UDDS or EDS shall be repeated as many times as required for
the biological test session.
(C) Light-duty dynamometers shall be calibrated prior to the start
of a biological test (40 CFR 86.118-78), verified weekly (40 CFR 86.118-
78), and recalibrated as required. Heavy-duty dynamometers shall be
calibrated and checked prior to the start of a biological test (40 CFR
86.1318-84), recalibrated every two weeks (40 CFR 86.1318-84(a)) and
checked as stated in 40 CFR 86.1318-84(b) and (c).
[[Page 523]]
(D) The fuel reservoir for the test vehicle/engine shall be large
enough to operate the test vehicle/engine throughout the daily
biological exposure period, avoiding the need for refueling during
testing.
(iii) An apparatus to integrate the large concentration swings
typical of transient-cycle exhaust is to be used between the source of
emissions and the exposure chamber containing the animal test cages(s).
The purpose of such apparatus is to decrease the variability of the
biological exposure atmosphere and achieve the necessary concentration
of CO or NOX, whichever is limiting.
(A) A large mixing chamber is suggested for this purpose. The mixing
chamber would be charged from the CVS at a constant rate determined by
the exposure chamber purge rate. Flow to the exposure chamber would
begin at the conclusion of the initial transient cycle with the
associated mixing chamber charge.
(B) A potential alternative apparatus is a mini-diluter (see, for
example, AIGER/CRADA, February, 1994 in Sec. 79.57(g)).
(C) [Reserved]
(iv) Emission dilution. (A) Dilution air can be pre-dried to lower
the relative humidity, thus permitting a lower dilution rate and a
higher concentration of hydrocarbons to be achieved without condensation
of water vapor.
(B) These procedures include requirements that the mean exposure
concentration in the inhalation test chamber on 90 percent or more of
the exposure days shall be controlled as follows:
(1) If the species being controlled is hydrocarbon or particulate,
the mean exposure concentration must be within 15 percent of the target
concentration for the single species being controlled.
(2) For other species, the mean exposure concentration must be
within 10 percent of the target concentration for the single species
being controlled.
(3) For all species, daily monitoring of CO, CO2,
NOX, SOX, and total hydrocarbons in the exposure
chamber shall be required. Analysis of the particle size distribution
shall also be performed to establish the stability and consistency of
particle size distribution in the test exposure.
(C) After the initial exhaust dilution to preserve the character of
the exhaust, the exhaust stream can be further diluted in the mixing
chamber (and/or after leaving the chamber) to achieve the desired
biological exposure concentrations.
(v) Verification procedures. (A) The entire system used to dilute
and transport whole combustion emissions (i.e., from exhaust pipe to
outlet in the biological testing chamber) shall be verified before any
animal exposures begin, and verified at least weekly during testing.
(See procedures at 40 CFR 86.119-90 for light-duty vehicles and
Sec. 86.1319-90 for heavy-duty engines.) Verification testing shall be
accomplished by introducing a known sample at the end of the vehicle/
engine exhaust pipe into the dilution system and measuring the amount
exiting the system. For example, an injected hydrocarbon sample could be
detected with a gas chromatograph (GC) and flame ionization detector
(FID) to determine the recovery factor.
(B) [Reserved]
(vi) Emission exposure quality control. (A) The tester shall
incorporate the additional quality assurance and safety procedures
outlined in Sec. 79.61(d) to control variability of emissions during the
generation of exposure emissions during health effect testing.
(B) These procedures include requirements that the mean exposure
concentration in the inhalation test chamber on 90 percent or more of
the exposure days shall be controlled as follows:
(1) If the species being controlled is hydrocarbon or particulate,
the mean exposure concentration must be within 15 percent of the target
concentration for the single species being controlled.
(2) For other species, the mean exposure concentration must be
within 10 percent of the target concentration for the single species
being controlled.
(3) For all species, daily monitoring of CO, CO2,
NOX, SOX, and total hydrocarbons in the exposure
chamber shall be required. Analysis of the particle size distribution
shall also be performed to establish the stability and consistency of
particle size distribution in the test exposure.
[[Page 524]]
(C) The testing facility shall allow an audit of its premises, the
qualifications, e.g., curriculum vitae, of its staff assigned to
testing, and the specimens and records of the testing for registration
purposes (as specified in Sec. 79.60).
(vii) To allow for customary laboratory scheduling and unforeseen
problems affecting the combustion emission generation or dilution
equipment, biological exposures may be interrupted on limited occasions,
as specified in Sec. 79.61(d)(5). Interruptions exceeding these
limitations shall cause the affected test(s) to be void. Testers shall
be aware of concerns for backup vehicles/engines cited in paragraph
(a)(7)(ii) of this section.
(3) Generating particulate and semi-volatile emissions for
biological testing. (i) Salmonella mutagenicity testing, pursuant to
Sec. 79.68, shall be conducted on extracts of the particulate and semi-
volatile emission phases separately. These emissions shall be generated
by operating the test vehicle/engine over the appropriate FTP driving
schedule (see paragraph (e)(2)(ii) of this section) and collected and
analyzed according to methods described in 40 CFR 86.1301 through 1344
(further information on this subject may be found in Perez, et al. CRC
Report No. 551, 1987 listed in Sec. 79.57(g)).
(A) Particulate emissions shall be collected on particulate filters
and extracted from the collection equipment for use in biological tests.
The number of repetitions of the applicable driving schedule required to
collect sufficient quantities of the particulate emissions will vary,
depending on the characteristics of the engine, the test fuel, and the
requirements of the biological test protocol. The particulate sample may
be collected on one or more filters, as necessary.
(B) Semi-volatile emissions shall be collected immediately
downstream from the particulate collection filters using porous polymer
resin beds, or their equivalent, designed for their capture. Semi-
volatile phase emissions shall be collected on one apparatus. The time
spent collecting sufficient quantities of the test substances in
emissions samples will vary, depending on the emission characteristics
of the engine and fuel or additive/base fuel mixture and on the
requirements of the biological test protocol.
(ii) The extraction method shall be determined by the specifications
of the biological test for which the emissions are used.
(iii) Particulate and semi-volatile emission storage requirements
are as specified in Sec. 79.57(e)(1)(iv).
(iv) Particulate and semi-volatile phase emission collection,
handling and extraction methods shall not alter the composition of the
collected material, to the extent possible.
(v) Particulate emissions shall not be combined with semi-volatile
phase emissions.
(f) Generation of evaporative emissions for characterization and
biological testing. (1) Except as provided in paragraph (f)(5) of this
section, an evaporative emissions generator shall be used to volatilize
samples of a fuel or additive/base fuel mixture for evaporative
emissions characterization and biological testing. Emissions shall be
collected and sampled using equipment and methods appropriate for use
with the compounds being characterized and the requirements of the
emission characterization analysis. In the case of potentially explosive
test substance concentrations, care must be taken to avoid generating
explosive atmospheres. The tester is referred to Sec. 79.61(d)(8) for
considerations involving explosivity.
(2) Evaporative Emissions Generator (EEG) Description. An EEG is a
fuel tank or vessel to which heat is applied causing a portion of the
fuel to evaporate at a desired rate. The manufacturer has flexibility in
designing an EEG for testing a particular fuel or fuel additive. The
sample used to generate emissions in the EEG shall be renewed at least
daily.
(i) The evaporation chamber shall be made from materials compatible
with the fuels and additives being tested and shall be equipped with a
drain.
(ii) The chamber shall be filled to 40 5 percent of its
interior volume with the fuel or additive/base fuel mixture being
tested, with the remainder of the volume containing air.
(iii) The concentration of the evaporated fuel or additive/base fuel
mixture in the vapor space of the evaporation
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chamber during the time emissions are being withdrawn for testing shall
not vary by more than 10 percent from the equilibrium concentration in
the vapor space of emissions generated from the fresh fuel or additive/
base fuel mixture in the chamber.
(A) During the course of a day's emission generation period, the
level of fuel in the EEG shall be maintained to within 7 percent of its
height at the start of the daily exposure period.
(B) The fuel used in the EEG shall be drained at the end of each
daily exposure. The EEG shall be refilled with a fresh supply of the
test formulation before the start of each daily exposure.
(C) The vapor space of the evaporation chamber shall be well mixed
throughout the time emissions are being withdrawn for testing.
(iv) The size of the evaporation chamber shall be determined by the
rate at which evaporative emissions shall be needed in the test animal
exposure chambers and the rate at which the fuel or the additive/base
fuel mixture evaporates. The rate of evaporative emissions may be
adjusted by altering the size of the EEG or by using one or more
additional EEG(s). Emission rate modifications shall not be adjusted by
temperature control or pressure control.
(v) The temperature of the fuel or additive/base fuel mixture in the
evaporation chamber shall be 130 deg.F5 deg.F. The vapors
shall maintain this temperature up to the point in the system where the
vapors are diluted.
(vi) The pressure in the vapor space of the evaporation chamber and
the dilution and sampling apparatus shall stay within 10 percent of
ambient atmospheric pressure.
(vii) There shall be no controls or equipment on the evaporation
chamber system that change the concentration or composition of the
vapors generated for testing.
(viii) Manufacturers shall perform verification testing of
evaporative emissions in a manner analogous to the verification testing
performed for combustion emissions.
(3) For biological testing, vapor shall be withdrawn from the EEG at
a constant rate, diluted with air as required for the particular study,
and conducted immediately to the biological testing chamber(s) in a
manner similar to the method used in Sec. 79.57(e), excluding the mixing
chamber therein. The rate of emission generation shall be high enough to
supply the biological exposure chamber with sufficient emissions to
allow for a minimum of fifteen air changes per exposure chamber per
hour. To allow for customary laboratory scheduling and for unforeseen
problems with the evaporative emission generation or dilution equipment,
biological exposures may be interrupted on limited occasions, as
specified in Sec. 79.61(d)(5). Interruptions exceeding these limitations
shall cause the affected test(s) to be void.
(4) For characterization of evaporative emissions, samples of
equilibrated emissions to the vapor space of the EEG shall be withdrawn
into Tedlar bags, then stored and analyzed as specified in
Sec. 79.52(b).
(5) A manufacturer (or group of manufacturers) may submit to EPA a
request for approval of an alternative method of generating evaporative
emissions for use in emission characterization and biological tests
required under this subpart.
(i) To be approved by EPA, the request must fully explain the
rationale for the proposed method as well as the technical procedures,
quality control, and safety precautions to be used, and must demonstrate
that the proposed method will meet the following criteria:
(A) The emission mixture generated by the proposed procedures must
be reasonably similar to the equilibrium composition of the vapor which
occurs in the vehicle fuel tank head space when the subject fuel or
additive/base fuel mixture is in use and near-maximum in-use
temperatures are encountered.
(B) The emissions mixture generated by the proposed method must be
sufficiently concentrated to provide adequate exposure levels in the
context of the required toxicologic tests.
(C) The proposed method must include procedures to ensure that the
emissions delivered to the biologic exposure chambers will provide a
reasonably constant exposure atmosphere over time.
[[Page 526]]
(ii) If EPA approves the request, EPA will place in the public
record a copy of the request, together with all supporting procedural
descriptions and justifications, and will notify the public of its
availability by publishing a notice in the Federal Register.
(g) References. For additional background information on the
emission generation procedures outlined in this paragraph (g), the
following references may be consulted. Additional references can be
found in Sec. 79.61(f).
(1) AIGER/CRADA (American Industry/Government Emissions Research
Cooperative Research and Development Agreement, ``Specifications for
Advanced Emissions Test Instrumentation'' AIGER PD-94-1, Revision 5.0,
February, 1994
(2) Black, F. and R. Snow, ``Constant Volume Sampling System Water
Condensation'' SAE 940970 in ``Testing and Instrumentation''
SP-1039, Society of Automotive Engineers, Feb. 28-Mar. 3, 1994.
(3) Perez, J.M., Jass, R.E., Leddy, D.G., eds. ``Chemical Methods
for the Measurement of Unregulated Diesel Emissions (CRC-APRAC Project
No. CAPI-1-64), Coordinating Research Council, CRC Report No. 551,
August, 1987.
(4) Phalen, R.F., ``Inhalation Studies: Foundations and
Techniques'', CRC Press, Inc., Boca Raton, Florida, 1984.
[59 FR 33093, June 27, 1994, as amended at 61 FR 36511, July 11, 1996;
63 FR 63792, Nov. 17, 1998]