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Fuels and Fuel Additives Registration Regulations

American Government Special Collections Reference Desk

American Government

Fuels and Fuel Additives Registration Regulations

Mary D. Nichols
Environmental Protection Agency
February 24, 1994

[Federal Register Volume 59, Number 37 (Thursday, February 24, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 94-4047]

[[Page Unknown]]

[Federal Register: February 24, 1994]



40 CFR Part 79



Fuels and Fuel Additives Registration Regulations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of reopening of comment period.


SUMMARY: On April 15, 1992, EPA published in the Federal Register a 
Notice of Proposed Rulemaking (NPRM) for Fuels and Fuel Additives (F/
FAs) Registration Regulations (57 FR 13168). The purpose of the 
proposed regulation would be to establish requirements for the 
registration of motor vehicle F/FAs as authorized by sections 211(b)(2) 
and 211(e) of the Clean Air Act (CAA). Under the proposed regulations, 
manufacturers of F/FAs would be required to conduct certain tests and 
submit information regarding the composition of emissions produced by 
such F/FAs and the effects of these emissions on public health and 
    EPA held a public hearing on the NPRM on May 28, 1992 and accepted 
written comments until June 30, 1992. Subsequent analysis indicated 
that additional public notice to clarify and reconsider a few specific 
compliance-related and technical issues would be helpful in developing 
the final rule. Today's action presents these issues and requests 
comments on EPA's proposals for addressing them. The issues addressed 
in this document are the following: Timing of requirements for new F/
FAs, alternative testing requirements in lieu of Tier 2, general 
emission generation methodology, mileage accumulation for the testing 
of atypical F/FAs, and base fuel specifications.

DATES: Written comments on the specific issues discussed in this 
document will be accepted until March 28, 1994.

ADDRESSES: Comments on this document should be submitted in duplicate 
to: EPA Air Docket (LE-131); Attention: Public Docket No. A-90-07; U.S. 
Environmental Protection Agency, 401 M Street SW., Washington, DC 
    All other materials relevant to this document have been placed in 
Docket No. A-90-07, located in the EPA Air Docket, room M-1500, 401 M 
Street SW., Washington, DC 20460; phone (202) 260-7548. The docket is 
open for public inspection from 8:30 a.m. until noon and from 1:30 p.m. 
to 3 p.m., Monday through Friday. As provided in 40 CFR part 2, a 
reasonable fee may be charged by EPA for photocopying services.

Regulatory Projects Branch, U.S. Environmental Protection Agency, 2565 
Plymouth Rd., Ann Arbor, Michigan 48105; phone (313) 668-4575.


I. Background

    The legal authority for the F/FA registration program is provided 
by section 211 of the CAA. Section 211(a), 42 USC section 7545, 
authorizes EPA to designate any fuel or fuel additive for registration 
and prohibits manufacturers of designated fuels or additives from 
selling such products unless they have been registered by EPA in 
accordance with section 211(b). In 1975, EPA issued regulations (40 CFR 
part 79) implementing basic registration requirements, as stipulated by 
section 211(b)(1), that required applicants to submit certain 
information, such as commercial identifying information, range of 
concentration, purpose-in-use, and chemical composition, in order to 
register a fuel or fuel additive.
    The CAA also gave EPA discretionary authority to establish 
additional registration requirements under section 211(b)(2). This 
section authorized EPA to require F/FA manufacturers ``to conduct tests 
to determine potential public health effects of such fuel[s] or 
additive[s] (including but not limited to, carcinogenic, teratogenic, 
or mutagenic effects),'' and to furnish other ``reasonable and 
necessary'' information to identify F/FA emissions and determine their 
effects on vehicular emission control performance and on the public 
health and welfare.
    EPA did not exercise its discretionary authority to require testing 
of F/FAs under section 211(b)(2) when the general registration 
regulations were issued in 1975. However, in the CAA Amendments of 1977 
(Public Law 95-95, August 7, 1977), Congress added section 211(e), 
which made implementation of section 211(b)(2) mandatory. On August 7, 
1990, EPA published an Advanced Notice of Proposed Rulemaking (ANPRM) 
(55 FR 32218) and, on April 15, 1992, published an NPRM (57 FR 13168) 
proposing additional registration requirements under sections 211(b)(2) 
and 211(e) of the CAA. The purpose of the rule would be to provide EPA 
with information for identifying and evaluating the potential adverse 
health effects of motor vehicle F/FA emissions and for guiding the 
direction of related regulatory actions in the future as specified in 
section 211(c). The reader is referred to the NPRM and Public Docket A-
90-07 for detailed information on the proposed registration 
    Subsequent to the publication of the proposal, a public hearing was 
held on May 28, 1992, followed by a written comment period which closed 
on June 30, 1992. A transcript of the public hearing and the written 
comments are contained in the docket.
    After careful evaluation of the comments and additional technical 
analysis, EPA determined that additional public notice to clarify 
certain key compliance issues and to modify certain proposed technical 
approaches would be beneficial. The next sections of this notice 
discuss the issues in question and request relevant comments from the 
public. EPA asks the public to focus their comments on the key areas 
discussed below. Comments on topics addressed in previous notices and 
comment periods will be treated as late communication to which EPA is 
not required to respond. The issues to be addressed are the following: 
(1) Timing of requirements for new F/FAs, (2) alternative testing 
requirements in lieu of Tier 2, (3) general emission generation 
methodology, (4) mileage accumulation for the testing of atypical F/
FAs, and (5) base fuel specifications.

II. Compliance-Related Issues

A. Timing of Requirements for New F/FAs

    The registration requirements proposed in the April 1992 NPRM were 
organized within a three-tiered health effects evaluation structure. 
Under Tier 1, F/FA manufacturers would be required to perform a 
literature search on the health and welfare effects of F/FA emissions, 
characterize the emissions, and provide exposure information. Tier 2 
would include short-term biological testing to screen for specific 
health effects endpoints, involving the exposure of laboratory animals 
to the whole emissions of fuels or fuel/additive mixtures. After 
receipt and review of manufacturers' Tier 1 and Tier 2 submittals, EPA 
would determine, on a case-by-case basis, if additional testing were 
needed under Tier 3 to evaluate the risk of a particular F/FA (or group 
of F/FAs) on human health or welfare. Tier 3 testing could include any 
emissions analysis, health effects, welfare effects, and/or exposure 
testing or analysis deemed necessary by EPA for this purpose.
    The organization of the F/FA program's requirements into 
hierarchical tiers was proposed, in part, to ensure that the rule would 
accommodate the goals of section 211(b) within the time restrictions of 
section 211(e). Section 211(e) requires that, for F/FAs registered as 
of the date of promulgation of the final rule, the ``requisite 
information'' be submitted to EPA within three years of that date. On 
the other hand, manufacturers seeking to register F/FA products after 
the date of promulgation would have to satisfy the testing requirements 
before registration would be granted.
    EPA judged that compliance with the Tier 1 and Tier 2 requirements 
should be achievable within the three-year time limit for registered F/
FAs; thus, these two tiers were proposed to be defined as the 
``requisite information'' for registration pursuant to its authority 
under CAA section 211(e). However, maintenance of such registration 
would be conditional on subsequent satisfaction of any Tier 3 
requirements which EPA might impose pursuant to its authority under CAA 
section 211(b). For consistency, the same definition of ``requisite 
information'' and the same Tier 3 arrangements were proposed to apply 
to both currently registered and new F/FAs.
    EPA intends to maintain these originally proposed provisions in the 
case of currently registered F/FA products. Thus, for continued 
registration of such F/FAs, compliance with Tier 1 and Tier 2 must 
occur within three years of promulgation of the final rule. As proposed 
in the NPRM, this registration would be conditional on subsequent 
satisfaction of any Tier 3 requirements which might be prescribed by 
the Agency. This means that if Tier 3 testing were prescribed for a 
fuel or fuel additive product registered as of the time of 
promulgation, the registration would be extended for that time which 
EPA specifies as necessary for completion of the prescribed Tier 3 
requirements. Only upon satisfactory completion of these requirements 
would re-registration occur.
    In the case of products for which manufacturers seek registration 
after promulgation of this rule, EPA is re-examining the 
appropriateness of the timing of these Tier 3 provisions. As discussed 
in the NPRM, EPA interprets section 211(b) in conjunction with section 
211(c), which gives EPA authority to control or prohibit the 
manufacture, introduction into commerce, offering for sale, or sale of 
any fuel or fuel additive if the Administrator finds that the emission 
products of such fuel or fuel additive ``causes, or contributes, to air 
pollution which may reasonably be anticipated to endanger the public 
health or welfare.'' In light of this responsibility, EPA believes that 
it should exercise particular caution in registering new F/FA products 
that are significantly different from or have a usage pattern which is 
significantly different in scope or character from currently registered 
F/FA products. The potential health risks associated with the use of 
new F/FAs could be higher, lower, or the same as those of current F/
FAs. Thus, before permitting the introduction of these products into 
the market, the Agency must have reasonable certainty that the public 
health consequences will not be made worse.
    Clarification is therefore needed concerning what constitutes a 
``new'' F/FA. EPA believes it is appropriate to distinguish between two 
types of unregistered products which a manufacturer might seek to 
register after the promulgation of the final rule: (1) F/FA products 
similar in composition and usage to those already allowed wide 
commercial distribution (e.g., registered for general use by other 
manufacturers), and (2) F/FA products which differ significantly in 
composition and/or usage from such current products.
    To formalize this distinction, EPA is proposing to make use of 
grouping system concepts and definitions previously discussed in the 
April 1992 NPRM. Specifically, EPA proposes that a F/FA product not 
registered by its manufacturer1 as of the date of promulgation of 
this rule be designated as ``registrable'' if it meets the program's 
criteria for grouping with a currently registered fuel or bulk 
additive2 in the same fuel family3. Conversely, a F/FA 
product not registered by its manufacturer as of the date of 
promulgation would be designated as ``new'' if it does not meet the 
program's criteria for grouping with a currently registered fuel or 
bulk additive in the same fuel family. In these definitions, the term 
``currently'' refers to the date on which EPA receives the registration 
application for the F/FA in question.

    \1\For purposes of these definitions, registration is product-
specific. Thus, if a particular fuel or additive product has not 
been registered by its manufacturer, then that manufacturer does not 
have the right to introduce, market, and/or sell this product, even 
if a compositionally similar or identical product has been 
registered by another manufacturer.
    \2\A ``bulk additive,'' sometimes called a ``general use'' 
additive, was defined in the NPRM as a product added to fuel at the 
refinery as part of the original blending stream or after the fuel 
is transported from the refinery, but before the fuel is purchased 
for introduction into the fuel tank of a motor vehicle. In contrast, 
an ``aftermarket additive,'' sometimes called a consumer additive, 
is an additive product marketed for introduction directly into the 
fuel system of a motor vehicle.
    \3\``Fuel family'' refers to the primary categorization of F/FAs 
within the proposed grouping system. A fuel family was defined in 
the NPRM as a set of F/FAs which share basic chemical and physical 
formulation characteristics and can be used in the same engine or 
vehicle. Seven such fuel families were originally defined (unleaded 
gasoline, leaded gasoline, diesel, methanol, ethanol, methane, and 
propane), although EPA now intends to delete the leaded gasoline 
family in view of the prohibition under CAA section 211(n) of on-
road use of leaded fuel after December 31, 1995. In the proposed 
definition of ``registrable,'' the restriction ``in the same fuel 
family'' means that the similarity of an applicant F/FA to a bulk 
additive currently registered for use in another fuel family would 
not suffice to make the applicant F/FA registrable. This restriction 
is consistent with the general principles of the grouping system, 
which permits grouping of F/FAs only within defined fuel families.

    According to these definitions, an unregistered F/FA which meets 
the criteria for grouping only with a currently registered aftermarket 
additive (and not also with a currently registered fuel and/or bulk 
additive) would not be registrable. This does not preclude an 
unregistered aftermarket additive from being registrable (since 
aftermarket additives can group with fuels and bulk additives), nor 
does it affect the registration status of currently registered 
aftermarket additives.
    For example, an unregistered detergent additive (either bulk or 
aftermarket) intended for use in unleaded gasoline and conforming to 
the ``substantially similar'' criteria for unleaded gasoline (56 FR 
5352) would be registrable, since it would be able to group with 
currently registered baseline unleaded gasoline fuels and bulk 
additives4. On the other hand, an unregistered chromium-containing 
additive intended for use in unleaded gasoline would be considered 
``new'' rather than ``registrable,'' because there are no currently 
registered chromium-containing fuels or bulk additives in the unleaded 
gasoline family with which the applicant additive could be grouped. 
Even if a chromium-containing product had previously been registered as 
an aftermarket additive for unleaded gasoline (prior to the ban on such 
aftermarket additives under CAA section 211(f)(1)(B)5 or as a bulk 
additive for use in another fuel family (e.g., leaded gasoline or 
diesel fuel), the applicant additive would still be considered ``new''.

    \4\The ability to join the unleaded gasoline baseline group 
assumes that the detergent additive does not exceed oxygen and 
sulfur limits applicable to the baseline unleaded gasoline category.
    \5\Until the 1990 CAA Amendments went into effect, the statutory 
language of section 211(f) was interpreted as applying only to 
unleaded gasoline fuels and related bulk additives. Thus, prior to 
November 15, 1990 (the effective date of the CAA Amendments), 
aftermarket additives intended for use in unleaded gasoline and 
containing elements other than carbon, hydrogen, oxygen, nitrogen, 
and sulfur were allowed to be registered. Under the 1990 CAA 
amendments, all types of motor vehicle F/FAs were placed under 
section 211(f) jurisdiction. All aftermarket additives that were not 
``substantially similar'' and were introduced on or after November 
15, 1990 were banned. However, this ban does not apply to products 
first introduced into commerce prior to November 15, 1990 [CAA 
section 211(f)(1)(B)]. Thus, ``non-sub-sim'' gasoline aftermarket 
additives which had been registered prior to that date were allowed 
to retain their registrations. These are so-called ``grandfathered'' 
aftermarket additives.

    Under the original proposal, new F/FA products would automatically 
be allowed on the market after submission of Tier 1 and Tier 2 data, 
whether or not significant health effects concerns had arisen and 
whether or not EPA had sufficient information to determine if action 
under section 211(c) were appropriate. However, to address the concerns 
described above in relation to section 211(c), EPA is now proposing to 
require that manufacturers of new F/FA products (i.e., F/FA products 
not registered by their specific manufacturers as of the date of 
promulgation and not fitting the registrable criteria) submit all 
testing requirements prior to registration, including Tier 3 when 
prescribed by the Agency. This means that if EPA were to identify a 
need for additional testing at the Tier 3 level for a new F/FA, 
registration would not be granted until satisfactory completion of all 
such requirements.
    On the other hand, EPA is proposing to grant registration to 
``registrable'' F/FAs upon the manufacturer's submittal of the basic 
registration application and other pre-Tier 1 notification requirements 
(see NPRM)6. Once registered, these products would be legally able 
to enter the market. Furthermore, these products would have the same 
testing and compliance requirements as those specified for currently 
registered products, i.e., three years from the date of promulgation 
for the completion of the Tier 1 and Tier 2 requirements and, if Tier 3 
testing were prescribed, additional time consistent with the 
incremental testing requirements. Manufacturers' compliance with these 
requirements could be accomplished independently or as a member of an 
existing group.

    \6\Even if an unregistered F/FA were ``registrable'', however, 
EPA could invoke other available regulatory authority under Federal 
law to prevent its commerical distribution if EPA were to determine 
that such action was necessary to protect the public health or 
welfare. For example, applicable sections of the Toxic Substances 
Control Act (TSCA)(15 U.S.C. section 2601 et seq.), such as the 
Significant New Use rule or the Premanufacturing Notification 
process, could be invoked to require health effects testing prior to 
commerical distribution of an F/FA product if, among other factors 
specified in TSCA, there is a change in the use of the product or an 
increase in the magnitude and/or duration of exposure to the product 
by human beings or the environment (15 U.S.C. section 2601 (a)(2)).

    EPA believes that the proposed distinctions between registrable and 
new F/FAs, both in terms of their definitions and their respective 
compliance requirements, reflect reasonable regard for the public 
health and welfare without undue interference in the F/FA marketplace. 
Because registrable F/FAs are defined such that they must be reasonably 
similar in composition and usage to current F/FAs, their entry onto the 
market would generally not be expected to increase the health or 
welfare risks potentially related to current F/FA emission exposures. 
In determining whether a manufacturer's product is registrable, the 
omission of aftermarket additives from the relevant population of 
currently registered F/FAs is intended to prevent a potentially large 
increase in public exposure to generally untested products which had 
previously been relatively limited in distribution and usage. It also 
ensures that the ability to group with a ``grandfathered'' aftermarket 
additive would not confer ``registrability'' on an unregistered F/FA. 
This is consistent with the congressional intent in CAA section 
211(f)(1)(B) to preclude introduction into commerce of new aftermarket 
additives which do not fit the ``substantially similar'' criteria. The 
omission of F/FAs in different fuel families from the relevant 
population of current F/FAs is also intended to prevent potential 
increases in exposure to untested products. Expanding the use of an 
additive from one fuel family to another (e.g., from diesel fuel to 
gasoline) would significantly increase the overall size of the 
potential market for the product and thus the potential exposure to its 
    Because of these safeguards, EPA believes that additional 
protection to the public health would generally not be achieved by 
prohibiting registrable F/FAs from entering the market while testing of 
these products (or groups of similar products) proceeds. In the case of 
``new'' F/FAs, however, EPA has no such assurances. By definition, 
these F/FAs would be dissimilar in composition and/or usage to 
currently registered products, and allowing their introduction could 
not reasonably be assumed to have no adverse effects on the health or 
welfare of the general population. For these F/FAs, therefore, EPA 
believes that it must protect the public health and welfare by 
requiring compliance with all data requests it deems necessary before 
exposing the public to potentially increased risk.
    Figure 1 summarizes the decision process for determining whether an 
unregistered F/FA product would be ``registrable'' (and thus handled 
much like a currently registered product), or whether an unregistered 
F/FA product would not be ``registrable'' and must complete all testing 
requirements before registration is granted.


    As a result of these modifications to the original proposal, EPA 
would have an opportunity to evaluate fully the potential health 
effects of truly new products before they enter the marketplace. On the 
other hand, F/FAs similar to those already registered would not be 
arbitrarily kept from the market during the compliance period simply 
because of the relationship between their date of introduction and the 
effective date of this rule.
    EPA interprets section 211(e) to support the approach contained in 
this notice. EPA believes that the reference in CAA section 211(e)(2) 
(A) and (B) to a ``fuel or fuel additive which is registered'' or 
``which is not registered'' is ambiguous as to whether it refers to the 
F/FA generally or to a particular product-specific registration. Given 
this ambiguity, EPA believes that it is reasonable to interpret the 
phrase ``fuel or fuel additive which is registered'' to refer to the F/
FAs generally. Further, EPA believes it is reasonable to interpret the 
phrase ``registered'' to include both F/FAs that are either 
``registered'' or ``registrable.'' ``Registrable'' F/FAs are 
sufficiently similar in composition and use to existing F/FAs that one 
would not expect them to have dissimilar health effects; and therefore, 
it is reasonable to interpret the phrase ``registered fuel or fuel 
additive'' to include not only those F/FAs that are identical, but also 
those that can group with existing F/FAs.
    Alternatively, EPA believes that the approach in this notice is 
consistent with section 211 because EPA interprets section 211(e)(3) 
(A) and (B) in conjunction with section 211(e)(3)(C), which gives EPA 
authority to exempt any F/FA from duplicative testing. Thus, even if 
one interprets the phrase ``fuel or fuel additive which [is/is not] 
registered'' to mean either that an identical F/FA must already have a 
registration, or to refer to a product-specific registration, EPA 
believes it is reasonable to interpret section 211(e)(3)(C) to allow F/
FAs that are similar in composition and usage to those already on the 
market to group with those similar F/FAs and complete the testing with 
the other F/FAs in their group. At the same time, EPA believes that for 
F/FAs that differ significantly in composition or usage from currently 
registered F/FAs, such testing would not be duplicative of testing of 
groups of registered F/FAs; and therefore, EPA is authorized under 
section 211(e) to require this information prior to registration.
    Under either theory, EPA's authority to obtain information is not 
limited to Tier 1 and Tier 2 data, because section 211(b)(2)(B) gives 
EPA authority to require any information necessary to assess the 
effects of emissions on public health or welfare. Therefore, EPA 
interprets section 211 (e) and (b) to give it the authority to require 
any necessary health or welfare effects information for F/FAs that are 
significantly different in composition or usage from currently 
registered products.
    EPA solicits comments on its interpretation of CAA section 211 as 
it applies to the approach outlined in this notice and on the proposed 
compliance requirements for F/FA products which manufacturers may seek 
to register after promulgation of this rule. EPA is proposing: (1) To 
allow those products fitting the definition of ``registrable'' to 
become registered and thus subject to the same compliance and timing 
requirements as currently registered products, and (2) to require 
manufacturers of ``new'' F/FAs (i.e., those not in conformance with the 
definition of ``registrable'') to submit any information EPA requires, 
potentially including Tier 3, prior to registration. Based on its 
analysis of the public comments on these proposed provisions, EPA may 
adopt both proposals, adopt one proposal, or reject both proposals.

B. Alternative Testing Requirements in Lieu of Tier 2

    As explained in the NPRM, the main purpose of the proposed rule is 
to obtain information for the identification and evaluation of 
potential health effects of F/FA emissions in order to guide EPA in 
future regulatory actions. CAA section 211(b)(2)(A) gives EPA the 
authority to require the manufacturer of any fuel or fuel additive ``to 
conduct tests to determine potential public health effects of such fuel 
or additive (including, but not limited to, carcinogenic, teratogenic, 
or mutagenic effects).'' Thus, the statute gives EPA discretion to 
require the examination of other endpoints of concern in addition to 
the mandatory areas of testing described above.
    The Tier 2 program in the NPRM proposed to establish a testing 
framework that incorporated the screening of several health effects 
endpoints relevant to the assessment of the public health impacts of F/
FA emissions, including those endpoints mandated by the statute. In 
general, EPA still intends to maintain a standard Tier 2 biological 
testing program as a requirement for registration. Thus, the prescribed 
Tier 2 tests to be included in the final rule would apply to nearly all 
F/FAs seeking compliance with registration requirements, to the extent 
that the results of the data search activities in Tier 1 do not include 
comparable existing information from adequately performed and properly 
documented previous studies.
    However, EPA is now proposing a special provision which would give 
EPA discretion to require different testing requirements in lieu of the 
standard Tier 2 program, in order to address specific health concerns 
for a particular fuel or fuel additive product. EPA recognizes that, in 
some special cases, more exhaustive or specifically focused tests might 
be warranted in lieu of the screening Tier 2 tests, based on already 
available health effects information. For example, for a particular 
fuel or fuel additive product, information could already be available 
to EPA (independent of this proposed program) which indicates that 
testing should be targeted to an identified health concern that is not 
specifically addressed in Tier 2 or that calls for more definitive 
testing than would ordinarily occur under Tier 2. The currently 
proposed testing program structure certainly allows EPA to require such 
tests under Tier 3 after the evaluation of the previous tiers. However, 
in this special case, requiring more definitive tests or other 
appropriate endpoint tests earlier in the testing program would result 
in overall savings to the manufacturer while providing EPA with the 
needed data earlier to assess the potential health risks for the 
particular fuel or fuel additive in question. Under this special 
provision EPA would also be able to prescribe additional tests to be 
performed along with the standard Tier 2 program as well as 
substituting different tests. EPA asks for comments on this proposed 
provision that would allow EPA to prescribe alternative tests in lieu 
of (or in addition to) the standard Tier 2 tests in special cases.
    If EPA decided to exercise its authority under this special 
provision, EPA would allow an appropriate time for completion of the 
prescribed tests. For instance, if ancillary tests to Tier 2 were 
prescribed for a registered F/FA, the usual three-year timeframe for 
completing Tier 1 and Tier 2 requirements would no longer apply. 
Instead, EPA would allow additional time for completion of the 
alternative testing program (i.e., Tier 2 as well as the ancillary 
tests prescribed under this provision) in this special case. Similar 
compliance allowances would be made if different tests (e.g., chronic 
tests) were prescribed in lieu of the standard Tier 2 screening tests. 
For registered F/FAs, EPA would notify the manufacturer (or group) by 
certified mail letter, within eighteen months of promulgation of the 
final rule, of the specific tests to be done in lieu of the standard 
Tier 2 regimen, along with a schedule for compliance and submittal of 
test results. A Federal Register notice would also be published to give 
the public opportunity to comment on the intended testing regimen. A 
public hearing would not be held, however. The responsible manufacturer 
(or group of manufacturers) would have 60 days to comment on the 
prescribed tests and timing requirements. If the responsible 
manufacturer did not provide any comments, EPA would assume that the 
manufacturer had consented in full with the prescribed testing program. 
Similar notification arrangements would apply to manufacturers of 
currently unregistered F/FAs. In this instance, EPA would notify the 
new applicant (by certified mail letter) of the nonstandard 
requirements within eighteen months of EPA's learning of the 
manufacturer's intent to register a product. EPA welcomes comments on 
the proposed notification and comment procedures for this special 
    In general, EPA considers the normal Tier 2 testing regimen to be 
applicable, appropriate, and valuable for the health effects evaluation 
of F/FA emissions, even if higher-level testing is later required under 
the provisions of Tier 3. Thus, EPA would exercise the special 
authority to prescribe other testing requirements in addition to or in 
lieu of the standard Tier 2 regimen only in exceptional cases. The 
exercise of this authority would be done wholly at EPA's discretion. F/
FA manufacturers would be specifically discouraged from submitting 
applications or requests to EPA for Tier 2 substitutions, and EPA would 
be under no obligation to consider or respond to any such requests.

III. Technical Issues

A. General Emission Generation Methodology

    The NPRM proposed that F/FA manufacturers would be required to 
conduct a detailed characterization of the emissions of their products, 
as well as biological tests in which animals are exposed to these 
emissions. The use of applicable portions of the standard Federal Test 
Procedure (FTP) was proposed for generating exhaust emissions for these 
purposes. For biological testing of products predominantly used in 
light-duty vehicle applications, EPA proposed the use of one light-duty 
vehicle operating over continuous, repeated Urban Dynamometer Driving 
Schedule (UDDS) cycles (i.e., a transient speed driving sequence used 
to simulate typical urban driving) performed on a chassis dynamometer. 
An engine dynamometer operated on the Engine Dynamometer Schedule (EDS) 
was presented as an option. The EDS is a transient engine speed versus 
torque time sequence commonly used in heavy-duty engine evaluation. It 
was proposed that the EDS would be used to generate emissions in heavy-
duty applications. EPA also proposed that all test vehicles and engines 
should possess all of the emission control equipment normally 
recommended by the manufacturer.
    In their comments on the NPRM, the regulated industry questioned 
the appropriateness of using the FTP to generate emissions for 
biological testing, given the inherent variable nature of FTP-generated 
emissions. In response to these comments, EPA is considering several 
alternative approaches as discussed below. EPA asks for comments on the 
suitability of these proposals and on alternative methods suitable for 
the generation of emissions to be used in the biological testing of F/
FAs. To be most useful, such comments should include a detailed 
discussion on the recommended methodology, including advantages and 
1. Non-Transient Methods
    EPA is considering the use of non-transient methods as an 
alternative approach to FTP or other transient cycles to reduce the 
potential variability in the emission stream. The rationale behind this 
approach is discussed below.
    The determination of an exposure/health effect relationship 
requires a constant, well-controlled, and measurable exposure 
environment. A high degree of variability in emission properties such 
as heat, pressure, water vapor, CO, NOx, CO2, total hydrocarbons, 
and specific chemical composition could complicate the measurement and 
determination of the actual exposure levels that occur during 
toxicology testing. During transient cycles, physical and chemical 
properties of the exhaust stream can vary significantly. In addition, a 
high percentage of emissions are produced in concentrated spikes 
(related to the enriched conditions present during accelerations) that 
result in a series of alternating high and low level exposures. This 
variability could be difficult to accommodate in the context of the 
inhalation toxicology tests proposed in this rule. Therefore, EPA is 
considering the use of single-mode (steady state) operating conditions 
for generating emissions in the F/FA testing program.
    In addition to reducing variability, non-transient methods might 
also provide a better simulation of ambient conditions. Ambient air 
contains emissions from many thousands of vehicles of varying 
technologies, age, and state of maintenance. At any point in time, 
these vehicles are in different stages of operation under various 
engine loads. As a collective average of the emissions from these 
sources, the ambient air typically varies gradually over a period of 
hours or days. In contrast, UDDS emissions vary significantly from 
second to second. For these reasons, the ambient air actually resembles 
a steady state condition more closely than a transient state.
    Another potential advantage of running the test vehicle or engine 
under single-mode conditions is that it would permit less sophisticated 
and less expensive dynamometer equipment (e.g., water-brake 
dynamometers) to be used for emission generation. This could help to 
encourage additional biological testing laboratories to obtain the 
equipment necessary for conducting the test exposures required in this 
program, and might also increase the feasibility of using portable 
dynamometers for these purposes.
    On the other hand, the use of a non-transient rather than a 
transient cycle for generating emissions raises legitimate concerns 
that the emission stream could be missing certain toxicologically 
active species which would ordinarily be generated in appreciable 
amounts only during accelerations. However, these concerns might be 
allayed to some extent by two other emission generation specifications 
which EPA is considering: the use of engine-out (non-catalyzed) rather 
than tailpipe catalyzed emissions (see section III.A.2, below) and the 
use of high-load, fuel-enriched operating conditions.
    To maximize the emission species occuring in the exhaust stream 
during non-transient operation, EPA is considering different vehicle/
engine operating specifications or emission performance requirements. 
One approach under consideration is to specify the speed and throttle 
requirements, e.g., 25 percent of full throttle at a constant speed of 
20 mph (the average speed of the FTP). An alternative method would be 
to specify a high load requirement directly (e.g., 50 percent load at 
20 mph). One factor to consider is that the vehicle/engine operating 
conditions must be achievable without exceeding the load which a 
typical well-maintained, modern engine can handle for prolonged periods 
of time without breaking down. EPA requests comments and advice on this 
practical constraint. A different approach would be to require the 
modification of electronic computer controls to manage fuel injection 
so as to achieve a suitably enriched air/fuel ratio under steady-state 
operation. Programming a vehicle to operate in open-loop mode is one 
example of this approach.
    Rather than specifying the operating conditions to be used during 
non-transient vehicle/engine operation, EPA could choose to specify 
performance criteria which would achieve suitable emission levels. 
These criteria would be based on selected exhaust or exposure 
concentrations of key emissions for biological testing (e.g., CO, total 
HC). This approach would allow operators the flexibility to determine 
the most appropriate vehicle/engine conditions and/or computer controls 
needed to obtain an exhaust stream containing the required 
concentration ranges of specific emissions. For example, EPA could 
require that the concentration of total hydrocarbons in the exhaust 
must exceed a specified amount and/or that the CO concentration be less 
than a specified maximum. Because different test vehicles/engines would 
be required to meet the same criteria, this approach might reduce the 
potential test-to-test variability which might result if EPA were to 
specify a particular set of operating conditions and require that set 
to be applied across all vehicle/engine technologies.
    EPA invites comments on the possibility of using a non-transient 
cycle rather than the FTP for generating emissions for biological 
testing. Specific comments are requested on the effectiveness of the 
various approaches discussed above for achieving the desired emission 
enrichment during steady-state operation. Comments on the specific 
speed, throttle, load specifications, computer controls, and/or 
performance criteria mentioned above are also requested, and 
suggestions as to suitable alternative methods or specifications are 
welcome. Such suggestions will be particularly helpful if supporting 
data and rationale are provided. Detailed emission speciation data/
profiles contrasting engine/vehicle operating conditions (e.g., 
transient versus non-transient, especially under engine-out conditions) 
are also solicited.
2. Alternative Approaches
    Although EPA is considering steady state conditions for the 
generation of emissions in the final rule, it has not excluded the 
possibility of using the previously proposed FTP method or other 
transient or semi-transient (e.g., multi-modal) methods. EPA solicits 
detailed comments on whether transient methods are necessary to ensure 
that toxicologically significant species will not be unintentionally 
omitted from the emission stream.
    EPA is considering the use of emission conditioning techniques that 
could potentially accommodate transient cycle emission generation 
within the context of the F/FA inhalation toxicity testing program. One 
option being considered would use constant dilution ratio equipment 
(e.g., the mini-diluter or variable flow rate ``constant volume 
sampling'' (VFR-CVS) systems) being developed and evaluated in the 
American Industry/Government Emissions Research, Cooperative Research 
and Development Agreement (AIGER CRADA) to limit the transient 
variability characteristics of classical CVS (variable dilution ratio) 
exhaust. With this equipment, the diluent can be managed to achieve 
desired CO, CO2 and water vapor concentrations (e.g., to avoid 
animal asphyxiation or water condensation) and sample temperatures 
prior to being directed to the biological exposure chambers. 
Concentration swings will occur when the engine air/fuel ratio diverges 
from stoichiometric combustion, but for only short durations of time. 
EPA recognizes that this is a developing technology and invites 
comments, suggestions, and supporting data on its possible application 
in the F/FA biological testing program.
    Another alternative that would allow management of the variability 
of transient vehicle exhaust is use of a mixing chamber between the 
classical CVS source and the exposure chamber. The transient exhaust 
would be injected into a large dilution/mixing/integration chamber 
prior to its delivery to the animal exposure chamber. This would allow 
necessary adjustment of the exhaust concentrations and integration of 
the large concentration swings typical of CVS exhaust, prior to 
exposing the animals. The mixing chamber would be charged from the CVS 
at a constant rate determined by the exposure chamber purge rate. The 
exposure chamber flow could begin at the conclusion of the initial 
transient cycle with the associated mixing chamber charge. EPA requests 
comments on the feasibility of using mixing chambers to condition 
diluted transient exhaust for animal exposure in the context of the F/
FA testing program.
3. Engine-Out Emissions
    EPA is also considering the use of engine-out (i.e., non-catalyzed) 
rather than catalyzed tailpipe emissions for biological testing, to 
assure that the test animals will be exposed to the full range of 
emission species potentially resulting from the combustion of F/FAs. 
With modern emission control technology in place, most of the ambient 
air pollutant species attributable to automobile exhaust come from two 
sources: malfunctioning vehicles (``high emitters'') and normal 
vehicles during their cold start period, when their engines run rich 
and their catalytic converters have not yet reached effective operating 
temperatures. The variety of emissions from these two important sources 
are not well represented by hot, catalyzed exhaust generated from well-
maintained, modern vehicles. Emissions during the cold-start include 
hundreds of organic chemical species which are generated before the 
catalytic converter reaches its effective temperature. Once the 
catalytic converter is warmed-up, its efficiency increases to the point 
where only a dozen or so simple compounds remain in readily measurable 
amounts in the catalyzed exhaust. Thus, the use of treated exhaust in 
the biological testing program would expose the laboratory animals to 
only a very few of the organic emission species associated with the 
combustion of the fuel or additive of interest.
    In vivo testing requires continuous air changes in the animal 
chambers to avoid confounding health effects (e.g., lung and skin 
irritations, hypoxia, bacterial infections, heat exhaustion, etc.) 
caused by a build-up of metabolic by-products (e.g., CO2, ammonia, 
humidity and body heat) of the animal test population. Because of the 
need for frequent air changes, the initial cold-start emissions would 
remain in the exposure chamber for only a few minutes before being 
flushed out. Assuming catalyzed emissions were used, the remaining 
hours of each day's test period would expose the animals only to the 
relatively few species that remain in hot, treated exhaust. Thus, the 
use of catalyzed exhaust for biological exposures could exclude from 
the tests relevant emission species that could potentially be harmful 
to human health or the environment. In contrast, the ambient air 
normally contains the full range of combustion emissions, since cold-
start emissions are continuously re-introduced and some ``high 
emitters'' are always in operation. Since humans experience continuous 
exposure to these emissions, EPA believes it is important that they be 
included in the test exposure atmosphere.
    Several possible methods have been considered for increasing the 
frequency and/or duration of biological exposures to actual cold-start 
emissions. These included the use of emission storage and retrieval 
systems, use of an enhanced engine and exhaust cooling system, and the 
use of a fleet of identical vehicles that could be interchanged to 
provide natural cooling periods. However, each of these methods could 
introduce still more technical challenges. Thus, EPA believes that 
production of a constant supply of genuine cold-start emissions could 
be an impractical requirement for the type of toxicology tests required 
in this program. Comments and suggestions on these issues are welcome.
    Instead of attempting to produce a constant supply of cold-start 
emissions, EPA is considering the possibility of requiring 
manufacturers to use engine-out emissions as a surrogate for cold-start 
emissions. Recognizing that an ineffective catalytic converter is the 
major (though not only) vehicle-related factor which differentiates the 
cold start, EPA has compared cold-start emissions and high-emitting 
vehicle emissions to engine-out emissions using available emission 
data. This analysis7 showed that, in terms of both chemical 
composition and relative concentrations, engine-out organic emissions 
closely resemble cold-start and high-emitting vehicle emissions. In 
addition, a comparison of FTP composite emissions showed that engine-
out and tailpipe organic emission species were nearly the same on a 
qualitative basis, although the engine-out emissions appeared at a 
greater overall concentration. Thus, bypassing the catalyst produced 
emissions representing a comprehensive aggregate of characteristic 
combustion products at enriched concentrations, including the species 
which are otherwise emitted only during the cold start. The enrichment 
of organic emissions is an important side benefit for the biological 
testing program because richer hydrocarbon streams will be available 
for toxicology testing for any given level of CO2 and water vapor. 
(It should be noted, however, that CO levels are also raised, and may 
themselves become a limiting factor.) EPA requests comments on the use 
of engine-out emissions for the F/FA biological testing program and 
welcomes suggestions regarding this proposal or other alternative 
approaches. To be most useful, such comments should include supporting 
emission data.

    \7\See memorandum to the docket from Stephen Mayotte, entitled 
``Engine-out versus Tailpipe Emissions in Light-duty Vehicles''.

    With the exception of exhaust after-treatment devices, EPA proposes 
that all normally required emission control equipment be present and 
fully operational on all test vehicles and heavy-duty engines used in 
the generation of engine-out emissions. This may require replacing 
catalytic converters and particulate traps with other devices capable 
of simulating the back pressure, residence time, and mixing 
characteristics usually provided by these devices. Another approach 
could be to install a blank catalyst (no catalytic wash coat) in the 
exhaust system where the production catalyst would normally be 
installed. EPA requests comments and suggestions on this or other 
suitable alternative methods that would ensure the appropriate 
operation of the exhaust system.

B. Mileage Accumulation for the Testing of Atypical F/FAs

    In the NPRM, EPA proposed 25,000 miles as the minimum mileage which 
must be accumulated on the emission-generation vehicle before 
generating emissions for characterization and animal testing purposes. 
For fuels and fuel additives containing atypical elements, mileage 
accumulation was proposed to continue after 25,000 miles, if needed, 
until the emissions of the atypical element(s) reached steady state or 
until the vehicle or engine has been operated for 80 percent of its 
estimated useful life (e.g., 80,000 miles for light-duty vehicles). 
``Steady state'' was defined in the proposal as the point at which the 
mass of the atypical elements emitted during the performance of one or 
more UDDS or engine dynamometer schedules is within 10 percent of the 
mass of the atypical elements that entered the combustion chamber 
during the driving cycles.
    Based in part on comments received from the regulated industry, EPA 
is now considering different mileage accumulation approaches. In the 
case of a fuel or fuel/additive mixture meeting baseline or non-
baseline criteria, EPA believes that an accumulation of 4,000 miles on 
a light-duty vehicle or light-duty truck or 125 hours on a heavy-duty 
vehicle (fueled exclusively with the fuel or fuel/additive mixture to 
be tested), should be sufficient to stabilize emissions. The 4,000 
mile/125 hour mileage accumulation requirements are consistent with the 
emission stabilization procedures used for emission-data vehicles in 
EPA's new vehicle certification program.8

    \8\40 CFR 86.094-26, Mileage and service accumulation; emission 

    In the case of F/FAs with atypical elements, EPA is concerned that 
the requirement to reach a mass-balance steady state prior to 
generating emissions for testing might be too stringent. In fact, in 
some cases, a measured input-output mass balance might never be 
reached. Thus, EPA is considering a different approach for atypical F/
FAs. The minimum mileage accumulation that vehicles/engines testing 
atypical F/FAs would be required to undergo would be 4,000 miles, the 
same mileage accumulation now proposed for the testing of baseline and 
non-baseline F/FAs. After completion of the 4,000 miles, the F/FA 
manufacturer would be required to identify and measure the atypical 
element(s) in the exhaust, if possible. Because the presence of the 
atypical species in specific emission fractions will be dependent on 
the nature of the particular atypical element, EPA would recommend 
examination of all emission fractions (i.e., vapor, semi-volatile, and 
particulate). If the atypical element(s) of interest are not detected 
in at least one of the emission fractions after 4,000 miles, the 
manufacturer would then need to continue mileage accumulation until the 
atypical element(s) are at high enough level(s) for accurate 
identification and measurement. The intervals at which the emissions 
should be examined for detection of the atypical element(s) is proposed 
to be left to the manufacturer's discretion. Once the atypical 
element(s) of interest are detected in at least one emission fraction, 
an additional 10,000 miles would be required prior to generation of 
emissions for purposes of emission characterization and biological 
    EPA solicits comments and suggestions on the proposed mileage 
accumulation requirements for baseline, non-baseline, and atypical F/
FAs. If alternative approaches are provided, EPA requests commenters to 
include supporting data and a detailed discussion so as to allow an 
appropriate analysis of the options.

C. Base Fuel Specifications

    The NPRM proposed the use of base fuels to represent theoretical 
``industry average'' or normative formulations for each defined fuel 
family. EPA was to develop chemical and physical specifications to 
define a specific base fuel (including a minimum required additive 
package) for each fuel family. The base fuels were proposed to serve as 
the group representatives in compliance with testing requirements for 
baseline F/FA groups. The base fuels were also proposed to serve as the 
fuel substrates into which additives which were undergoing evaluation 
would be mixed prior to emission generation and testing. Tests 
conducted on the emissions of the base fuel would then serve as 
controls against which tests on the emissions of the additive/base fuel 
mixture would be compared.
    Although base fuel definitions for the conventional fuel families 
(gasoline and diesel) were discussed in a memorandum to the docket 
(``Base Fuel Determination Procedures for the Proposed Fuels and Fuel 
Additives Rulemaking,'' see Public Docket No. A-90-07), EPA did not 
specify at that time the required additive package for conventional 
fuels or the base fuel specifications for alternative fuels. The 
proposed specifications for the unleaded gasoline and diesel base fuels 
are shown in Table 1 and Table 2, respectively. Comments are requested 
on these specifications, with particular emphasis on the additive 
functions proposed to be included in each base fuel. The base additive 
packages are intended to include only those additive functions that are 
essential for fuel production or engine operation and/or those required 
by law. Selection of the specific product within each specified 
additive functional category would be up to the formulator of the base 
fuel and/or the test operator. However, additive products which include 
elements other than carbon, hydrogen, oxygen, and nitrogen would not be 
allowed as part of the base fuel/additive formulation. The base 
additives would be required to be used at their minimum effective 
concentrations in the base fuel.

            Table 1.--Unleaded Gasoline Base Fuel Properties            
API Gravity...............................................  57.425
Benzene, vol%.............................................  1.532 and N2, mole%, max.................................     4.0
Sulfur (odorant additive), ppmv, max............................     16 

               Table 6.--Propane Base Fuel Specifications               
RVP, psig, max..................................................     208
Evaporative temperature, 95%,  deg.F, max.......................     -37
Propane, vol%, min..............................................    92.5
Propylene, vol%, max............................................     5.0
Butane, vol%, max...............................................     2.5
Sulfur (odorant additive), ppmw, max............................    120 

    Some gasoline detergents have been shown to cause intake system 
deposits when used in M85 applications. Likewise, lubricating oils 
containing calcium have been shown to cause injector tip deposits in 
M100 applications. Therefore, EPA recommends that F/FA producers 
determine the methanol compatibility of lubricating oils as well as 
fuel additives used in the gasoline portion of the M85 base fuel. EPA 
requests comments on this issue.
2. Ethanol
    In the NPRM, EPA proposed two baseline groups for the ethanol fuel 
family: E100 group and E85 group. However, EPA is now considering 
defining only one group for baseline ethanol formulations. This single 
baseline ethanol group would be represented by E85 base fuel. The 
rationale behind this proposal is that fuel ethanol is required to 
contain at least 5 percent denaturant, which means that, in actuality, 
E100 formulations contain only 95 percent ethanol (i.e., E95). 
Furthermore, gasoline is normally used as the denaturant for ethanol 
fuels. EPA believes that there would be little incremental value in 
requiring tests of E95 in addition to E85, and thus proposes to create 
a single baseline ethanol group represented by an E85 base fuel.
    The E85 base fuel would contain no elements other than carbon, 
hydrogen, oxygen, nitrogen, sulfur, chlorine, and copper. The chlorine 
(as chloride) would be permitted as a contaminant remaining from 
ethanol production, and would be limited to no more than 0.0004 percent 
by mass. The sulfur content in the E85 base fuel may not exceed 0.004 
percent by mass. Copper, also a contaminant from ethanol production, 
would be limited to 0.07 mg/L.
    The E85 base fuel would contain 85 percent by volume chemical grade 
ethanol, blended with 15 volume percent unleaded gasoline base fuel. No 
additives, beyond those included in the gasoline base fuel portion of 
the ethanol blends, would be included in the E85 base fuel. Additives 
used in the gasoline component of E85 should be ethanol-compatible. A 
summary of the ethanol base fuel specifications is provided in Table 4.
3. Methane (CNG, LNG)
    The methane fuel family would be represented by a natural gas base 
fuel whose elemental composition is limited to CHONS, with the sulfur 
present only as an odorant for leak detection purposes and limited to 
16 parts per million (by volume). The added odorant should 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. No other additives would be included in the base fuel. 
The proposed methane base fuel specifications are presented in Table 5.
4. Propane (LPG)
    Special-duty propane, as defined in ASTM specification D-1835, is 
proposed to serve as the propane base fuel. The propane base fuel may 
contain no elements other than CHONS, with the sulfur present as an 
added odorant for leak detection purposes and limited to 120 ppm (by 
weight). The added odorant should 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. No other 
additive would be allowed included in the base fuel. The proposed base 
fuel specifications for propane are presented in Table 6.

IV. Public Participation

    EPA desires full public participation in arriving at its final 
decisions, and therefore solicits comments on all aspects of this 
notice from all interested parties. However, EPA does request that 
comments be limited to the specific issues identified and discussed in 
this notice. EPA does not intend to respond to comments submitted at 
this time which concern other aspects of the proposed program. Ample 
opportunity for such comments was already provided at the public 
hearings and during the comment periods which followed publication of 
the ANPRM and NPRM. For those submitting comments, whenever applicable, 
full supporting rationale, data, and detailed analysis should be 
submitted to allow EPA to make maximum use of the comments. All 
comments should be directed to the EPA Air Docket, Docket No. A-90-07 
(see ADDRESSES). Comments will be accepted until March 28, 1994.

V. Statutory Authority

    The statutory authority for this proposal is provided by sections 
205(b) and (c), 211, and 301(a) of the Clean Air Act as amended [42 
U.S.C. 7524(b) and (c), 7545, and 7601(a), Public Law 95-95].

List of Subjects in 40 CFR Part 79

    Environmental protection, Fuels, Fuel additives, Gasoline, Motor 
vehicle pollution, Penalties.

    Dated: February 15, 1994.
Mary D. Nichols,
Assistant Administrator for Air and Radiation.
[FR Doc. 94-4047 Filed 2-23-94; 8:45 am]

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