Fuels and Fuel Additives Registration Regulations

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 79

[FRL-4840-7]

Fuels and Fuel Additives Registration Regulations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of reopening of comment period.

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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

welfare.

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

20460.

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.

FOR FURTHER INFORMATION CONTACT: Ines del C. Figueroa, Special

Regulatory Projects Branch, U.S. Environmental Protection Agency, 2565

Plymouth Rd., Ann Arbor, Michigan 48105; phone (313) 668-4575.

SUPPLEMENTARY INFORMATION:

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

requirements.

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.

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\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.

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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''.

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\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.

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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.

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\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)).

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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

emissions.

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.

TP24FE94.017

BILLING CODE 6560-50-P

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

provision.

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

disadvantages.

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.

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\7\See memorandum to the docket from Stephen Mayotte, entitled

``Engine-out versus Tailpipe Emissions in Light-duty Vehicles''.

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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

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

requirements.

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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

testing.

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]

BILLING CODE 6560-50-P