In general, for existing information to fulfill the Tier 2 testing requirements, it must include the in vivo inhalation exposure to whole motor vehicle emissions ( combustion or evaporative, as applicable), except for the few in vitro studies acceptable for carcinogenicity/ mutagenicity assessment. In order to be acceptable, previous toxicity studies must include exposure to non catalyzed emissions, as required in this final rule. EPA is requiring the use of an evaporative emission generator for the evaporative emission testing. However, EPA will accept previous inhalation exposure studies of whole evaporative emissions in which the emissions were generated using standard evaporative emission procedures under FTP conditions. Raw product tests, using F/ FAs in the uncombusted state, are not considered adequate replacements for Tier 2 combustion emission testing. In addition, studies using whole aerosolized preparations or tests on individual emission products of the fuel or additive cannot be used as substitutes for whole emission testing for either combustion or evaporative emissions. The reason for this requirement is that, as explained in Section III. A. 2 of this preamble, this rule focuses on the effects of whole emissions rather than raw F/ FAs or individual emission products. Tests performed on the emissions of F/ FAs which are classified in the same group as the subject fuel or additive are considered relevant, but tests on products not conforming to the grouping criteria of the subject fuel or additive do not apply. Other important parameters to consider in determining if existing studies are adequate include: the type and number of test subjects, the number and adequacy of dosages, the methodology and duration of exposure, and the technical methods used for monitoring the progress of the test and for analyzing the results. Generally, 90 days is the minimum acceptable length of exposure. However, an existing study having a shorter exposure period might be considered adequate if the test results are positive, i. e., adverse effects are observed. Previously conducted studies using mammals other than rodents may be acceptable in lieu of rodent testing, if the existing studies meet all other applicable criteria for adequacy. For carcinogenicity and mutagenicity, the Salmonella assay is always required because of its broad sensitivity and specificity for detecting chemical exposures having mutagenic and/ or carcinogenic potential. Manufacturers should note ( see Table 2) that when a registrant needs to conduct new Tier 2 testing, two in vivo assays ( MN and SCE), in addition to the Salmonella assay, are required to satisfy the carcinogenicity endpoint. However, in lieu of new testing, a manufacturer may rely on one existing in vivo assay for carcinogenicity, in addition to the Salmonella assay and another in vitro assay. In other words, two in vivo tests for carcinogenicity are required if new testing is performed, but only one in vivo study is required if the manufacturer relies on existing carcinogenicity information. The reason for this is that the incremental costs of performing the two specified in vivo assays ( MN and SCE) within the 90 day inhalation protocol ( as required in this final rule) is low in comparison with the amount of useful data obtained. This approach is cost effective because the same animals used in the inhalation study can also be used for the in vivo carcinogenicity assays. In fact, fewer resources will be spent to do both the MN and SCE assays within a single group of inhalation exposed animals than to conduct just one of these tests along with a separate in vitro carcinogenicity assay ( in addition to the Salmonella assay).

D. Alternative Tier 2 Provision The Tier 2 tests described above pertain to all designated F/ FAs, unless mitigated by special provisions or comparable data from adequately performed and documented previous studies. In general, EPA considers this standard testing program to be necessary for the health effects evaluation of F/ FA emissions, even if further evaluation may be required under the provisions of Tier 3. However, this final rule also adopts the special provision discussed in the Reopening Notice, under which EPA retains the authority to modify the standard Tier 2 test requirements in certain instances. The exercise of this authority will be done wholly at EPA's initiative and discretion. The alternative Tier 2 provision is intended to provide a degree of flexibility to EPA when available information indicates that, in a specific case, another testing regimen is preferable to the standard set of Tier 2 tests. There are three scenarios under which EPA generally anticipates the possible use of this provision. First, for a particular fuel or fuel additive ( or group), information may be available ( independent of the requirements of this rule) which may cause EPA to be concerned about potential health effects related to an endpoint not specifically addressed in Tier 2. In such an instance, the alternative Tier 2 provision allows EPA to require additional studies targeted to the identified area of concern, even though these studies are not normally included in Tier 2. While the standard structure of this rule also allows EPA to prescribe the additional tests under Tier 3, the alternative Tier 2 provision enables EPA to prescribe and receive the desired data earlier in the process. This flexibility is particularly important given that this final rule allows up to six years for Tier 2 submittal. When the additional testing can be coordinated with the standard Tier 2 testing program, the alternative Tier 2 provision will also save costs relative to conducting the additional tests at a separate point in time. Second, independent of the information to be submitted under this rule for a particular F/ FA product ( or group), EPA may identify a potentially significant public health risk related to a Tier 2 endpoint, such that EPA knows that more definitive testing will be required for this endpoint than is ordinarily required under Tier 2. Again, EPA could require such testing under Tier 3 after the evaluation of Tier 2. However, the alternative Tier 2 provision can facilitate earlier and potentially more efficient acquisition of the required data. If appropriate to the case at hand, EPA would substitute the more definitive endpoint test for the standard Tier 2 test ( with appropriate deadline adjustment). In such a case, EPA's authority to waive the requirement to provide the respective Tier 2 test derives from its authority in section 211( e) to provide exemptions from testing when such testing would be duplicative. In this example, because the substituted test would address the endpoint more rigorously than the standard Tier 2 assessment, it would be duplicative to require both evaluations. Third, EPA may identify concerns about the effects of F/ FA emissions involving different engine and/ or emission control technologies than those ordinarily required for generating the emissions tested in Tier 2. For example, biological testing using catalyzed instead of non catalyzed emissions might be required if emission species of concern are present in the catalyzed exhaust of a fuel or additive that are not represented in the untreated exhaust.\ 58\ In this case, EPA could prescribe a Tier 2 program using catalyzed instead of non catalyzed emissions under the alternative Tier 2 provision. Otherwise, the manufacturer of this product would likely be required to conduct a second series of biological tests with catalyzed emissions, under Tier 3.

\ 58\ As described in Section VI. A, the use of non catalyzed emissions are normally required in the Tier 2 toxicology tests. Under Tier 1, however both catalyzed and non catalyzed emissions are required to be characterized.

In summary, the alternative Tier 2 provision will give EPA the flexibility, when indicated, to prescribe additional tests to be performed along with the standard Tier 2 program, to substitute different tests, and/ or to modify the underlying vehicle/ engine specifications for Tier 2. When EPA exercises its authority under this special provision, it will allow an appropriate time for completion of the prescribed alternative tests. EPA may also use the alternative Tier 2 authority to waive certain Tier 2 endpoint evaluations ( generally on occasions when additional and/ or more rigorous tests are being required for other Tier 2 endpoints). However, Tier 2 endpoint tests will not be waived in the absence of adequate information or requirements for more rigorous testing of the endpoint( s). EPA intends to exercise this special authority only in exceptional cases. When EPA decides to use the alternative Tier 2 provision, EPA will notify the responsible manufacturer ( or group) by certified mail letter of the specific modifications in lieu of the standard Tier 2 program, along with a schedule for compliance and submittal of test results. The manufacturer ( or group of manufacturers) will have 60 days to comment on the prescribed alternative Tier 2 testing program and timing requirements. If the responsible manufacturer does not provide any comments, EPA will assume that the manufacturer has consented in full with the prescribed testing regimen. EPA will publish a notice in the Federal Register to inform the public of its intent to require alternative testing for a particular F/ FA manufacturer and that a copy of the letter to the manufacturer is available in the public record of this rule for review and comment. Additional correspondence between EPA and the responsible manufacturer regarding alternative testing requirements will also be placed in the public record. After receipt and review of all comments received ( or, if no comments are received), EPA will publish a notice of final action on the proposed alternative Tier 2 requirements in the Federal Register. In the Reopening Notice, EPA proposed to notify manufacturers of proposed alternative Tier 2 requirements within 18 months of promulgation of the final rule ( for registered F/ FAs) or within 18 months of EPA's receipt of intent to register ( for currently unregistered F/ FAs). Comments received from the industry indicated that this notification period was too long relative to the proposed three year deadline for submittal of Tier 2 results. However, EPA believes the proposed notification period is reasonable, given that this final rule allows manufacturers up to six years for submittal of Tier 2 results. Furthermore, EPA believes that restricting the time period for exercising the alternative Tier 2 authority is unnecessary and disadvantageous to the public interest as well as the regulated industry, since this provision establishes a mechanism to provide needed data on a timely basis and to eliminate unnecessary screening studies when substitute tests will be required. Therefore, while EPA will endeavor to notify manufacturers of proposed alternative Tier 2 requirements within 18 months, this final rule permits EPA to notify manufacturers of proposed alternative Tier 2 requirements at any time prior to EPA's receipt of Tier 2 data. If a manufacturer receiving such notification has already begun the standard Tier 2 toxicology testing, then EPA will refrain from requiring the testing; however, in such cases, the manufacturer is required to submit the results of the standard Tier 2 tests within one year of the date when testing began. In other cases, EPA will consider the potential costs, burdens, and timing factors in making its final decisions on alternative Tier 2 requirements.

IX. Tier 3 Requirements A. Scope On the basis of the submitted Tier 1 and/ or Tier 2 data, or any other available information, EPA will determine whether further testing and/ or analysis for the subject fuel or fuel additive is needed under the provisions of Tier 3. Given the variety of evaluations included in Tiers 1 and 2 and the wide range of possible interrelated outcomes which could be obtained, EPA proposed to use its discretion in determining the need for Tier 3 testing on a case by case basis. Decisions on the need for follow up testing within Tier 3 would depend on expert scientific judgment as to the availability of adequate data to enable a health risk evaluation and the need for more definitive information for developing regulatory decisions. EPA requested comments on the proposed discretionary nature of Tier 3 determinations and on a possible alternative approach involving the establishment of    automatic triggers'' for Tier 3 decisions, i. e., specific outcomes of Tiers 1 and 2 which would make Tier 3 testing mandatory. Responses included both support and opposition to the proposed Tier 3 discretionary approach. EPA evaluated all comments and determined that decisions on Tier 3 requirements should remain at the discretion of EPA. In order to accomplish the goals of the program, it is essential for EPA to be able to examine the Tier 1 and Tier 2 data prior to prescribing additional tests. The need for and content of Tier 3 testing will most often be dependent on the results of the earlier tiers. In these cases, decisions on Tier 3 can only be reasonably specified after EPA's review of the applicant's initial submittal. The purpose of Tier 3 is not to fill all data gaps, but to establish a program that provides the Administrator with the necessary and reasonable information to make regulatory decisions. Based on this rationale, EPA judges that it is neither practical nor desirable to specify criteria which will automatically force F/ FA manufacturers to perform additional testing under Tier 3. Thus, EPA will use its discretion to determine Tier 3 requirements on a case by case basis, allowing EPA to target specific regulatory needs. Although EPA can use the Tier 3 data to support regulatory actions, referral to Tier 3 level is not mandatory before beginning actions under CAA section 211( c). The need for Tier 3 testing and/ or analysis will depend, in part, on whether Tier 1 and/ or Tier 2 data provide sufficient toxicity and exposure information to determine the potential health risks associated with a particular fuel or fuel additive. The endpoints to be addressed and the nature of the studies to be performed under Tier 3 are to be determined on a case by case basis. Tier 3 studies will most often be required to further explicate the results of the tests/ analyses performed under Tiers 1 and 2 or to address other areas of concern highlighted by the literature search. If additional toxicity testing is required under Tier 3, the test might entail whole emissions ( as in Tier 2), or the testing of one or more individual emission species identified to be of particular concern. EPA could also use other information ( available outside this program) to require testing under Tier 3. While the specific objectives and scope of Tier 3 testing will vary depending on the concerns identified in the earlier tiers or any other information available to EPA, examples of possible areas for further testing are: chronic/ lifetime studies, chemical disposition/ metabolism studies, exposure studies, dosimetry analyses, additional emission characterization/ speciation, additional modeling analysis, environmental toxicity tests, testing using different emission generation procedures or emission control systems, or any other additional evaluation approach EPA deems necessary to assess the health and/ or welfare effects of a particular fuel or fuel additive. The previous examples and the discussion below in no way limit the scope of Tier 3 or EPA's authority to require further testing under this program. Today's rule specifically includes under Tier 3 any health effects testing to be performed on aerosol additives ( see Section X. C for details on the special provision for aerosol products). Due to the special nature and use of this type of product, EPA judges that any testing needs will require non standard test procedures that can be better addressed under Tier 3. EPA will review the composition information and literature data on the specific aerosol product and will determine if health effects testing is needed on a case by case basis. For example, if available literature, submitted under Tier 1, indicates that a component of an aerosol product is highly toxic, and the product is widely produced, then Tier 3 testing on the aerosol product would likely be indicated. Modeling of potential exposures, atmospheric reactivity, and/ or environmental fate/ partitioning may also be required under Tier 3, as explained in Section III. C. For example, if a fuel or additive is widely distributed and Tier 2 data indicate serious concern for health effects, EPA might require more extensive exposure analysis and/ or modeling under Tier 3 to better define potential risks. Although the grouping mechanism included in this rule allows F/ FA manufacturers to submit Tier 1 and Tier 2 data on the representative of a designated group for purposes of registration, EPA retains the authority under Tier 3 to require testing on any member product of a group. Thus, when follow up testing is required under Tier 3 authority, the specified test( s) could be required to be conducted on the selected representative or on any other member of an existing group. Testing on additional F/ FA products could be required if EPA identifies a concern for any member of the group other than the group representative. For example, the testing representative for the M85 group ( consisting of methanol formulations containing 50 95 percent methanol) is an M85 base fuel containing 85 percent methanol by volume. In the future, other methanol fuels could enter the market and be used extensively, triggering a concern for exposure and potential health risks. In this case, EPA could require Tier 3 testing for another methanol formulation within the M85 group. Another possible Tier 3 effort could involve the testing of combinations of oxygenates. Although groups for non baseline gasolines are defined on the basis of individual oxygenates, EPA could request additional testing to address mixtures of oxygenates under Tier 3 authority. For example, if a registered non baseline gasoline formulation containing a mixture of oxygenates is widely produced and used, resulting in high exposures and potential health risks, EPA could require testing of this formulation under Tier 3. Tier 3 tests for this formulation could involve standard Tier 1 or Tier 2 tests, testing for other endpoints not addressed under Tier 2, or testing for other areas of concern ( e. g., exposure analysis, environmental testing, etc.). EPA also retains the authority to require additional testing using different vehicle/ engine technologies and/ or emission generation specifications than those prescribed for Tier 1 and Tier 2 analyses. To reduce the costs of the program, today's action requires the use of a single vehicle model for emission generation. However, if EPA determines that emissions from other applicable vehicle/ engine technologies might differ significantly for a given fuel or additive/ base fuel mixture, then EPA may require additional emission characterization and/ or toxicological testing under Tier 3 using different vehicle/ engine technology. Also, although standard Tier 2 tests are to be conducted using non catalyzed emissions ( as discussed in Section VI. A), EPA could require the use of catalyzed emissions for testing under Tier 3. When a determination has been made that Tier 3 testing is required, EPA will inform the responsible manufacturer by certified mail of the purpose and nature of the testing to be performed along with a schedule for compliance and submittal of the Tier 3 report to EPA. EPA will also publish a notice in the Federal Register, notifying the public that the letter to the manufacturer is available in the public record for review and comment. The affected manufacturer's comments and EPA's response to these comments will be placed in the public record, as well. After receipt and review of all comments received ( or, if no comments are received), EPA will publish a notice of final action on the proposed Tier 3 requirements in the Federal Register. EPA proposed in the NPRM to provide the responsible manufacturer or group a 30 day comment period to respond to EPA's requirements under Tier 3. In their commentary, the regulated industry asked EPA to extend this comment period to 60 days to allow for appropriate time for review, analysis, and preparation of a written response to EPA regarding the designated protocol( s) to be used for Tier 3 tests. EPA judged that this request was reasonable, thus today's rule gives F/ FA manufacturers 60 days to comment on the EPA prescribed Tier 3 requirements. The responsible manufacturer is expected to submit detailed protocols for review and approval by EPA prior to beginning Tier 3 testing. Tier 3 tests must comply with the pre approved specifications given by EPA. If manufacturers experience unforeseen difficulties while conducting the prescribed Tier 3 tests approved by EPA ( e. g., excess mortality observed half way through a chronic bioassay), they will be allowed to request a modification of the requirements. This mechanism would apply to unusual circumstances that are outside the control of the manufacturer. If testing problems are identified, EPA must be notified as soon as possible so that requirements can be modified.

B. Criteria for Referral to Tier 3 This section presents some of the guidelines and considerations which EPA will use in determining the necessity for additional testing under a discretionary Tier 3 testing approach. Consistent with the discretionary decision making process for Tier 3, this discussion is not intended to provide an exhaustive, limiting, or definitive listing of relevant criteria. The decision to require manufacturers to submit additional testing on the health, environmental, or welfare effects of F/ FA emissions will take into account the cumulative information provided by Tiers 1 and 2, including previous scientific data, emissions characterization data, biological test results, and any ancillary information which may be available to EPA. Thus, decisions to require Tier 3 level testing will be made only after all the requirements of Tiers 1 and 2 have been adequately satisfied ( with the exception of special cases as discussed in Section VIII. D). Adherence to this principle will prevent unnecessarily costly or poorly targeted decisions based on piecemeal, out of context information, and will promote more precise identification and evaluation of data gaps, and more cost efficient coordination of potential test requirements. Ultimately, EPA must be able to decide whether or not the use of a fuel or fuel additive is likely to create unacceptable health or welfare risks. If a risk decision is made possible by the information from Tiers 1 and 2, then Tier 3 will not be required. However, if such a risk decision cannot be made on the basis of the Tiers 1 and 2 data, then Tier 3 testing will be mandated. Therefore, to make a determination on the need for Tier 3 testing, EPA scientists will evaluate the extent to which the results of Tiers 1 and 2 are adequate for such decisions, guided by the basic principles of risk assessment. A risk assessment requires the merging of a health effects assessment ( including hazard identification and concentration response relationship) and an exposure assessment. Such an assessment can range from a qualitative to a highly quantitative analysis, depending upon the extent of the available data. EPA recognizes that a quantitative assessment might not be possible at the end of Tier 2.\ 59\ However, Tiers 1 and 2 might indicate that little hazard is present and that exposures may be quite low and limited geographically. In such a case, there may be no reason to pursue further testing at the Tier 3 level to improve risk assessment information. On the other hand, Tiers 1 and 2 might suggest that a hazard is likely and that exposures could be significant because of the production volume and ubiquitous use of a product, but the data may still be inadequate for a quantitative risk assessment. In this case, Tier 3 testing could be indicated to provide the needed information.

\ 59\ However, if adequate information exists, EPA does not rule out the possibility of conducting such risk assessment.

In general, the principles and critical data elements of the risk assessment process will provide a useful guide for identifying whether meaningful information gaps remain and for determining the specific objectives of potential Tier 3 testing. However, EPA does not intend to conduct a formal risk assessment as part of its decision on whether to promote a fuel or fuel additive ( or group) to Tier 3. Rather, EPA will evaluate the quality and certainty of the toxicity and concentrationresponse data and consider qualitatively whether such data weighs in favor of or against further testing. A formal risk assessment will be more likely to be developed at such a time that there is a need for action to control or prohibit a product under the regulatory authority of CAA section 211( c). The following sections discuss key factors which EPA will consider in identifying the need for and content of Tier 3 testing. 1. Statistical Issues As previously mentioned, scientific judgment will be exercised in determining whether Tier 3 testing is indicated. An important factor in such judgments will be the interpretation of and significance ascribed to    negative'' results obtained in Tiers 1 and 2. To address this issue, EPA will consider statistical information such as the probability of Type I and Type II errors. A Type I error occurs when a false positive conclusion is made, while a Type II error is a false negative conclusion. The acceptability of a specific Type II error is related to the acceptability of false negatives in the particular study being performed. For example, from a toxicological perspective, screening assays often have a relatively high probability of producing false negative ( Type II) outcomes, since some major aspects of organ or tissue toxicity are not being examined. Thus, an acceptable Type II error for screening assays will typically be high. However, the level of Type II error considered acceptable should be tempered by the goal of the study. A higher false negative conclusion ( e. g., Type II error of 0.2) will generally be acceptable if it refers to an effect of minimal severity at a high exposure test level relative to ambient concentration and if few people are likely to be exposed. The converse will also hold true. Scientifically sound statistical analyses are a crucial part of any reliable study and will provide key information for EPA to make judgments on whether or not Tier 3 testing is needed. While it is not feasible to list all possible scenarios and results for each Tier 2 endpoint, the above discussion describes how some of the statistical factors will be incorporated into EPA's decisions. 2. Exposure Assessment The Tier 1 requirements will provide EPA with information on the composition of F/ FA emissions and potential exposures to F/ FA products. This information includes: ( 1) Types and emission rates of speciated emission components, ( 2) possible literature search findings on ambient, occupational, or epidemiological exposures, ( 3) literature information on the potential fate and environmental effects, and ( 4) a qualitative exposure analysis ( submitted by the manufacturer or group) based on the production and use of the F/ FA product( s). As mentioned above, this information will be considered qualitatively by EPA in determining the extent of potential exposures and whether additional testing or analysis is needed to assess risks quantitatively. As discussed earlier, EPA has the authority to require exposure modeling or analysis under Tier 3. Significant public health concerns might sometimes be revealed by the submitted information on product composition, total annual production volume and market distribution data, and emissions data. This might be the case, for example, if there was a significant annual release of emission compounds with known toxicities, or if the anticipated exposures approached or exceeded current estimates of apparently safe levels of known toxicants. In the case of high volume fuels and their associated bulk additives, EPA will generally assume that human and environmental exposures will be of sufficient level and extent that significant observed adverse effects could indicate a need for follow up in Tier 3. This exposure assumption reflects the high production and consumption of these products, either at the present time or as anticipated in the future. Thus, decisions to refer these products to Tier 3 will be based on the degree to which additional testing is needed to clarify the results and potential health effect and environmental implications identified in the previous tiers. On the other hand, it cannot be assumed that fuel additives used in relatively low concentrations or produced in relatively low volumes will automatically be excused from Tier 3. For these products, test results indicative of severe health effects and/ or high exposure levels ( e. g., during consumer use) might be cause for escalation to Tier 3. 3. Health Assessment General criteria for evaluating the potential public health effects associated with fuel and additive emissions will include: ( 1) The number of positive and negative outcomes related to each endpoint, ( 2) the identification of a concentration effect relationship, ( 3) the statistical sensitivity and significance of such studies, ( 4) the severity of the observed effects ( e. g., whether the effects will likely lead to incapacitating or irreversible conditions), and ( 5) the consistency and clarity of apparent mechanisms, target organs, and outcomes. Additional parameters which will influence the decision on whether to require Tier 3 will include: ( 1) The nature and amount of known toxic agents in the emissions stream and ( 2) the observation of lesions which specifically implicate inhalation as an important exposure route for inducing adverse health effects. These criteria will be evaluated in conjunction with the Tier 1 and Tier 2 results to determine whether or not higher level testing is needed. In this decision, both the biological and statistical significance of the Tiers 1 and 2 results will be taken into account. Generally, escalation to Tier 3 may be judged necessary when remaining uncertainties about the significance of observed outcomes and/ or potential exposures interfere with EPA's ability to make reasonable estimates of potential health risks. On the other hand, if no statistically significant effects are obtained at any exposure level in a scientifically sound Tier 2 study ( or existing test submitted in lieu of Tier 2 testing and not contradicted by other published reports of equal or greater reliability), and if other major sources of concern do not arise ( e. g., toxic effects of structurally related compounds), then Tier 3 testing is not likely to be required for the endpoint in question. This discussion assumes that relevant, high quality statistical analyses have been done to permit the negative test results to be properly evaluated and interpreted. The statistical analyses recommended for Tier 2, including determination of Type I and II error ( as discussed in Section IX. B. 1), should enable reasonable conclusions to be drawn as to the significance of negative findings. Factors to be taken into account include the toxicological nature of the findings and the exposure levels used in the test. For example, if the statistical analyses are applied to a    severe'' endpoint ( e. g., major fetal abnormalities, major lung pathology, etc.) and the exposure in question is moderate, then a relatively low Type II error level may be appropriate. In contrast, if a high concentration limit test causes a relatively minor effect ( e. g., a small change in estrous cyclicity), a higher Type II error may be allowed, effectively increasing the chance of false negative conclusions. 4. Evaluation of Tier 2 Results The specific outcomes which will be considered positive and negative results for each Tier 2 test were mentioned briefly in the previous descriptions of Tier 2 requirements ( see Section VIII. B) and are defined and interpreted more precisely in the regulatory text of this final rule. For example, three primary assays ( i. e., Salmonella, MN, and SCE) are included in Tier 2 for the screening of carcinogenicity and mutagenicity. As compared with appropriate controls, a statistically significant concentration related positive response in any one of these assays could be cause for concern, as will be positive outcomes for at least one concentration in two or more of these tests. Such outcomes will be indicative of mutagenic and/ or carcinogenic risk. Positive results will also indicate that the emissions could initiate some of the mechanisms involved in carcinogenesis. However, these results will generally not in themselves be sufficient to determine whether the emissions were in fact carcinogenic because the development of cancer is a multi step process. Depending on the internal and historical consistency of the results and their relationship to projected exposures, further testing might be required to determine the significance of the mutagenic and/ or carcinogenic activity/ risks in human populations exposed by inhalation. In contrast, if no statistically significant results are obtained in the three assays and no conflicting results are found in the literature or in any other Tier 2 tests, then Tier 3 follow up of potential carcinogenic/ mutagenic effects is not likely to be required. To take another example, determination of the need to investigate further reproductive or teratogenic risks will take into account the outcome of the results of the estrous cyclicity measurements, the histopathological evaluation of reproductive organs, the outcome of the fertility screen, and the outcome of the teratogenicity evaluation. If negative results are obtained in the above evaluations ( according to statistically sound principles), and if these results are not refuted by the existing literature, then additional testing is not likely to be required at the Tier 3 level for reproductive or teratogenic effects. Positive results for the teratogenicity study will include a decrease in neonatal viability relative to that in control studies, a significant change in the proportion of viable male versus female fetuses or offspring, the presence of soft tissue or skeletal abnormalities, and an increased rate of embryonic or fetal resorption. Other positive outcomes related to reproductive effects, such as decreased fertility, decreased litter size, abnormal changes in vaginal cytology or reproductive organ histopathology, will be indicative of hazards to the adult reproductive systems. The need for additional evaluation under Tier 3 will depend on the specificity, severity, and consistency of results, the presence or absence of a concentrationeffect relationship, and the significance of these outcomes in view of projected exposures. The greater the remaining uncertainty regarding the risk of reproductive or teratogenic effects after analysis of such factors, the higher will be the likelihood that Tier 3 will be required. Similarly, consistent negative results ( according to statistically sound principles) obtained in other Tier 2 tests, in the absence of significant related concerns raised in the literature, will ( in all likelihood) make Tier 3 unnecessary. If adverse effects are found at Tier 2 and/ or reported in the literature, EPA will determine if Tier 3 follow up is required by attempting to evaluate the nature, severity, and significance of the findings in light of the likely exposures. If EPA determines that Tier 3 testing is required to resolve the remaining uncertainties, the Tier 3 requirements will reflect both positive and negative results. For example, if the results of Tier 2 were positive for pulmonary effects but negative for neurotoxicity ( according to criteria discussed earlier), and if these results were consistent with the literature, only pulmonary toxicity would be a likely candidate for Tier 3 follow up testing.

C. Potential Tier 3 Tests To be most cost effective, Tier 3 testing will be designed to address specific data gaps regarding health effects endpoints of concern or health and environment related issues requiring further analysis. For instance, Tier 3 requirements could potentially include further emission characterization procedures, perhaps involving additional vehicles and/ or more rigorous pre conditioning methods, to identify and quantify harmful emission products with greater precision. Higher order modeling calculations or exposure field studies could be required to resolve uncertainties in the Tier 1 emissions exposure information. Health or welfare effects testing requirements will be aimed at providing sufficient information to make sound conclusions about the degree of health or welfare risk. If more than one endpoint is of concern, EPA will attempt to reduce testing costs by permitting combined protocols insofar as possible. Tier 3 tests for specific endpoints could require the determination of a NOAEL. Depending on the endpoint under evaluation, consideration will be given to including a mid duration examination in the case of chronic inhalation tests. A mid duration evaluation will be useful for affirming the adequacy of exposure levels and, in some cases, might enable interim risk conclusions to be drawn which will avoid the need for further examination. Inhalation studies will generally make use of rodent species, but higher order mammals could be required. While Tier 3 testing requirements will be targeted to critical areas of concern, EPA will also exercise its judgment to avoid the false economy of establishing overly narrow requirements. Just as requirements for too many assays would be wasteful of resources, requirements for too few assays might result in inconclusive findings, creating needs for still further testing at greater total expense than would have been necessary at the start. Similarly, EPA will consider the value of including secondary evaluations as useful and low cost adjuncts to tests already required. For example, if the histopathology of a specified target organ was the primary examination required at the conclusion of an inhalation exposure, other organs could be weighed and saved in storage for a limited time period, at low incremental expense. If indicated, these other organs would then be available for subsequent examination, avoiding the possible need to repeat the chronic inhalation procedures to assess the effects on other organs. Because the specific health testing requirements which will be imposed in Tier 3 will be tailored to individual circumstances, precise test guidelines cannot be provided in advance. However, some examples of testing scenarios which might be required under Tier 3 are cited in Sec. 79.54 in the accompanying regulatory text. Where possible, existing standard guidelines for these tests are referenced. It should be recognized, however, that such guidelines might need to be revised to accommodate emission inhalation requirements and/ or to evaluate certain structures or functions which the current guidelines do not adequately address. Study parameters which might require modification include exposure routes and concentrations, species selection, number of animal subjects, examination procedures and frequencies, and analytic requirements. Furthermore, interim advances in the underlying science and testing technology may provide superior approaches which could be available for use by the time Tier 3 requirements are implemented.

X. Special Provisions The following sections describe special provisions included in the F/ FA registration program to avoid duplication of effort, to alleviate the financial impact on small businesses, and to ease the burdens of the program on the regulated industry in general.

A. Experimental F/ FAs EPA requested comments on the possibility of providing a temporary program exemption or deferment for experimental F/ FAs. Eligibility for this special provision was to be limited to unregistered products ( i. e., F/ FAs which are not registered as of the effective date of this final rule) or registered products that had not been placed into wholesale or retail commerce prior to promulgation of this rule. The regulated industry provided comments questioning the need for a special provision for experimental F/ FAs under this rulemaking because a provision for experimental products already exists under existing registration rules. EPA agrees with the comments received and today's rule relies on existing regulations under 40 CFR 79.4( a)( 3) and 79.4( b)( 2) for the exemption of experimental F/ FAs. 40 CFR section 79.4( a)( 3) exempts fuels used for research, development or testing, and 40 CFR section 79.4( b)( 2) similarly exempts fuel additives. Based on these existing provisions, any designated F/ FA product sold to automobile, engine, or component manufacturers for research, development or test purposes, or sold to automobile manufacturers for factory fill, and not in any case offered for commercial sale to the public, is exempted from the registration requirements of today's rule.

B. Relabeled Products A company's product is registered as    relabeled'' if it is simply a repackaged and rebranded version of a formulation which is already registered by another manufacturer and is procured from that manufacturer for sale or use. Requiring companies which sell relabeled products to conduct the testing program in today's rulemaking would clearly duplicate the efforts of the original manufacturer. Thus, under the authority of CAA section 211( e)( 3)( C), which provides that the Administrator may    exempt any person from such regulations with respect to a particular fuel or fuel additive upon a finding that any additional testing of such fuel or fuel additive would be duplicative of adequate existing testing,'' today's rule includes a special provision exempting relabeled products from the evaluation and testing requirements. For relabeled products, only basic registration information will be required, as described below in Section XII. A. About half of the 4,800 fuel additives registered ( as of March 1994) are relabeled products. Manufacturers of these relabeled products will therefore not be required to comply with the health and welfare effects assessment provisions of the F/ FA registration program.

C. Aerosols Several commenters requested an exemption for aftermarket aerosol additives because of the nature of their mode of application and their low frequency of use. EPA examined available data on aerosol products and concluded that the required testing procedures of this rule are not well suited to this type of product. The evaluation of currently registered additives indicates that aerosols include carburetor cleaners and engine starters that are sprayed into the air intake valve of the engine and are used only intermittently and, even then, for only a very brief period of time ( i. e., a few seconds). Because of their intermittent use and method of use, it is unlikely that their recommended application would affect the overall characteristics of vehicle emissions. Direct exposure to the aerosol product itself is likely to be a more important source of potential hazards than is exposure to its combustion or evaporative emission products. Thus, the evaluation of potential health and welfare effects of aerosols would require a different testing regimen tailored to the specific nature of these products. Today's rule therefore establishes a special provision for aerosols. Manufacturers of aftermarket aerosol additives are required to provide only the basic registration data required for all F/ FA manufacturers ( see Section XII. A), plus a literature survey of existing information on their products and a discussion on the potential exposures. Thus, the standard emission characterization and Tier 2 tests are not required for aerosol products. The literature search ( as described in Section VII. A) must include existing data on potential health and welfare effects on the uncombusted aerosol product as a whole and on the individual components of the product. The analysis of potential exposures should be based on the total annual production volume data and the market distribution of the product, as explained in Section VII. C. EPA will review the submitted information and will determine if there is a need to require testing on a case by case basis. Thus, if testing of an aerosol is prescribed by EPA, the testing is to be performed under Tier 3. Using this approach, EPA will be able to tailor specific tests ( as needed) addressing the particular problems related to aerosol product exposure.

D. Small Business Provisions In the NPRM, EPA requested comments on the possibility of establishing special provisions for small businesses. The regulated industry expressed concerns regarding the costs of the program and the potential impact of the F/ FA regulations on the financial status of small companies. EPA understands that small businesses might be particularly affected by the F/ FA regulations due to their smaller resource base, generally lower rate of representation in trade organizations and, consequently, their potentially limited opportunity to participate in grouping and cost sharing arrangements. In view of these circumstances, EPA is including in today's rule special provisions to alleviate the economic impact of this rule on small manufacturers of F/ FAs, taking into consideration the comments received. EPA examined the distribution of currently registered F/ FA companies across various sales ranges and identified a sales level which will define a    small business'' for the purposes of this rule. A comparison between registered fuel manufacturers and registered additive manufacturers indicates that the distribution across sales ranges is similar for both industries. Each industry appears to be made up of many small companies and relatively few larger companies. Approximately a fifth of registered fuel manufacturers and a third of registered additive manufacturers have sales above $ 100 million. For both industries, most of the companies with sales under $ 100 million tend to cluster under $ 50 million. Thus, within each of the industries, companies tend to cluster above $ 100 million and below $ 50 million in sales. Furthermore, companies with sales below $ 50 million also tend to have sales below $ 10 million, especially within the additive industry. Based on the analysis of F/ FA manufacturers' sales data, EPA identified $ 50 million as a reasonable sales level for differentiating between small and large companies within each industry.\ 60\ As a result, this final rule defines a small business as any motor vehicle fuel or fuel additive manufacturer with total annual sales of less than $ 50 million.\ 61\ The small business provisions established for this rule are defined below.

\ 60\ In cases where subsidiary, divisional, or other complex business arrangements exist, the business entity to which this sales level pertains is the parent company with ultimate ownership. The    ultimate'' parent is defined as the uppermost headquarters or topmost company encompassing all related parents, subsidiaries, divisions, branches, or other operating units. This definition follows that used by the Small Business Administration. It also helps to ensure that companies will not subdivide merely to become eligible for the small business provisions of this program. \ 61\   Total annual sales'' means the average of the manufacturer's sales revenue in each of the previous three years ( i. e., the three years prior to the submittal of the supplemental notification form required under this rule).

Special provisions for small F/ FA companies were developed based on assumptions regarding the degree to which manufacturers will have the opportunity to group with other manufacturers to share costs, and the degree to which information on similar products can be expected to be submitted by larger companies. A review of EPA's registration data base shows that nearly every registered F/ FA manufacturer produces at least one baseline or nonbaseline product. Hence, even if generous special provisions are provided for small manufacturers of these products, EPA is assured that test data on such products will still be submitted by other, larger companies which do not qualify for the special provisions. Therefore, in regard to registration of products in the baseline and non baseline categories, this final rule requires small businesses ( i. e., companies with annual sales less than $ 50 million) to submit only the basic registration data for their baseline and/ or non baseline products. Such companies are not required to meet the Tier 1 and Tier 2 requirements in order to register their baseline and non baseline F/ FAs. Since the larger companies will still be submitting the data for these products, this provision does not compromise EPA's ability to get the necessary information to evaluate the potential health and welfare effects of baseline and non baseline products. The above assumption, however, is not valid in the case of atypical F/ FAs. Analysis of current registrations shows that there are fewer atypical products than baseline products and fewer large companies that produce atypical F/ FAs. Therefore, if the same small business provisions described above for baseline/ non baseline F/ FAs were also applied to atypical F/ FAs, then there would be no data submitted for many atypical F/ FAs. EPA would then be unable to evaluate the health and welfare effects for these atypical products. Nevertheless, EPA realizes that the testing program will be particularly burdensome for very small manufacturers of atypical F/ FAs. In part, this is due to the added compliance requirements for atypical products ( e. g., more rigorous mileage accumulation requirements prior to emission generation ( see Section VI. E) and more extensive emission characterization requirements ( see Section VII. B). An even greater impact results from the fact that grouping opportunities for these manufacturers might be quite limited. Not only do atypical products tend to be unique, but also, the smallest manufacturers rarely are members of the dominant trade associations which are most likely to take the lead in organizing and administering F/ FA group functions. Thus, high program costs could fall on manufacturers with low financial resources and perhaps few opportunities to share the costs. Based on the above reasons, this final rule includes additional special provisions applicable to the atypical F/ FAs of small businesses. However, these provisions apply to fewer manufacturers and are less liberal than those established for baseline and non baseline products. Specifically, for manufacturers of atypical products with less than $ 10 million in annual sales ( rather than the $ 50 million sales level applicable to manufacturers of baseline/ non baseline F/ FAs), the minimal requirements of the program include only basic registration and Tier 1 data. These requirements fall between those applicable to small manufacturers of baseline/ non baseline F/ FAs and the general requirements of the program for larger manufacturers. In summary, manufacturers qualifying for small business special provisions for their baseline and non baseline products ( having less than $ 50 million annual sales) are excused from both Tier 1 and Tier 2 requirements, while small manufacturers qualifying for special provisions for their atypical products ( having less than $ 10 million annual sales) are excused only from Tier 2 requirements for these products. Since small business provisions are based on both the annual sales and the product category, the possibility exists for a manufacturer to have some products excused from program requirements while having to comply with testing requirements for others. For example, an additive manufacturer having both baseline and atypical products and annual sales of $ 30 million can use the special small business provision for the baseline additives, but not for the atypical products. Pursuant to CAA section 211( b), F/ FAs which are excused from any program requirements under these special provisions may still be subject to testing under Tier 3 at EPA's discretion ( on a case by case basis). The Tier 3 testing might include ( but would not be necessarily limited to) information which would otherwise have been required under the provisions of Tier 1 and/ or Tier 2.

XI. Timing and Compliance Requirements The timing and compliance requirements for the F/ FA registration program are dependent on the type of product and the registration status of the product. As discussed in Section III. A of this preamble, both Tier 1 and Tier 2 are mandatory requirements for all F/ FAs ( or groups), except as may be modified by any applicable special provisions. Special provisions affecting the content and/ or timing of these requirements are discussed in Sections VII. A. 3, VIII. D, and X of this preamble. For F/ FAs registered as of the effective date of this rule, Tier 1 data and evidence of a suitable contractual arrangement for satisfactory completion of Tier 2 requirements must be submitted to EPA within three years of the effective date. The results of Tier 2 must be submitted to EPA no later than six years from the effective date. The schedule for completion of any Tier 3 requirements which EPA may prescribe will be determined based on the nature of the particular requirements. The general reporting format for submittal of all of these requirements is described in Section XII. For registrable F/ FAs, i. e., F/ FAs not registered as of the effective date of this rule but meeting the criteria for grouping with a currently registered fuel or bulk additive in the same fuel family, the content and timing of requirements is essentially the same as for the currently registered F/ FAs. Thus, manufacturers of these products will be granted registration and be permitted to market registrable F/ FAs upon EPA's receipt of basic registration data for such products. In contrast, for manufacturers of new F/ FAs ( i. e., F/ FAs that are not currently registered and do not meet the registrable criteria), all testing requirements must be completed prior to registration and introduction into commerce, including Tier 3 when prescribed by EPA. After receipt of Tier 1 and/ or Tier 2 data, EPA will determine whether the submitted information is in compliance with the specified guidelines and whether further testing of a particular fuel or fuel additive is required under the provisions of Tier 3. For registered F/ FAs, EPA intends to determine the adequacy of the submitted data within two years after receipt. However, if EPA is unable to inform the registered manufacturer of the adequacy of the Tier 1 and/ or Tier 2 data within two years after submittal, EPA retains the authority to require that satisfactory data be submitted if, upon subsequent review, EPA finds that the original submittal was inadequate for compliance. In such a case, EPA will not hold the manufacturer liable for penalties for violating this rule from the time period between the date on which the data were due and the date on which EPA informs the responsible manufacturer of a violation. Regarding new F/ FAs, EPA will send a notification of compliance within six months after submission of Tier 1 and Tier 2 data. If the manufacturer of the new F/ FA product does not receive a notification of compliance with Tier 1 and Tier 2 within this time frame, then the manufacturer should assume that the Tier 1 and Tier 2 requirements have been satisfactorily met. EPA's determination of the need for Tier 3 testing for new F/ FAs will occur within six months after EPA notifies the manufacturer of satisfactory compliance with Tier 1 and Tier 2 requirements or within twelve months of the Tier 1 and Tier 2 submittal, whichever occurs first. If Tier 3 testing is deemed necessary, EPA will notify the responsible manufacturer ( or group) by certified letter of the specific Tier 3 requirement( s) along with a schedule for compliance and a deadline for submittal of the Tier 3 report to EPA ( see Section IX. A). This final rule gives the responsible manufacturer ( or group) 60 days to comment on the prescribed Tier 3 requirements, compliance schedule, and submission deadline. In the event that EPA receives no comment within the given period, the manufacturer will be assumed to have consented in full to the prescribed Tier 3 requirements. Compliance with Tier 3 requirements is not optional. Registered ( and registrable) F/ FAs required to undergo Tier 3 testing will retain their registration for that time determined to be necessary for the completion of Tier 3 tests. This registration will be contingent on the satisfactory compliance with the Tier 3 requirements according to a timetable determined by EPA to be appropriate to those requirements. When Tier 3 is prescribed for new F/ FAs ( i. e., those not meeting the registrable criteria), EPA may withhold registration until completion of all testing requirements. For new F/ FAs, EPA will determine whether the Tier 3 requirements have been met within one year of receiving the Tier 3 submittal. If Tier 3 requirements are satisfied, then EPA will send a notification to the manufacturer granting registration to the new F/ FA product. Registration of new F/ FAs will not occur until that time when EPA determines that all Tier 3 requirements have been satisfactorily met. As described above, EPA's review times for data on new F/ FAs are shorter than those for registered F/ FAs. The reason for this discrepancy is that manufacturers of new F/ FAs are barred from marketing such products until EPA approves their compliance with all testing requirements and grants them registration. On the other hand, manufacturers of registered products can maintain their registration, and thus their ability to sell their products, while EPA is reviewing their submitted data. Thus, to ensure that undue hindrance is not created for manufacturers of new products wanting to enter the marketplace, EPA has abbreviated the review times for new F/ FA products. Notwithstanding the granting of a registration ( or continued registration for registered F/ FAs), if EPA determines that a fuel or fuel additive causes or contributes to air pollution that may reasonably be anticipated to endanger the public health or welfare, then EPA could invoke available regulatory authority under CAA section 211( c). Referral to Tier 3 is not required for EPA to begin a regulatory action under 211( c). If additional testing is needed to make up for deficiencies in information content or testing technique/ procedures related to Tier 1, Tier 2, and/ or Tier 3, then the original compliance deadlines will still be in force. Manufacturers of existing products who fail to submit data in the prescribed time frames or who submit data from tests that do not comply with the specified guidelines will be in violation of this rule and will be subject to the penalties specified in CAA section 211( d). According to CAA section 211( d), persons who fail to submit any information or conduct any tests required by the Administrator under CAA section 211( b) shall be liable to the United States for a civil penalty of not more than $ 25,000 for every day of such violation plus the amount of economic benefit or savings resulting from the violation. Each day after the due date for submission of data will constitute a separate day of violation. Civil penalties will be assessed in accordance with CAA sections 205( b) and ( c), which permit EPA to proceed either in court or in an administrative action. If a group of manufacturers commits to performing joint testing, each manufacturer would separately be in violation of the rule. However, the Administrator would retain the authority to remit or mitigate any penalty under CAA section 211( d). In addition to the above penalties, the district courts of the United States have jurisdiction to compel the furnishing of information and/ or the conduct of tests required under CAA section 211( b). This means that, in addition to the financial penalties, persons failing to submit data or comply with the specified guidelines would still need to submit the data originally required. Furthermore, if EPA determines that the data requirements of the rule were not met, EPA could revoke the registration of the fuel( s) or additive( s) in question. Because EPA recognizes that unusual circumstances, outside the control of the manufacturer, may occasionally interfere with the manufacturer's ability to comply with the provisions of the rule, today's rule contains a mechanism to allow manufacturers to request modification of the requirements under some specific circumstances. This special mechanism allows persons who experience unforeseen problems or accidents in conducting the EPA prescribed tests to request modification of the requirements in order to avoid being in violation of the rule. This mechanism would apply to unusual mechanical problems or other unavoidable problems that could arise during the performance of the required tests. The modification requests must be submitted as soon as the manufacturer is aware of the difficulty, but not later than thirty days following the event precipitating the request. Additional details on this special mechanism for modification of requirements is included in the regulatory text of this rule.

XII. Reporting Requirements The materials to be submitted to EPA include the basic registration data, a summary report with Tier 1 and Tier 2 results, and associated appendices. If the results of Tiers 1 and 2 are submitted at the same time, then the summary report must include both Tier 1 and Tier 2 information and associated appendices, as described below. If Tier 1 and Tier 2 results are submitted separately, then two individual reports must be provided to EPA, i. e., Tier 1 report and Tier 2 report. In such a case, each individual report must include the summary information applicable to the respective tier ( including a cover page, executive summary, test substance information, a summary of tier results, conclusions, and associated appendices). If the Tier 2 report for registered F/ FAs is not submitted within three years after the effective date of the final rule, then evidence of a suitable arrangement for completion of Tier 2 ( e. g., a copy of a signed contract with a qualified laboratory to conduct the required Tier 2 tests) must be submitted to EPA prior to that date. F/ FA manufacturers who must conduct additional testing under Tier 3 are required to submit a Tier 3 report when the designated Tier 3 testing is complete. The nature of the information to be included in the basic registration data, reports, and associated appendices is described below.

A. Basic Registration Data The basic information already required for F/ FA registration includes product and manufacturer identification, concentration and purpose in use, and specific compositional data. Today's rule adds the following items to the basic registration data requirements: total annual production volume data, marketing distribution data, notification about group participation, and notification on the use of special provisions ( i. e., relabeled products, aerosols, and small business, as discussed in Section X). Manufacturers of F/ FAs registered as of the effective date of this rule must submit the additional basic registration data items to EPA within six months of that date. Other manufacturers are strongly encouraged to submit the basic registration data prior to starting the evaluation tiers ( i. e., Tier 1, Tier 2, and/ or Tier 3). The production volume information is to be reported in units of gallons per year for F/ FA products that are generally sold in liquid form and kilograms per year for F/ FA products that are generally sold in solid form. For F/ FAs already in production, the submitted figure must reflect the most recent annual period as well as the volume projected to be produced in the third subsequent year. For products not yet in production, the best estimate of expected total production volume during the third year of production must be provided. Market distribution data for each product must also be provided. For fuels and bulk additives, the distribution data must be reported as the percent of total annual sales volume marketed in each Petroleum Administration for Defense District ( PADD), as defined in Sec. 79.59( b)( 3) of this rule. For aftermarket additives, the distribution data must be reported as the percent of total annual sales volume marketed in each state. For products not yet in production, the manufacturer must report projected distribution data by PADD or state, as applicable. Manufacturers of F/ FAs registered as of the effective date of this rule who intend to comply with registration requirements as part of a group must identify the person or entity which is organizing the testing for the applicable group. Similarly, if an applicant is relying on another manufacturer's ( or group's) previous registration materials in compliance with the testing requirements for an unregistered product, then the other manufacturer or group must be identified. In addition, the manufacturer of the unregistered product must provide evidence that the original submitter has been notified and that reimbursement will occur. The basic registration data must be submitted ( or resubmitted) individually for each product being registered, using EPA forms which are in effect at the time of the submittal. This requirement pertains to all F/ FA products registered as of the effective date of this rule, including relabeled products, as well as those for which first time registration is sought after promulgation of this rule. If the basic registration data previously submitted for a currently registered fuel or additive is accurate and complete, then a statement asserting that this is so will suffice in lieu of the submittal of duplicate information. A finding by EPA that this information is not, in fact, accurate and complete as claimed will result in the report being considered inadequate. A fuel manufacturer may at any time modify an existing fuel registration by submitting a request to EPA to add or delete a bulk additive to the existing registration information for such fuel product, provided that any additional additive must be registered by EPA for use in the specific fuel family to which the fuel product belongs. The addition or deletion of a bulk additive to a fuel registration does not necessarily cause the fuel to be considered    new''. However, if the change affects the grouping of such registered fuel, it may affect the testing responsibilities of the fuel manufacturer.

B. Summary Report This report will provide a summary of the evaluation procedures, results, and conclusions, pertaining to Tier 1 and/ or Tier 2 requirements.\ 62\ References used to support Tier 1 and/ or Tier 2 conclusions must be cited in the report. A cover page must be included, identifying the test substance, the manufacturer's name and address, a designated contact person and phone number, and grouping information ( if applicable). The grouping information must identify the group name or grouping criteria, all products and manufacturers to which the report pertains, and the name and address of the responsible organization or entity reporting for the group. The body of the summary report must be divided into the following sections.

\ 62\ These reporting requirements may pertain to separate submittals for Tier 1 and Tier 2 or a single submittal for both tiers, depending on the relative timing of these compliance activities.

1. Executive Summary This section must include a brief description of the general results and conclusions for the tier( s) included in the report ( i. e., Tier 1 and/ or Tier 2), emphasizing information and test data which provide evidence for potential adverse health and/ or welfare effects. 2. Test Substance Information This section must include a detailed test substance description, including ( as applicable) base fuel parameter values or test fuel composition ( if other than base fuel), and test additive composition. The base fuel description must include the types and concentrations of base fuel additive components and values for each of the parameters specified in the base fuel definition for the applicable fuel family. Similar parameter values must be identified for test fuels other than base fuels. 3. Tier 1 Summary This section is intended to provide an overview of Tier 1 analyses. Detailed procedural descriptions, tables, and other outputs are to be included in the appendices. a. Literature Search. The search methods must be described, including the identity of data bases and time periods accessed. Any in house and/ or other unpublished studies included in the literature search must also be described briefly. The results and conclusions of the literature search with respect to potential health and welfare effects of the subject fuel or fuel additive must be summarized. If test documentation provided by the literature search is used to satisfy some or all of the other program requirements, the relevant studies must be discussed and their adequacy to fulfill the specific purposes of the associated program requirements must be justified. Finally, the person( s) or contractors conducting the search are to be identified. b. Emission Generation and Characterization. This section of the summary report must identify the vehicle selected and describe the procedures followed in vehicle/ engine preparation and maintenance and in the generation, storage, and processing of emissions for testing. For group submissions, the report must include a complete description of the group representative used in the generation of emissions. A description of the analytic methods used to characterize the F/ FA emission products must also be provided. Problems encountered in generating and/ or characterizing the emissions must be discussed, including attempts to resolve the problems and their potential effects on testing outcomes. The laboratories performing these procedures must be identified. c. Exposure Analysis. This section must include a qualitative discussion on the potential exposures to the general, area specific, and/ or special at risk population groups based on the production and use of the particular fuel or additive in question. For group submissions, the analysis must consider potential exposures due to all members of the group. When available, EPA recommends the use of existing modeling data to support the exposure analysis. 4. Tier 2 Summary For each study, the objectives, principles, and general procedures must be outlined and the findings and conclusions summarized. Discussion must be included regarding problems encountered during the performance of the tests and the methods used to resolve them. This discussion must include the impact which such problems may have had on the study outcomes. 5. Conclusions Further testing needs must be identified or else a discussion must be provided explaining why the results of Tiers 1 and/ or Tier 2 should not trigger Tier 3 testing requirements.

C. Appendices Detailed information in support of the general discussions contained in the summary report are to be submitted as appendices to the report. In regard to the literature search, the appendices must contain ( 1) summary tables of existing studies regarding health and environmental effects, including such information as the type of study, species/ strain used, exposure concentration( s), duration of study, endpoints evaluated, results ( incidence and statistical significance), and references, ( 2) a complete copy of reference lists and associated abstracts obtained from data base searches ( in printed form or on 3\ 1/ 2\ inch ( IBM compatible) computer diskettes), ( 3) complete documentation of in house studies and other unpublished information sources, and ( 4) complete documentation ( e. g., copies of journal articles) of previous studies which are being cited in satisfaction of Tier 1 and/ or Tier 2 test requirements. Appendices to the emission characterization section must contain detailed protocols, copies of all relevant laboratory reports, a list of all speciated emission products and their emission rates, and documentation and results of calibration/ verification procedures. For the section that discusses potential exposures, an appendix must be provided for detailed background information on the production volume and market distribution data used in the exposure analysis. If exposure models are used, background calculations and/ or model data must also be included in an appendix. An appendix is also required for each of the tests conducted in compliance with Tier 2 requirements. These appendices must contain the full detailed study protocol, complete laboratory report, statistical analysis of the findings, and scientific conclusions. These materials must conform to the reporting requirements of the individual study guidelines as well as the general standards for recordkeeping and reporting specified in the GLP standards of this final rule ( see Sec. 79.60). A final appendix must be provided, containing laboratory certifications and associated personnel credentials.

D. Tier 3 Report Reports for additional tests required under the Tier 3 provisions must include a cover page with identifying information as described above for the Tier 1 and 2 summary report( s). The report must begin with a discussion of the concerns arising under the previous tiers which led to the Tier 3 requirements, the specific objectives of the additional studies, and a summary of pertinent results and conclusions. References used in support of Tier 3 conclusions must be cited in the report. The Tier 3 summary discussion must be supported with appendices containing the kinds of documentation discussed above with respect to Tier 2. The laboratory conducting the required tests must be identified, and relevant certifications and personnel credentials provided.

E. Confidential Business Information CAA section 211( b)( 2)( B) states that the results of tests    conducted in conformity with test procedures and protocols established by the Administrator,'' pursuant to CAA section 211( b)( 2)( A), shall not be considered confidential. Thus, health and welfare information supplied to EPA in compliance with Tier 1, Tier 2, and Tier 3 testing requirements will be made available to the public. Manufacturers ( or groups) claiming business confidentiality on any information submitted under the F/ FA testing program must make a claim of confidentiality in writing at the time of submittal of the reporting requirements. To assert a business confidentiality claim the submitter must clearly mark the confidential information and must submit a separate document setting forth the claim and listing each location at which the confidential information appears in the submitted data. If any person subsequently requests access to the test data submitted under the F/ FA testing program ( other than health and welfare effects information) and such information is subject to a claim of business confidentiality, the request and any subsequent disclosure will be governed by the provisions of 40 CFR part 2.

XIII. Administrative Requirements A. Administrative Designation and Regulatory Analysis Under Executive Order 12866 ( 58 FR 51735), EPA must determine whether the regulatory action is    significant'' and therefore subject to the Office of Management and Budget ( OMB) review and the requirements of the Executive Order. The Order defines    economically significant regulatory action'' as one that is likely to result in a rule that may: ( 1) Have an annual effect on the economy of $ 100 million or more or adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, public health or safety, or State, local, or tribal governments or communities; ( 2) create a serious inconsistency or otherwise interfere with an action taken or planned by another agency; ( 3) materially alter the budgetary impact of entitlements, grants, user fees, or loan programs or the rights and obligations of recipients thereof; or ( 4) raise novel legal or policy issues arising out of legal mandates, the President's priorities, or the principles set forth in the Executive Order. A regulatory support document which presents EPA's analysis of the cost impacts of this final rule is available for review in the public docket ( A 90 07). EPA estimates that the costs to industry for submittal of the requisite data for Tiers 1 and 2 would total approximately $ 66 million, assumed to be incurred over the first threeyear period after promulgation of this final rule. Thus, the average annual cost during this period would be about $ 22 million. In the subsequent three years, Tier 3 requirements might cost an additional $ 1 million annually, per product or group. If ten products or groups were required to conduct Tier 3 testing in the three year period following the initial compliance period, the cost would be $ 10 million per year. These projected overall costs are far less than the $ 100 million annual cost criterion which is a major determinant in defining an    economically significant regulatory action.'' In addition, this final rule is not expected to adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, public health or safety, or State, local, or tribal governments or communities. Although not    economically significant'' based on the above criteria, this final rule is still considered a    significant regulatory action'' pursuant to the terms of Executive Order 12866 and was thus submitted to OMB for review. Any written comments from OMB and any EPA response to OMB's comments are available in the public docket for this rule.

B. Regulatory Flexibility Act Under section 605 of the Regulatory Flexibility Act, 5 U. S. C. 601 et seq., the Administrator is required to assess the economic impact of regulatory actions on small businesses. Accordingly, a Regulatory Flexibility Analysis ( RFA) has been prepared for this rule and is presented as part of the Regulatory Support Document ( available in the public docket). The RFA compares the financial impacts of this rule on small F/ FA manufacturers to the impacts on large F/ FA manufacturers. The analysis explains the small business definition specifically developed in this rule to provide special provisions for small F/ FA manufacturers ( see Section X. D) and assesses the effectiveness of these provisions. This final rule defines a small business as any motor vehicle fuel or fuel additive manufacturer with total annual sales of less than $ 50 million. A comparison of companies classified as small under this definition to those classified as small by the Small Business Administration ( SBA) reveals that the F/ FA program definition classifies a larger number of F/ FA manufacturers as small, and more closely groups companies with similar financial characteristics. Based on this analysis, EPA determined that the small business definition established in this rule is reasonable and applicable to the F/ FA industry. Impacts of this rule on F/ FA manufacturers were determined by projecting the effects of the estimated compliance costs on each company's return on assets ( ROA). In general, a reduction in ROA ( after compliance costs) to less than 2.5 percent is indicative of financial distress. A ROA less than  4 percent indicates that a company is in severe financial distress, and a ROA less than  30 percent generally indicates closure. According to these ROA thresholds, results of the RFA show that approximately 68 unique F/ FA manufacturers ( 43 additive manufacturers, 23 fuel manufacturers, and 2 that produce both fuels and additives) could potentially be pushed into some level of financial distress. All of these companies are classified as small ( i. e., have sales less than $ 50 million). The majority of these companies would fall into the first level of financial distress; however, less than one fifth of them ( 12 companies) would potentially be in danger of closure. In relation to the total population of F/ FA manufacturers, the companies potentially falling into some level of financial distress account to about six percent, with about 1.2 percent potentially in danger of closure. As previously described, this final rule includes two types of special provisions for small businesses. With respect to baseline and non baseline F/ FAs, all small manufacturers ( i. e., annual sales under $ 50 million) are excused from all Tier 1 and Tier 2 testing requirements. A segment of these small manufacturers, i. e., those having sales under $ 10 million, are also excused from Tier 2 testing responsibility for their atypical F/ FAs. Nevertheless, all twelve of the manufacturers who are projected to be in danger of closure as a result of this rule are very small companies with one or more atypical F/ FAs. The RFA analysis shows that the special provision for small manufacturers with atypical products lowers overall compliance costs for 60 such manufacturers by roughly $ 20 million ( as compared with costs that would otherwise occur in the absence of this special provision). Without this provision, an additional 15 manufacturers of atypical products would potentially be pushed into closure. It should be noted that the RFA has assumed no changes in prices, sales, product mix, or financial strategies. In many cases, a portion of regulatory costs can be actually passed on to consumers or back to suppliers. Manufacturers also have the option of reformulating a product to a    baseline'' standard which has much lower compliance costs, or even of dropping products with the greatest cost and smallest profit potential. A more detailed discussion on circumstances which could mitigate compliance cost impacts is provided in the RFA.

C. Recordkeeping Requirements The information collection requirements in this rule have been submitted for approval to OMB under the Paperwork Reduction Act, 44 U. S. C. 3501 et seq. An Information Collection Request document has been prepared by EPA ( ICR # 1696.01) and a copy may be obtained from Sandy Farmer, Information Policy Branch, EPA, 401 M Street SW., Washington, DC 20460 or by calling 202 260 2740. These requirements are not effective until OMB approves them and a technical amendment to that effect is published in the Federal Register. This collection of information has an estimated annual reporting and recordkeeping burden averaging 43 hours per response. These estimates include time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding the burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Chief, Information Policy Branch; EPA; 401 M Street, SW., ( Mail Code 2136); Washington, DC 20460; and to the Office of Information and Regulatory Affairs, Office of Management and Budget, Washington, DC 20503, marked    Attention: Desk Officer for EPA.''

XIV. Electronic Availability of Rulemaking Documents Electronic copies of the preamble, the Regulatory Support Document and Regulatory Flexibility Analysis, the Summary and Analysis of Comments, and the regulations for the Fuels and Fuel Additives Registration rulemaking are available on the Office of Air Quality Planning and Standards ( OAQPS) Technology Transfer Network Bulletin Board System ( TTNBBS). Instructions for accessing TTNBBS and downloading F/ FA files are described below. TTNBBS can be accessed using a dial in telephone line ( 919 541 5742) and a 1200, 2400, or 9600 bps modem ( equipment up to 14.4 Kbps can be accommodated). The parity of the modem should be set to N or none, the data bits to 8, and the stop bits to 1. When first signing on to the bulletin board, the user will be required to answer some basic informational questions to register into the system. After registering, proceed through the following options from a series of menus:

( M) OMS ( K) Rulemaking and Reporting ( 3) Fuels ( 4) Fuels/ Fuel Additives A list of   . ZIP'' files will be displayed, all of which relate to the Fuels and Fuel Additives Registration rulemaking. The four documents listed will be in the form of   . ZIP'' files and are identified by the following titles:

   FFA PRE. ZIP'' ( Preamble)    FFA RSD. ZIP'' ( Regulatory Support Document and Regulatory Flexibility Analysis)    FFA COM. ZIP'' ( Summary and Analysis of Comments)    FFA REG. ZIP'' ( Regulations)

File information can be obtained from the    READ. ME'' file. Choose from the following options when prompted:

< D> ownload, < P> rotocol, < E> xamine, < N> ew, < L> ist, < H> elp or < ENTER> to exit.

To download a file, e. g., < D> filename. ZIP, the user needs to choose a file transfer protocol appropriate for the user's computer from the options listed on the terminal. The user's computer is then ready to receive the file by invoking the user's resident file transfer software. Programs and instructions for de archiving compressed files can be found under < S> ystems Utilities from the top menu, under < A> rchivers/ de archivers. TTNBBS is available 24 hours a day, 7 days a week except Monday morning from 8 12 EST, when the system is down for maintenance and backup. For help in accessing the system, call the systems operator at 919 541 5384 in Research Triangle Park, North Carolina, during normal business hours EST.

List of Subjects in 40 CFR Part 79 Environmental protection, Fuel additives, Fuels, Gasoline, Incorporation by reference, Motor vehicle pollution, Penalties, Reporting and recordkeeping requirements.

Dated: May 27, 1994. Carol M. Browner, Administrator.

Part 79 of title 40 of the Code of Federal Regulations is amended as follows: 1. The authority citation for part 79 is revised to read as follows:

Authority: 42 U. S. C. 7414, 7524, 7545 and 7601.

2. Section 79.2 is amended by revising paragraphs ( d), ( e), and ( f) to read as follows:

Sec. 79.2 Definitions. * * * * * ( d) Fuel manufacturer means any person who, for sale or introduction into commerce, produces, manufactures, or imports a fuel or causes or directs the alteration of the chemical composition of, or the mixture of chemical compounds in, a bulk fuel by adding to it an additive. ( e) Additive means any substance that is intentionally added to a fuel named in the designation ( including any added to a motor vehicle's fuel system) and that is not intentionally removed prior to sale or use. ( f) Additive manufacturer means any person who produces, manufactures, or imports an additive for use as an additive and/ or sells or imports for sale such additive under the person's own name. * * * * * 3. Section 79.3 is revised to read as follows:

Sec. 79.3 Availability of information.

The availability to the public of information provided to, or otherwise obtained by, the Administrator under this part shall be governed by part 2 of this chapter except as expressly noted in subpart F of this part. 4. Section 79.4 is amended by revising paragraph ( b)( 1) to read as follows:

Sec. 79.4 Requirement of registration.

* * * * * ( b) Additives. ( 1) No manufacturer of any fuel additive designated under this part shall, after the date by which the additive must be registered under this part, sell, offer for sale, or introduce into commerce such additive for use in any type of fuel designated under this part unless the Administrator has registered that additive for use in that type of fuel. * * * * * 5. Section 79.6 is revised to read as follows:

Sec. 79.6 Requirement for testing.

Provisions regarding testing that is required for registration of a designated fuel or fuel additive are contained in subpart F of this part. 6. Section 79.10 is revised to read as follows:

Sec. 79.10 Application for registration by fuel manufacturer.

Any manufacturer of a designated fuel who wishes to register that fuel shall submit an application for registration including all of the information set forth in Sec. 79.11. If the manufacturer produces more than one grade or brand of a designated fuel, a manufacturer may include more than one grade or brand in a single application, provided that the application includes all information required for registration of each such grade or brand by this part. Each application shall be signed by the fuel manufacturer and shall be submitted on such forms as the Administrator will supply on request. 7. Section 79.11 is amended by revising the introductory text of the section, removing the period in paragraph ( h) and adding a semicolon and paragraphs ( i) and ( j) to read as follows:

Sec. 79.11 Information and assurances to be provided by the fuel manufacturer.

Each application for registration submitted by the manufacturer of a designated fuel shall include the following: * * * * * ( i) The manufacturer of any fuel which will be sold, offered for sale, or introduced into commerce for use in motor vehicles manufactured after model year 1974 shall demonstrate that the fuel is substantially similar to any fuel utilized in the certification of any 1975 or subsequent model year vehicle or engine, or that the manufacturer has obtained a waiver under 42 U. S. C. 7545( f)( 4); and ( j) The manufacturer shall submit, or shall reference prior submissions, including all of the test data and other information required prior to registration of the fuel by the provisions of subpart F of this part. 8. Section 79.12 is revised to read as follows:

Sec. 79.12 Determination of noncompliance.

If the Administrator determines that an applicant for registration of a designated fuel has failed to submit all of the information required by Sec. 79.11, or determines within the applicable period provided for Agency review that the applicant has not satisfactorily completed any testing which is required prior to registration of the fuel by any provision of subpart F of this part, he shall return the application to the manufacturer, along with an explanation of all deficiencies in the required information. 9. Section 79.13 is amended by revising paragraph ( a) to read as follows:

Sec. 79.13 Registration.

( a) If the Administrator determines that a manufacturer has submitted an application for registration of a designated fuel which includes all of the information and assurances required by Sec. 79.11 and has satisfactorily completed all of the testing required by subpart F of this part, the Administrator shall promptly register the fuel and notify the fuel manufacturer of such registration. * * * * * 10. Section 79.20 is revised to read as follows:

Sec. 79.20 Application for registration by additive manufacturer.

Any manufacturer of a designated fuel additive who wishes to register that additive shall submit an application for registration including all of the information set forth in Sec. 79.21. Each application shall be signed by the fuel additive manufacturer and shall be submitted on such forms as the Administrator will supply on request. 11. Section 79.21 is amended by revising the introductory text of the section and paragraph ( d) and adding paragraphs ( h) and ( i) to read as follows:

Sec. 79.21 Information and assurances to be provided by the additive manufacturer.

Each application for registration submitted by the manufacturer of a designated fuel additive shall include the following: * * * * * ( d) The specific types of fuels designated under Sec. 79.32 for which the fuel additive will be sold, offered for sale, or introduced into commerce, and the fuel additive manufacturer's recommended range of concentration and purpose in use for each such type of fuel. * * * * * ( h) The manufacturer of any fuel additive which will be sold, offered for sale, or introduced into commerce for use in any type of fuel intended for use in motor vehicles manufactured after model year 1974 shall demonstrate that the fuel additive, when used at the recommended range of concentration, is substantially similar to any fuel additive included in a fuel utilized in the certification of any 1975 or subsequent model year vehicle or engine, or that the manufacturer has obtained a waiver under 42 U. S. C. 7545( f)( 4). ( i) The manufacturer shall submit, or shall reference prior submissions, including all of the test data and other information required prior to registration of the fuel additive by the provisions of subpart F of this part. 12. Section 79.22 is revised to read as follows:

Sec. 79.22 Determination of noncompliance.

If the Administrator determines that an applicant for registration of a designated fuel additive has failed to submit all of the information required by Sec. 79.21, or determines within the applicable period provided for Agency review that the applicant has not satisfactorily completed any testing which is required prior to registration of the fuel additive by any provision of subpart F of this part, he shall return the application to the manufacturer, along with an explanation of all deficiencies in the required information. 13. Section 79.23 is amended by removing paragraph ( b), by redesignating paragraph ( c) as paragraph ( b), and by revising paragraph ( a) to read as follows:

Sec. 79.23 Registration.

( a) If the Administrator determines that a manufacturer has submitted an application for registration of a designated fuel additive which includes all of the information and assurances required by Sec. 79.21 and has satisfactorily completed all of the testing required by subpart F of this part, the Administrator shall promptly register the fuel additive and notify the fuel manufacturer of such registration. * * * * * 14. Section 79.31 is amended by revising paragraph ( b) to read as follows:

Sec. 79.31 Additives.

* * * * * ( b) All designated additives must be registered by July 7, 1976. * * * * * 15. A new subpart F, consisting of Secs. 79.50 79.68, is added to part 79 to read as follows:

Subpart F Testing Requirements for Registration Sec. 79.50 Definitions. 79.51 General requirements and provisions. 79.52 Tier 1. 79.53 Tier 2. 79.54 Tier 3. 79.55 Base fuel specifications. 79.56 Fuel and fuel additive grouping system. 79.57 Emission generation. 79.58 Special provisions. 79.59 Reporting requirements. 79.60 Good laboratory practice ( GLP) standards for inhalation exposure health effects testing. 79.61 Vehicle emissions inhalation exposure guideline. 79.62 Subchronic toxicity study with specific health effect assessments. 79.63 Fertility assessment/ teratology. 79.64 In vivo micronucleus assay. 79.65 In vivo sister chromatid exchange assay. 79.66 Neuropathology assessment. 79.67 Glial fibrillary acidic protein assay. 79.68 Salmonella typhimurium reverse mutation assay.

Subpart F Testing Requirements for Registration Sec. 79.50 Definitions.

The definitions listed in this section apply only to subpart F of this part. Additive/ base fuel mixture means the mixture resulting when a fuel additive is added in specified proportion to the base fuel of the fuel family to which the additive belongs. Aerosol additive means a chemical mixture in aerosol form generally used as a motor vehicle engine starting aid or carburetor cleaner and not recommended to be placed in the fuel tank. Aftermarket fuel additive means a product which is added by the end user directly to fuel in a motor vehicle or engine to modify the performance or other characteristics of the fuel, the engine, or its emissions. Atypical element means any chemical element found in a fuel or additive product which is not allowed in the baseline category of the associated fuel family, and an    atypical fuel or fuel additive'' is a product which contains such an atypical element. Base fuel means a generic fuel formulated from a set of specifications to be representative of a particular fuel family. Basic emissions means the total hydrocarbons, carbon monoxide, oxides of nitrogen, and particulates occurring in motor vehicle or engine emissions. Bulk fuel additive means a product which is 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. Emission characterization means the determination of the chemical composition of emissions. Emission generation means the operation of a vehicle or engine or the vaporization of a fuel or additive/ fuel mixture under controlled conditions for the purpose of creating emissions to be used for testing purposes. Emission sampling means the removal of a fraction of collected emissions for testing purposes. Emission speciation means the analysis of vehicle or engine emissions to determine the individual chemical compounds which comprise those emissions. Engine Dynamometer Schedule ( EDS) means the transient engine speed versus torque time sequence commonly used in heavy duty engine evaluation. The EDS for heavy duty diesel engines is specified in 40 CFR part 86, appendix I( f)( 2). Evaporative Emission Generator ( EEG) means a fuel tank or vessel to which heat is applied to cause a portion of the fuel to evaporate at a desired rate. Evaporative emissions means chemical compounds emitted into the atmosphere by vaporization of contents of a fuel or additive/ fuel mixture. Evaporative fuel means a fuel which has a Reid Vapor Pressure ( RVP, pursuant to 40 CFR part 80, appendix    E'') of 2.0 pounds per square inch or greater and is not supplied to motor vehicle engines by way of sealed containment and delivery systems. Evaporative fuel additive means a fuel additive which, when mixed with its specified base fuel, causes an increase in the RVP of the base fuel by 0.4 psi or more relative to the RVP of the base fuel alone and results in an additive/ base fuel mixture whose RVP is 2.0 psi, or greater. Excluded from this definition are fuel additives used with fuels which are supplied to motor vehicle engines by way of sealed containment and delivery systems. Federal Test Procedure ( FTP) means the body of exhaust and evaporative emissions test procedures described in 40 CFR 86 for the certification of new motor vehicles to Federal motor vehicle emissions standards. Fuel family means a set of fuels and fuel additives which share basic chemical and physical formulation characteristics and can be used in the same engine or vehicle. Manufacturer means a person who is a fuel manufacturer or additive manufacturer as defined in Sec. 79.2 ( d) and ( f). Nitrated polycyclic aromatic hydrocarbons ( NPAH) means the class of compounds whose molecular structure includes two or more aromatic rings and contains one or more nitrogen substitutions. Non catalyzed emissions means exhaust emissions not subject to an effective aftertreatment device such as a functional catalyst or particulate trap. Oxygenate compound means an oxygen containing, ashless organic compound, such as an alcohol or ether, which may be used as a fuel or fuel additive. Polycyclic aromatic hydrocarbons ( PAH) means the class of hydrocarbon compounds whose molecular structure includes two or more aromatic rings. Relabeled additive means a fuel additive which is registered by its original manufacturer with EPA and is also registered and sold, unchanged in composition, under a different label and/ or by a different entity. Semi volatile organic compounds means that fraction of gaseous combustion emissions which consists of compounds with greater than twelve carbon atoms and can be trapped in sorbent polymer resins. Urban Dynamometer Driving Schedule ( UDDS) means the 1372 second transient speed driving sequence used by EPA to simulate typical urban driving. The UDDS for light duty vehicles is described in 40 CFR part 86, appendix I( a). Vapor phase means the gaseous fraction of combustion emissions. Vehicle classes/ subclasses means the divisions of vehicle groups within a vehicle type, including light duty vehicles, light duty trucks, and heavy duty vehicles as specified in 40 CFR part 86. Vehicle type means the divisions of motor vehicles according to combustion cycle and intended fuel class, including, but not necessarily limited to, Otto cycle gasoline fueled vehicles, Otto cycle methanol fueled vehicles, diesel cycle diesel fueled vehicles, and diesel cycle methanol fueled vehicles. Whole emissions means all components of unfiltered combustion emissions or evaporative emissions. Sec. 79.51 General requirements and provisions.