A 99 02 IV D 01 Responses to Significant Comments on the Proposed Revision to the Definition of Volatile Organic Compounds  Exclusion of t Butyl Acetate 64 FR 52731, September 30, 1999 Docket Number OAR 2003 0084 U. S. Environmental Protection Agency October 26, 2004 2 This document, along with the notice of final rulemaking, presents the response of the Environmental Protection Agency ( EPA) to significant public comments received on the proposed rule making entitled " Revision to Definition of Volatile Organic Compounds  Exclusion of t Butyl Acetate" published Thursday, September 30, 1999 ( 64 FR 52731). The responses presented in this document are intended to augment the responses to comments that appear in the notice of final rulemaking. The full text of the comments referred to in this document is located in the docket for this action, which has docket number OAR 2003 0084 ( legacy docket A 99 02). This docket is located at the Air and Radiation Docket and Information Center ( 6102), U. S. Environmental Protection Agency, 1200 Pennsylvania Avenue, NW, Washington, DC 20460.

Comments have been summarized by the EPA below, followed by EPA response. Comments on a particular subject have been grouped together. Individual comments or groups of similar comments are numbered consecutively here for easy referral. Often the same or similar comment was made by several commenters. The name of commenters associated with particular comments are given in the summary of comments below. The number beside the commenter's name is the document number placed by EPA on the comment letter when it was logged into the docket.

The Overall Intent of the Exemption Policy Comment 1. The primary purpose of an exemption policy should be to encourage replacement of current emissions with emissions of compounds with lower adverse environmental impacts for applications where elimination of emissions is not feasible. [ W. P. L. Carter ( II D 15)]. The EPA should adopt as a general policy the expansion of VOC delisting opportunities for negligibly reactive compounds to encourage substitution of highly reactive compounds. The use of a molar comparison with ethane would prevent EPA from exempting more compounds. This would impede substitution of less reactive compounds for more reactive compounds. Restricting the availability of the exemption would not encourage pollution prevention. [ The Aluminum Association of America ( II D 17)]. The EPA should design VOC listing criteria to minimize ozone formation by encouraging use of compounds that would displace materials already in use that have higher propensity for ozone formation. [ Penreco and Printing Industries of America ( IID 18)]. The proposed change to per mole basis will actually impair efforts to improve air quality by limiting the number of exempt compounds and reducing opportunities for product formulators to use lower reactivity compounds in place of highly reactive VOCs [ Chemical Manufacturers Association ( II D 28)]. The EPA should eventually move toward a solvent substitution policy based on individual VOC reactivities [ Eastman Chemical Company ( II D 31)].

Response: One of the most pervasive themes in the comments received is the contention that EPA should move to a solvent substitution program whose purpose should be to encourage substitution of lower reactive compounds for higher reactive compounds. The intent of EPA's current VOC exemption policy, however, is to avoid placing an undue regulatory burden on the use of compounds that do not significantly contribute to the formation of harmful concentrations of ozone. Once a compound is exempted, emissions of the compound may increase significantly 3 due to substitution and new uses of the compound. Because these potential increases are exempt from control, it is important that the compounds be negligibly reactive and not simply marginally less reactive than compounds that they may replace. If by exempting negligibly reactive compounds EPA encourages the substitution of negligibly reactive compounds for highly reactive compounds, this is an added benefit.

EPA is currently evaluating a variety of scientific, legal, and practical issues associated with the design and implementation of a policy to encourage further substitution, such as the use of VOC reactivity scales. To address these issues, EPA is working with the State of California and the Reactivity Research Working Group, a government/ industry/ academic working group established under NARSTO ( formerly the North American Research Strategy for Tropospheric Ozone) to identify research priorities related to VOC reactivity. The results of these efforts will be considered by EPA as part of a multi year review of our current VOC policy and addressed through future rulemakings.

Mass v. Molar Basis for Comparison of VOCs Comment 2. The ideal basis for making comparisons for VOC exemption decisions would be atmospheric impact per unit of use in production or economic activity. It is difficult to do this directly since it would depend on the application involved. The best one could do would be to provide the best approximation to the impact of use. Solvents will often be substituted on a volume basis. The volume basis would be better approximated by mass than by moles [ W. P. L. Carter ( II D 15)].

Response: In concept, the idea of comparing environmental impact when substituting a volume of a lower reactivity compound for an equal volume of a higher reactivity compound on a per unit of production basis is a good one. This might conceivably occur in a paint or coating where a volume of solvent in a can of paint is removed and replaced by an equal volume of another solvent which has lower reactivity. However, a VOC exemption policy is not the same thing as a VOC substitution policy. With an exemption, there is no guarantee that exempted compounds will only be used to substitute for equal volumes of non exempt compounds. In fact, to many people, one of the attractive features of an exemption is that it will allow more use of a compound in a coating than would be allowed ordinarily under reasonably available control technology ( RACT) rules. Currently, State laws limit the VOC content of coatings to certain limits usually expressed as total pounds of VOC per gallon of coating or as pounds of total VOC per gallon of coatings solids. However, an exempt compound is not subject to these VOC limitations and larger amounts of the exempt compound can be added to a coating. Therefore, while a compound with lower reactivity may be substituted for a higher reactivity non exempt VOC, the substitution may not be made at equal volumes. In other words, the manufacturer may use a far larger amount of an exempt compound. Equal substitution per unit of production cannot be assumed to occur when a compound is exempted, unless additional regulations were to be enacted to limit use of the exempted solvent. The EPA is deferring further consideration of the mole versus gram issue until it can reexamine its exemption policy as a whole. 4 Comment 3. Since emissions are regulated on a mass basis, reactivity characterization must be consistent with the mass basis to promote environmental progress [ The Aluminum Association of America ( II D 17)]. The per gram comparison basis is the only proactive way to measure both reactivity of organic compounds and their emissions. [ The Chemical Manufacturers Association ( II D 28)].

Response: There is no reason why these two very different things ( i. e., compound reactivity and volume of emissions) need to be considered on the same basis. Emissions from products and industrial processes are easily measured on a weight basis, and it is appropriate to regulate these on a basis of mass of emissions. Reactivity involves chemical reactions for which calculations are of necessity made by chemists on a mole basis. In the chemical industry, theoretical yields from chemical reactions are routinely calculated using moles, and the manufactured chemicals are then sold by weight. There is no contradiction in this. For practical reasons, EPA and States regulate VOCs on a weight basis. However, EPA is working with the State of California and the RRWG to evaluate other methods of regulating VOC emissions, such as through the use of VOC reactivity scales. As EPA considers the future use of exemptions and reactivity scales, EPA is deferring further consideration of the most appropriate metrics for exemptions until it can reexamine its exemption policy as a whole. For a further explanation of the use of the mole basis for reactivity calculations see the paper " Scientific Basis of an Improved EPA Policy on Control of Organic Emissions for Ambient Ozone Reduction," Basil Dimitriades, Journal of the Air and Waste Management Association, volume 49, page 821  838, July 1999. A copy of this article has been added to the docket.

Comment 4. Ozone formation in the atmosphere is determined more by the overall mass of organic compounds in the atmosphere than the molar reaction rate of a single compound. Controlling the mass of organic carbon compounds would lower the ozone level to a greater extent [ than looking at molar reactivity of individual compounds.] [ Penreco and Printing Industries of America ( II D 18)].

Response: Ozone formation is determined by both the molar reactivities of the individual compounds and their total mass in the air. The EPA's current reactivity policy is to limit as much as is practical the total mass of emissions to the atmosphere of all volatile organic compounds regardless of reactivity of individual compounds ( although exempting negligibly reactive compounds) since they all contribute to ozone formation to some degree. In cases where additional mass based control measures are technologically infeasible but further control is needed, EPA is evaluating the potential for using reactivity scale based control measures or other measures to encourage VOC substitution to further decrease ozone formation.

Comment 5. If the EPA does go to a per mole basis, this should not apply to compounds ( such as acetone) which have already been exempted. [ Chemical Manufacturers Association ( Including comments by the Solvents Council and the Acetone Panel) ( II D 27)].

Response: To date there has been only one exemption, that of acetone, which EPA granted 5 solely on a mass comparison basis. The EPA stated in the September 30, 1999 proposal that at this time we have no intention of revisiting that exemption. However since EPA is not changing its policy regarding gram versus mole with this final notice, the issue is not presented here.

Comment 6. A commenter denies that per mole comparisons are the " proper scientific basis" for determining VOC reactivity exemptions. [ W. P. L. Carter, ( II D 15)]. Other commenters support the use of the " per gram" basis rather than the " per mole basis" for determining VOC exemptions [ The Aluminum Association ( II D 17), Penreco and printing Industries of America, ( II D 18), Chemical Specialities Manufacturers Association ( II D 23) Lyondell ( II D 25), Union Carbide Corporation ( II D 27), Chemical Manufacturers Association ( II D 28) ]. Another commenter says various scientists suggest both mole and gram bases may have scientific merit ( Exxon Chemical Company ( II D 16)].

Response: With this action, EPA is not finalizing a decision that only molar comparisons are acceptable or valid. In large part, EPA's argument for using a mole based comparison to compare the reactivity of a compound to that of ethane for the purpose of exemption decisions is based on smog chamber experiments which were conducted in the 1970s. These experiments were done by comparing ozone produced by equal molar volumes of compounds in a smog chamber. It is these experiments that led to ethane being exempted. More information about the original basis for the ethane exemption is given in the paper " Scientific Basis of an Improved EPA Policy on Control of Organic Emissions for Ambient Ozone Reduction," Basil Dimitriades, Journal of the Air and Waste Management Association, volume 49, page 821  838, July 1999. A copy of this article has been added to the docket.

Comment 7. The EPA's primary argument for using mole based comparisons when making exemption decisions is that mole based substitutions were used in the smog chamber experiments that were used as the basis for EPA's 1977 policy judgment that ethane has " negligible" ozone reactivity [ W. P. L. Carter ( II D 15)]. The chamber studies used for the initial ethane exemption do not provide a scientific basis to justify a switch to a mole basis [ Chemical Manufacturers Association ( II D 28)]. The original chamber studies which identified ethane for exemption are out of date and should not be used for policy making now. According to this commenter, an EPA scientist has acknowledged this in a recent paper. The commenter claims that there are a number of reasons that the original studies are now considered flawed. The original chamber studies indicate propane, not ethane, should be the bench mark for determining whether a compound should be classified as negligibly reactive. The national ambient air quality standard on which the studies were based was considerably more stringent than the current ozone standard. [ Chemical Manufacturers Association ( II D 28), comment on propane also made by Halogenated Solvents Industry Alliance, Inc. ( II D 26)]. Only a single compound was used, whereas modern chambers use multi components to evaluate synergistic effects. [ W. P. L. Carter ( II D 15), Eastman Chemical Company ( II D 31)]. The small chamber used may have had significant wall effects that could have led to high ozone readings. [ Eastman Chemical Company ( II D 31)].

Response: A main part of EPA's argument in the proposal for using a mole based comparison to 6 compare the reactivity of a compound to that of ethane for the purpose of exemption decisions was based on the smog chamber experiments which were conducted in the 1970s. This series of experiments used equi molar amounts of compounds and determined which of those showed ozone concentrations in the chamber of 0.08 ppm., the then current national ambient standard for oxidants. Ethane, which resulted in ozone levels below this limit, was later judged to be negligibly reactive in the 1977 policy statement. Propane, which gave ozone yields right at 0.08 ppm, and compounds which gave higher ozone yields were not judged to be negligibly reactive in the 1977 policy.

If this experiment were repeated today, it might be done somewhat differently. For instance, modern chambers use multi component mixtures to evaluate synergistic effects. Such multi pollutant mixtures would likely give higher ozone yields, so it is not obvious what the results would be. The size of the chamber may have contributed to wall effects that could have influenced the results. Likewise, the ozone ambient air quality standard has been changed since these runs were made. Nevertheless, these chamber runs were conducted according to acceptable procedures in use at the time. The EPA has no reason to reject these experimental results as an influence on our current policy, which has been in effect since 1977.

Comment 8. Several comments state that there should be no change in the EPA's exemption policy until the EPA has had a chance to complete its overall review of reactivity policy and determine whether broader policy changes are needed. [ W. P. L. Carter ( II D 15), Exxon Chemical Company ( II D 16), Chemical Manufacturers Association ( II D 28), The Aluminum Association of America ( II D 17), Penreco and Printing Industries of America ( II D 21), Eastman Chemical Company ( II D 31)]. Another commenter believes further refinement of the regulatory system in terms of reactivity should await more definitive understanding of reactivity issues. During the interim, the mass based standard should be continued [ National Paint and Coatings Association ( II D 22)]. Some commenters said the EPA should wait until the Reactivity Research Working Group ( RRWG) completes its research program before making a policy change with regard to VOC exemption decisions. [ The Aluminum Association of America ( II D 17), Penreco ( II D 18)].

Response: The EPA has decided to postpone deciding the issue of the gram versus mole basis for reactivity comparisons with ethane for VOC exemptions until further consideration can be given by EPA to the issue. Therefore the exemption of t butyl acetate ( TBAC) as a VOC in this final rule is based on policy existing before the September 30, 1999 proposal.

Comment 9. The molar comparison basis makes exemption of higher molecular weight compounds more difficult. [ W. P. L. Carter ( II D 15)] The per mole basis will penalize heavier molecular weight compounds [ The Aluminum Association of America ( II D 17), Penreco and Printing Industries of America ( II D 18), Chemical Manufacturers Association ( II D 28)]. One commenter recommends that using carbon number or amount ( by weight) of carbon, and discounting heavy substitutes such as chlorine or oxygen, would be a more suitable method to measure reactivity. [ Penreco and Printing Industries of America ( II D 18)]. Another comment 7 points out that heavier, higher molecular weight compounds are less likely to remain in the atmosphere. The commenter says that EPA recognized this distinction in the § 183( e) Consumer Product rule [ in 40 CFR 59.209] which does not apply to less volatile products (< 0.1 mm Hg., boiling point > 421

F, carbon number > 12.) [ Penreco and Printing Industries of America ( II D 18)].

Response: Some high molecular weight compounds have been found in the vapor state in the atmosphere. For example alkanes with carbon numbers as high as C28 have been measured in the atmosphere. A weight basis for exemption may favor such heavy compounds if the weight increases more rapidly than the photochemical reactivity does. One example of this is halogenated compounds with chlorine or bromine atoms, which are very heavy. A molecule of such a compound may have a similar photochemical reactivity to an alkane molecule which has the same number of carbon atoms, but without the heavy halogen atom. The compounds may have similar reactivity per molecule or mole, but the heavy halogenated compound will have a much lower reactivity per gram, since it is so heavy. The idea of considering reactivity per carbon atom which one commenter suggests would reduce the problem of lowering reactivity per gram by adding a heavy atom to the molecule. Reactivity per carbon atom would tend to give more equal treatment to compounds. This idea might have some merit, but EPA has not examined all the implications of such an approach and is not ready to adopt such an approach at this time. The fact that EPA Consumer Product rule does not regulate organic compounds below 0.1 mm Hg vapor pressure does not bear on the VOC exemption issue. This vapor pressure exemption is solely for the purpose of implementing this particular rule, and the rule itself states unequivocally that this exemption is not intended to modify EPA definition of VOC. Incidently, the Consumer Product rule does not have a boiling point > 421

F exemption as indicated by the comment.

As stated above, the EPA has decided, based on comments received, that the issue of gram versus mole basis is sufficiently complex to warrant further consideration. The EPA is making no policy change regarding a gram versus mole basis with this final rule for the TBAC exemption.

Comment 10. Dr. William Carter refers to the 1977 experiments as being EPA's main argument for using a mole based approach, since these experiments were on an equi mole basis. He said EPA gave no justification as to why a mole based rather than a mass based substitution was used in these experiments. An appropriate way to deal with this ( short of re doing the study) is to make appropriate corrections to the data so that their policy implications can be properly interpreted. Ethane has a molecular weight that is approximately 2.3 times lower than the average of all VOCs measured in ambient air. This means that had the substitutions in the chamber experiments been done on a mass basis, the amount of ethane added should have been 2.3 times higher that the amount they actually used. If it is assumed that the amount of O 3 formed in the experiments is approximately proportional to the amount of VOC added, then a compound that is 2.3 times less reactive than ethane should form about the same amount of O 3 in a mass based substitution experiment as ethane did in a mole based experiment. In other words, the data from the 1977 study could be used to support a mass based exemption standard only with the reactivity 8 borderline being reduced by a factor of 2.3. [ W. P. L. Carter ( II D 15)].

Response: It is worth considering whether, to most appropriately use the reactivity criteria established in the 1977 experiments, the molar based borderline should remain as ethane, but the weight based borderline should be different. As discussed in response to Comment 7, there are a variety of aspects of the 1977 experiments and the interpretation of their results that could be reconsidered. EPA believes that these issues should be considered together as part of a broader review of the use of exemptions and reactivity metrics.

This issue is discussed further in the paper " Scientific Basis of an Improved EPA Policy on Control of Organic Emissions for Ambient Ozone Reduction," Basil Dimitriades, Journal of the Air and Waste Management Association, volume 49, page 821  838, July 1999. A copy of this article has been added to the docket.

Comment 11. The molar comparison is the proper scientific basis and EPA should not continue to use the per gram comparison basis. [ The Institute of Clean Air Companies ( II D 12), Occidental Chemical Corporation ( II D 29), James C. Berry ( II D 30), Institute for Research and Technical Assistance ( II D 33)].

Response: Several commenters agreed with EPA's position in the proposal notice that the mole comparison is the most appropriate basis for comparing reactivities to ethane for the purpose of granting exemptions. All the commenters who opposed the TBAC exemption favor the per mole comparison basis. Most, if not all, of the commenters who favor the TBAC exemption think the per gram basis should be used. As stated above, EPA is deferring issuing a policy change on the gram versus mole issue at this time and is using the policy which was in effect prior to the September 30, 1999 proposal. Based upon the issues raised by commenters, EPA plans to reexamine the question of the proper basis for comparison in conjunction with a larger reappraisal of EPA's exemption policy.

Comment 12. TBAC reactivity on a molar basis is 1.5 times that of ethane. The difference is significant. Why is this not given more emphasis? [ James C. Berry ( II D 30)].

Response: The EPA is using the per gram basis to evaluate the TBAC exemption petition, in accordance with current policy. On a per gram basis, TBAC is less reactive than ethane.

Comment 13. Historically, EPA has evaluated a chemical's reactivity by looking at the hydroxyl radical reaction rate constant, k OH . The k OH of TBAC and ethane are 4.4 x 10 13 cm3/ molecule sec and 2.7 x 10 13 cm3/ molecule sec, respectively. By this standard, TBAC is more reactive than ethane. [ Occidental Chemical Corporation ( II D 29)].

Response: Historically, EPA has evaluated a chemical's reactivity by looking at the hydroxyl radical reaction rate constant, k OH . The first time that EPA used the incremental reactivities prepared by Dr. William P. L. Carter was when it exempted cyclic, branched or linear completely 9 methylated siloxanes on October 5, 1994. Prior to that time, EPA had made all exemption decisions using k OH values which expressed the rate of reaction of a compound with the OH radical and which were expressed in units of cm3/ molecule sec. On the k OH basis, TBAC would have a higher reactivity than ethane and would not have been exempted. However, EPA has used the incremental reactivity method for acetone and methyl acetate since first using it for volatile methylated siloxanes. The EPA is using the incremental reactivity method on a gram basis to evaluate this petition, and on that basis TBAC is less reactive than ethane.

Comment 14. It is a basic principle of chemistry that reactions occur between compounds on a molar basis. The EPA should use the most scientific approach for exemption decisions. [ Occidental Chemical Corporation ( II D 29)].

Response: Basic chemistry does indicate that chemical reactions occur on a molar basis. However, the contribution of a VOC to ozone formation is a function of the chain of chemical reactions in which the VOC and its reaction products participate. The ozone contribution of this chain of reactions can be expressed in terms of either moles or grams of the VOC. The EPA's current policy ( see 60 FR 31633) does allow the per gram basis. Based on the important questions raised by comments on the per gram versus mole basis, EPA has decided to defer consideration of revising policy on this issue.

Comment 15. The Agency appears to be ignoring the opinions of its own experts. Occidental cites statements by an EPA scientist in a July 1999 Journal of the Air & Waste Management Association article ( Scientific Basis of an Improved EPA Policy on Control of Organic Emissions for Ambient Ozone Reduction) and statements made in presentations by two EPA representatives at the Photochemical Reactivity Workshop held on May 12 14, 1998 in favor of the mole basis as opposed to the gram basis. [ The Institute of Clean Air Companies ( II D 12), Occidental Chemical Corporation ( II D 29)].

Response: The EPA employees did make comments concerning the mole basis at the workshop and in the journal article cited. Although these were not official Agency policy statements, the EPA has not ignored these statements. As the comments on the gram versus mole issue discussed in the proposal indicate, this is a complex issue. The EPA has decided to defer issuing a revised policy statement on this issue pending further consideration.

Comment 16. There is no meaningful difference between the reactivities of TBAC and ethane on a per mole basis. TBAC has twice the reactivity of ethane on a per mole basis. Both of these are on the low end of the reactivity scale in comparison with most other organic compounds. [ Lyondell Chemical Company ( II D 25)].

Response: Both ethane and TBAC are near the low end of the reactivity scale, although TBAC is 1.5 to 2.3 times as high as ethane on a per mole basis. The EPA considers this to be significant. TBAC has lower reactivity than ethane on a gram basis. 10 Comment 17. Lyondell states that Occidental Chemical Corporation ( or Occidental) asserts that EPA's 1978 reactivity policy is clear that comparisons of reactivity must be done on a molar, not gram basis. Lyondell says that the Occidental assertion is untrue. Assuming the 1977 policy is meant, since there is no 1978 policy, this policy statement does not mention the mole vs. gram distinction. As discussed above, until the proposal to exempt TBAC was issued, every EPA document that mentioned this issue stated that the EPA would compare compounds to ethane on a per gram basis. [ Lyondell Chemical Company ( II D 25)].

Response: The 1977 policy did not specify a basis, either per gram or per mole, for determining VOC exemptions. However, early exemptions seem to have been made using either k OH values expressed on a per molecule basis or data from smog chamber experiments conducted on a molar basis. In fact, all compounds which were exempted prior to the acetone exemption in 1995 are less reactive than ethane on a mole basis. Acetone is the only exempted compound which is not less reactive than ethane on a mole basis. The 1977 policy does not actually say that ethane is to be used as a benchmark for comparisons. The use of ethane as a benchmark came later as petitioners made the argument that the compounds named in their petitions were less reactive than ethane which was listed as negligibly reactive in the 1977 policy. The fact that ethane was listed as negligibly reactive in large part based on experiments which were conducted by an equi molar comparison of compounds in a smog chamber is not spelled out in the 1977 policy. The EPA discussed the gram vs mole issue in the acetone proposal and in the final rule which was issued in 1995. In the acetone exemption decision, EPA explicitly chose to use the weight ( gram) basis for the ethane comparison. The EPA also mentioned the per gram basis as an approach " presently favored  but not officially endorsed" in a 1995 report to Congress on consumer products. In the methyl acetate exemption ( 63 FR 17331) in 1998, EPA indicated that it had considered that action on both a gram and mole basis.

Comment 18. Lyondell states that Occidental claims that EPA made an " exception" to its permole policy when it exempted acetone and that the use of acetone is soaring as a result of this " mistake." Lyondell states that the acetone decision was not an exception. It was simply the first time that the Agency had to address the mole vs. gram issue explicitly. In that action, EPA said it would compare compounds to ethane on a gram basis. The use of acetone has not " soared" as a result of being excluded as a VOC. Annual growth rates of acetone sales are only slightly higher than before the exemption was granted. In any event, much of the acetone being used is replacing compounds with substantially higher photochemical reactivity. [ Lyondell Chemical Company ( II D 25)].

Response: The acetone exemption was the first time that EPA specified a comparison basis ( either per gram or per mole) for making reactivity determinations. Prior to this time, EPA had made exemption determinations using k OH values ( except for the case of volatile methyl siloxanes as explained below.). The k OH values are on a molecule basis, which is analogous to a mole basis, but the basis was not directly stated prior to the acetone action. The EPA first considered a new system of incremental reactivities developed by Dr. W. P. L. Carter in 1994 for methylated siloxanes. These siloxane compounds were very unusual in that they showed negative reactivity, 11 which meant that they did not produce ozone on either a gram or mole basis. The EPA used Carter's incremental reactivities again in the 1994 acetone proposal. Incremental reactivities were used instead of k OH values for acetone partially because reaction with the OH radical is not the main pathway by which acetone breaks down in the atmosphere. This was the only time until now that a compound has been exempted solely on a reactivity per gram basis. Other compounds exempted since then are low enough in reactivity to be below ethane on either a per gram or per mole basis. In a sense, acetone was an exception in that it is the only compound exempted until now which is more reactive than ethane on a mole basis. However, no clearly stated policy requiring a mole basis had been announced prior to that action.

Although published data on acetone use since 1995 are difficult to find, EPA has not seen any indication that acetone use has shown any unusual expansion since the exemption of acetone in 1995. The EPA has not been able to obtain quantitative information which indicated the extent, if any, to which acetone has been substituted for other more toxic or more photochemically reactive chemicals.

The General Scientific Basis of the Exemption Policy Comment 19. The Halogenated Solvents Industry Alliance argues that the basis on which EPA proposed to exempt TBAC is " sufficiently vague and lacking in objective criteria" that the decision suffers from the same lack of an " intelligible principle" as found by the U. S. Court of Appeals for the D. C. Circuit in ruling on the 8 hour ozone NAAQS. The Court found that EPA had failed to articulate an " intelligible principle" used to select the level of the NAAQS and thereby had assumed an unconstitutional delegation of authority from Congress to the executive branch. [ Halogenated Solvents Industry Alliance ( II D 26)].

Response: Apparently this commenter is referring to EPA's statement in the proposal saying that the EPA will evaluate petitions that were submitted prior to the September 30, 1999 proposal notice based on the extent of reliance on past EPA statements concerning the acceptability of the per gram basis and the extent to which the exemption would further the purpose of the Clean Air Act. However, EPA has decided not to finalize a change in the VOC exemption policy with respect to the mass or molar basis for comparison and is proceeding with the final rule for TBAC based on the existing policy. Therefore, the commenter's concerns are not relevant to this final rule. Furthermore, the D. C. Circuit's ruling cited by the commenter has been overturned by the Supreme Court.

Comment 20. Dr. Carter has published ( via his website) a more recent reactivity value for TBAC than the values submitted with the petition and on which the decision to propose the exemption is based. The new number ( 0.60 relative TBAC to ethane incremental reactivity on a gram basis) is higher than the most recent TBAC value in the petition ( 0.38). The most recent published value by Dr. Carter shows that TBAC is 2.32 times as reactive as ethane on a molar basis. Dr. Carter has published 3 relative incremental values for TBAC relative to ethane between November 1996 and August 1998. These values are 0.76, 0.38 and 0.60. Variations of this magnitude may be 12 acceptable for developing science, but they are totally unacceptable as the basis for regulation. [ Occidental Chemical Corporation ( II D 29)].

Response: Dr. Carter has revised his reactivity scales several times giving slightly different values for some chemicals including TBAC. While the values for TBAC have been revised several times, all of the values cited by the commenter support the conclusion that TBAC is less reactive than ethane on a mass basis. Variations in reactivity scales over time, which are primarily due to changes in the chemical mechanism used to calculate the scales, can be problematic for some regulatory purposes. However, EPA does not believe that these types of changes will alter the conclusions in this case.

Comment 21. One commenter states that EPA should await the outcome of a review of the current science on reactivity before it decides borderline cases such TBAC. [ Halogenated Solvents Industry Alliance, Inc. ( II D 26)]. Lyondell Chemical Company says that Occidental Chemical Corporation suggests that the EPA should not make a decision about excluding TBAC until Agency has completed its reevaluation of its VOC exemption policy. Lyondell says the reevaluation will take several years. According to Lyondell, there is no reason to postpone the benefits of exempting TBAC until EPA is able to implement a new policy. [ Lyondell ( II D 25)].

Response: There is no set date for revising the current policy. This will depend on information which is now being collected, and any decision to make major revisions to the policy could be several years away. The EPA thinks that it has enough information about TBAC to proceed with the exemption of this particular compound at this time.

Benefits or Impacts of a TBAC Exemption Comment 22. Eighteen commenters specifically indicate their support for the TBAC exemption. [ HCI USA Distribution Co., Inc. ( II D 01), HCI Chemtech Distribution Inc. ( II D 02), BASF Automotive Refinish ( II D O3), Chase HumiSeal ( II D 04), The Valspar Corporation ( II D 05), Advance Chemical Dist. Inc ( II D 07), Gemini ( II D 08), DAP ( II D 10), Finish Technologies, Inc ( II D 11), Intercostal Paint Co. Inc. ( II D 13), Ashland Specialty Chemical Company ( II D 14), Penrico and Printing Industries of America ( II D 18), Reichold ( II D 20), National Paint and Coatings Association ( II D 22), Chemical Specialities Manufacturers Association ( II D 23), Firestone Building Products Company ( II D 24), Lyondell ( II D 25), Eastman Chemical Company ( II D 31)].

Response: The EPA recognizes that there is considerable industrial support for excluding this chemical from VOC control requirements.

Comment 23. Four commenters oppose the TBAC exemption. [ Institute of Clean Air Companies ( II D 12), Occidental Chemical Corporation ( II D 29), James C. Berry ( II D 30), Institute for Research and Technical Assistance ( II D 33)]. ( Note  The EPA received additional comment letters after the close of the formal comment period. One was from the California EPA ( III D 13 02), which urged the U. S. EPA to consider carefully any possible health risks which might be associated with TBAC before proceeding with the exemption. Another was a joint letter from Environmental Health Coalition, Natural Resources Defense Council, Sierra Club of California and Coalition for Clean Air ( III D 05), which urged EPA to deny the petition.)

Response: Several commenters give reasons why EPA should not exempt TBAC from VOC controls. The EPA has carefully considered these comments, but has decided to grant the exemption for TBAC. The EPA's responses to these comments are discussed in various places in this response to comment document with the specific comments.

Comment 24. According to one commenter, adding TBAC to the list of negligibly reactive compounds will greatly encourage substitution of an environmentally benign product for products that purportedly pose greater environmental risks due to having greater reactivity or being hazardous air pollutants ( HAPs). [ Firestone Building Products Company ( II D 24)]. Lyondell states that TBAC can substitute for higher photochemical reactivity solvents and HAPs. In particular, Lyondell states that several companies have evaluated TBAC as a substitute for toluene and xylene, and that TBAC will fill a growing need for VOC exempt solvent. According to Lyondell, exempting TBAC will substantially reduce ozone formation since published reactivity values show toluene and xylene are 20 to 50 times as reactive as TBAC. Lyondell also states that exempting TBAC will substantially reduce HAP emissions. Lyondell estimates that TBAC will replace more than 150 million pounds of HAP solvents per year and thus reduce HAP emissions by over 75,000 tons per year. [ Lyondell Chemical Company ( II D 25)]. Several companies say that TBAC can be used as a substitute for toluene and xylene and possibly other HAPs in some products. [ HCI USA Distribution Co. Inc. ( II D 01), Valspar Corp. ( II D 05), Advance Chemical Dist. Inc ( II D 07), Gemini ( II D 08), DAP ( II D 10), Finish Technologies, Inc. ( II D 11), Intercostal Paint Co., Inc. ( II D 13), Ashland Speciality Chemical Company ( II D 14), Reichold ( II D 20), Firestone Building Products Company ( II D 24), Lyondell ( II D 25)]. One commenter says that even though preliminary tests indicate that TBAC may not achieve the same level of print quality as the aromatic hydrocarbon solvents, EPA's proposal opens the door for research that could ultimately prove useful in providing regulatory relief and at the same time benefit the environment. [ Gravure Association of America ( II D 19)]. A coatings producer says that TBAC would replace most of the parachlorobenzotrifluoride ( PCBTF) in its most popular coatings. [ Chase HumiSeal ( II D 04)] Another company says that TBAC will likely be used in connection with Oxsol 100 ( a brand of PCBTF) because of the slower evaporation rate of Oxsol 100. [ The Valspar Corporation ( II D 05)]. One commenter suggests that TBAC may be added as a thinner on top of other solvents already in low VOC coatings, because more solvent makes high solids paints easier to spray. [ James C. Berry ( II D 30)].

Response: One of the main arguments that the petitioners present in favor of the exemption is that companies will substitute TBAC for more environmentally harmful chemicals, resulting in an overall environmental benefit. It seems evident that TBAC has physical properties which would allow companies to substitute it for several commonly used solvents, including some, such as toluene and xylene, which are classified as hazardous air pollutants. Some toluene and xylene may 14 be replaced because they are HAPs, and industries are lowering the content of HAPs in many products used at facilities subject to standards under section 112 of the Clean Air Act.. However, EPA is not able to confirm how much HAP reduction will actually take place. TBAC currently costs much more than xylene or toluene. This cost differential may play a role in whether widespread substitution will occur, although TBAC may become less costly if it is manufactured in larger amounts. As EPA stated in the proposal, the possibility of substitution is not the basis for EPA's decision to grant the exemption.

Comment 25. TBAC may be a greenhouse gas presenting a problem of unknown magnitude. In the atmosphere it will break down to CO 2 which is a greenhouse gas. [ James C. Berry ( II D 30)].

Response: It is unlikely that the use of TBAC would contribute in any significant way to global warming and climatic change. Though TBAC can be oxidized into carbon dioxide ( CO 2) and water vapor, both greenhouse gases, the amount of these byproducts are insignificant compared to the registered inventory of U. S. greenhouse gas emissions. Water vapor is the most abundant greenhouse gas, accounting for two thirds of the natural greenhouse effect. However, human activities whether the use of TBAC or other processes that release water vapor have not significantly altered natural atmospheric concentrations of water vapor. For this reason, emissions of water vapor are not an area of concern in the policy debate about climate change. CO 2 emissions, on the other hand, are the main focus of the climate change debate because atmospheric concentrations of CO 2 have increased by over 30% since pre industrial times. The main sources of U. S. CO 2 emissions include the burning of fossil fuels ( coal, oil and gas) to generate energy for buildings, homes and transportation. 1997 U. S. CO 2 emissions were 1,488 million metric tons of carbon equivalent. An accounting of the CO 2 resulting from the use of TBAC would not likely change this number.

Comment 26. A commenter says that the potential increase in emissions is unlimited and could be very large. [ James C. Berry ( II D 30)].

Response: It is possible that the eventual emissions of TBAC could be very large once exempted from substantive controls as a VOC, since this compound is expected to find wide use as an industrial solvent. Lyondell has predicted that TBAC could replace over 75,000 tons/ year of hazardous air pollutants, and it is possible that replacement of HAPs will be only a part of TBAC usage. To the extent that TBAC use replaces the use of more photochemically reactive solvents, this increase in use will be associated with a decrease in ozone formation. However, even if a large increase in TBAC emissions occurs, the compound might still account for only a few percentage points of all organic compounds emitted into the air. The EPA is not exempting TBAC from record keeping, reporting or inventory requirements. If emissions eventually become so large that the situation seems to present a problem, EPA will evaluate what, if any, action needs to be taken at that time.

Comment 27. Lyondell, the petitioner for the exemption, states that the proposal to exclude TBAC from the VOC definition is based on a substantial body of scientific evidence. Lyondell lists 15 several studies which are in the docket on environmental effects of TBAC, including biodegradation, aerosol formation, global warming, environmental fate, and toxicity studies. [ Lyondell Chemical Company ( II D 25)].

Response: Lyondell has provided a variety of studies examining the potential environmental effects of TBAC, all of which conclude that TBAC does not pose a significant risk to the environment or public health. The EPA has examined these materials, and agrees that the available data does not indicate any serious health or environmental problems. However, as discussed below in response to Comment 33, EPA believes that it would be prudent to conduct further chronic toxicity testing to resolve the uncertainty associated with the limited evidence that is currently available. Lyondell has agreed to work with EPA to further assess the potential for chronic toxicity.

Comment 28. Lyondell claims that exempting TBAC will substantially reduce ozone formation. Based on reactivity values published by Dr. Carter, toluene is approximately twenty times more reactive than TBAC and m xylene is approximately 50 times more reactive on a weight basis. Lyondell concludes that under conditions where VOC emissions have their maximum impact on ozone formation, a pound of TBAC emitted into the air will cause about 50 times less ozone than a pound of xylene. According to Lyondell, the use of TBAC in place of high reactivity solvents will produce substantial reductions in ozone formation and could be an important tool for addressing the persistent ozone problems of many large urban areas. [ Lyondell Chemical Company ( II D 25)].

Response: To the extent that TBAC is used to substitute for more reactive compounds, such as toluene or xylene, for which it is a good technical substitute, TBAC use will help decrease the ozone formation of VOC emissions. The California Air Resources Board has estimated that maximum substitution could decrease the ozone forming potential of statewide emissions by 1.3%. While there is a possibility that increases in TBAC use beyond substitition will offset the benefits of substitution, EPA believes that the TBAC exemption will lead to a net environmental improvement. However, the basis for the EPA's decision to exempt TBAC is its relative reactivity on a gram basis compared to that of ethane.

Comment 29. Lyondell states that TBAC partitions almost exclusively to air and does not bioaccumulate in the environment. Specifically, according to Lyondell little TBAC will accumulate in soil or water. [ Lyondell Chemical Company ( II D 25)].

Response: Accumulation in ground water could be a serious problem, and EPA would view any evidence that this is occurring with concern. From the data on environmental fate which Lyondell submitted, the EPA does not anticipate that this will be a problem.

Comment 30. Occidental argues that because TBAC is more expensive than common solvents ( like toluene and xylene) it will not replace these solvents, but will replace parachlorobenzotrifluoride or PCBTF ( OXSOL ® 100), which is manufactured by Occidental and is several times more expensive than TBAC. Lyondell contends that the large number of testimonial letters in the docket gives evidence that companies will replace significant amounts of toluene and 16 xylene. Lyondell suggests that if cost is the only relevant factor then Occidental would not be able to sell any OXSOL, which is much more expensive than virtually every other solvent used in the coatings industry. [ Lyondell Chemical Company ( II D 25)].

Response: There is a possibility that TBAC may displace much OXSOL from the market due to the cost difference. However, one commenter said that TBAC is not an exact replacement for OXSOL and that some OXSOL may still be used. It is not clear to EPA how much TBAC will displace toluene and xylene. See response to Comment 24, above.

Comment 31. Occidental suggests that if TBAC replaces OXSOL air quality would be harmed because TBAC has a higher reactivity than OXSOL. Lyondell counters that OXSOL is not a very active solvent for many coating resins, therefore fewer pounds of TBAC are needed in a coating. Therefore, when TBAC replaces OXSOL, the reduction in pounds of solvent emitted outweighs what Lyondell perceives as the minimal difference in reactivity between the two compounds. [ Lyondell Chemical Company ( II D 25)].

Response: The EPA has not done an analysis of the relative propensity for ozone formation of these two compounds considering the amount used in similar products formulated with each. The basis for exemption of TBAC from VOC emissions limitations and VOC content requirements is its reactivity relative to ethane on a per gram basis, not its relationship to OXSOL.

Comments About the Toxicity of TBAC Comment 32. Several commenters discuss whether or not EPA should consider a chemical's toxicity when deciding whether the chemical should be exempt from regulations as a VOC. The Halogenated Solvents Industry Alliance, Inc., states that consideration of a chemical's toxicity in connection with EPA's determination as to whether it should be exempt from regulation as a VOC, without consideration of the other regulations that apply to the chemical, would be inappropriate and contrary to the Clean Air Act. The commenter explains that hazardous air pollutants are controlled under section 112 of the CAA, an entirely separate regulatory structure from the regulations governing VOC use [( II D 26)]. The Institute for Research and Technical Assistance, on the other hand, supports the consideration of environmental effects other than reactivity ( such as toxicity and ozone depletion) in making VOC exemption decisions. This commenter explains that the maximum achievable control technology ( MACT) standards for hazardous air pollutants ( HAPs), promulgated under section 112, do not always provide protection because toxicity data that would allow a chemical to be classified as a HAP is not available or particular significant uses of a HAP ( such as perchloroethylene for brake cleaners ) may not be covered by a MACT standard. This commenter urges EPA to institute a procedure to evaluate other health and environmental problems posed by the compounds that are the subject of petitions for exemption from VOC regulations and to delay granting exemptions for pending petitions until the necessary data is available [( II D 33)]. Occidental Chemical Corporation suggests that EPA has considered toxicity concerns in granting VOC exemptions in the past and cites perchloroethylene as an example of a chemical that was only delisted as a VOC when it was certain that toxicity concerns 17 had been addressed. [ Occidental Chemical Corporation ( II D 29)].

Response: The purpose in controlling VOCs is the attainment of the Ozone National Ambient Air Quality Standard ( NAAQS) for ozone. The justification for listing a compound as " negligibly reactive" and exempting it from control requirements in State implementation plans for ozone attainment is that such a compound contributes insignificantly to ozone formation. However, if a compound is exempted from controls, companies may find a large economic advantage to using increased amounts of the compound. The EPA would want to be aware of situations in which a VOC exemption will increase the use of a compound that could pose a significant public health risk . As discussed further below, EPA has examined the available evidence concerning the potential toxicity of TBAC and does not believe that there is sufficient evidence of a toxic risk associated with TBAC to warrant foregoing the potential benefits of reduced ozone formation and exposure. As for how non ozone impacts will be dealt with in future policy decisions, EPA expects to address these issues in its pending review of the overall VOC exemption policy.

Comment 33. A number of commenters raise concerns about the potential toxicity of TBAC. Occidental Chemical Corporation [ II D 29] suggests that the petitioner has failed to provide subchronic or chronic toxicity testing data or data from repeated dose studies for any exposure route. Occidental suggests that the petitioner has relied on data generated for Tertiary Butyl Alcohol ( TBA) as a surrogate for establishing the chronic toxicity of TBAC on the basis that TBAC is metabolized by simple hydrolysis to acetic acid and TBA. Occidental suggests that the use of TBA as a surrogate for TBAC's subchronic and chronic toxicity may not be appropriate ( e. g., methyl tertiary butyl ether ( MTBE) also metabolizes to TBA but MTBE's toxic profile is much different than that of TBAC.) In addition, Occidental claims that EPA has indicated that there may be toxicological concerns about TBA itself. Occidental claims that no chemical should be introduced into the marketplace where chronic exposure is likely without appropriate toxicity studies. Occidental points out that the American Conference of Governmental Industrial Hygienists ( ACGIH) has decided not to establish a short term exposure limit for TBAC until additional toxicological data and industrial hygiene experience is available, and that the ACGIH is concerned that the threshold limit value listed for the isomer s butyl acetate, a related compound, is not the most appropriate level to ensure safe use and handling.

Other commenters also suggest denying the TBAC petition based on toxicity concerns [ Environmental Health Coalition ( signed by Environmental Health Coalition, Natural Resources Defense Council, Sierra Club of California and Coalition for Clean Air)( III D 05)] or delaying a decision to exempt TBAC until further toxicity testing can be completed [ California Environmental Protection Agency ( signed by Air Resources Board, Office of Environmental Health Hazard Assessment, and State Water Resources Control Board)( III D 02), Institute for Research and Technical Assistance ( III E 03)]. According to the California Environmental Protection Agency, ( i) the health effects data available for TBAC are limited; ( ii) a review of these data indicates that TBAC has low acute inhalation, oral, dermal and ocular toxicity; ( iii) no chronic, developmental, or reproductive toxicity data are available for TBAC; ( iii) and no genetic toxicity or carcinogenicity data are available for TBAC. Due to the lack of information on TBAC, the commenters assert that it is not possible to assess the potential for adverse effects from prolonged exposure. However, TBAC has been demonstrated to be substantially metabolized to TBA in rats. 18 While genetic toxicity data for TBA are mixed, information from one genotoxicity study suggests that TBA may cause oxidative deoxyribonucleic acid ( DNA) damage. TBA has been shown to induce renal tumors in male rats and thyroid tumors in female mice, raising a concern that exposure to TBAC may result in a cancer risk [ California Environmental Protection Agency ( signed by Air Resources Board, Office of Environmental Health Hazard Assessment, and State Water Resources Control Board)( III D 02), Environmental Health Coalition ( III D 05), Institute for Research and Technical Assistance ( III E 03)].

The petitioners respond to some of these criticisms and state that Occidental's claims that there is a lack of short term toxicological information are inconsistent with the public record. The petitioners call attention to a full range of acute toxicity testing that has been performed for TBAC and provided to EPA, which they claim shows that TBAC is not acutely toxic by oral, dermal, or inhalation routes. The petitioners state that Occidental suggests that TBAC metabolizes to TBA and acetic acid in the body and may cause developmental effects. The petitioners claim that acetic acid rapidly metabolizes in the body and is not of concern except for cases of extreme exposure. The petitioners acknowledge that TBA can cause renal tumors in male rats but argues that these effects are not seen in humans and that TBA causes reproductive and developmental effects in female mice only at large doses far above environmental exposure. The petitioners explain that, in summary, TBAC cannot reasonably be expected to result in chronic health effects [ Lyondell Chemical Company ( II D 25)].

Since the the close of the comment period, the California Air Resources Board, in conjuction with California's Office of Environmental Health Hazard Assessment, has completed a draft health risk assessment of a VOC exemption for TBAC in the state of California. The assessment quantifies 1) the potential benefits associated with decreased ozone formation as a result of TBAC substituting for more reactive compounds, and 2) the potential cancer risks associated with increased exposure to TBAC, based on the limited animal testing data available. A copy of this draft assessment is included in the docket. [ III G 05]

As input into California's assessment, Lyondell submitted to EPA and California a variety of additional information about chronic toxicity. Copies of this information [ III H 03], as well as a copy of Lyondell's critiques of California's assessment, are included in the docket. [ III F 14 and III H 06]

Response: The EPA has carefully reviewed the limited data that is available on the chronic toxicity of TBAC, including California's health risk assessment, and has reviewed the data available about the potential health benefits due to reduced ozone exposure from the use of TBAC as a substitute for more reactive substances. The EPA has concluded that 1) there is insufficient evidence of a significant toxic risk to justify not granting the exemption petition and 2) granting the exemption will provide a net improvement in public health and environmental quality. However, given the potential for increased use of TBAC, EPA believes that it would be prudent to conduct further chronic toxicity testing to resolve the uncertainty associated with the limited evidence that is currently available.

In response to these concerns, Lyondell has agreed to work with EPA to perform testing to 19 develop additional data on the chronic toxicity of TBAC. As part of this effort, Lyondell will conduct a tiered series of tests designed to confirm and elucidate the mechanisms of potential toxicity observed in the limited data available. Lyondell will submit the testing results to an independent scientific peer consultation panel that will make recommendations to EPA and Lyondell as to whether further testing is appropriate. Based on the information currently available and experience with similar compounds, EPA believes that the first tier of testing is likely to be sufficient to resolve much of the current uncertainty. Until this round of tests is completed and evaluated, Lyondell has agreed to limit their annual production of TBAC. The EPA will take appropriate regulatory action if the results of the testing program justify such action.

The EPA believes that moving forward with the exemption and simultaneously pursuing additional toxicity testing is a responsible risk management approach that allows society to benefit from lower ozone exposures while protecting against other potential chronic risks.

Comment 34. Given the lack of toxicity data, Occidental claims that the Agency can not support claims that TBAC will be used as a substitute for more toxic substances such as toluene or xylene, that the Agency's record of decision is deficient, and its decision is arbitrary. [ Occidental Chemical Corporation ( II D 29)].

Response: The proposal does mention possible environmental benefits from solvent substitution, which the petitioner claims will take place if TBAC is exempted. Based on evidence presented by the petitioner, comments received from potential users, and the impact assessment by CARB, EPA believes that, if exempted, TBAC is likely to substitute for other solvents that are much more photochemically reactive and are listed as hazardous air pollutants. While the exemption decision is based on the reactivity comparison with ethane, EPA believes that the exemption of TBAC is likely to result in a net environmental improvement.

Comment 35. Occidental claims that EPA should have considered the fact that formaldehyde and methyl ethyl ketone are the primary decomposition products of TBAC in the atmosphere and the fact that formaldehyde is reactive, toxic, and a listed HAP [ Occidental Chemical Corporation ( IID 29)]. The petitioner explains that this claim is untrue and is based on a predicted " upper limit" mechanism presented in the petition. This mechanism was a purely speculative worse case exercise to calculate an " upper limit" reactivity. According to the petitioner, this mechanism has been superseded by later work that shows that TBAC oxidizes primarily to acetic anhydride, acetone and organic nitrates. [ Lyondell Chemical Company ( II D 25)].

Response: It appears that Occidental's concerns about the atmospheric decomposition products of TBAC have been alleviated by more recent research.

Comment 36. Occidental argues that if TBAC is exempted from regulation as a VOC, sales of TBAC would quickly exceed the high production volume ( HPV) chemical quantity of one million pounds per year. Lyondell has not performed all the fifteen tests used by EPA to screen HPV chemicals. [ Occidental Chemical Corporation ( II D 29)]. The petitioner has stated that it has initiated a testing program designed to meet the criteria established under EPA's " high production volume" chemical testing program and that this testing should be completed before the high 20 volume production threshold level of sales has occurred. [ Lyondell Chemical Company ( II D 25)].

Response: The completion of testing under the HPV Challenge Program is voluntary and not a prerequisite for excluding TBAc from the definition of VOC.

Comment 37. Both the South Coast Air Quality Management District ( SCAQMD) and the California Air Resources Board ( CARB) have submitted letters to EPA urging that the Agency proceed with the decision to exclude TBAC from the VOC definition. [ Lyondell Chemical Company ( II D 25)].

Response: The August 20, 1997 SCAQMD letter ( I C 04) does say that the SCAQMD believes that TBAC should be exempted and urges the U. S. EPA to proceed with the regulatory actions necessary to exempt TBAC. The October 3, 1997 CARB letter ( I C 09) urges the EPA to proceed with its evaluation, but does not make a recommendation on whether or not TBAC should be exempted. Subsequently, on August 28, 2000, the California Environmental Protection Agency wrote another letter to the U. S. EPA ( signed by the CARB, the Office of Environmental Health Hazard Assessment, and the State Water Resources Control Board) [ III D 02] which says that the CARB has initiated its own review of TBAC. The August 28 letter expresses concern that several agencies of the California Environmental Protection Agency now have regarding the U. S. EPA's proposed revision of the definition of VOC to exclude TBAC, because of possible toxic health effects. All of these letters are in the docket for this action.

Comment 38. Occidental asserts that since 1989, the Agency's policy has been to consider the environmental benefits of a substance when deciding whether it should be exempt from the definition of VOC [ Occidental Chemical Corporation ( II D 29)]. Another commenter points out that in granting VOC exempt status to certain HCFC's, EPA took into account the benefits of the chemicals in terms of their potential to replace ozone depleting compounds noting that " there is a strong need to facilitate the use of environmentally acceptable substitutes that have little or no impact on stratospheric ozone." [ Chemical Manufacturers Association ( II D 28)].

Response: On January 18, 1989, the EPA issued a rule exempting four halocarbon compounds ( HCFC 123, HFC 134a, HCFC 1141b, and HCFC 142b) as VOCs in response to an industry petition. The industry petition cited two primary reasons for the request: 1) the low photochemical reactivity of the compounds ( much lower than ethane) and 2) the assertion that if the U. S. is to meet its commitments embodied in the Montreal Protocol on Substances that Deplete the Ozone Layer, substitutes for the regulated CFCs must be developed and unnecessary barriers to their commercialization and use should be removed. The EPA agreed with the industry contention that there is a strong need to facilitate the use of environmentally acceptable substitutes that have little of no impact on the stratospheric environment. The EPA granted the exemptions due to the low photochemical reactivity of the compounds and also noted that the effect of this action will be to facilitate the transition away from stratospheric ozone depleting chemicals without adversely affecting efforts to control ground level ozone concentrations. So, while the desirable benefits of promoting environmentally acceptable substitutes were considered in this action, the exemption was granted because of the low photochemical reactivity of the compounds relative to ethane. The purpose in controlling VOCs is the attainment of the NAAQS for ozone. The justification for 21 listing a compound as " negligibly reactive" and exempting it from control requirements in State implementation plans for ozone attainment is that such a compound contributes insignificantly to ozone formation. However, if a compound is exempted from controls, companies may find a large economic advantage to using increased amounts of the compound. The Agency would want to know if any VOC exemption led to increased use of a compound with significant toxic properties. The EPA is not finally resolving issues concerning non ozone environmental impacts of VOC exemptions in this notice, but is considering issuing a future policy statement concerning such issues.

Comments About Detrimental Reliance Comment 39. Several commenters state that companies have relied on past EPA statements regarding acceptability of the per gram basis for comparing a compound's reactivity to that of ethane. According to these commenters, companies may have spent considerable amounts of resources in research based on this EPA policy . [ Advance Chemical Dist. Inc ( II D 07), Exxon Chemical Company ( II D 16), Lyondell ( II D 25), Penreco and Printing Industries of America ( II D 18), Chemical Specialities Manufacturers Association ( II D 23)]. Lyondell specifically states that it substantially relied on the EPA's past statements regarding the per gram approach.[ Lyondell Chemical Company ( II D 25)]. According to one commenter, the EPA is departing from past practice without a rational justification, which raises significant procedural concerns. [ The Aluminum Association of America ( II D 18)]. Occidental, on the other hand, contends that EPA has not articulated a defensible legal standard under the Clean Air Act for addressing the pending petitions, and that there is no place in the standard setting process for consideration of business development costs in regulating chemicals that contribute to the formation of ozone. Occidental states that the Clean Air Act does not allow the Administrator to use her discretion to exclude a compound from regulation based on whether a company spends a little or a lot of money in developing that chemical for market. Occidental also contends that the notice is too vague about how the significant reliance criterion will be applied in the future. In addition, according to Occidental, EPA ignored " the significant reliance" argument when it exempted acetone. A company commenting on that action said it had made business investments in developing products used for industrial parts cleaning which could be used in place of acetone, which was then controlled as a VOC. If acetone were exempted, the company said it would lose its business investment and future profits. The EPA recognized that this might be the case, but went ahead with the acetone exemption anyway. [ Occidental Chemical Corporation ( II D 29)].

Response: These comments resulted from EPA's statement in the September 39, 1999 proposal that EPA would evaluate future exemption petitions only on a per mole basis, but would grandfather already received petitions for evaluation on either a per gram or per mole basis, if the petition met certain conditions, such as furthering the purpose of the Clean Air Act and demonstrating significant detrimental reliance. In this final rule, EPA is exempting TBAC under the existing VOC exemption policy, on a per gram basis, and is not changing the VOC exemption policy at this time. Thus, today's action does not involve grandfathering. The EPA notes, however, that reliance by a petitioner on a past policy, while an important consideration, is not in and of itself a sufficient reason to grandfather a VOC exemption petition. 22 Comment 40. A commenter asks why EPA is considering costs to the petitioner ( who spent money in research after relying on EPA policy statements on per gram basis) while ignoring millions of dollars spent by the paint industry and coatings users to switch to low VOC coatings in reliance on past EPA regulations restricting emissions of these VOC compounds. According to this commenter, much of this work will be ignored if users are allowed to return to solvent based coatings with unlimited solvent content. [ James C. Berry ( II D 30)].

Response: Industry has made large expenditures in developing low solvent coatings over the years since the mid 1970s when specific emission limitations for industrial paints began to be recommended on a national basis. However, no companies which have formulated low solvent coatings commented in opposition to the granting of the exemption for TBAC. In fact, the National Paint and Coatings Association ( NPCA), which represents many paint companies which have developed low solvent coatings, wrote in support of the exemption. The NPCA said, " The wider the spectrum of such exempt materials, the more opportunities exist for reformulating a fuller range of cost effective lower VOC coatings." [ NPCA ( II D 22)]. As stated above, today's action does not involve grandfathering, and EPA is no longer considering the costs to the petitioner. The EPA notes, however, that one problem with basing a grandfathering approach solely on costs incurred by the petitioner is that such an approach does not take into account costs incurred by others in the industry.

Comment 41. According to Occidental, most, if not all, petitioners had notice nearly two years ago of EPA's judgement regarding the impropriety of using the gram comparison rather than the molar comparison for assessing its ozone forming potential. [ Occidental Chemical Corporation ( IID 29)].

Response: The EPA said in the August 25, 1997 ( 62 FR 44926) proposal to exempt methyl acetate that it was considering the proposal on a per mole as well as on a per gram basis. Also, EPA speakers made public statements at a May 1998 Photochemical Reactivity Workshop to the effect that a review of the original 1977 experimental work used to select ethane as the exemption cut off showed that the experiments were done on a molar basis, and that comparisons to ethane on a weight basis may not be valid. However, as stated in response to Comment 15, these comments were not intended as official Agency policy statements. The EPA is considering these issues as part of a review of the overall exemption policy but has not yet changed its policy.

Comment 42. The notice is inconsistent in that on page 52734 it says the Agency will no longer utilize the weight based comparison and on that same page says that for petitions listed in Table 1, it will consider the " significant reliance" demonstrated by each petitioner on a case by case basis. [ Occidental Chemical Corporation ( II D 29)].

Response: The EPA proposed to change its policy to grandfather the Table 1 petitions if they met certain criteria. However, the EPA is not changing its policy at this time. Thus, grandfathering is no longer at issue.

Comment 43. Lyondell refers to a letter from a representative of ARCO ( now Lyondell) to a research scientist at EPA. In this letter, ARCO presents reactivity data for TBAC on both a per 23 gram and per mole basis. ARCO asserts that in a subsequent telephone conversation this scientist said it appears that TBAC would qualify for exemption on a per gram basis. [ Lyondell Chemical Company ( II D 25)].

Response: The ARCO letter to EPA research scientist ( I C 01) and the follow up letter that the scientist wrote to ARCO subsequent to the telephone conversation ( I B 01) are both in the docket for this rule. The EPA scientist does not mention in his letter that TBAC may be eligible for exemption on a per gram basis, but rather advises the ARCO representative to discuss the TBAC issue with an EPA regulatory policy official.

Comment 44. According to Occidental, the reference in the 1995 § 183( e) Consumer Products Report to Congress regarding use of the gram basis for exemption does not establish a strong basis for the petitioner's detrimental reliance. That reference refers to the protocol " presently favored." Occidental says that in using that phrase, EPA was conveying that it was re evaluating its position. The Report to Congress statement says that the protocol favored by EPA for VOC reactivity testing calls for a measurement of the species k OH reactivity relative to that of ethane. TBAC has a k OH value larger than that of ethane. On this basis, EPA should not have further evaluated TBAC. [ Occidental Chemical Corporation ( II D 29)].

Response: The 183( e) report to Congress statement did refer to k OH reactivity, but said that a per gram basis was preferred by one office of EPA, although it did not tell how k OH would be expressed on a per gram basis. The usual k OH units are on a molecular basis. The statement in the footnote indicated that this approach was " presently favored  but not officially endorsed" which clearly indicated that this was not meant to be a definitive policy statement. At any rate, EPA is not using a " grandfathering" analysis as the basis for the TBAC exemption final rule.


[Federal Register Volume 77, Number 89 (Tuesday, May 8, 2012)]
[Notices]
[Pages 27048-27054]
[FR Doc No: 2012-10961]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. CP12-106-000]

Tennessee Gas Pipeline Company, L.L.C.; Notice of Intent To
Prepare an Environmental Assessment for the Proposed Line 524j-200
Abandonment Project and Request for Comments on Environmental Issues

    The staff of the Federal Energy Regulatory Commission (FERC or
Commission) will prepare an environmental assessment (EA) that will
discuss the environmental impacts of the Line 524J-200 Abandonment
Project involving abandonment of facilities by Tennessee Gas Pipeline
Company, L.L.C. (TGP) in Lafourche Parish, Louisiana. The Commission
will use this EA in its decision-making process to determine whether
the project is in the public convenience and necessity.
    This notice announces the opening of the scoping process the
Commission will use to gather input from the public and interested
agencies on the project. Your input will help the Commission staff
determine what issues they need to evaluate in the EA. Please note that
the scoping period will close on May 31, 2012.
    This notice is being sent to the Commission's current environmental
mailing list for this project. State and local government
representatives should notify their constituents of this proposed
project and encourage them to comment on their areas of concern.
    TGP provided landowners with a fact sheet prepared by the FERC
entitled ``An Interstate Natural Gas Facility On My Land? What Do I
Need To Know?''. This fact sheet addresses a number of typically-asked
questions, including the use of eminent domain and how to participate
in the Commission's proceedings. It is also available for viewing on
the FERC Web site (www.ferc.gov).

Summary of the Proposed Project

    TGP proposes to abandon in place approximately 9.8 miles of 24-
inch-diameter natural gas pipeline, known as Line 254J-200, in
Lafourche Parish, Louisiana. In order to comply with the U.S.
Department of Transportation's Pipeline and Hazardous Materials Safety
Administration's regulations, TGP must replace a portion of the
pipeline or remove the pipeline from service by December 31, 2012. TGP
proposes to cut, cap, and abandon the pipeline in place. Construction
of the project would disturb less than one acre of land. The general
location of the project facilities is shown in appendix 1.\1\
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    \1\ The appendices referenced in this notice will not appear in
the Federal Register. Copies of appendices were sent to all those
receiving this notice in the mail and are available at www.ferc.gov
using the link called ``eLibrary'' or from the Commission's Public
Reference Room, 888 First Street NE., Washington, DC 20426, or call
(202) 502-8371. For instructions on connecting to eLibrary, refer to
the last page of this notice.
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The EA Process

    The National Environmental Policy Act (NEPA) requires the
Commission to take into account the environmental impacts that could
result from an action whenever it considers the issuance of a
Certificate of Public Convenience and Necessity. NEPA also requires us
\2\ to discover and address concerns the public may have about
proposals. This process is referred to as ``scoping.'' The main goal of
the scoping process is to focus the analysis in the EA on the important
environmental issues. By this notice, the Commission requests public
comments on the scope of the issues to address in the EA. We will
consider all filed comments during the preparation of the EA.
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    \2\ ``We,'' ``us,'' and ``our'' refer to the environmental staff
of the Commission's Office of Energy Projects.

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    In the EA we will discuss impacts that could occur as a result of
the abandonment of the proposed project under these general headings:
     Geology and soils;
     Land use;
     Water resources, fisheries, and wetlands;
     Cultural resources;
     Vegetation and wildlife;
     Air quality and noise;
     Endangered and threatened species; and
     Public safety
    We will also evaluate reasonable alternatives to the proposed
project or portions of the project, and make recommendations on how to
lessen or avoid impacts on the various resource areas.
    The EA will present our independent analysis of the issues. The EA
will be available in the public record through eLibrary. Depending on
the comments received during the scoping process, we may also publish
and distribute the EA to the public for an allotted comment period. We
will consider all comments on the EA before making our recommendations
to the Commission. To ensure we have the opportunity to consider and
address your comments, please carefully follow the instructions in the
Public Participation section beginning on page 4.
    With this notice, we are asking agencies with jurisdiction by law
and/or special expertise with respect to the environmental issues of
this project to formally cooperate with us in the preparation of the
EA.\3\ Agencies that would like to request cooperating agency status
should follow the instructions for filing comments provided under the
Public Participation section of this notice.
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    \3\ The Council on Environmental Quality regulations addressing
cooperating agency responsibilities are at Title 40, Code of Federal
Regulations, Part 1501.6.
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Consultations Under Section 106 of the National Historic Preservation
Act

    In accordance with the Advisory Council on Historic Preservation's
implementing regulations for section 106 of the National Historic
Preservation Act, we are using this notice to initiate consultation
with the applicable State Historic Preservation Office (SHPO), and to
solicit their views and those of other government agencies, interested
Indian tribes, and the public on the project's potential effects on
historic properties.\4\ We will define the project-specific Area of
Potential Effects (APE) in consultation with the SHPO as the project
develops. On natural gas facility projects, the APE at a minimum
encompasses all areas subject to ground disturbance (examples include
construction right-of-way, contractor/pipe storage yards, compressor
stations, and access roads). Our EA for this project will document our
findings on the impacts on historic properties and summarize the status
of consultations under section 106.
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    \4\ The Advisory Council on Historic Preservation's regulations
are at Title 36, Code of Federal Regulations, Part 800. Those
regulations define historic properties as any prehistoric or
historic district, site, building, structure, or object included in
or eligible for inclusion in the National Register of Historic
Places.
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Public Participation

    You can make a difference by providing us with your specific
comments or concerns about the project. Your comments should focus on
the potential environmental effects, reasonable alternatives, and
measures to avoid or lessen environmental impacts. The more specific
your comments, the more useful they will be. To ensure that your
comments are timely and properly recorded, please send your comments so
that the Commission receives them in Washington, DC on or before May
31, 2012.
    For your convenience, there are three methods which you can use to
submit your comments to the Commission. In all instances please
reference the project docket number (CP12-106-000) with your
submission. The Commission encourages electronic filing of comments and
has expert staff available to assist you at<PHONE_NUMBER> or
<EMAIL_ADDRESS>    (1) You can file your comments electronically using the eComment
feature on the Commission's Web site (www.ferc.gov) under the link to
Documents and Filings. This is an easy method for interested persons to
submit brief, text-only comments on a project;
    (2) You can file your comments electronically using the eFiling
feature on the Commission's Web site (www.ferc.gov) under the link to
Documents and Filings. With eFiling, you can provide comments in a
variety of formats by attaching them as a file with your submission.
New eFiling users must first create an account by clicking on
``eRegister.'' You must select the type of filing you are making. If
you are filing a comment on a particular project, please select
``Comment on a Filing''; or
    (3) You can file a paper copy of your comments by mailing them to
the following address: Kimberly D. Bose, Secretary, Federal Energy
Regulatory Commission, 888 First Street NE., Room 1A, Washington, DC
20426.

Environmental Mailing List

    The environmental mailing list includes federal, state, and local
government representatives and agencies; elected officials; Native
American Tribes; other interested parties; and local libraries and
newspapers. This list also includes all affected landowners (as defined
in the Commission's regulations) who are current right-of-way grantors,
whose property may be used temporarily for project purposes, or who own
homes within certain distances of aboveground facilities, and anyone
who submits comments on the project. We will update the environmental
mailing list as the analysis proceeds to ensure that we send the
information related to this environmental review to all individuals,
organizations, and government entities interested in and/or potentially
affected by the proposed project.
    If we publish and distribute the EA, copies will be sent to the
environmental mailing list for public review and comment. If you would
prefer to receive a paper copy of the document instead of the CD
version or would like to remove your name from the mailing list, please
return the attached Information Request (appendix 2).

Becoming an Intervenor

    In addition to involvement in the EA scoping process, you may want
to become an ``intervenor'' which is an official party to the
Commission's proceeding. Intervenors play a more formal role in the
process and are able to file briefs, appear at hearings, and be heard
by the courts if they choose to appeal the Commission's final ruling.
An intervenor formally participates in the proceeding by filing a
request to intervene. Instructions for becoming an intervenor are in
the User's Guide under the ``e-filing'' link on the Commission's Web
site.

Additional Information

    Additional information about the project is available from the
Commission's Office of External Affairs, at (866) 208-FERC, or on the
FERC Web site at www.ferc.gov using the ``eLibrary'' link. Click on the
eLibrary link, click on ``General Search'' and enter the docket number,
excluding the last three digits in the Docket Number field (i.e., CP12-
106). Be sure you have selected an appropriate date range. For
assistance, please contact FERC Online Support at
<EMAIL_ADDRESS>or toll free at<PHONE_NUMBER>, or for TTY,
contact<PHONE_NUMBER>. The

eLibrary link also provides access to the texts of formal documents
issued by the Commission, such as orders, notices, and rulemakings.
    In addition, the Commission now offers a free service called
eSubscription which allows you to keep track of all formal issuances
and submittals in specific dockets. This can reduce the amount of time
you spend researching proceedings by automatically providing you with
notification of these filings, document summaries, and direct links to
the documents. Go to www.ferc.gov/esubscribenow.htm.
    Finally, public meetings or site visits will be posted on the
Commission's calendar located at www.ferc.gov/EventCalendar/EventsList.aspx along with other related information.

    Dated: May 1, 2012.
Kimberly D. Bose,
 Secretary.
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[FR Doc. 2012-10961 Filed 5-7-12; 8:45 am]
BILLING CODE 6717-01-C


[Federal Register: January 13, 2010 (Volume 75, Number 8)]
[Rules and Regulations]
[Page 1705-1706]
[DOCID:fr13ja10-7]

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DEPARTMENT OF HOMELAND SECURITY

Coast Guard

33 CFR Part 117

[USCG-2009-1107]
RIN 1625-AA09

Drawbridge Operation Regulations; Curtis Creek, Baltimore, MD

AGENCY: Coast Guard, DHS.

ACTION: Notice of temporary deviation from regulations.

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SUMMARY: The Commander, Fifth Coast Guard District, has issued a
temporary deviation from the regulations governing the operation of the
I695 Bridge across Curtis Creek, mile 0.9, at Baltimore, MD. The
deviation is necessary to facilitate mechanical repairs to the bridge.
This temporary deviation allows the drawbridge to remain in the closed
position during the deviation period.

DATES: This deviation is effective from 8 a.m. on January 9, 2010, to 8
p.m. on March 28, 2010.

ADDRESSES: Documents mentioned in this preamble as being available in
the docket are part of docket USCG-2009-1107 and are available online
by going to http://www.regulations.gov, inserting USCG-2009-1107 in the
``Keyword'' box, and then clicking ``Search.'' This material is also
available for inspection or copying the Docket Management Facility (M-
30), U.S. Department of Transportation, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590,
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays.

FOR FURTHER INFORMATION CONTACT: If you have questions on this rule,
call or e-mail Mr. Bill H. Brazier, Bridge Management Specialist, Fifth
Coast Guard District; telephone<PHONE_NUMBER>, e-mail
<EMAIL_ADDRESS>If you have questions on viewing the docket,
call Renee V. Wright, Program Manager, Docket Operations, telephone
(202) 366-9826.

SUPPLEMENTARY INFORMATION: The Maryland Transportation Authority, who
owns and operates this double-leaf bascule drawbridge, has requested a
temporary deviation from the current operating regulations set forth in
33 CFR 117.557 to facilitate mechanical repairs.
    The I695 Bridge, a double-leaf bascule drawbridge, has a vertical
clearance in the closed position to vessels of 58 feet, above mean high
water. The draw of the bridge shall open on signal if at least a

one-hour notice is given to the Maryland Transportation Authority in
Baltimore, as required by 33 CFR 117.557.
    Under this temporary deviation, the drawbridge will be maintained
in the closed position to vessels to facilitate repairs to trunnion
bearings on two separate closure periods. The first period will begin
at 8 a.m. on January 9, 2010, until and including 8 p.m. on February 6,
2010; and the second period will start again at 8 a.m. on March 1,
2010, until and including 8 p.m. on March 28, 2010. Vessels may pass
underneath the bridge while the bridge is in the closed position. There
are no alternate routes for vessels transiting this section of Curtis
Creek and the bridge will not be able to open in the event of an
emergency.
    Coast Guard vessels bound for the Coast Guard Yard at Curtis Bay,
as well as a significant amount of commercial vessel traffic, must pass
beneath the I695 Bridge. The Coast Guard has carefully coordinated the
restrictions with the Yard and the commercial users of the waterway.
Additionally, the Coast Guard will inform unexpected users of the
waterway through our Local and Broadcast Notices to Mariners of the
closure periods for the bridge so that vessels can arrange their
transits to minimize any impact caused by the temporary deviation.
    In accordance with 33 CFR 117.35(e), the drawbridge must return to
its regular operating schedule immediately at the end of the designated
time period. This deviation from the operating regulations is
authorized under 33 CFR 117.35.

    Dated: December 24, 2009.
Waverly W. Gregory, Jr.,
Chief, Bridge Administration Branch, Fifth Coast Guard District.
[FR Doc. 2010-437 Filed 1-12-10; 8:45 am]
BILLING CODE 9110-04-P