Air Quality: Revision to Definition of Volatile Organic CompoundsExclusion of Methyl Acetate

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 51

[FRL-5880-7]

RIN 2060-AH27

Air Quality: Revision to Definition of Volatile Organic

Compounds--Exclusion of Methyl Acetate

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action proposes to revise EPA's definition of volatile

organic compounds (VOC) for purposes of preparing State implementation

plans (SIP's) to attain the national ambient air quality standards

(NAAQS) for ozone under title I of the Clean Air Act (Act) and for any

Federal implementation plan (FIP) for an ozone nonattainment area. This

proposed revision would add methyl acetate to the list of compounds

excluded from the definition of VOC on the basis that this compound has

negligible contribution to tropospheric ozone formation. This compound

has potential for use as a solvent in paints, inks and adhesives.

Methyl acetate appears to be promising as a solvent for wood furniture

coatings.

DATES: Comments on this proposal must be received by September 24,

1997. Requests for a hearing must be submitted by September 24, 1997.

ADDRESSES: Comments should be submitted in duplicate (if possible) to:

Air and Radiation Docket and Information Center (6102), Attention:

Docket No. A-97-32, U.S. Environmental Protection Agency, 401 M Street,

SW, Washington, DC 20460. Comments should be strictly limited to the

subject matter of this proposal, the scope of which is discussed below.

Public Hearing: If anyone contacts EPA requesting a public hearing,

it will be held at Research Triangle Park, NC. Persons wishing to

request a public hearing/wanting to attend the hearing or wishing to

present oral testimony should notify Mr. William Johnson, Air Quality

Strategies and Standards Division (MD-15), U.S. Environmental

Protection Agency, Research Triangle Park, NC 27711, telephone (919)

541-5245. The EPA will publish notice of a hearing, if requested, in

the Federal Register. Any hearing will be strictly limited to the

subject matter of the proposal, the scope of which is discussed below.

The EPA has established a public docket for this action, A-97-32,

which is available for public inspection and copying between 8 a.m. and

4 p.m., Monday through Friday, at EPA's Air and Radiation Docket and

Information Center, (6102), 401 M Street, SW, Washington, DC 20460. A

reasonable fee may be charged for copying.

FOR FURTHER INFORMATION CONTACT: William Johnson, Office of Air Quality

Planning and Standards, Air Quality Strategies and Standards Division

(MD-15), Research Triangle Park, NC 27711, phone (919) 541-5245.

Interested persons may call Mr. Johnson to see if a hearing will be

held and the date and location of any hearing.

SUPPLEMENTARY INFORMATION:

Regulated entities. Entities potentially regulated by this action

are those which use and emit VOC and States which have programs to

control VOC emissions.

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Category Examples of regulated entities

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Industry............................... Industries that manufacture and

use paints, inks and

adhesives.

States................................. States which have regulations

to control volatile organic

compounds.

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This table is not intended to be exhaustive, but rather provides a

guide for readers regarding entities likely to be regulated by this

action. This table lists the types of entities that EPA is now aware

could potentially be regulated by this action. Other types of entities

not listed in the table could also be regulated. If you have questions

regarding the applicability of this action to a particular entity,

consult the person listed in the preceding FOR FURTHER INFORMATION

CONTACT section.

I. Background

On July 30, 1996, Eastman Chemical Company submitted a petition to

the EPA which requested that methyl acetate be added to the list of

compounds which are considered to be negligibly reactive in the

definition of VOC at 40 CFR 51.100(s). The petitioner based the request

on a comparison of the reactivity of methyl acetate to that of ethane

which has already been listed since 1977 as having negligible

reactivity. In a number of cases in the past, EPA has accepted

compounds with lower reactivity than ethane as negligibly reactive (62

FR 12583, 61 FR 52848, and 61 FR 4588).

One common way to evaluate reactivity is to look at the reaction

rate constant (kOH) value which is a measure of the rate

with which the compound reacts with hydroxyl (OH) radical. This

reaction is usually the first step in a series through which the

compound breaks down and participates in increased ozone formation. If

the OH reaction step is slow, the compound usually will not react

rapidly to form ozone. A kOH value higher than that of

ethane indicates that the compound reacts rapidly with OH. The high

kOH value generally indicates a high ozone formation rate,

but this may or may not be true depending on how the VOC behaves

subsequent to the OH attack.

The best available kOH value available for methyl

acetate is 3.4 x 10-13 cm3

molecule-1 sec-1 which is larger than the

kOH value for ethane (i.e., 2.4 x 10-13

cm3 molecule-1 sec-1). This seems to

indicate that methyl acetate is more reactive than ethane, but

additional studies have shown that this is not actually the case. These

studies, which were carried out by Dr. William P. L. Carter of the

University of California at Riverside, indicate that the reactivity of

methyl acetate is comparable to that of ethane.

Based on literature information, Dr. Carter conceived two

alternative mechanisms for the atmospheric photooxidation of methyl

acetate--one leading to a higher ozone yield and one to a lower yield--

and tested them against his smog chamber data. The mechanism that

showed the best agreement with his data was the one leading to low

ozone yield. Using that mechanism in a mechanistic model, Dr. Carter

computed the reactivity (i.e., maximum incremental reactivity) of

methyl acetate relative to that of ethane for 39 different sets of

urban conditions. Results showed methyl acetate reactivity to be

significantly lower (on an ozone-formed, per gram, VOC basis) than that

of ethane for all sets of conditions. The average value is only 40

percent of that of ethane. Based on these results, Dr. Carter concluded

that methyl acetate is less reactive than ethane.

Some uncertainties are due to the assumptions imbedded in the

mechanism used by Dr. Carter to compute reactivities. Dr. Carter made

one assumption concerning the nature of the main intermediate product

from the photooxidation of methyl acetate, and another one concerning

the atmospheric chemistry of that product. While the assumptions are

consistent with existing knowledge, and are supported also by the good

agreement between mechanism and smog chamber data, they were,

nevertheless, accepted without direct experimental verification (e.g.,

the analytical system used was not sufficient for identifying the

``assumed'' intermediate product), and are, therefore, subject to some

uncertainty.

[[Page 44927]]

Even so, the data presented are sufficiently valid to strongly support

acceptance of the petition.

As mentioned above, the data presented in Dr. Carter's study are

reported on a weight basis, i.e., grams of ozone-formed, per gram, of

VOC reacted. In one case in the past (60 FR 31633) where maximum

incremental reactivity data were presented, EPA has examined a

reactivity petition solely on a weight basis. However, for the methyl

acetate petition, EPA has also looked at the data on a mole basis,

i.e., amount of ozone-formed, per mole, of VOC reacted. Use of a per

mole basis is consistent with previous reactivity determinations based

on kOH values expressed in units of cm3

molecule-1 sec-1. This is also consistent with

the experimental work, done on a mole basis, which was used to

originally list ethane as negligibly reactive. The choice of weight

basis versus mole basis is significant. Given the relative low

molecular weight of ethane, use of the per gram basis tends to result

in more VOC (higher molecular weight ones) falling into the

``negligibly reactive'' class relative to the per mole basis.

On a mole basis, the average reactivity value of methyl acetate for

the 39 cities is lower than that for ethane. In 28 out of the 39 cases,

methyl acetate's reactivity is less than that of ethane. Based on these

results, EPA concludes that the existing scientific evidence does not

support a methyl acetate reactivity higher than that of ethane.

II. Proposed Action

Today's proposed action is based on EPA's review of the material in

Docket No. A-97-32. The EPA hereby proposes to amend its definition of

VOC at 40 CFR 51.100(s) to exclude methyl acetate as a VOC for ozone

SIP and ozone control for purposes of attaining the ozone NAAQS. The

revised definition will also apply for purposes of any FIP for ozone

nonattainment areas (40 CFR 52.741(a)(3)). States are not obligated to

exclude from control as a VOC those compounds that EPA has found to be

negligibly reactive. However, if this action is made final, States

should not include these compounds in their VOC emissions inventories

for determining reasonable further progress under the Act (e.g.,

section 182(b)(1)) and may not take credit for controlling these

compounds in their ozone control strategy.

III. Administrative Requirements

A. Docket

The docket is an organized and complete file for all information

submitted or otherwise considered by EPA in the development of this

proposed rulemaking. The principle purposes of the docket are: (1) To

allow interested parties to identify and locate documents so that they

can effectively participate in the rulemaking process; and, (2) to

serve as the record in case of judicial review (except for interagency

review materials) (section 307(d)(7)(A)).

B. Executive Order 12866

Under Executive Order 12866 (58 FR 51735, October 4, 1993), the

Agency must determine whether a regulatory action is ``significant''

and therefore subject to Office of Management and Budget (OMB) review

and the requirements of this Executive Order. The Order defines

``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 obligation 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.

Pursuant to the terms of Executive Order 12866, it has been

determined that this rule is not ``significant'' because none of the

listed criteria apply to this action. Consequently, this action was not

submitted to OMB for review under Executive Order 12866.

C. Unfunded Mandates Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub.L.

104-4, establishes requirements for Federal agencies to assess the

effects of their regulatory actions on State, local, and tribal

governments and the private sector. Under section 202 of the UMRA, EPA

generally must prepare a written statement, including a cost-benefit

analysis, for proposed and final rules with ``Federal mandates'' that

may result in expenditures to State, local, and tribal governments, in

the aggregate, or to the private sector, of $100 million or more in any

1 year. Before promulgation of an EPA rule for which a written

statement is needed, section 205 of the UMRA generally requires EPA to

identify and consider a reasonable number of regulatory alternatives

and adopt the least costly, most cost effective, or least burdensome

alternative that achieves the objective of the rule, unless EPA

publishes with the final rule an explanation of why that alternative

was not adopted. Before EPA establishes any regulatory requirements

that may significantly or uniquely affect small governments including

tribal governments, it must have developed, under section 203 of the

UMRA, a small government plan which informs, educates and advises small

governments on compliance with the regulatory requirements. Finally,

section 204 provides that for any proposed or final rule that imposes a

mandate on a State, local or tribal government of $100 million or more

annually, the Agency must provide an opportunity for such governmental

entities to provide input in development of the proposed rule.

Since today's rulemaking is deregulatory in nature and does not

impose any mandate on governmental entities or the private sector, EPA

has determined that sections 202, 203, 204 and 205 of the UMRA do not

apply to this action.

D. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) of 1980 requires the

identification of potentially adverse impacts of Federal regulations

upon small business entities. The Act specifically requires the

completion of an RFA analysis in those instances where the regulation

would impose a substantial impact on a significant number of small

entities. Because this proposed rulemaking imposes no adverse economic

impacts, an analysis has not been conducted. Pursuant to the provision

of 5 U.S.C. 605(b), I hereby certify that the proposed rule will not

have a significant impact on a substantial number of small entities

because no additional costs will be incurred.

E. Paperwork Reduction Act

This proposed rule does not change any information collection

requirements subject to OMB under the Paperwork Reduction Act, 44

U.S.C. 3501 et seq.

List of Subjects in 40 CFR Part 51

Environmental protection, Administrative practice and procedure,

Air pollution control, Carbon monoxide, Intergovernmental relations,

Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting and

recordkeeping requirements, Sulfur oxides, Volatile organic compounds.

[[Page 44928]]

Dated: August 18, 1997.

Carol M. Browner,

Administrator.

For reasons set forth in the preamble, part 51 of chapter I of

title 40 of the Code of Federal Regulations is proposed to be amended

as follows:

PART 51--REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF

IMPLEMENTATION PLANS.

1. The authority citation for part 51 is revised to read as

follows:

Authority: 42 U.S.C. 7401-7671q.

2. Section 51.100 is proposed to be amended by revising paragraph

(5) introductory text and paragraph (s)(1) to read as follows:

Sec. 51.100 Definitions.

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(s) Volatile organic compounds (VOC) means any compound of carbon,

excluding carbon monoxide, carbon dioxide, carbonic acid, metallic

carbides or carbonates, and ammonium carbonate, which participates in

atmospheric photochemical reactions.

(1) This includes any such organic compound other than the

following, which have been determined to have negligible photochemical

reactivity: methane; ethane; methylene chloride (dichloromethane);

1,1,1-trichloroethane (methyl chloroform); 1,1,2-trichloro-1,2,2-

trifluoroethane (CFC-113); trichlorofluoromethane (CFC-11);

dichlorodifluoromethane (CFC-12); chlorodifluoromethane (HCFC-22);

trifluoromethane (HFC-23); 1,2-dichloro 1,1,2,2-tetrafluoroethane (CFC-

114); chloropentafluoroethane (CFC-115); 1,1,1-trifluoro 2,2-

dichloroethane (HCFC-123); 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1-

dichloro 1-fluoroethane (HCFC-141b); 1-chloro 1,1-difluoroethane (HCFC-

142b); 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124); pentafluoroethane

(HFC-125); 1,1,2,2-tetrafluoroethane (HFC-134); 1,1,1-trifluoroethane

(HFC-143a); 1,1-difluoroethane (HFC-152a); parachlorobenzotrifluoride

(PCBTF); cyclic, branched, or linear completely methylated siloxanes;

acetone; perchloroethylene (tetrachloroethylene); 3,3-dichloro-

1,1,1,2,2-pentafluoropropane (HCFC-225ca); 1,3-dichloro-1,1,2,2,3-

pentafluoropropane (HCFC-225cb); 1,1,1,2,3,4,4,5,5,5-decafluoropentane

(HFC 43-10mee); difluoromethane (HFC-32); ethylfluoride (HFC-161);

1,1,1,3,3,3-hexafluoropropane (HFC-236fa); 1,1,2,2,3-pentafluoropropane

(HFC-245ca); 1,1,2,3,3-pentafluoropropane (HFC-245ea); 1,1,1,2,3-

pentafluoropropane (HFC-245eb); 1,1,1,3,3-pentafluoropropane (HFC-

245fa); 1,1,1,2,3,3-hexafluoropropane (HFC-236ea); 1,1,1,3,3-

pentafluorobutane (HFC-365mfc); chlorofluoromethane (HCFC-31); 1

chloro-1-fluoroethane (HCFC-151a); 1,2-dichloro-1,1,2-trifluoroethane

(HCFC-123a); 1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxy-butane

(C4F9OCH3); 2-(difluoromethoxymethyl)-

1,1,1,2,3,3,3-heptafluoropropane

((CF3)2CFCF2OCH3); 1-

ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane

(C4F9OC2H5); 2-

(ethoxydifluoromethyl)-1,1,1,2,3,3,3-heptafluoropropane

((CF3)2CFCF2OC2H5

); methyl acetate and perfluorocarbon compounds which fall into these

classes:

(i) Cyclic, branched, or linear, completely fluorinated alkanes;

(ii) Cyclic, branched, or linear, completely fluorinated ethers

with no unsaturations;

(iii) Cyclic, branched, or linear, completely fluorinated tertiary

amines with no unsaturations; and

(iv) Sulfur containing perfluorocarbons with no unsaturations and

with sulfur bonds only to carbon and fluorine.

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[FR Doc. 97-22509 Filed 8-22-97; 8:45 am]

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