[Federal Register Volume 70, Number 5 (Friday, January 7, 2005)]
[Proposed Rules]
[Pages 1640-1654]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-346]



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Part IV





Environmental Protection Agency





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40 CFR Parts 51 and 52



Revisions to the California State Implementation Plan and Revision to 
the Definition of Volatile Organic Compounds (VOC)--Removal of VOC 
Exemptions for California's Aerosol Coating Products Reactivity-Based 
Regulation; Proposed Rule

  Federal Register / Vol. 70, No. 5 / Friday, January 7, 2005 / 
Proposed Rules  

[[Page 1640]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 51 and 52

[OAR-2003-0200; FRL-7857-6]


Revisions to the California State Implementation Plan and 
Revision to the Definition of Volatile Organic Compounds (VOC)--Removal 
of VOC Exemptions for California's Aerosol Coating Products Reactivity-
Based Regulation

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The EPA is proposing to approve a new consumer products 
regulation as part of the California State Implementation Plan (SIP) 
for ozone under the Clean Air Act (CAA) as amended in 1990. This 
California regulation adopts an innovative approach to reduce ozone 
formation from volatile organic compounds (VOC) in aerosol coating 
products. The EPA is also proposing to approve the use of California's 
Tables of Maximum Incremental Reactivity (MIR) to allow implementation 
of the new regulation in California. We are also proposing to revise 
EPA's definition of VOCs so that compounds which we previously 
identified as negligibly reactive and exempt from EPA's regulatory 
definition of VOCs will now count towards a product's reactivity-based 
VOC limit for the purpose of California's aerosol coatings regulation. 
We are taking comments on this proposal and we plan to follow with a 
final action.

DATES: Comments must be received on or before March 8, 2005.

ADDRESSES: Submit your comments, identified by Docket ID No. OAR-2003-
0200, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Agency Web site: http://www.epa.gov/edocket. EDOCKET, 
EPA's electronic public docket and comment system, is EPA's preferred 
method for receiving comments. Follow the on-line instructions for 
submitting comments.
     E-mail: [email protected].
     Fax: 202-566-1741.
     Mail: OAR Docket: OAR-2003-0200, Environmental Protection 
Agency, Mailcode: 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 
20460.
     Hand Delivery: EPA/DC, Public Reading Room, Room B102, EPA 
West Building, 1301 Constitution Avenue, NW., Washington, DC. Such 
deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. OAR-2003-0200. 
EPA's policy is that all comments received will be included in the 
public docket without change and may be made available online at http://www.epa.gov/edocket, including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through EDOCKET, regulations.gov, or e-
mail. The EPA EDOCKET and the federal regulations.gov websites are 
``anonymous access'' systems, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through EDOCKET or regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit EDOCKET on-line or see the Federal Register of May 31, 
2002 (67 FR 38102).
    For additional instructions on submitting comments, go to Unit I of 
the SUPPLEMENTARY INFORMATION section of this document.
    Docket: All documents in the docket are listed in the EDOCKET index 
at http://www.epa.gov/edocket. Although listed in the index, some 
information is not publicly available, i.e., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, is not placed on the Internet and will be 
publicly available only in hard copy form. Publicly available docket 
materials are available either electronically in EDOCKET or in hard 
copy at the OAR Docket, OAR-2003-0200, EPA/DC, EPA West, Room B102, 
1301 Constitution Ave., NW., Washington, DC. The Public Reading Room is 
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The telephone number for the Public Reading Room is 
(202) 566-1744, and the telephone number for the OAR Docket is (202) 
566-1742.

FOR FURTHER INFORMATION CONTACT: Stanley Tong, Rulemaking Office (AIR-
4), Environmental Protection Agency, Region IX, 75 Hawthorne St., San 
Francisco, CA 94105; telephone number: (415) 947-4122; fax number: 
(415) 947-3579; e-mail address: [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. What Should I Consider as I Prepare My Comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
EDOCKET, regulations.gov or e-mail. Clearly mark the part or all of the 
information that you claim to be CBI. For CBI information in a disk or 
CD ROM that you mail to EPA, mark the outside of the disk or CD ROM as 
CBI and then identify electronically within the disk or CD ROM the 
specific information that is claimed as CBI). In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
    i. Identify the rulemaking by docket number and other identifying 
information (subject heading, Federal Register date and page number).
    ii. Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
    iii. Explain why you agree or disagree; suggest alternatives and 
substitute language for your requested changes.
    iv. Describe any assumptions and provide any technical information 
and/or data that you used.
    v. If you estimate potential costs or burdens, explain how you 
arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
    vi. Provide specific examples to illustrate your concerns, and 
suggest alternatives.
    vii. Explain your views as clearly as possible, avoiding the use of 
profanity or personal threats.

[[Page 1641]]

    viii. Make sure to submit your comments by the comment period 
deadline identified.
    ix. Please strictly limit comments to the subject matter of this 
proposal, the scope of which is discussed below. Please identify the 
section/subsection on which you are commenting so we can group similar 
comments together and better understand the context of your comment.
    x. EPA requests that you also send a copy of your comments to: 
Andrew Steckel, Rulemaking Office Chief (AIR-4), U.S. Environmental 
Protection Agency, Region IX, 75 Hawthorne Street, San Francisco, CA 
94105-3901.
    3. Docket Copying Costs. A reasonable fee may be charged for 
copying.

B. How Do I Request a Public Hearing?

    If you wish to request a public hearing to submit comments 
concerning this proposal please contact Mr. Stanley Tong, Rulemaking 
Office (AIR-4), U.S. Environmental Protection Agency, 75 Hawthorne 
Street, San Francisco, CA 94105, telephone (415) 947-4122. Requests for 
a public hearing must be made by January 27, 2005. The EPA will publish 
a notice of a hearing, if a hearing is requested, in the Federal 
Register. Because the State has already held a public notice and 
comment period for its aerosol coatings rule, any EPA hearing will be 
strictly limited to the proposed EPA approval of the rule and its 
inclusion in the California SIP and to the proposed change in the 
definition of VOCs for 40 CFR 51.100(s). The hearing will not cover the 
reactivity limits or other specifics of California's rule. If a public 
hearing is requested, it will be held near our Region IX office in San 
Francisco, CA.

C. Throughout This Document, ``We,'' ``Us'' and ``Our'' Refer to EPA

D. How Can I Get Copies of This Document and Other Related Information?

    1. In addition to accessing the official public docket at http://www.epa.gov/edocket/, you can also inspect copies of the submitted SIP 
revision at our Region IX office during normal business hours. EPA 
requests that you contact the person listed in the For Further 
Information Contact section to schedule your inspection. You may also 
see copies of the submitted SIP revision during normal business hours 
by appointment at the California Air Resources Board, Stationary Source 
Division, Rule Evaluation Section, 1001 ``I'' Street, Sacramento, CA 
95814.
    2. A copy of California's aerosol coating products regulation can 
also be downloaded from the following internet addresses. Please be 
advised that these are not EPA Web sites and may not contain the same 
version of the regulations that were submitted to EPA. http://www.arb.ca.gov/consprod/regs/aeropnt.pdf http://www.arb.ca.gov/consprod/regs/Aeropnt.doc

Table of Contents

I. The State's Submittal.
    A. What regulations did the State submit?
    B. Are there other versions of this regulation?
    C. What is the purpose of the submitted CARB regulation?
III. EPA's Evaluation and Action.
    A. How is EPA evaluating the regulation?
    B. Does the regulation meet the evaluation criteria?
    C. Public comment and final action.
IV. Background Information.
    A. Why was this regulation submitted?
    B. What is photochemical reactivity?
    C. Why is use of the relative reactivity concept appropriate in 
California's aerosol coatings rule?
    D. Are California's relative reactivity-based regulations 
appropriate for areas outside of California?
    E. How will the effectiveness of this reactivity-based program 
be evaluated?
    F. How has CARB addressed concerns about air toxics and ozone-
depleting substances?
    G. What changes in enforcement strategies will likely occur due 
to this relative reactivity-based regulation?
IV. Summary of CARB's Aerosol Coatings Regulation.
    A. What does CARB's regulation require?
V. Future Actions.
    A. What action will be taken to determine if this reactivity-
based regulation is effective?
    B. How will future uses of relative reactivity be evaluated?
VI. Statutory and Executive Order Reviews.

I. The State's Submittal

A. What Regulations Did the State Submit?

    Table 1 lists the regulations addressed by this proposal with the 
date that they were adopted and submitted to EPA by the California Air 
Resources Board (CARB).

                     Table 1.--Submitted Regulations
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               Regulation title                   Adopted     Submitted
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Aerosol Coating Products......................     5/1/2001    3/13/2002
Tables of Maximum Incremental Reactivity (MIR)     5/1/2001    3/13/2002
 Values.......................................
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    On May 7, 2002, we found that this submittal meets the completeness 
criteria in 40 CFR Part 51, Appendix V, as required before formal EPA 
review.

B. Are There Other Versions of This Regulation?

    There is no previous version of the aerosol coating products 
regulation approved by EPA into the SIP, although CARB adopted an 
earlier version of this regulation on March 23, 1995, and submitted it 
to us on December 18, 1998. On November 19, 1998, CARB adopted 
amendments to this earlier regulation. The CARB did not submit these 
amendments to us as a SIP revision. There is no previous stand-alone 
version of the Tables of MIR values in the SIP applicable to aerosol 
coatings. Today, we are proposing approval of the CARB aerosol coatings 
rule submitted to us on March 13, 2002. While we can act on only the 
most recently submitted version of this regulation, we have reviewed 
materials CARB provided with the previous SIP submittals for 
informational purposes. Thus, this version of the aerosol coatings rule 
replaces the earlier versions developed by CARB and, if we approve it, 
will be the first such rule in the California SIP.

C. What Is the Purpose of the Submitted CARB Regulation?

    The regulation covers aerosol coatings, aerosol clear coatings, and 
aerosol stains. It applies to any person who sells, supplies, offers 
for sale, applies, or manufactures for use in California any aerosol 
coating subject to the limits in the regulation. The regulation imposes 
reactivity-based VOC limits on these products for purposes of reducing 
ozone caused by VOC emissions.
    In the current SIP submittal, CARB has developed a new approach for 
regulating VOC emissions from aerosol coatings. Traditionally, the VOC 
emissions from aerosol and other coatings have been controlled by 
limiting the mass of all VOCs in a product, and VOC content limits of 
aerosol coatings were expressed as a maximum percent by mass of all 
VOC. The new approach taken by CARB incorporates the concept of VOC 
photochemical reactivity. This concept relies on the fact that the same 
weight/amount of some VOCs (e.g., xylene) has the potential to form 
more ozone, or to form ozone more quickly, than the same weight/amount 
of other VOCs (e.g., propane) once they are emitted into the ambient 
air under the same conditions.
    The CARB estimates that its previous mass-based VOC control rule 
for aerosol coatings resulted in statewide aerosol coating VOC 
emissions reductions of 9

[[Page 1642]]

tons per day (tpd) from the 1989 baseline estimated VOC emissions of 30 
tpd of VOC. The CARB calculates that the new reactivity-based aerosol 
coatings rule in the current submittal would achieve the ``equivalent'' 
of an additional 3.1 tpd of VOC mass-based reductions statewide. In 
other words, CARB estimates that this rule will achieve reactivity-
based VOC reductions that would be the equivalent of 12.1 tons of mass-
based VOC reductions from the 1989 baseline, measured in terms of ozone 
reduction. The CARB intends its new regulation to encourage 
manufacturers to reduce use of VOCs with higher reactivity, thereby 
achieving more ozone reductions than through traditional VOC mass-based 
regulations.

III. EPA's Evaluation and Action

A. How Is EPA Evaluating the Regulation?

    Generally, SIP regulations must be enforceable (see section 
110(a)(2)(A) of the CAA), must at a minimum require Reasonably 
Available Control Technology (RACT) and Reasonably Available Control 
Measures (RACM) in nonattainment areas (see, for example, sections 
172(c)(1), 182(a)(2)(A) and 182(b)(2)), must not interfere with 
attainment and reasonable further progress or any other applicable 
requirement of the CAA, and must achieve the pollution reduction 
requirements of the CAA (see section 110(l)). The CARB's aerosol 
coatings regulation applies to both ozone attainment and non-attainment 
areas statewide. Because this regulation covers nonmajor area sources 
that are not covered by a Control Techniques Guidelines (CTG) document, 
it is not subject to the RACT requirements for ozone nonattainment 
areas (CAA, section 182(b)(2)).
    Guidance and policy documents that we used to help evaluate 
enforceability requirements includes: Issues Relating to VOC Regulation 
Cutpoints, Deficiencies, and Deviations; Clarification to Appendix D of 
November 24, 1987 Federal Register,'' (Blue Book), May 25, 1988, 
(revised 1/11/90), Office of Air Quality Planning and Standards. We 
also relied on several technical reports and journals to evaluate 
CARB's SIP submittal. These reports and journals are referenced in 
footnotes in the body of this proposal and are included in the docket 
for this proposal.

B. Does the Regulation Meet the Evaluation Criteria?

    We believe that the aerosol coatings rule will improve the SIP by 
establishing stringent VOC limits for this product category, by 
improving enforcement through labeling and reporting requirements, and 
by creating an incentive for the use of solvents with relatively low 
contribution to ozone formation. The regulation is generally consistent 
with relevant policy and guidance regarding enforceability. Our 
approval of the rule would also be consistent with CAA section 110(l), 
because there is no prior version of the aerosol coatings regulation in 
the SIP and ozone reductions resulting from the approval of this 
regulation into the SIP will help in the State's efforts to achieve 
attainment with the national ambient air quality standard (NAAQS) for 
ozone. RACT requirements do not apply to the source category covered by 
the CARB rule because RACT applies to major stationary sources in 
nonattainment areas and source categories covered by a CTG. Because of 
their widespread use in relatively small amounts, aerosol coatings are 
considered area sources rather than major stationary sources. EPA has 
not issued a CTG or a rule for this category. However, even though 
federal RACT or consumer product requirements do not yet apply, CARB 
took the initiative in 1995 to go beyond basic federally mandated VOC 
reduction requirements by adopting an aerosol coatings regulation with 
two tiers of aggressive mass-based VOC limits. In its current SIP 
submittal, CARB is amending its existing regulation by replacing the 
mass-based limits with reactivity-based limits intended to achieve 
additional ozone reduction benefits.
    Although CARB's existing mass-based aerosol coatings regulation has 
significantly reduced emissions from aerosol coatings, CARB has 
concluded that more reductions are needed to help reduce the high ozone 
concentrations in Southern California and the Central Valley. The CARB 
also believes that some VOC mass-based limits in the previous version 
of the rule presented particularly difficult reformulation challenges 
for manufacturers of water-based coatings,\1\ and the State concluded 
that it may not be feasible to achieve additional VOC reductions from a 
traditional VOC mass-based program. The current SIP submittal relies on 
the relative reactivity concept, that is, the fact that individual 
species of VOC react in the atmosphere to form different amounts of 
ozone or to form ozone at different rates. The CARB hopes to target VOC 
emission reductions to better control a product's contribution to ozone 
formation by encouraging reductions of higher reactivity VOCs, rather 
than by treating all VOCs in a product alike through a mass-based rule. 
The submitted regulation therefore consists of reactivity-based limits 
that replace the existing mass-based VOC limits for aerosol spray 
coatings.
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    \1\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Chapter VII, page 60, May 5, 2000.
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    Although EPA is supportive of reactivity-based programs, we 
recognize that they may be more complex to develop, enforce, and 
evaluate than mass-based programs. As a result, it is particularly 
important for us to evaluate the State agency's ability to implement 
such programs. The CARB has addressed these concerns partly through an 
extensive public process spanning over 3 years in the development of 
the aerosol coatings rule. The CARB held eight public workshops and 
over 20 meetings with industry, leading scientists, local air 
districts, and EPA. The CARB also gathered detailed information on the 
sales and composition of aerosol coatings, funded extensive research on 
VOC reactivity scales and their applicability to environmental 
conditions in California, and took steps intended to ensure that no 
backsliding would occur from adoption of the relative-reactivity 
approach. To account for potential changes in MIR values as scientific 
knowledge improves, CARB also committed to improve and update its 
program by including in its Board resolution \2\ the provision ``[t]o 
review the Tables of Maximum Incremental Reactivity (MIR) Values 18 
months after the effective date of the amendments, and every 18 months 
thereafter, to determine if modifications to the MIR values are 
warranted.'' The CARB will also ``[r]eview the reactivity-based limits 
before January 1, 2007 to determine if modifications are necessary to 
reflect changes to the MIR values and return to the Board with any 
recommended modifications to the reactivity-based limits.'' \3\
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    \2\ State of California Air Resources Board Resolution 00-22, 
June 22, 2000, Agenda Item No. 00-6-1.
    \3\ State of California Air Resources Board Resolution 00-22, 
June 22, 2000, Agenda Item No. 00-6-1.
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    Additional details about the comparison of reactivity-based 
reductions to VOC mass-based reductions, the appropriateness of CARB's 
reactivity research to areas outside of California, and the evaluation 
of the effectiveness of CARB's regulation are provided in the 
Background section below.

[[Page 1643]]

    Information normally found in a Technical Support Document (TSD) is 
incorporated into this proposed rule. A separate TSD has not been 
written for this proposed rulemaking.

C. Public Comment and Final Action

    Because EPA believes the submitted aerosol coatings regulation 
fulfills all relevant requirements, we are proposing to approve it into 
the California SIP as authorized in section 110(k)(3) of the CAA. We 
are also proposing to approve the use of CARB's Tables of MIR values in 
California for the purpose of implementation of the aerosol coatings 
regulation. We intend to grant SIP credit for the ozone equivalent VOC 
mass-based reductions that are achieved by CARB's reactivity-based 
regulation. Details on the methodology CARB used to determine the 
equivalent VOC mass-based tonnage reduction achieved by its reactivity 
regulation is discussed in the CARB staff report.\4\
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    \4\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Chapter II, page 37, May 5, 2000.
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    Currently, EPA's regulatory definition of VOC (40 CFR 51.100(s)) 
excludes certain compounds, such as methane and ethane, which EPA has 
determined to have negligible photochemical reactivity with respect to 
the formation of ozone. California's reactivity-based regulation, 
however, requires the inclusion of the assigned MIR scale reactivity 
value of each organic compound present in the volatile portion of a 
product, even if the compound's reactivity value is so low that EPA has 
previously determined it to be negligibly reactive and therefore 
exempt.
    In order to approve CARB's aerosol coatings rule, EPA proposes to 
modify our regulatory definition of VOC so that compounds previously 
excluded will now be counted towards a product's reactivity-based VOC 
limit for the limited purpose of CARB's aerosol coatings reactivity-
based regulation. Under 40 CFR 51.100(s), EPA has excluded compounds 
from the definition of VOC in recognition of the fact that individual 
organic compounds differ with respect to their incremental contribution 
to ozone formation. EPA's exemption-based system separates organic 
compounds into reactive and negligibly reactive compounds. The CARB's 
reactivity-based regulation makes this distinction unnecessary because 
CARB's rule assigns each compound a reactivity factor that accounts for 
its relative contribution to ozone formation. These previously exempted 
compounds will continue to be excluded from the Federal definition of 
VOCs for other purposes.
    We will accept comments from the public on this proposed approval 
of the CARB aerosol rule into the SIP and the proposed modification of 
our definition of VOC for the next 60 days. Unless we receive 
convincing new information during the comment period, we intend to 
publish a final approval action that will incorporate the regulations 
listed in Table 1 into the federally enforceable SIP and modify our 
definition of VOC to support CARB's aerosol coating rule.
    The EPA, with CARB's assistance, intends to evaluate the 
performance of this reactivity-based regulation in 3 years. This will 
allow time to compile data on the implementation of, and compliance 
with, the regulation, and will allow time to conduct additional 
technical analysis such as modeling efforts needed to evaluate the 
effect of the regulation on ambient ozone levels. We encourage CARB to 
use this time to collect data on the costs and effectiveness of this 
regulation, both to the regulated entities and to the regulators. In 
particular, EPA is interested in how implementation of this regulation 
affects the development of detailed emission inventories, as well as 
industry compliance costs, including recordkeeping and compliance 
testing, manufacturing or material costs, product quality and price. 
Towards this goal, we are relying upon CARB's Board resolution \5\ 
which ``[d]irects the Executive Officer to take the following actions: 
(1) Monitor the progress of manufacturers in meeting the reactivity-
based VOC limits, (2) propose any future regulatory modifications that 
may be appropriate, and (3) continue to evaluate emerging technologies 
for aerosol coatings to determine if additional ozone reductions will 
be feasible in the future.''
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    \5\ State of California Air Resources Board Resolution 00-22, 
June 22, 2000, Agenda Item No. 00-6-1.
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    The proposed approval of CARB's aerosol coatings regulation based 
upon VOC reactivity is limited to this source category for this State. 
EPA believes that relative reactivity-based regulations may help 
provide the flexibility necessary to achieve further emissions 
reductions from some source categories to address persistent ozone 
nonattainment problems in areas of the country that need further 
reductions in VOC emissions to come into attainment with federal ozone 
standards. EPA is committed to continuing its support of research on 
the suitability of relative reactivity-based regulations to other 
geographic regions and to other source categories through the national 
Reactivity Research Working Group (RRWG) of which CARB and EPA are 
members.\6\ The purpose of the RRWG is to encourage and sponsor 
research on scientific questions concerning VOC reactivity which may be 
of interest to regulators. This group is affiliated with NARSTO 
(formerly known as the North American Research Strategy for 
Tropospheric Ozone) and is a voluntary organization currently composed 
of industry, government and academic representatives. The group has an 
open membership and anyone may attend the meetings and participate.
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    \6\ See ``VOC Reactivity'' at http://www.cgenv.com/Narsto/.
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    The EPA is specifically seeking public comment on how reactivity-
based programs might affect industry compliance and recordkeeping costs 
to support effective implementation and enforcement, and how industry 
and regulatory agency costs and staff requirements might change with 
respect to emission inventories.
    We are not seeking comments on the reactivity limits or other 
specifics of CARB's rule; nor are we seeking comments on EPA's VOC 
exemption process. The EPA has previously published in 63 FR 48792 
(September 11, 1998) its views on reactivity as it relates to the 
regulation of VOC emissions from consumer products pursuant to CAA 
Sec.  183(e) and this proposal should not be construed as a change in 
the Agency's interpretation of that provision. When commenting, please 
indicate which section of this proposal you are commenting on so we can 
group similar comments together.

III. Background Information

A. Why Was This Regulation Submitted?

    Ground level ozone, commonly referred to as ``smog,'' is a serious 
air pollutant that harms human health and the environment. Ground level 
ozone is a complex problem that is difficult to control in part because 
ozone is not emitted directly by specific sources. It forms in the air 
when there are chemical reactions between nitrogen oxides 
(NOX) and VOCs in the presence of heat and sunlight. 
Therefore, one way to reduce ozone levels in many areas is to control 
emissions of VOCs. Section 110(a) of the CAA requires States to submit 
regulations that control VOC emissions as part of the State's SIP.

B. What Is Photochemical Reactivity?

    There are thousands of individual species of VOC chemicals that can

[[Page 1644]]

combine with NOX and the energy from sunlight to form ozone. 
The impact of a given VOC on formation of ground-level ozone is 
sometimes referred to as its ``reactivity.'' It is generally understood 
that not all VOCs are equal in their effects on ground-level ozone 
formation. Some VOCs react extremely slowly and changes in their 
emissions have limited effects on ozone pollution episodes. Some VOCs 
form ozone more quickly, or they may form more ozone than other VOCs. 
Others not only form ozone themselves, but also enhance ozone formation 
from other VOCs. By distinguishing between more reactive and less 
reactive VOCs, however, it should be possible to decrease ozone 
concentrations further or more efficiently than by controlling all VOCs 
equally.
    Assigning a value to the reactivity of a compound is not 
straightforward. Reactivity is not simply a property of the compound 
itself; it is a property of both the compound and the environment in 
which the compound is found. The reactivity of a single compound varies 
with VOW-NOX ratios, meteorological conditions, the mix of 
other VOCs in the atmosphere, and the time interval of interest. 
Designing an effective regulation that takes account of these 
interactions is difficult, and implementing and enforcing such a 
regulation carries the extra burden of characterizing and tracking the 
full chemical composition of VOC emissions.
1. History of EPA's VOC Policy
    Historically, EPA's general approach to regulation of VOC emissions 
has been based upon control of total VOCs by mass, without 
distinguishing between individual species of VOC. EPA considered the 
regulation of VOCs by mass to be the most effective and practical 
approach based upon the scientific and technical information available 
when EPA developed its VOC control policy.
    EPA issued the first version of its VOC control policy in 1971, as 
part of EPA's SIP preparation guidance.\7\ In that guidance, EPA 
emphasized the need to reduce the total mass of VOC emissions, but it 
also suggested that substitution of one compound for another might be 
useful when it would result in a clearly evident decrease in reactivity 
and thus tend to reduce photochemical oxidant formation. This latter 
statement encouraged States to promulgate SIPs with VOC emission 
substitution provisions similar to the Los Angeles County Air Pollution 
Control District's (LACAPCD) Rule 66,\8\ which allowed some VOCs that 
were believed to have low to moderate reactivity to be exempted from 
control. The exempt status of many of those VOCs was questioned a few 
years later, when research results indicated that, although some of 
those compounds do not produce much ozone close to the source, they may 
produce significant amounts of ozone after they are transported 
downwind from urban areas.\9\
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    \7\ U.S. Environmental Protection Agency. ``Requirements for 
Preparation, Adoption, and Submittal of Implementation Plans.'' 
Federal Register, 36 FR 15486-15506 (1971).
    \8\ County of Los Angles, Air Pollution Control District (1972). 
Rules and Regulations. Rule 66 (1966). Amended November 2, 1972.
    \9\ Dimitriades, B. ``Oxidant/03 Air Quality Benefits from 
Emission Substitution.'' In: ``Proceedings. Hydrocarbon Control 
Feasibility. Its Impact on Air Quality'' (and references herein). 
Speciality Conference, Air Pollution Control Association, April, 
1977.
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    In 1977, this research led EPA to issue the second version of its 
VOC policy under the title ``Recommended Policy on Control of Volatile 
Organic Compounds,'' (42 FR 35314, July 8, 1977) offering its own, more 
limited list of exempt organic compounds. The 1977 policy identified 
four compounds that have very low photochemical reactivity and 
determined that their contribution to ozone formation and accumulation 
could be considered negligible. The policy exempted these ``negligibly 
reactive'' compounds from VOC emissions limitations in programs 
designed to meet the ozone NAAQS. Since 1977, the EPA has added other 
compounds to the list of negligibly reactive compounds based on new 
information as it has been developed. In 1992, the EPA adopted a formal 
regulatory definition of VOC for use in SIPs, which explicitly excludes 
compounds that have been identified as negligibly reactive [40 CFR 
51.100(s)]. To date, EPA has exempted 53 compounds or classes of 
compounds in this manner.
    In effect, EPA's current VOC exemption policy has resulted in a 
two-bin system in which most compounds are treated equally as VOCs and 
are controlled and a separate smaller group of compounds are treated as 
negligibly reactive and are exempt from VOC control.\10\ This approach 
was intended to encourage the reduction of emissions of all VOCs that 
participate in ozone formation. From one perspective, it appears that 
this approach has been relatively successful. EPA estimates that, 
between 1970 and 2003, VOC emissions from man-made sources nationwide 
have declined by 54 percent. This decline in VOC emissions has helped 
to decrease average ozone concentration by 29 percent (based on 1-hour 
averages) and 21 percent (based on 8-hour averages) between 1980 and 
2003. These reductions have occurred even though, between 1970 and 
2003, population, vehicle miles traveled, and gross domestic product 
have risen 39 percent, 155 percent and 176 percent respectively. 
[Latest Findings on National Air Quality: 2002 Status and Trends, EPA 
454/K-03-001, August 2003; and The Ozone Report Measuring Progress 
through 2003, EPA 454/K-04-001, April 2004; Environmental Protection 
Agency, Office of Air Quality Planning and Standards, Research Triangle 
Park, North Carolina]
---------------------------------------------------------------------------

    \10\ It should be noted that EPA has also taken VOC reactivity 
into consideration in other ways, such as the development of the 
consumer and commercial product regulations under CAA Sec.  183(e). 
EPA considered VOC reactivity as a factor in developing the federal 
consumer products program as directed by the statute, and EPA's 
approach was confirmed by the courts. See, Allied Local & Regional 
Mfrs. Caucus v. EPA, 215 F.3d 61 (D.C. Cir. 2000), cert. denied 532 
U.S. 1018 (2001). The EPA plans to develop its own regulation for 
aerosol coating products under CAA Sec.  183(e). Our future 
regulation may differ from CARB's regulation. If this turns out to 
be the case, a process will need to be developed to verify that the 
State's requirements and limits are at least as stringent as those 
in the national standard.
---------------------------------------------------------------------------

    On the other hand, some have argued that a reactivity-based 
approach for reducing VOC emissions would be more effective than the 
current mass-based approach. One group of researchers conducted a 
detailed modeling study of the Los Angeles area and concluded that, 
compared to the current approach, a reactivity-based approach could 
achieve the same reductions in ozone concentrations at significantly 
less cost--or for a given cost, could achieve a significantly greater 
reduction in ozone concentrations.\11\ EPA recognizes that, in theory, 
a well designed reactivity-based program, in which each individual VOC 
is regulated more or less stringently based on its actual contribution 
to ozone formation, would be more efficient than the current approach. 
On the other hand, there are significant practical difficulties 
involved in designing, implementing, and enforcing such a program. We 
believe that the CARB program we are proposing to approve today will 
help EPA and other States to evaluate whether the benefits of a 
reactivity-based approach are sufficient to outweigh these practical 
difficulties.
---------------------------------------------------------------------------

    \11\ A. Russell, J. Milford, M. S. Bergin, S. McBride, L. 
McNair, Y. Yang, W. R. Stockwell, B. Croes, ``Urban Ozone Control 
and Atmospheric Reactivity of Organic Gases,'' Science, 269: 491-
495, (1995).
---------------------------------------------------------------------------

    We also recognize that, in spite of the progress that most parts of 
the country

[[Page 1645]]

have made in reducing ozone concentrations, further reductions in VOC 
emissions will likely be needed to bring a number of areas into 
attainment with the 8-hour ozone standard. In particular, in areas 
where significant VOC emission controls are already in place, further 
mass-based emission reductions may be difficult or very expensive to 
achieve. In such situations, regulations that distinguish between 
individual VOCs and create an incentive to shift production and use 
from more reactive VOCs to less reactive VOCs may provide the 
flexibility necessary to continue progress towards attainment of the 
ozone NAAQS.
2. History of CARB's Reactivity Work
    Regulatory authorities in California have been experimenting with 
the concept of reactivity-based regulations for some time. The first 
regulation in California that took reactivity into account was Rule 
66,\12\ adopted in the mid 1960s by LACAPCD. This rule restricted 
emissions of certain classes of compounds which were defined by the 
rule as photochemically reactive based on their chemical structure 
(e.g., compounds having olefinic type of unsaturation) to 40 pounds per 
day, but allowed up to 3000 pounds per day emissions for many other 
organic compounds which were not defined by the rule as photochemically 
reactive. In other words, Rule 66 sought to regulate certain VOCs more 
than others, based on the assumption that some VOCs participate more in 
ozone formation. Rule 66 was very influential at the time and versions 
of it were adopted by several other States. However, the VOC control 
approach taken by Rule 66 has been superseded by EPA's definition of 
VOC (57 FR 3941, February 3, 1992), which was based on the 1977 EPA 
policy statement and which only exempted a smaller number of negligibly 
reactive compounds.
---------------------------------------------------------------------------

    \12\ The South Coast Air Quality Management District (SCAQMD), 
the successor agency to LACAPCD, renamed this Rule 442.
---------------------------------------------------------------------------

    Like EPA's 1977 policy, Rule 66 was really a ``two bin'' system 
which tightly controlled certain compounds, which were defined as more 
photochemically reactive, and applied a much lesser level of control to 
a large class of compounds, which were regarded as less reactive. The 
main difference between Rule 66 and the later EPA VOC definition 
approach was the criteria for classifying compounds as exempt (or 
subject to lesser control), with the EPA definition allowing a much 
smaller group of compounds to be considered non-reactive or exempt.
    In 1991 California adopted regulations intended to differentiate 
between species of VOC based upon a reactivity scale, instead of a two 
bin system. The 1991 rules were the Low-Emission Vehicles and Clean 
Fuels regulations that CARB intended to reduce VOC emissions by mass 
from motor vehicles generally, but which also took into account VOC 
reactivity differences in organic gas when comparing the emissions from 
alternatively fueled vehicles (AFVs).\13\ \14\ Although not a full-
blown attempt to regulate VOCs by their relative reactivity, CARB 
nonetheless began the exploration of the MIR scale as a mechanism to 
distinguish between VOCs and encourage reduction of more reactive VOCs.
---------------------------------------------------------------------------

    \13\ California Air Resources Board ``Proposed Regulations for 
Low-Emission Vehicles and Clean Fuels-Staff report and Technical 
Support Document,'' State of California, Air Resources Board, 
Sacramento, CA, August 13, 1990.
    \14\ California Air Resources Board ``Proposed Regulations for 
Low-Emission Vehicles and Clean Fuels-Final Statement of Reasons,'' 
State of California, Air Resources Board, July, 1991.
---------------------------------------------------------------------------

    Today's proposal addresses CARB's most recent effort to utilize the 
concept of VOC relative reactivity and the MIR scale to regulate VOC 
emissions. This rule reflects a major shift from the traditional mass-
based control strategies for reduction of VOC emissions and introduces 
this concept in a far more significant way than in CARB's previous 
actions. In connection with the SIP submittal for this aerosol coatings 
rule, CARB has provided additional supporting information in the form 
of journal articles and reports which describe VOC reactivity research 
efforts.
3. What Research Has Been Conducted in Reactivity?
    Much of the work on reactivity scales that CARB used as a basis for 
its aerosol coatings rule was done at the University of California at 
Riverside by William P. L. Carter. Carter investigated 18 different 
ozone reactivity scales.\15\ All of these scales are based on chamber 
studies intended to evaluate the impact of a given VOC on ozone 
formation under certain assumed conditions. The three most prominent 
scales he developed were:
---------------------------------------------------------------------------

    \15\ Carter, William P. L., ``Development of Ozone Reactivity 
Scales for Volatile Organic Compounds,'' J. Air & Waste Manage. 
Assoc., 44: 881-899, (1994).
---------------------------------------------------------------------------

    i. Maximum Incremental Reactivity (MIR) scale--an ozone yield scale 
derived by adjusting the NOX emissions in a base case to 
yield the highest incremental reactivity of the base reactive organic 
gas mixture.\16\
---------------------------------------------------------------------------

    \16\ The CARB's reactivity regulation defines the term Reactive 
Organic Compound (ROC) as any compound that has the potential, once 
emitted to contribute to ozone formation in the troposphere. ROCs 
include compounds which are excluded from EPA's definition of VOCs 
as found in 40 CFR 51.100(s).
---------------------------------------------------------------------------

    ii. Maximum Ozone Incremental Reactivity (MOIR) scale--an ozone 
yield scale derived by adjusting the NOX emission in a base 
case to yield the highest peak ozone concentration.
    iii. Equal Benefit Incremental Reactivity (EBIR) scale--an ozone 
yield scale derived by adjusting the NOX emissions in a base 
case scenario so VOC and NOX reductions are equally 
effective in reducing ozone.
    In addition to Carter's work, there have been other attempts to 
create reactivity scales. One such effort is the work of R. G. Derwent 
and M. E. Jenkins, who have published articles on a scale called the 
photochemical ozone creation potential (POCP) scale.\17\ This scale was 
derived for the conditions prevalent in Europe. The POCP scale is 
roughly consistent with those of Carter although, as expected, there 
are some differences because the POCP scale is based on European 
conditions.
---------------------------------------------------------------------------

    \17\ See, for example, R. G. Derwent and M.E. Jenkin, 
``Hydrocarbons and the Long-Range Transport of Ozone and PAN Across 
Europe,'' Atmospheric Environment, 25A, No. 8, 1661-1678, (1991).
---------------------------------------------------------------------------

    The CARB has relied most heavily on Carter's research for its 
regulatory development and CARB has used the MIR scale for development 
of the aerosol coating regulation.\18\ The MIR scale is designed using 
certain assumptions about meteorological and environmental conditions 
where ozone production is most sensitive to changes in hydrocarbon 
emissions and, therefore, is intended to represent conditions where VOC 
emission controls will be most effective. The MIR scale is expressed as 
grams of ozone formed per gram of organic compound reacted. Each 
compound is assigned an individual MIR value, which enables the 
reactivities of different compounds to be compared quantitatively. 
Individual MIR values now exist for many commonly used compounds, and a 
list of these individual values comprises a scale.
---------------------------------------------------------------------------

    \18\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Chapter II, page 12, May 5, 2000.
---------------------------------------------------------------------------

    To evaluate reactivity scales and ensure that VOC reactivity is 
used appropriately in its proposals, CARB created the Reactivity 
Scientific Advisory Committee (RSAC), a group of leading researchers in 
the field of atmospheric science. This group reviews CARB's reactivity 
related work

[[Page 1646]]

and convenes periodically in meetings which are open to the public to 
comment on CARB's work.
    The EPA has been closely following the scientific literature on 
reactivity scales, and is interested in how such reactivity scales 
might be applied to national programs or programs in other States. 
Because reactivity depends on the characteristics of the environment as 
well as the compound, scales are developed to represent a particular 
set of environmental conditions in certain geographic locations. It is 
not clear whether a single scale can represent actual ozone formation 
over the whole country where meteorological and environmental 
conditions vary considerably. Many scales, including the MIR scale are 
derived for ozone formed during one day of reaction time. The EPA is 
interested in whether such scales adequately represent the ozone 
formation from VOCs during multi-day stagnation events or long-range 
transport of pollutants, in such places as those seen in the Northeast 
section of the country, which may take place over several days.
    To help answer such questions, EPA and CARB are participating in 
the RRWG, which sponsored three atmospheric photochemical modeling 
studies to examine how changing the reactivity of the mix of VOC 
emissions might affect ozone formation across wide geographical areas 
over time. The three areas that researchers studied were the Houston 
area, North Carolina, and the eastern half of the United States. The 
EPA anticipates that these three studies and follow-up efforts will 
help to answer many questions about the potential use of relative 
reactivity in developing, implementing, and enforcing VOC regulatory 
programs.

C. Why Is Use of the Relative Reactivity Concept Appropriate in 
California's Aerosol Coatings Rule?

    There are five classes of nonattainment for the 1-hour ozone 
standard, ranging from marginal to extreme. The Los Angeles--South 
Coast Air Basin Area and the San Joaquin Valley--San Joaquin Valley Air 
Basin in California are currently the only areas in the nation in the 
worst category of extreme nonattainment (40 CFR 81.305 and 69 FR 
20550). Under the 8-hour standard, there are no areas classified under 
the ``extreme'' ozone non-attainment category. South Coast is 
classified as severe non-attainment and San Joaquin is classified as 
serious non-attainment under the 8-hour standard. Because of the 
elevated ozone levels in Los Angeles, the San Joaquin Valley and 
elsewhere in California, CARB has adopted many innovative rules and 
regulations to help reduce ozone precursor emissions. These efforts 
include adopting regulations which go beyond current federally-mandated 
VOC reduction requirements, such as regulating a wider variety of area 
and mobile sources and establishing aggressive emission standards that 
force development of new low-emission technologies.
    As one such effort, CARB already adopted a statewide regulation in 
1995 limiting the VOC mass content of 35 categories of aerosol 
coatings. This regulation contained two tiers of VOC limits and a 
provision to extend the compliance deadline for up to 5 years for each 
aerosol coating category if it was determined that the limits were not 
feasible. On November 19, 1998, CARB amended the regulation to relax 
the limits for 12 coating categories after determining that the 
original limits were not feasible even with the 5-year extension. CARB 
made limits for 11 other categories more stringent. The CARB also 
extended the compliance date to January 1, 2002, for all 35 product 
categories covered by the aerosol coating rule to provide time for 
manufacturers to comply with the new limits.
    In the current SIP submittal, CARB has determined that even with 
the extended compliance date, some of the VOC content limits remain 
technologically challenging. In order to preserve the air quality 
benefits of its 1998 rule, while at the same time allowing 
manufacturers greater flexibility in reformulating their products, CARB 
is replacing its pre-existing mass-based VOC limits for aerosol spray 
coatings with reactivity-based limits that are designed to achieve 
equivalent air quality benefits. The CARB's explicit goal was to 
develop reactivity-based limits that would ensure that the ozone 
reduction commitment from its second tier mass-based VOC limits would 
not be compromised.\19\ For the reasons set forth below, EPA believes 
that CARB's amended aerosol spray coating regulation achieves this 
goal.
---------------------------------------------------------------------------

    \19\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Executive Summary, page 2, May 5, 2000.
---------------------------------------------------------------------------

1. Equivalency of Air Quality Benefits
    i. Sufficient information about the source category. In order to 
determine equivalent ozone reductions and set appropriate limits, CARB 
collected detailed product speciation information and sales data from 
manufacturers. For the aerosol coatings category, CARB found that over 
80 percent of the species of VOCs typically used as ingredients were 
well-studied and an additional 17 percent of the species typically used 
would need only minor adjustment for uncertainty in their MIR values. 
In other words, CARB concluded that the reactivity values of over 95 
percent of the VOCs generally used in the specific category of aerosol 
coatings were fairly well-studied and understood.\20\ The accuracy and 
completeness of the VOC inventory, and the availability of 
scientifically reviewed and published reactivity values for those VOCs 
used in aerosol coatings may not be available for other consumer 
product categories. The CARB's reactivity regulation defines the term 
``reactive organic compound'', or ``ROCs,'' as any compound that has 
the potential, once emitted, to contribute to ozone formation in the 
troposphere. The ROCs include compounds which EPA has excluded from the 
regulatory definition of VOCs found in 40 CFR 51.100(s). To minimize 
confusion to the reader, we will continue to use the term ``VOC'' in 
the remainder of this proposal, instead of ``ROC.'' When the term 
``VOC'' is used in the context of CARB's reactivity-based aerosol 
coatings rule, the reader should remember that this refers to all VOCs, 
including those compounds that are excluded from EPA's regulatory 
definition of VOC. The accurate identification and measurement of 
individual VOC compounds and development of accurate MIR values is 
crucial to the effectiveness of a reactivity program.\21\
---------------------------------------------------------------------------

    \20\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Chapter IV, page 36, May 5, 2000.
    \21\ B.J. Finlayson-Pitts, J.N. Pitts Jr, ``Atmospheric 
Chemistry of Tropospheric Ozone Formation: Scientific and Regulatory 
Implications,'' J. Air Waste Manage. Assoc. 43:1091-1100, (1993).
---------------------------------------------------------------------------

    ii. Sufficient information about the reactivity scale and its 
applicability to California. In conjunction with this SIP submittal, 
CARB provided a listing of approximately 50 research articles to help 
support its conclusion that this aerosol coatings regulation based upon 
VOC relative reactivity is appropriate for conditions in California and 
that the MIR scale chosen by CARB is the most appropriate scale for 
this regulation.
    As stated earlier, CARB relies on the work of Carter in the 
development of the scale for the aerosol coatings rule. Carter 
investigated 18 different ozone reactivity scales and concluded 
``[t]hat the MIR scale (or a scale similar to it,

[[Page 1647]]

such as one based on integrated ozone over the standard) is appropriate 
for regulatory applications where a reactivity scale is required.'' 
\22\ He determined that, while different reactivity scales might give 
different reactivity orderings of VOCs, for most VOC species the 
general rankings among the different scales were very similar. He also 
found that even relatively large variations in the base ROG mixture 
\23\ had, in most cases, only a small effect on relative reactivity. 
For example, a two-fold increase in the amount of aromatics in the base 
mixture of VOCs in the chamber study resulted in less than a 20 percent 
change in the relative MIR reactivity. From this it could be inferred 
that significant changes in the ambient mixture of VOCs in the 
atmosphere would not significantly change the relative MIR value.
---------------------------------------------------------------------------

    \22\ W.P.L. Carter, ``Development of Ozone Reactivity Scales for 
Volatile Organic Compounds,'' J. Air Waste Manage. Assoc. 44:881-
899, (1994).
    \23\ From Carter's article on ``Development of Ozone Reactivity 
Scales for Volatile Organic Compounds,'' the term ``base ROG 
mixture'' means the mixture of Reactive Organic Gases (ROGs) 
initially present or emitted in the Empirical Kinetic Modeling 
Approach (EKMA) scenarios except for biogenic VOCs, VOCs present 
aloft, or VOCs added for the purpose of calculating their 
incremental reactivities.
---------------------------------------------------------------------------

    The various studies conducted to date show good agreement in 
reactivity values for most VOC species between normalized reactivity 
scales generated by airshed models and Carter's box-modeled 
calculations. For example, Bergin et al.,\24\ summarized a number of 
papers comparing reactivity scales predicted by airshed models to those 
predicted by Carter using a box-model. Most of the papers are based on 
simulations conducted with the Carnegie Mellon/California Institute of 
Technology model (CIT) for Los Angeles using the ozone episode of 
August 27-29, 1987. Bergin reports that airshed model-derived spatially 
weighted results behave similarly to MIRs.\25\ The report further 
states that the greatest differences were found for formaldehyde and 
other compounds whose reactivities were highly dependent on photolytic 
reactions, and in general, airshed model results for Los Angeles agree 
well with MIRs, and further show that individual organics have very 
different ozone formation impacts.
---------------------------------------------------------------------------

    \24\ M. Bergin, W.P.L. Carter, J. Milford, P.J. Ostrowski, A.G. 
Russell, Reactivity Assessments, Reactivity Research Working Group 
(May 5, 1999). (ftp://ftp.cgenv.com/pub/downloads/RRWGdoc/assess-2.pdf).
    \25\ M. Bergin, W.P.L. Carter, J. Milford, P.J. Ostrowski, A.G. 
Russell, Reactivity Assessments, Reactivity Research Working Group, 
Page 12, (May 5, 1999). (ftp://ftp.cgenv.com/pub/downloads/RRWGdoc/assess-2.pdf).
---------------------------------------------------------------------------

    While Bergin's reactivity assessment indicates a general support 
for the concept of relative reactivity, she also points out that gaps 
exist in the current knowledge base of the scientific community and 
points to areas where further investigation is needed. For example, 
Bergin acknowledges that although airshed model results for Los Angeles 
agree well with MIRs, such a study has not been conducted for other 
regions. Also, Bergin suggested that additional work is needed to 
examine the effects of aromatics under several different conditions, 
and that Eastern transport conditions should also be examined in a 
multi-day scenario. The RRWG is currently reviewing studies which 
examine the reactivities in the eastern half of the United States which 
will help to answer some of these questions.
    Similarly, recent work by Martien and Harley found that ``[f]or 
most species studied'' * * * ``[r]eactivity scales developed by 3-D 
modeling resulted in similar rankings of individual VOC when compared 
to reactivity scales developed by Carter using a box model.'' \26\ They 
also point out that ``[S]ite-to-site differences (in reactivity values) 
can be large when absolute reactivity scales are considered. The 
variation in reactivity across sites is reduced when reactivity is 
measured on a relative rather than absolute scale. Differences in 
relative reactivity may still occur as a function of location, with 
differences likely to be magnified where absolute reactivities are 
low.''
---------------------------------------------------------------------------

    \26\ P. Martien, R.Harley, ``Development of Reactivity Scales 
via 3-D Grid Modeling of California Ozone Episodes,'' Final report 
prepared for California Air Resources Board, May 2002.
---------------------------------------------------------------------------

    One study submitted by CARB to EPA attempts to address the issue of 
whether the MIR scale adequately represents VOC reactivity in transport 
scenarios. Kaduwela and his associates \27\ assessed for the first time 
whether box-model based scales are applicable to regional-scale 
domains, which include transport of pollutants through urban and rural 
areas. They did this by conducting grid-based photochemical simulations 
in a regional domain in central California for five compounds and found 
a linear correlation between box-model based scales and regional grid-
based scales. These studies indicate a correlation between box-model 
scales used in Carter's work and the more detailed scales. Therefore, 
CARB concludes that the box-model's lack of physical detail and shorter 
episode time does not limit the suitability of the MIR values with 
respect to concerns about transport within California.
---------------------------------------------------------------------------

    \27\ A. Kaduwela, V. Hughes, L. Woodlouse, P. Allen, J. DaMassa, 
A. Ranzieri, ``Photochemical Reactivity of Organic Compounds in 
Central California: A Grid-Based Modeling Study,'' Presented at 
Stanford University, CA July 26-28, 1999.
---------------------------------------------------------------------------

    During an October 1999 RSAC meeting, a member of the public asked 
the RSAC whether the scenarios used to calculate MIRs are realistic. 
The RSAC committee ``[r]esponded that the relative reactivity doesn't 
change between scenarios and that, in a study which examined an 
exposure metric calculated by a 3-D model, the relative reactivities 
correlated well with MIRs.'' \28\ At the same meeting, a member of the 
public also asked the RSAC if MIR conditions were appropriate for 
California. The committee's response was that whether MIR conditions 
were appropriate for California was a policy decision. The CARB's SIP 
submittal states \29\ that ``[w]hile the MIR scale has been extensively 
tested as appropriate for use in California, we caution that our 
research has focused on California atmospheric conditions only. As 
such, the suitability of using the MIR scale for regulatory purposes in 
other parts of the United States has not been demonstrated, and may not 
be appropriate.''
---------------------------------------------------------------------------

    \28\ Minutes of the Reactivity Scientific Advisory Committee, 
October 8, 1999, http://www.arb.ca.gov/research/reactivity/rsac/oct99-min.html.
    \29\ State Implementation Plan (SIP) Submittal letter from 
Michael Kenny (CARB) to Wayne Nastri (US EPA, Region IX), March 13, 
2002.
---------------------------------------------------------------------------

    iii. Approach to Uncertainty. Although the MIR values are 
calculated with what a peer reviewed report \30\ describes as a 
``state-of-the-science'' chemical mechanism, the reactivity values of 
some VOCs are still uncertain,\31\ while those of other VOCs have been 
more thoroughly studied and will not likely change with further 
research. To account for this uncertainty, CARB has applied Carter's 
uncertainty ranking which defines 6 categories or ``bins'' to describe 
the ``certainty'' of the chemical mechanism used to determine the MIR 
values. The uncertainty scale is subjective, but it is described as 
Carter's best judgment of the certainty scientists currently have of an 
organic compound's chemical

[[Page 1648]]

reaction mechanism and its effect on that compound's estimated MIR 
value \32\. If the MIR value of a compound is relatively certain or if 
there are some uncertainties but the MIR value is not expected to 
change significantly, the compound is assigned to bin one. If the 
current mechanism is probably incorrect and biases in atmospheric 
reactivity predictions are uncertain, the compound is assigned to bin 
six. When calculating an equivalent ozone reduction, CARB identifies 
which of the 6 bins a compound is in, and then multiplies the 
compound's MIR value with a factor of between 1 and 2 to compensate for 
the uncertainty of that MIR value. The uncertainty factors associated 
with each bin were developed by CARB with input from Carter. The CARB 
applies an uncertainty factor of 1.0 to compounds classified within 
uncertainty bins one and two; a factor of 1.25 to compounds in bin 
three; a factor of 1.5 to compounds in bin four; and a factor of 2.0 
for compounds in bins five and six. For certain hydrocarbon solvents 
defined under the regulation, CARB uses an uncertainty factor of 1.15. 
The CARB also developed a methodology for those compounds used in 
aerosol coatings that did not have published MIR values. The 
methodology, which was reviewed by the RSAC, provides an estimate for 
the presumed upper limit MIR value. No adjustment factor is applied to 
the upper limit MIRs as the method infers the highest reactivity of the 
chemical.\33\
---------------------------------------------------------------------------

    \30\ W.R. Stockwell, ``Review of the Updated Maximum Incremental 
Reactivity Scale of Dr. William Carter,'' Prepared for the 
California Air Resources Board, Page 151, November 29, 1999--A copy 
can be found in section 4N of CARB's SIP submittal for this rule.
    \31\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Chapter II, Page 13, May 5, 2000.
    \32\ W.R. Stockwell, ``Review of the Updated Maximum Incremental 
Reactivity Scale of Dr. William Carter,'' Prepared for the 
California Air Resources Board, Page 122, November 29, 1999--A copy 
can be found in section 4N of CARB's SIP submittal for this rule.
    \33\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Chapter IV, pages 32-37, May 5, 2000.
---------------------------------------------------------------------------

    Other researcher 34 35 36 looking into the aspects of 
uncertainties in chemical reaction rate parameters, used in the model 
to calculate MIRs, believe that the uncertainties in the chemical rate 
parameters have directionally similar effects on the reactivities of 
most compounds. That is, if compound ``a'' had a higher reactivity 
value than compound ``b,'' then after taking into account the 
uncertainties in their chemical rate parameters, compound ``a'' would 
generally still have a higher reactivity value than compound ``b.'' 
These researchers conclude that the significance of these uncertainties 
could be minimized by using reactivities in a relative sense, as CARB 
has done in this rule.
---------------------------------------------------------------------------

    \34\ Y. Yang, W.R. Stockwell, J.B. Milford, ``Uncertainties in 
Incremental Reactivities of Volatile Organic Compounds,'' Environ. 
Sci. Technol., 29, 1336-1345, (1995).
    \35\ M.S. Bergin, A.G. Russell, J.B. Milford, ``Effects of 
Chemical Mechanism Uncertainties on the Reactivity Quantification of 
Volatile Organic Compounds Using a Three-Dimensional Air Quality 
Model,'' Environ. Sci. Technol., 32, 694-703, (1998).
    \36\ N.L. Kelly, T.Y. Chang, ``An experimental Investigation of 
Incremental Reactivities of Volatile Organic Compounds,'' 
Atmospheric Environment, 33, 2101-2110, (1999).
---------------------------------------------------------------------------

    iv. Do Federal VOC exemptions apply to CARB's program?
    Because CARB's regulation attempts to account for the actual 
contribution to ozone formation by each organic compound, it does not 
exempt any reactive compounds, including those that EPA has exempted 
from the definition of VOC pursuant to 40 CFR 51.100(s). In order to 
get a more accurate calculation of a product's impact on ozone 
formation, CARB uses the assigned reactivity value of each compound, 
however high or low its MIR value. Therefore, compounds such as 
acetone, which are excluded from EPA's definition of VOCs in 40 CFR 
51.100(s), are counted towards the compliance limit under CARB's 
reactivity-based regulation.
    v. No backsliding. In developing the proposed reactivity limits, 
one of CARB's goals was to ensure that the ozone reduction commitment 
from the existing mass-based VOC limits for aerosol spray coatings 
would not be compromised. In certain situations, however, a reactivity-
based regulation could result in increased ozone concentrations over a 
traditional VOC mass-based regulation. For instance, because the MIR 
scale is based on a 1-day simulation, during a multi-day episode, a 
manufacturer could substitute the proper amount or too much of a lower 
reacting compound for a higher reacting one and thereby increase ozone 
formation over longer periods of time.
    While we believe there are circumstances under which ozone 
formation could potentially increase because of use of reactivity-based 
VOC limits, we also recognize that the same unintended consequences can 
occur with current mass-based VOC rules. The CARB reported \37\ that 
one company intended to comply with stricter CARB VOC mass-based limits 
by using less total VOC, but also by increasing the amount of much more 
reactive VOCs to compensate for solvency needs in the product. The CARB 
also reported that another large company indicated that its compliance 
strategy with more stringent VOC mass limits would be to increase the 
aromatic content (increasing reactivity) in its products. In these 
instances, CARB points out that the increased reactivity of the VOC 
emissions likely reduces the benefits of the lower mass of VOC 
emissions. There is no evidence to suggest, however, that regulated 
entities will always choose to use smaller amounts of higher reactivity 
compounds in place of lower reactivity compounds when a product's mass-
based VOC limit is reduced. In any event, it is impossible to predict 
whether the use of smaller amounts of more reactive VOCs will result in 
more ozone without knowing how the identity and proportions of the 
other VOC ingredients in the product will change. While we acknowledge 
that there is the potential for this unintended consequence of mass-
based controls, we generally believe that achieving significant mass 
reductions of VOCs is directionally correct in most situations. As 
noted above, however, EPA believes that reactivity-based approaches 
such as the one developed by CARB may be a promising alternative to 
mass-based approaches in some cases where additional VOC controls are 
necessary.
---------------------------------------------------------------------------

    \37\ California Air Resources Board letter from Michael Kenny to 
Deborah Jordan, U.S. EPA, Region IX, dated July 24, 2000.
---------------------------------------------------------------------------

    Revisions to the SIP should contribute to progress towards reaching 
attainment with the NAAQS and not relax emission standards or retreat 
from emission reduction goals already achieved. Towards these goals, 
CARB has assured EPA that there will be no backsliding as a result of 
the use of the relative reactivity approach. With assistance from CARB, 
EPA intends to monitor the effectiveness of the aerosol coatings rule 
to ensure that the rule obtains the intended and required reductions in 
ambient ozone levels.
2. Evaluation and Revision
    The development, maintenance, evaluation, and revision of a 
reactivity-based VOC regulation requires significant resources and 
technical expertise. The CARB's commitment to the reactivity concept is 
evidenced by funding, between 1989 to the present, over $4,000,000 
worth of research on reactivity related projects including modeling, 
chemical mechanism development, atmospheric chemistry and VOC 
speciation.
    Similarly, we believe that additional resources and technical 
expertise are needed to implement and enforce a reactivity-based 
regulation than for a traditional mass-based regulation. For example, 
under a mass-based VOC regulation, analysis of a coating to

[[Page 1649]]

determine compliance largely requires simply determining the weight 
difference of a sample before and after heating it in an oven \38\. 
This testing is relatively easy and inexpensive, thereby facilitating 
enforcement by the regulating authority or others.
---------------------------------------------------------------------------

    \38\ See 40 CFR 60, appendix A Reference Method 24.
---------------------------------------------------------------------------

    In contrast, determining compliance of the same product with a 
reactivity-based regulation is more complex and consequently more 
expensive. Here, the laboratory needs to identify and quantify each 
individual VOC present in the sample, possibly with multiple gas 
chromatography with mass spectrometry (GC/MS) runs. In order to 
determine compliance, the regulatory agency then must multiply the 
concentration of each compound in the aerosol coating by its MIR value 
and then sum the results to determine the product's total MIR value. In 
some cases, the MIR values for isomers of compounds are different, such 
as for ortho, meta and para xylenes (MIR = 7.49, 10.61, and 4.25 
respectively). Speciation of isomers increases the complexity of the 
analysis. In addition, the identification of hydrocarbon solvents by 
boiling point range and aromatic content will add an additional step to 
the analysis. The CARB laboratory staff routinely uses GC/MS techniques 
to analyze products for a relatively small number of compounds excluded 
from EPA's regulatory definition of VOC which may be in consumer 
products, so CARB has some experience with these analytical techniques. 
Further, CARB is ``[f]ully prepared to vigorously enforce this 
regulation'' and their ``[e]nforcement inspectors and laboratory staff 
have expertise and resources to collect and test aerosol coating 
products to verify compliance with the regulation.'' \39\
---------------------------------------------------------------------------

    \39\ State Implementation Plan submittal letter from Michael 
Kenny (CARB) to Wayne Nastri (U.S. EPA, Region IX), March 13, 2002.
---------------------------------------------------------------------------

    Because any complex regulation can potentially multiply the 
opportunities for non-compliance, whether intentional or inadvertent, 
EPA believes that an intensive program to monitor and enforce 
compliance is a critical element to any VOC reactivity-based 
regulation.

D. Are California's Relative Reactivity-Based Regulations Appropriate 
for Areas Outside of California?

    1. The CARB's technical support for this program in California does 
not necessarily demonstrate that VOC reactivity-based programs would be 
appropriate or effective in other areas or for other regulatory 
programs. The CARB's SIP submittal cautions that its research has 
focused only on California atmospheric conditions and that the 
suitability of the MIR scale for regulatory purposes in other areas has 
not been demonstrated. The CARB further states \40\ that VOC relative 
``[r]eactivity needs to be examined for the rest of the country.'' and 
that they ``[s]upport these investigations and plan to continue CARB's 
participation in the RRWG.''
---------------------------------------------------------------------------

    \40\ State Implementation Plan Submittal letter from Michael 
Kenny (CARB) to Wayne Nastri (US EPA Region IX), March 13, 2002.
---------------------------------------------------------------------------

    EPA is aware that only recently has there been published, 
coordinated scientific research to attempt to address questions 
concerning the use of VOC reactivity-based regulations in other 
locations. For example, a recent NARSTO report describes limitations to 
ozone control using a VOC reactivity-based approach. The NARSTO report 
suggested that the approach might only be effective when the ambient 
conditions are ``[V]OC limited and where natural hydrocarbon emissions 
are not dominant.'' \41\ In addition, the NARSTO report states that 
``[t]he reactivity of specific VOCs can change from locale to locale, 
and thus the specifics of the approach must be regionally tailored.'' 
As noted earlier, the RRWG has sponsored a series of recent studies 
exploring these issues.
---------------------------------------------------------------------------

    \41\ The NARSTO, An Assessment of Tropospheric Ozone Pollution--
A North American Perspective, page 3-19, July 2000.
---------------------------------------------------------------------------

    One of the concerns with the representativeness of MIR values is 
that they are based on a model which simulates reactions over a single 
day and may not account for slower reacting compounds which might 
continue to form ozone over several days. These slower reactions could 
result in more ozone formation than is predicted by the MIR scale in 
areas experiencing multi-day stagnation events or increased ozone 
formation in downwind areas due to pollutant transport.
    The MIR scale is basically a reduced-form model, or a model of a 
model, which attempts to characterize in a single number the relative 
contribution of individual compounds to the formation and accumulation 
of ozone in a complex atmospheric system. Thus, a particular chemical 
mechanism and set of assumed environmental conditions are implicit in 
the MIR scale. The purpose of comparing the MIR scale to reactivities 
calculated using an airshed model is to evaluate whether the MIR scale, 
as a reduced-form model, adequately represents the behavior of the more 
complex airshed model, which takes into account spatially and 
temporally varying meteorology and emissions. If comparisons show a 
disagreement between the MIR values and the airshed derived values, 
that may suggest that it may not be appropriate to try to capture the 
behavior of the system in the single scale. If comparisons do show an 
agreement, this would suggest that the MIR scale can reproduce the 
behavior of the complex system, at least for the set of conditions 
considered.
    Several researchers have performed such comparisons, including 
Bergin, Derwent and Stockwell. Bergin et al.,\42\ calculated reactivity 
values using a more detailed three-dimensional photochemical model and 
compared their results against the values calculated by the simpler 
model used to develop CARB's reactivity program for their alternative 
fuels program. Bergin found that results were well correlated between 
Carter's simpler model and their more detailed model. However, these 
researchers also found that toluene, ethylbenzene, two xylene species, 
and some aldehydes had lower reactivity values predicted by the more 
detailed model as compared to the simpler model. Bergin concluded that 
differences in the predicted reactivity values were possibly due to 
multi-day simulation periods and the inclusion of cloud cover by the 
more detailed model.
---------------------------------------------------------------------------

    \42\ M.S. Bergin, A.G. Russell, J.B. Milford, ``Quantification 
of Individual VOC Reactivities Using a Chemically Detailed, Three-
Dimensional Photochemical Model,'' Environ. Sci. Technol., 29, 3029-
3037, (1995).
---------------------------------------------------------------------------

    Derwent \43\ also reports that single-day or multi-day conditions 
appear to be important in establishing quantitative reactivity scales 
for the less reactive organic compounds. Stockwell,\44\ who completed 
the peer review of Carter's reactivity mechanism, states that single-
day scenarios are used to calculate incremental reactivities by 
definition, but even relatively unreactive organic compounds may have a 
non-negligible effect on ozone concentrations if multiple-day scenarios 
are considered. When he calculated incremental reactivities for 
multiple-days for polluted European conditions, he found that ethane's 
MIR value increased over 6 times from a MIR value of 0.19 on the first 
day to 1.17 on the 6th day. He also found that Dimethyoxymethane's MIR

[[Page 1650]]

value increased as the length of the simulation period increased.
---------------------------------------------------------------------------

    \43\ R.G. Derwent, M.E. Jenkin, S.M. Saunders, M.J. Pilling, 
``Characterization of the Reactivities of Volatile Organic Compounds 
Using a Master Chemical Mechanism,'' J. Air and Waste Manage. 
Assoc., 51, 699-707, (2001).
    \44\ W.R. Stockwell, H. Geiger, K.H. Becker, ``Estimation of 
Incremental Reactivities for Multiple Day Scenarios: An Application 
to Ethane and Dimethyoxymethane,'' Atmospheric Environment, 35, 929-
939, (2001).
---------------------------------------------------------------------------

    While we are uncertain whether results based on European conditions 
might generally apply to conditions found in California or the United 
States, these studies raise two questions. First, is the increase in 
MIR values during a multi-day stagnation event mainly a concern for 
slower reacting compounds or a more widespread issue, and second, 
should any changes be made to MIR scale values to account for the 
apparent increases in reactivity values in multi-day stagnation 
scenarios. Additional research may be needed in this area to understand 
more fully the impacts of multi-day scenarios on relative reactivity 
values and the prevalence of transport and multi-day stagnation 
conditions on a regional scale within California's ozone nonattainment 
areas and ozone nonattainment areas in other parts of the country. 
While we have some concerns about the greater level of effort required 
to develop, implement, and enforce reactivity-based programs, we 
believe that California has the resources and technical expertise 
needed to develop and maintain a complex program such as this one.

E. How Will the Effectiveness of This Reactivity-Based Program Be 
Evaluated?

    1. We plan to evaluate the effectiveness of the aerosol coatings 
rule in 3 years. Areas we may review include changes in the composition 
and quantity of VOC emissions, which would require establishing a 
baseline of current emissions.
    2. We are also interested in evaluating changes in ambient air 
quality that result from the use of the relative reactivity approach in 
this rule. We recognize that currently available computer models have 
limitations in their ability to evaluate the actual ambient effects of 
reducing emissions of specific VOC species from a particular product 
category. Also, while it is possible to show an air quality benefit of 
substituting individual VOCs with lower reactivity for more reactive 
ones using a three-dimensional photochemical model, it is not clear 
that current photochemical modeling systems are adequate to predict the 
impacts of the wide variety of simultaneous substitutions that may 
occur under an MIR-weighted regulatory program. The EPA, with CARB's 
assistance, plans to investigate possible modeling enhancements to 
evaluate the effects of the aerosol coatings rule, and hopes to 
identify modeling ``experiments'' to further test the MIR's predictive 
performance.
    While a VOC reactivity-based regulation may result in a more 
efficient regulation in terms of more flexible reformulation options 
for manufacturers and an additional control strategy to reduce 
tropospheric ozone, we are also interested in how costs under a 
reactivity-based regulation might change for monitoring and 
recordkeeping. Under a reactivity-based program, emission inventory 
efforts may increase for industry periodically to provide fully 
speciated product information and for regulatory agencies to input this 
information into emission inventory data bases. We are interested in 
the public's comment on how the industry's and regulatory agency's 
costs and staff requirements might change with respect to emission 
inventories.
    3. As stated earlier, CARB intends to keep up to date on VOC 
reactivity research through a review of the MIR values every 18 months 
and a review of the reactivity limits before January 1, 2007.

F. How Has CARB Addressed Concerns About Air Toxics and Ozone-Depleting 
Substances?

    The CARB's aerosol coatings regulation prohibits the use of three 
toxic air contaminants: Methylene chloride, perchloroethylene and 
trichloroethylene. While the regulation does not ban the use of other 
compounds listed as ``hazardous air pollutants'' that are commonly used 
in aerosol coatings such as xylene and toluene, CARB believes that 
emissions of these other toxic compounds are likely to be reduced 
through the overall emission limits imposed on the individual product 
categories. Regulated entities will have an incentive to use less of 
compounds like toluene and xylene because of their higher reactivity, 
and this will outweigh the interest in choosing VOCs based solely upon 
their cost.
    The CARB's regulation also prohibits the sale, supply, application, 
or manufacture for use in California, of any aerosol coating product 
which contains a stratospheric ozone-depleting substance. Existing 
product formulations which contain an ozone-depleting substance that 
complies with the reactivity limits and was sold in California during 
1997 or product formulations containing an ozone-depleting substance 
that was sold in California during 1997 that is reformulated to meet 
the reactivity limits, as long as the content of the ozone-depleting 
substances in the reformulated product does not increase, are exempted 
from this provision.

G. What Changes in Enforcement Strategies Will Likely Occur Due to This 
Relative Reactivity-Based Regulation?

    1. How will testing for compliance change under CARB's aerosol 
coatings regulation? As discussed earlier, under a traditional mass-
based regulation, analysis of a coating to determine compliance is 
performed using EPA Reference Method 24.\45\ This method involves 
heating the sample in an oven and determining the weight difference of 
the sample before and after heating. Additional analysis is needed to 
account for the propellant and, if present in the sample, compounds 
which are excluded from EPA's definition of VOCs. Under a mass-based 
rule, the laboratory does not need to know which individual 
hydrocarbons are present in order to perform Method 24, other than to 
identify if a limited number of excluded compounds are present in the 
coating. Manufacturers are generally willing to reveal the proportions 
of exempt substances because that helps to demonstrate compliance with 
the mass-based VOC limits.
---------------------------------------------------------------------------

    \45\ See 40 CFR 60, appendix A, Reference Method 24.
---------------------------------------------------------------------------

    Determining compliance under a reactivity-based regulation is more 
complex, but still within the capabilities of CARB's laboratory. 
Specifically, the regulator must perform expensive and complex GC/MS 
analysis to identify and quantify each VOC present in the product in 
order to calculate the product weighted MIR. To facilitate this 
compliance determination, CARB's aerosol coatings rule allows CARB to 
request manufacturers to provide a listing of the VOCs and their 
concentrations in each product so the laboratory knows which VOCs to 
analyze for and their target concentrations. While laboratories could 
perform the analysis without such a listing, it would be substantially 
more difficult, time-consuming, and expensive. This increased 
difficulty in assuring compliance is among the reasons that EPA is 
concerned that CARB allocate sufficient resources to monitor and 
enforce the reactivity-based limits.
    2. How does a reactivity regulation affect the availability of 
emissions data? In the past, determining compliance with emission 
limits under a mass-based VOC rule such as CARB's aerosol coatings rule 
did not raise concerns about confidential business information (CBI) 
because one could determine compliance with the product's VOC limit 
without ever having to know all of the individual VOC ingredients 
present

[[Page 1651]]

in the product. However, under a reactivity-based rule, one would need 
to know the specific VOCs in a product and their proportions (i.e., the 
product formulation) in order to determine compliance with its 
reactivity-based VOC limit. Because this information is an integral 
part of determining compliance with the product's reactivity-based 
limit, the list of VOCs would be considered ``emissions data,'' which 
must generally be available to the public.\46\ However, industry may 
view the release of such detailed VOC information to the general public 
or to their business competitors as a major concern because of the 
potential for release of trade secrets and propriety CBI.
---------------------------------------------------------------------------

    \46\ Emissions data is defined in 40 CFR 2.301(a)(2)(i).
---------------------------------------------------------------------------

    To help resolve these competing issues, we note that aerosol 
coatings are composed of a VOC portion and a portion made up of various 
non-reactive compounds such as resins and solids which, based on CARB's 
aerosol coatings regulation, do not contribute to ozone formation and 
are assigned an MIR value of zero. Consistent with section 114(c) of 
the CAA, and our regulations concerning the release of emissions data 
at 40 CFR Sec.  2.301, we believe the public's right to emissions data 
is satisfied by assuring access to the portion of the data which 
comprises the VOCs alone. Information on the non-reactive compounds, 
i.e., those that do not contribute to ozone formation, would not need 
to be released, thereby preserving potential trade secrets.
    The CARB and the aerosol coatings industry held discussions and 
reached an agreement that CARB VOC testing results and company-supplied 
formulation data required to be submitted by Section 94526 of CARB's 
aerosol coatings regulation would be made available to the public, upon 
request, to allow others to verify compliance with the reactivity-based 
aerosol coating regulation. It was further agreed that non-reactive 
compounds in each product formulation would be ``lumped'' or aggregated 
to protect confidentiality.\47\
---------------------------------------------------------------------------

    \47\ The CARB letter from Michael Kenny to Jack Broadbent, U.S. 
EPA, Region IX, dated May 16, 2002.
---------------------------------------------------------------------------

    Both CARB and EPA will retain their authority to access all 
ingredient information, including non-VOC ingredients or information 
otherwise claimed to be CBI, in order to determine compliance with the 
regulation.
    The availability to the public of VOC ingredient information 
constituting emissions data only applies to information gathered to 
confirm compliance with CARB's aerosol coatings rule. Confidential 
information such as survey data submitted by companies under Section 
94524 of CARB's aerosol coatings regulation to CARB and EPA in support 
of any future rule development efforts, will continue to be handled in 
accordance with applicable CBI regulations.
    We believe that this compromise between the competing objectives of 
disclosure of emissions data and protection of CBI provides a basis for 
approving CARB's innovative reactivity-based regulation into the SIP. 
We also believe that the compromise is consistent with the purpose of 
CAA Sec.  114(c) and EPA's regulations defining emissions data.

IV. Summary of CARB's Aerosol Coatings Regulation

A. What Does CARB's Regulation Require?

    The CARB has previously controlled VOC emissions from aerosol 
coatings in California by limiting the mass of VOCs in the product, 
with limits expressed as maximum allowable percent by mass of VOC. 
CARB's new approach relies on the fact that individual VOCs may form 
different amounts of ozone, or form ozone more quickly, once they are 
emitted into the air. The CARB is implementing a regulation that would 
limit ozone formation by taking into account the relative reactivity of 
different VOC ingredients.
    The CARB's aerosol coatings regulation contains sections on 
applicability, definitions, limits and requirements, exemptions, 
administrative requirements, variances, test methods, Federal 
enforceability and references tables of MIR values for different 
compounds including hydrocarbon solvents.
1. What Does CARB's Aerosol Coatings Regulation Cover?
    This section contains a very brief summary of key portions of 
CARB's regulation. The reader should refer to the actual regulation 
\48\ for additional details.
---------------------------------------------------------------------------

    \48\ http://www.arb.ca.gov/consprod/regs/aeropnt.pdf http://www.arb.ca.gov/consprod/regs/Aeropnt.doc or California Code of 
Regulations, Title 17, Division 3, Chapter 1, Subchapter 8.5, 
Article 3.
---------------------------------------------------------------------------

    The regulation applies to aerosol coatings, aerosol clear coatings 
and aerosol stains. It applies to any person who sells, supplies, 
offers for sale, applies or manufactures for use in California any 
aerosol coating subject to the limits in the regulation. The regulation 
prohibits the commercial application of non-complying aerosol coating 
products.
    The regulation does not apply to aerosol lubricants, mold releases, 
automotive underbody coatings, electrical coatings, cleaners, belt 
dressings, anti-static sprays, layout fluids and removers, adhesives, 
maskants, rust converters, dyes, inks, and leather preservatives or 
cleaners. The regulation also does not apply to aerosol coating 
products manufactured in California for shipment and use outside of 
California.
    Aerosol coating products manufactured beginning June 1, 2002, for 
general coating categories as defined in the regulation and January 1, 
2003, for specialty coatings need to comply with the reactivity-based 
VOC limits specified in the regulation. Aerosol products manufactured 
before the effective dates must comply with the existing mass-based VOC 
limits. However, products labeled with the applicable reactivity-based 
VOC limit, must meet that limit. The regulation contains a sell-through 
provision whereby products manufactured prior to the effective date can 
be sold, supplied, offered for sale, or applied up to 3 years after the 
effective date.
    The regulation prohibits the use of the toxic air contaminates 
methylene chloride, trichloroethylene, and perchloroethylene. It also 
prohibits the use of stratospheric ozone-depleting substances in 
aerosol coating products except in limited situations allowed by the 
regulation.
    The regulation contains labeling and reporting requirements, and 
provisions for a regulated entity to request a variance from the VOC 
reactivity limits if the entity cannot comply due to extraordinary 
reasons beyond reasonable control. The test method section specifies 
that CARB Method 310 is to be used to determine compliance with the 
regulation. Alternative test methods may be used which are shown to 
identify and quantify accurately each ingredient, after approval in 
writing by the CARB Executive Officer. However, as stated in the 
aerosol coatings regulation,\49\ for purposes of Federal 
enforceability, EPA is not bound by approval determinations made by the 
CARB Executive Officer for variances or test methods. While EPA 
believes CARB would not approve major test method modifications that 
might compromise the integrity of a test result, or grant a variance 
request that would adversely

[[Page 1652]]

impact an approved attainment demonstration, EPA can pursue separate 
action to ensure that test results are enforceable, accurate, and 
reproducible, and that a variance does not adversely impact attainment.
---------------------------------------------------------------------------

    \49\ California Code of Regulations, Title 17, Division 3, 
Chapter 1, Subchapter 8.5, Article 3, Sec.  94528.
---------------------------------------------------------------------------

    Variances and major modifications to test methods must be submitted 
to EPA and must be approved into the SIP before they can be Federally 
enforceable. For the purposes of Federal enforceability, facilities 
operating under a variance or modified test method approved by the CARB 
Executive Officer must continue to comply with the original regulation 
until the variance or major test method modification is also approved 
by EPA into the SIP. The EPA does not normally approve Executive 
Officer discretion in regulations submitted for SIP approval as this 
would allow potentially significant modifications to a regulation or 
test method without subsequent review and approval by EPA.
    We are proposing to approve this Executive Officer provision in 
this rule because this is a new and innovative program and, as such, 
may require a temporary variance or an unanticipated modification to 
the test method in the short term, and the regulation states that EPA 
is not bound by the decisions of the Executive Officer. The EPA intends 
to monitor CARB's implementation of these rule provisions and we will 
review test method modifications and variance requests on a case-by-
base basis.

V. Future Actions

A. What Action Will Be Taken To Determine if This Reactivity-Based 
Regulation Is Effective?

    The EPA will continue to work with CARB to evaluate how VOC 
emissions from this source category change in response to the 
regulation and how these emission changes will affect ambient air 
quality. We will also continue to work with CARB to evaluate the 
appropriateness of MIR values for VOC reactivity ranking under the 
environmental conditions of interest in California. The EPA's proposed 
approval of CARB's aerosol coatings regulation is predicated, in part, 
on CARB's commitment to ensuring that the regulation in fact achieves 
the intended environmental goals. The CARB's SIP submittal letter \50\ 
states that CARB officials ``[i]ntend to follow the implementation of 
this regulation closely to ensure the air quality benefits predicted 
are fully achieved. If they are not, CARB is obligated to identify and 
secure additional regulatory measures to meet our SIP commitments.'' 
``[M]oreover, if in fact the aerosol coating regulation is not as 
effective as predicted, we are fully prepared to reevaluate the source 
category to determine how best to achieve the most stringent limits 
that are technologically and commercially feasible.''
---------------------------------------------------------------------------

    \50\ SIP submittal letter from Michael Kenny (CARB) to Wayne 
Nastri (U.S. EPA, Region IX), March 13, 2002.
---------------------------------------------------------------------------

B. How Will Future Uses of Relative Reactivity Be Evaluated?

    The CARB views the aerosol coatings rule as a means to determine 
the feasibility of additional reactivity-based measures for other 
source categories.\51\ The EPA is working as a participant in the RRWG 
to explore whether reactivity-based approaches are appropriate and 
useful for other source categories and in other parts of the country. 
Members of the RRWG have a variety of research projects underway to 
provide needed information about the utility and effectiveness of 
relative reactivity-based VOC controls. The EPA is committed to the 
process begun under the RRWG of assuring that future applications of 
the relative reactivity approaches are based on a sound scientific 
foundation and are practical, enforceable, and effective.
---------------------------------------------------------------------------

    \51\ California Air Resources Board, ``Initial Statement of 
Reasons for the Proposed Amendments to the Regulation for Reducing 
Volatile Organic Compound Emissions from Aerosol Coating Products,'' 
Chapter II, page 18, May 5, 2000.
---------------------------------------------------------------------------

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866, (58 FR 51735, October 4, 1993) the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to the Office of Management and Budget (OMB) 
review and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    For the change in definition of VOCs, EPA has determined that this 
proposed rule is not a ``significant regulatory action'' under the 
terms of Executive Order 12866 and is therefore not subject to OMB 
review. For the proposed approval of CARB's rule into the SIP, OMB has 
exempted this regulatory action from Executive Order 12866 review.

B. Paperwork Reduction Act

    For the change in the definition of VOCs, this proposed rule does 
not contain any information collection requirements subject to OMB 
review under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
    For the proposed approval of CARB's regulation into the SIP, this 
proposed action does not contain any information collection 
requirements that would require any person to provide information to 
EPA, however CARB's regulation contains requirements for the aerosol 
coating industry to provide information to CARB.

C. Regulatory Flexibility Act (RFA)

    The RFA generally requires an agency to prepare a regulatory 
flexibility analysis of any rule subject to notice and comment 
rulemaking requirements under the Administrative Procedure Act or any 
other statute unless the agency certifies that the rule will not have a 
significant economic impact on a substantial number of small entities. 
Small entities include small businesses, small organizations, and small 
governmental jurisdictions.
    After considering the economic impacts of today's proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities.
    This proposed rule will not impose any requirements on small 
entities. Today's change to the definition of VOC does not directly 
regulate any entities. The RFA analysis does not consider impacts on 
entities which the action in question does not regulate. See Motor & 
Equipment Manufacturers Ass'n v. Nichols, 142 F. 3d 449, 467 (D.C. Cir. 
1998); United Distribution Cos. v. FERC, 88 F. 3d 1105, 1170 (D.C. Cir. 
1996), cert. denied, 520 U.S. 1224 (1997).
    For the proposed approval of CARB's regulation into the SIP, this 
proposed rule will not have a significant impact on a substantial 
number of small entities because SIP approvals under section 110 and 
subchapter I, part D of the CAA

[[Page 1653]]

do not create any new requirements but simply act on requirements that 
the State is already imposing. Therefore, because the Federal SIP 
approval does not create any new requirements, I certify that this 
action will not have a significant economic impact on a substantial 
number of small entities.
    Moreover, due to the nature of the Federal-State relationship under 
the CAA, preparation of flexibility analysis would constitute Federal 
inquiry into the economic reasonableness of State action. The CAA 
forbids EPA to base its actions concerning SIPs on such grounds. Union 
Electric Co. v. U.S. EPA, 427 U.S. 246, 255-66 (1976); 42 U.S.C. 
7410(a)(2).

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 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 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 by State, local, and tribal governments, in 
the aggregate, or the private sector, of $100 million or more in any 1 
year. Before promulgating an EPA rule for which a written statement is 
needed, section 205 of 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 objectives of the rule. The provisions of section 205 do 
not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation 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 UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    For the proposed change in the definition of VOCs, today's 
rulemaking contains no Federal mandates (under the regulatory 
provisions of title II of the UMRA) for State, local, or tribal 
governments or the private sector.
    For the proposed approval of CARB's regulation into the SIP, EPA 
has determined that the proposed approval action does not include a 
Federal mandate that may result in estimated costs of $100 million or 
more to either State, local, or tribal governments in the aggregate, or 
to the private sector. This Federal action proposes to approve pre-
existing requirements under State or local law, and imposes no new 
requirements. Accordingly, no additional costs to State, local, or 
tribal governments, or to the private sector, result from this action.
    Thus, today's rule is not subject to the requirements of sections 
202 and 205 of UMRA.
    In addition, EPA has determined that this rule contains no 
regulatory requirements that might significantly or uniquely affect 
small governments in accordance with section 203 of UMRA.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    This proposed rule does not have federalism implications. It will 
not have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132. Today's proposed rule does not 
impose any new mandates on State or local governments. The change to 
the definition of VOCs merely assists CARB in implementing its aerosol 
coatings reactivity regulation. The proposed approval of this 
regulation into the SIP acts on a State regulation implementing a 
Federal standard, and does not alter the relationship or the 
distribution of power and responsibilities established in the CAA. 
Thus, Executive Order 13132 does not apply to this rule.
    In the spirit of Executive Order 13132, and consistent with EPA 
policy to promote communications between EPA and State and local 
governments, EPA specifically solicits comment on this proposed rule 
from State and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' This proposed rule does not 
have tribal implications, as specified in Executive Order 13175. The 
proposed change to the definition of VOCs merely assists CARB in 
implementing its aerosol coatings reactivity regulation and does not 
impose any direct compliance costs. The proposed approval of CARB's 
regulation into the SIP acts on a State regulation and does not alter 
the relationship between the Federal government and Indian Tribes, as 
specified in Executive Order 13175. Thus, Executive Order 13175 does 
not apply to this rule. The EPA specifically solicits additional 
comment on this proposed rule from tribal officials.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    Executive Order 13045: ``Protection of Children from Environmental 
Health and Safety Risks'' (62 FR 19885, April 23, 1997) applies to any 
rule that: (1) Is determined to be ``economically significant'' as 
defined under Executive Order 12866, and (2) concerns an environmental 
health or safety risk that EPA has reason to believe may have a 
disproportionate effect on children. If the regulatory action meets 
both criteria, the Agency must evaluate the environmental health or 
safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    While this proposed rule is not subject to the Executive Order 
because it is not economically significant as defined in Executive 
Order 12866, we have reason to believe that ozone has a 
disproportionate effect on active children who play outdoors. (See 62 
FR 38856 and 38859 July 18, 1997). However, we do not expect today's 
proposed approval of CARB's regulation into the SIP to result in an 
adverse

[[Page 1654]]

impact, as it is intended to be an ozone neutral action. The CARB has 
indicated that they have designed their new reactivity-based limits to 
achieve the same ozone reductions as the mass-based limits they 
supplant. Also, we do not expect today's proposed change to the 
definition of VOC to result in any adverse impact, because it increases 
the number of compounds subject to regulation as VOCs for the purpose 
of California's aerosol coatings reactivity-based regulation.

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This rule is not subject to Executive Order 13211, ``Actions That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 
28355, May 22, 2001) because it is not a significant regulatory action 
under Executive Order 12866.

I. National Technology Transfer Advancement Act

    Section 12(d) of the National Technology Transfer Advancement Act 
of 1995 (``NTTAA''), Public Law No. 104-113, Sec.  12(d) (15 U.S.C. 272 
note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    For the change in definition of VOCs, this proposed rulemaking does 
not involve technical standards. Therefore, EPA is not considering the 
use of any voluntary consensus standards. For the proposed approval of 
CARB's regulation into the SIP, the State regulation references 
standard test methods and makes modifications to American Society for 
Testing and Materials (ASTM) D3074-94, D3063-94 and D2879-97 to support 
the regulatory objectives.
    The EPA welcomes comments on this aspect of the proposed rulemaking 
and, specifically, invites the public to identify potentially-
applicable voluntary consensus standards and to explain why such 
standards should be used in this regulation.

List of Subjects

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 compound.

40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Ozone, Reporting and recordkeeping requirements, Volatile 
organic compound.

    Authority: 42 U.S.C. 7401 et seq.

    Dated: December 29, 2004.
Michael O. Leavitt,
Administrator.

PART 51--REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF 
IMPLEMENTATION PLANS.

    1. The authority citation for part 51 continues to read as follows:

    Authority: 42 U.S.C. 7401, 7411, 7412, 7413, 7414, 7470-7479, 
7501-7508, 7601, and 7602.

    2. Section 51.100 is proposed to be amended by adding paragraph 
(s)(6) as follows:


Sec.  51.100  Definitions.

* * * * *
    (s) * * *
    (6) For the purposes of determining compliance with California's 
aerosol coatings reactivity-based regulation, (as described in the 
California Code of Regulations, Title 17, Division 3, Chapter 1, 
Subchapter 8.5, Article 3), any organic compound in the volatile 
portion of an aerosol coating is counted towards that product's 
reactivity-based limit. Therefore, the compounds identified in this 
section [i.e., Sec. 51.100 (s)] as negligibly reactive and excluded 
from EPA's definition of VOCs are to be counted towards a product's 
reactivity limit for the purposes of determining compliance with 
California's aerosol coatings reactivity-based regulation.
* * * * *
[FR Doc. 05-346 Filed 1-6-05; 8:45 am]
BILLING CODE 6560-50-P