SUPPLEMENTARY INFORMATION:

Throughout this document whenever “we,” “us,” or “our” is used, we mean the EPA. We use multiple abbreviations and terms in this rule. While this list may not be exhaustive, for ease of reading and for reference purposes, the EPA defines the following terms and acronyms here:

BACM Best Available Control Measures

BACT Best Available Control Technology

CAA Clean Air Act

CBI Confidential Business Information

CTG Control Technique Guidelines

EGLE Michigan Department of Environment, Great Lakes, and Energy

E.O. Executive Order

EPA Environmental Protection Agency

FR Federal Register

MAPCR Michigan Air Pollution Control Rules

NAAQS National Ambient Air Quality Standard

NEPA National Environmental Policy Act

NO_X  Nitrogen Oxide

NSR New Source Review

PBI Proprietary Business Information

RACM Reasonably Available Control Measures

RACT Reasonably Available Control Technology

RFA Regulatory Flexibility Analysis

SBA Small Business Administration

SIP State Implementation Plan

TSD Technical Support Documentation

UMRA Unfunded Mandates Reform Act

VOC Volatile Organic Compound

Table of Contents

I. What action is the EPA taking?

II. Background Information

III. Public Comments

IV. Incorporation by Reference

V. Statutory and Executive Order Reviews

I. What action is the EPA taking?

The EPA is approving various revisions and additions to MAPCR Parts 6 and 8 into the Michigan SIP as described in the Preamble above. The EPA is approving these revisions as meeting the Moderate VOC and NO_X RACT requirements of Clean Air Act (CAA) sections 182(b)(2) and 182(f), respectively, for the Western Michigan nonattainment areas under the 2015 ozone standard. EPA is also approving MAPCR Rules 336.1660 and 336.1662, which limit VOC emissions from consumer products and architectural and industrial maintenance coatings, as SIP strengthening measures for the areas. SIP revisions to Rules 336.1801, ( printed page 55275) 336.1802, 336.1803, 336.1810, 336.1818, 336.1841(8), 336.1842(10), and 336.1844(9) are responsive to different CAA requirements and will be considered in a separate rulemaking.

II. Background Information

The Michigan Department of Environment, Great Lakes, and Energy (Michigan or EGLE) submitted the VOC SIP revisions on March 7, 2024, supplemented on May 2, 2024, and NO_X SIP revisions on May 5, 2025, supplemented on August 6, 2025. On February 27, 2026 (91 FR 9793), the EPA proposed to approve revisions and additions to MAPCR Parts 6 and 8 to meet the Moderate VOC and NO_X RACT requirements for the Western Michigan nonattainment areas under the 2015 ozone standard. The EPA also proposed to approve rules that limit VOC emissions from consumer products and architectural and industrial maintenance coatings, as SIP strengthening measures for the Western Michigan nonattainment areas under the 2015 ozone standard.

The EPA is incorporating by reference Michigan rules R 336.1601, except for R 336.1601(a); R 336.1602; R 336.1606; R 336.1607; R 336.1608; R 336.1609; R 336.1610; R 336.1610a; R 336.1611; R 336.1618; R 336.1620; R 336.1620a; R 336.1621; R 336.1621a; R 336.1622; R 336.1623; R 336.1624; R 336.1624a; R 336.1625; R 336.1627; R 336.1628; R 336.1629; R 336.1630; R 336.1631; R 336.1632, except for R 336.1632(9); R 336.1633; R 336.1634; R 336.1635; R 336.1636; R 336.1637; R 336.1638; R 336.1639; R 336.1640; R 336.1641; R 336.1642; R 336.1643; R 336.1644; R 336.1660; R 336.1661 (Rescinded); R 336.1662; effective April 18, 2023; R 336.1840; R 336.1841,except for R 336.1841(8); R 336.1842, except for R 336.1842(10); R 336.1843; R 336.1844, except for R 336.1844(9); R 336.1845; and R 336.1846; effective April 28, 2025.

An explanation of the CAA requirements, a detailed analysis of the revisions, and the EPA's reasons for proposing approval were provided in the notice of proposed rulemaking and will not be restated here. The EPA provided a 30-day review and comment period for this action in the proposal. The comment period ended on March 30, 2026. The EPA reopened the 30-day comment period on April 23, 2026, and this extension ended on May 26, 2026. The EPA received eleven comments in total—one supportive, six not relevant, and four adverse.

The six comments that are not relevant to this action covered a variety of topics including: a general statement regarding the ozone layer, information on a VOC control technology intended to reduce VOC emissions from open containers. All of the comments received are included in the docket for this action. We do not consider these six comments to be germane or relevant to this action and therefore not adverse to this action. These comments lack the required specificity to the proposed SIP revision and the relevant requirements of CAA section 110. Moreover, none of these comments address a specific regulation or provision in question or recommend a different action on the SIP submission from what the EPA proposed.

III. Public Comments

Comment: The commenter asserts that the EPA requires States to adopt the “best available controls” when determining RACT and cites more stringent requirements in other States for the following categories:

• VOC RACT:
  • Surface coating of cans, coils, paper, fabrics, automobiles, and light-duty trucks (San Joaquin Valley, CA)
  • Existing Aerospace Manufacturing and Rework Operations (Oregon, Pennsylvania)
  • Existing Metals Parts, Metal Products, and Motor Vehicle Surfacing Coating Lines (Delaware)
• NO_X RACT:
  • Boilers (San Joaquin Valley, CA)
  • Combustion turbines (San Joaquin Valley, CA and Connecticut)
  • Internal combustion engines (South Coast AQMD, CA)

Response: The EPA disagrees with the commenter's interpretation of RACT. The EPA has long defined RACT as the lowest emission limitation that a particular source is capable of meeting through application of control technology that is reasonably available, considering technological and economic feasibility (44 FR 53762, September 17, 1979).

RACT is distinct from Best Available Control Technology (BACT), which applies under the New Source Review (NSR) program (see CAA section 169(3) and 40 CFR 51.166). RACT applies to existing sources and reflects a different statutory standard.

The existence of more stringent emission limits in other States does not establish that such limits are reasonably available in Michigan. The examples cited by the commenter are from areas classified as Serious or Extreme nonattainment; these areas may choose to go beyond RACT for attainment planning purposes. The Michigan rules in this action are to address Moderate requirements in the West Michigan nonattainment areas, for which RACT is the applicable control level under CAA section 182(b)(2).

Therefore, EPA finds that differences in emission limits across other States are expected and consistent with the CAA.

Comment: That commenter argues Michigan must justify any deviation from the most stringent controls and has failed to demonstrate technological or economic infeasibility.

Response: The EPA disagrees with the commenter's interpretation of the RACT requirement. The CAA does not require States to adopt the most stringent controls implemented anywhere in the country. Rather, States must demonstrate that their selected controls meet the RACT standard, which is based on reasonable technological and economic feasibility.

Michigan conducted a due diligence review consistent with the EPA's guidance, including evaluation of Control Technique Guidelines (CTGs), existing SIP-approved rules, and controls implemented in other States. Differences in requirements reflect variation in source characteristics and feasibility considerations.

The EPA finds that Michigan has provided an adequate basis for its RACT determinations.

Comment: That commenter asserts that Michigan failed to provide sufficient justification for higher exemption thresholds, did not include sufficient detail—such as facility-specific data—in its five percent equivalency analysis to enable meaningful public input or the EPA review, and relied on assumptions that the commenter asserts affect the analysis.

Response: The EPA finds that Michigan's submittal satisfies applicable CAA requirements and adequately addresses the issues raised by the commenter.

First, Michigan has adopted the more stringent exemption threshold of 15 pounds per day (2.7 tons per year) for the Western Michigan nonattainment areas under the 2015 ozone standard through rules R 336.1610a, R 336.1620a, R 336.1621a, and R 336.1624a. These rules implement VOC RACT for the relevant source categories. Therefore, Michigan has met Moderate VOC RACT requirements for these categories in those areas.

Second, the exemption threshold SIP revisions commenter references apply to areas outside of the Western Michigan nonattainment areas under the 2015 ozone standard where RACT and a five ( printed page 55276) percent equivalency analysis are not required. Although Michigan submitted a five percent equivalency analysis, the EPA is evaluating and approving these revisions under CAA section 110(l). The EPA is not approving rules R 336.1610, R 336.1620, R 336.1621, and R 336.1624 as RACT.

Under CAA section 110(l), the relevant inquiry is whether the SIP revision will interfere with attainment, reasonable further progress (RFP), or any other applicable requirement. Michigan's analysis demonstrates that the revised exemption thresholds will not result in an increase in VOC emissions that would interfere with these requirements.

Because the EPA's approval is based on CAA section 110(l), the commenter's concerns regarding the level of detail in the five percent equivalency analysis, including the absence of facility-specific data and assumptions used in that analysis, do not affect the approvability of the revision. The EPA finds that the record contains sufficient information to conclude that the revisions will not interfere with applicable CAA requirements.

The EPA therefore concludes that Michigan's analysis provides an adequate basis for approval.

Comment: That commenter states that the EPA should clarify that the approval of EGLE's proposed SIP submission to apply only to the West Michigan nonattainment areas as the title of the proposed rule is highly misleading if it is intended apply to the whole State.

Response: The EPA acknowledges the commenter's concerns; however, this proposed and final action only approves this SIP submission as meeting the RACT requirement for the West Michigan areas. Michigan would have to make a new submission to meet RACT requirements for other nonattainment areas in the State.

Comment: Two commenters allege that the technical support documentation (TSD) was not adequately available during the public comment period.

Response: The EPA acknowledges these commenters' concern regarding availability of technical support documentation. In response, the EPA extended the public comment period to ensure that the TSD was available for a full 30-day review period.

The EPA finds that providing the TSD for a full 30-day public comment period afforded adequate opportunity for meaningful public participation consistent with the CAA and Administrative Procedure Act. Therefore, the EPA concludes that the extended comment period addressed both commenters' concerns and provided sufficient opportunity for review and comment.

Comment: The commenter asserts that the EPA's proposal fails to document CAA 110(a) SIP approval criteria under 42 U.S.C. 7410(a)(2).

Response: CAA 110(a) contains infrastructure SIP (iSIP) requirements, and the EPA has taken action on infrastructure requirements and approved iSIP elements for Michigan in separate actions; therefore, it is not relevant to address in this action.

Comment: That commenter states that the EPA's proposal fails to document source-specific RACT determinations, comparison to EPA CTGs, or evaluation against current best available control measures (BACM).

Response: The EPA finds that Michigan's submittal satisfies applicable CAA requirements for RACT and adequately addresses the issues raised by the commenter. Michigan provided source-specific RACT analyses and conducted a due diligence review consistent with the EPA's guidance, including evaluation of CTGs, existing SIP-approved rules, and controls implemented in other States. RACT is distinct from BACM, which applies under CAA 189(b)(1)(B) and does not apply to ozone nonattainment areas. RACT applies to existing sources and reflects a different statutory standard. Therefore, The EPA finds that Michigan has provided an adequate basis for its RACT determinations.

Comment: That commenter claims the EPA's proposal fails to document RFP demonstrations to comply with CAA 172(c)(2)

Response: The EPA has taken action on and approved RFP requirements in a separate action (91 FR 9453, February 26, 2026).

Comment: That commenter claims the EPA's proposal fails to document an anti-backsliding analysis to comply with CAA 193.

Response: The EPA finds that Michigan's submittal does not trigger a need for an anti-backsliding analysis under CAA 193 as no control requirements are being removed but rather added or strengthened.

Comment: That commenter insists the EPA's proposal fails to document a National Environmental Policy Act (NEPA) significance determination or a basis for any claimed exemption.

Response: The EPA determined that this action is not a “major federal action” that significantly affects the quality of the human environment as it is approving State choices as meeting the CAA and does not impose any additional requirements beyond those required by State law.

Comment: That commenter alleges that the EPA's proposal does not document an environmental justice analysis under Executive Order (E.O.) 12898 and E.O. 14008.

Response: An environmental justice analysis is not required as both E.O. 12898 and E.O. 14008 were rescinded.

Comment: That commenter claims the EPA's proposal fails to document a children's health analysis for ozone under E.O. 13045 and fails to provide a reasoned explanation under State Farm, Encino,West Virginia v. EPA, and Loper Bright.

Response: This action is not subject to E.O. 13045 and these court decisions because it merely approves State choices as meeting the CAA and does not impose any additional requirements beyond those required by State law.

Comment: That commenter states that the EPA's proposal fails to document Tribal consultation under E.O. 13175.

Response: This action is not approved to apply on any Indian reservation land or in any other area where the EPA or an Indian Tribe has demonstrated that a Tribe has jurisdiction. In those areas of Indian country, the rule does not have Tribal implications and will not impose substantial direct costs on Tribal governments or preempt Tribal law.

Comment: That commenter insists the EPA's proposal fails to document an E.O. 13132 federalism analysis.

Response: This action does not have federalism implications as specified in E.O. 13132.

Comment: That commenter asserts that the EPA should develop an Initial Regulatory Flexibility Analysis (RFA) or revised certification with supporting evidence to demonstrate a lack of significant economic impact on a substantial number of small entities.

Response: An RFA is inapplicable to this rulemaking because the regulatory analysis provisions of the RFA are only triggered by a threshold determination by the Agency that this rule will have a significant economic impact on a substantial number of small entities. Because the Agency has certified this rule will not have a significant economic impact, section 603 and 604 of the RFA do not apply to this rulemaking. 5 U.S.C. 605(b).

Comment: That commenter states that the proposal does not provide an Unfunded Mandates Reform Act (UMRA) analysis as to whether this action imposes a Federal intergovernmental mandate.

Response: The EPA has already complied with any UMRA obligation by including in the proposed rulemaking ( printed page 55277) its determination that this rule will not result in expenditures exceeding $100 million in any one year, pursuant to 2 U.S.C. 1532(a). The Agency need not complete any further statement under 2 U.S.C. 1532.

Comment: That commenter alleges the proposal fails to document Centralized Regulatory Review Under E.O. 12866 section 3(f) and E.O. 14094.

Response: This action does not require this documentation as SIP actions are exempt from review under E.O. 12866 and E.O. 14094 was revoked.

Comment: That commenter insists the EPA's proposal fails to document the basis for re-opening the comment period.

Response: The EPA is not required to document the basis for re-opening a comment period; however, the public was made aware that the public comment period was reopened in response to a comment.

Comment: That commenter claims the EPA's proposal does not comply with E.O. 13272 as it does not document consultation with the Small Business Administration (SBA) Office of Advocacy.

Response: This action will not have any significant economic impact on a substantial number of small entities and merely approves State choices as meeting the CAA and does not impose any additional requirements beyond those required by State law, therefore consultation with the SBA is not warranted.

IV. Incorporation by Reference

In this rule, the EPA is finalizing regulatory text that includes incorporation by reference. In accordance with the requirements of 1 CFR 51.5, the EPA is finalizing the incorporation by reference of the Michigan Regulations described in section II of this preamble and set forth in the amendments to 40 CFR part 52 below. The EPA has made, and will continue to make, these documents generally available through www.regulations.gov, and at the EPA Region 5 Office (please contact the person identified in the FOR FURTHER INFORMATION CONTACT section of this preamble for more information). Therefore, these materials have been approved by the EPA for inclusion in the SIP, have been incorporated by reference by the EPA into that plan, are fully federally enforceable under CAA sections 110 and 113 as of the effective date of the final rulemaking of the EPA's approval, and will be incorporated by reference in the next update to the SIP compilation.^[1]

V. Statutory and Executive Order Reviews

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, the EPA's role is to approve State choices, provided that they meet the criteria of the CAA. Accordingly, this action merely approves State law as meeting Federal requirements and does not impose additional requirements beyond those imposed by State law. For that reason, this action:

• Is not a significant regulatory action subject to review by the Office of Management and Budget underExecutive Order 12866 (58 FR 51735, October 4, 1993);
• Is not anExecutive Order 14192 (90 FR 9065, February 6, 2025) regulatory action because this action is not significant under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified inExecutive Order 13132 (64 FR 43255, August 10, 1999);
• Is not subject toExecutive Order 13045 (62 FR 19885, April 23, 1997) because it approves a State program;
• Is not a significant regulatory action subject toExecutive Order 13211 (66 FR 28355, May 22, 2001); and
• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA.

In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where the EPA or an Indian Tribe has demonstrated that a Tribe has jurisdiction. In those areas of Indian country, the rule does not have Tribal implications and will not impose substantial direct costs on Tribal governments or preempt Tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

This action is subject to the Congressional Review Act, and the EPA will submit a rule report to each House of the Congress and to the Comptroller General of the United States. This action is not a “major rule” as defined by 5 U.S.C. 804(2).

Under CAA section 307(b)(1), petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by October 26, 2026. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed, and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. (See section 307(b)(2).)

For the reasons stated in the preamble, 40 CFR part 52 is amended as follows:

91 FR 55274