President Trump Invokes National Security to Delay Mercury and Air Toxics Standards

As part of a broader series of orders regarding the coal industry, President Donald Trump issued a proclamation on April 8, 2025, entitled "Regulatory Relief for Certain Stationary Sources to Promote American Energy."

This Holland & Knight alert focuses on President Trump’s Mercury and Air Toxics Standards (MATS) proclamation, which extended the compliance deadline for updated requirements of the U.S. Environmental Protection Agency's (EPA) MATS rule by two years, from July 8, 2027 to July 8, 2029.

Background

Section 112 of the Clean Air Act (CAA) outlines the EPA's authority to issues national emission standards for hazardous air pollutants (NESHAPs). In 2012, EPA issued the first such standards applicable to fossil fuel-fired power plants, commonly known as MATS. MATS has been controversial since its adoption, including a trip to the U.S. Supreme Court in 2015, where the court ruled 5-4 that EPA had unreasonably failed to consider costs at an early stage of the process.

In May 2024, the EPA finalized the most significant updates to MATS since the standards were initially issued, including changes to certain emission standards for coal-fired power plants. The original deadline for power plants to comply with the updated standards was July 8, 2027, three years after the rule's effective date.

President Trump's MATS Proclamation

President Trump's MATS proclamation exempts certain power plants from the July 8, 2027, compliance deadline for the updated standards. Although the typical compliance deadline for a NESHAP is three years after its effective date, the CAA allows the president to exempt sources from compliance for up to two years, with the potential for multiple extensions beyond that. To invoke the presidential exemption under CAA Section 112(i)(4), the President must determine that 1) the technology to implement the EPA standard is "not available" and 2) that an exemption "is in the national security interests of the United States."

President Trump's proclamation expressly cited his authority under CAA Section 112(i)(4) and included various statements relevant to the pair of presidential determinations required under CAA:

• Regarding Technological Availability. The president's proclamation states that the technology to implement the rule "does not exist in a commercially viable form sufficient" to implement and comply with the rule by its 2027 deadline.
• Regarding National Security. The president's proclamation states that the 2027 compliance deadline would undermine national security by, among other things, risking the shutdown of coal-fired power plants, which, in turn, would "leave America vulnerable to electricity demand shortages, increased dependence on foreign energy sources, and potential disruptions of our electricity and energy supplies, particularly in times of crisis."

The proclamation stated that it would apply to a specific list of stationary sources – identified in an "Annex I" to the proclamation – and exempts those sources for the full two-year period permissible under the CAA until July 8, 2029. The CAA authorizes the president to make additional extensions beyond the initial two-year period and requires the president to report to Congress regarding his initial exemption and any subsequent extensions.

The Bigger Picture

President Trump's MATS proclamation of April 8, 2025, is merely the latest development in a long history that is still being written.

Most immediately, the MATS proclamation comes in the wake of EPA's establishment of a brief window in March 2025 to submit requests for presidential exemptions under Section 112(i)(4) for the MATS rule and eight other NESHAPs, including rules affecting the synthetic organic chemical manufacturing industry, sterilization facilities, rubber tire manufacturers, coke ovens, lime manufacturing plants and more. Facilities and affected sources were directed to send an email containing the relevant emissions standards or limitations, the length of the requested extension and a justification supporting their request in terms of technological availability and national security interests. The deadline for this short-lived email submission was March 31, 2025.

The MATS proclamation also exists against the backdrop of President Trump's Day One executive order, "Unleashing American Energy," which directed certain agencies to review "actions that impose an undue burden on the identification, development or use of domestic energy resources." On March 12, 2025, EPA Administrator Lee Zeldin announced 31 distinct initiatives to advance the directive, including a reconsideration of the MATS rule. A reconsideration of the MATS rule could ultimately lead to changes in the MATS rule itself, with longer-term regulatory consequences than the two-year compliance extension provided by President Trump's MATS proclamation. However, the reconsideration process can also be more resource-intensive and complicated, particularly under the uniquely complex CAA rulemaking procedures that would likely apply to such an effort. Parties with interests in potentially reconsidered NESHAPs should prepare for key opportunities to engage in the rulemaking process, particularly if they possess new emissions data or cost data since the relevant NESHAP was finalized.

Trump's 2025 Executive Orders: Updates and Summaries

Holland & Knight's Public Policy & Regulation Group is actively monitoring and reviewing President Trump's executive orders and other actions. View a comprehensive tracking chart of executive order summaries on our website.

Information contained in this alert is for the general education and knowledge of our readers. It is not designed to be, and should not be used as, the sole source of information when analyzing and resolving a legal problem, and it should not be substituted for legal advice, which relies on a specific factual analysis. Moreover, the laws of each jurisdiction are different and are constantly changing. This information is not intended to create, and receipt of it does not constitute, an attorney-client relationship. If you have specific questions regarding a particular fact situation, we urge you to consult the authors of this publication, your Holland & Knight representative or other competent legal counsel.