Ecovyst Inc

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2024. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure.

Management recognized that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Based on the evaluation of our disclosure controls and procedures as of December 31, 2024, our Chief Executive Officer and Chief Financial Officer concluded that, as of such date, our disclosure controls and procedures were not effective because of the material weakness in internal control over financial reporting as discussed below.

Management’s Annual Report on Internal Control over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act as a process, designed by, or under the supervision of the Company’s principal executive and principal financial officers and effected by the Company’s board of directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. Internal control over financial reporting includes maintaining records that in reasonable detail accurately and fairly reflect our transactions and dispositions of assets; providing reasonable assurance that transactions are recorded as necessary for preparation of our financial statements; providing reasonable assurance that receipts and expenditures are made only in accordance with management and board authorizations; and providing reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on our financial statements. Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. Our management assessed the effectiveness of our internal control over financial reporting as of December 31, 2024. In making this assessment, management used the criteria for effective internal control over financial reporting described in the “Internal Control-Integrated Framework” (2013) set forth by the Committee of Sponsoring Organizations of the Treadway Commission (“COSO”).

Based on the assessment, management concluded that, as of December 31, 2024, our internal control over financial reporting was not effective.

A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of a company’s annual or interim financial statements will not be prevented or detected on a timely basis.

A material weakness exists in relation to the Company’s controls over the accounting of its Zeolyst Joint Venture. The Company does not have sufficient controls designed to ensure its proportionate share of the earnings from the Zeolyst Joint Venture, an equity method investee underlying the Company’s financial statements, were completely, accurately, and timely recorded. This material weakness resulted in immaterial adjustments to our equity in net income from affiliated companies and investments in affiliated companies as of and for the fiscal years ended December 31, 2024, 2023 and 2022, and for the interim periods contained within those fiscal years. This material weakness could result in a material misstatement of our equity in net income from affiliated companies and investments in affiliated companies that would not be prevented or detected on a timely basis.

The effectiveness of our internal control over financial reporting as of December 31, 2024 has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report, which is included in Item 8.

Plan for Remediation of Material Weakness

We are in the process of developing a plan to remediate the material weakness described above. Our plan will include designing and implementing appropriate controls designed to ensure our proportionate share of the earnings from the Zeolyst Joint Venture are completely, accurately, and timely recorded in our financial statements. This material weakness will not be considered remediated until the applicable controls are designed, implemented and operate for a sufficient period of time and management has concluded, through testing, that these controls are operating effectively.

Changes in Internal Control Over Financial Reporting

No changes in our internal control over financial reporting occurred during the quarter ended December 31, 2024 that materially affected, or which are reasonably likely to materially affect, our internal control over financial reporting.