COMPASS MINERALS INTERNATIONAL INC

Disclosure Controls and Procedures

Our Chief Executive Officer and Chief Financial Officer have conducted an evaluation of the effectiveness of the design and operation of the Company’s disclosure controls and procedures (as defined in Rule 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934) as amended (the Exchange Act) under the supervision and with the participation of the Company’s management. Based on that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that as a result of the material weaknesses in internal control over financial reporting as described below, the Company’s disclosure controls and procedures were ineffective as of December 31, 2025.

Per Rules 13a-15(e) and 15d-15(e), the term disclosure controls and procedures means controls and other procedures of an issuer that are designed to ensure that information required to be disclosed by the issuer in the reports that it files or submits under the Exchange Act (15 U.S.C. 78a et seq.) 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 an issuer in the reports that it files or submits under the Exchange Act is accumulated and communicated to the issuer’s management, including its Chief Executive Officer and Chief Financial Officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure.

Our management, including our Chief Executive Officer and Chief Financial officer, does not expect that our disclosure controls and procedures or our internal control over financial reporting will prevent all errors and all fraud due to inherent limitations of internal controls. Because of such limitations, there is a risk that material misstatements will not be prevented or detected on a timely basis by internal control over financial reporting. However, these inherent limitations are known features of the financial reporting process. Therefore, it is possible to design into the process safeguards to reduce, though not eliminate, this risk.

In light of the material weaknesses described below, management performed additional analysis and other procedures to ensure that our consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (GAAP). Accordingly, our Chief Executive Officer and Chief Financial Officer have concluded that the Company’s Condensed Consolidated Financial Statements included in this Form 10-Q present fairly, in all material respects, our financial position, results of operations and cash flows for the periods presented in conformity with U.S. GAAP.

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.

A material weakness, as defined in Rule 12b-2 under the Exchange Act, is a deficiency, or combination of control deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of the Company’s annual or interim consolidated financial statements will not be prevented or detected on a timely basis.

As disclosed in our Annual Report on Form 10-K for the fiscal year ended September 30, 2024 and our Annual Report on Form 10-K for the fiscal year ended September 30, 2025, we previously identified material weaknesses in our internal control over financial reporting. The Company, due to a limited allocation of trained, knowledgeable resources, did not conduct an effective risk assessment process to identify and evaluate at a sufficient level of detail all relevant risks of material misstatement, including fraud risks associated with the necessary approval of transactions. Additionally, the Company did not have an effective information and communication process that identified and assessed the source of and controls necessary to ensure the reliability of information used in financial reporting and that ensured complete, reliable information was made available to financial reporting personnel on a timely basis to fulfill their roles and responsibilities. As a consequence of the material weaknesses described above, internal control deficiencies related to the design and operation of process-level controls were determined to be ineffective throughout the Company’s financial reporting processes.

Remediation Efforts and Status of Material Weakness

We have and are in the process of implementing a number of measures to address the material weaknesses that have been identified including the following:

•We are enhancing our risk assessment process to ensure it is sufficiently robust to identify and analyze all relevant risks of material misstatements, including fraud and the impact of significant changes in the business on the identification of risks and the related impacts to the design of controls.

•We hired additional accounting professionals who possess the requisite technical accounting and internal control over financial reporting knowledge.

•We are educating and training control owners regarding internal control processes and procedures.

•We implemented internal controls to ensure that all journal entries are properly approved, specifically we redesigned and implemented process level control activities over journal entries. We plan to test the operating effectiveness of these controls in the fiscal year ended September 30, 2026.

•We are redesigning and implementing a balance sheet account reconciliation controls, including an approval process and additional process level controls, that includes the appropriate level of precision, support and documentation.

•We are establishing monitoring and oversight controls to identify non-recurring, complex transactions and designing and implementing process level controls to ensure the accuracy and completeness of our financial statements and related disclosures.

•We are in the process of redesigning our corporate organization structure to ensure effective information and communication across the organization and to support financial reporting processes and internal controls.

Changes in Internal Control Over Financial Reporting

Other than the remediation efforts noted above, there were no changes in the Company’s internal control over financial reporting during the most recently completed fiscal quarter ending December 31, 2025 that has materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II. OTHER INFORMATION