NL INDUSTRIES INC

To the Board of Directors and Stockholders of NL Industries, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of NL Industries, Inc. and its subsidiaries (the "Company") as of December 31, 2024 and 2023, and the related consolidated statements of operations, of comprehensive income, of stockholders’ equity and of cash flows for each of the three years in the period ended December 31, 2024, including the related notes (collectively referred to as the "consolidated financial statements"). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2024 in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits of these consolidated financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matters

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Environmental Remediation and Related Matters

As described in Note 17 to the consolidated financial statements, management evaluates the potential range of the Company’s liability for environmental remediation and related costs at sites where the Company has been named as a potentially responsible party (PRP) or defendant. As of December 31, 2024, management accrued approximately $69 million related to approximately 30 sites associated with remediation and related matters. Liabilities related to environmental remediation and related matters (including costs associated with damages for property damage and/or damages for injury to natural resources) are recorded when management determines that estimated future expenditures are probable and reasonably estimable. As disclosed by management, environmental remediation and related costs accruals (and the potential range of the Company’s liabilities) are adjusted as further information becomes available or as circumstances change which involves management’s judgment regarding current facts and circumstances for each site and is subject to various assumptions and estimates.

The principal considerations for our determination that performing procedures relating to environmental remediation and related matters is a critical audit matter are the significant judgment by management when assessing the accruals and the potential range of the Company’s liabilities and when determining whether estimated future expenditures are probable and reasonably estimable, which in turn led to a high degree of auditor judgment, subjectivity and effort in performing procedures and evaluating evidence related to management’s assessment of the accruals and the potential range of the liabilities.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls relating to management’s evaluation of environmental remediation and related matters, including controls over determining whether estimated future expenditures are probable and reasonably estimable, as well as the related financial statement disclosures. These procedures also included, among others, (i) obtaining the rollforward of environmental accrual activity for each matter and, for a sample of sites, reviewing and discussing site activity with management, (ii) obtaining and evaluating responses to letters of audit inquiry from internal and external legal counsel, and (iii) evaluating the sufficiency of the Company’s environmental remediation and related matters disclosures.

/s/PricewaterhouseCoopers LLP

Dallas, Texas

March 6, 2025

We have served as the Company’s auditor since 1924.