CECO ENVIRONMENTAL CORP

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark one)

☒ Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the fiscal year ended December 31,2025

or

☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Commission File No.0-7099

Registrant’s telephone number, including area code: (214)357-6181

Securities registered under Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐No ☒

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No☒

The aggregate market value of voting and non-voting common stock held by non-affiliates of the registrant was$832.7 million based upon the closing market price and shares of common stock outstanding as of June 28, 2025, the last business day of our most recently completed second fiscal quarter. For the purpose of the foregoing calculation only, all directors and executive officers of the registrant and owners of more than 10% of the registrant’s common stock are assumed to be affiliates of the registrant. This determination of affiliate status is not necessarily conclusive for any other purpose.

As of February 18, 2026, the registrant had 35,665,813 shares of common stock, par value $0.01 per share, outstanding.

Documents Incorporated by Reference

Portions of the definitive Proxy Statement for the 2026 Annual Meeting of Stockholders, which is to be filed with the Securities and Exchange Commission within 120 days of the fiscal year ended December 31, 2025, are incorporated by reference into Part III of this Annual Report to the extent described herein.

CECO Environmental Corp.

ANNUAL REPORT ON FORM 10-K

For the year ended December 31, 2025

TABLE OF CONTENTS

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K includes forward-looking statements within the meaning of the Securities Act of 1933 and the Securities Exchange Act of 1934 (the “Exchange Act”) which are intended to be covered by the safe harbor for “forward-looking statements” provided by the Private Securities Litigation Reform Act of 1995. Any statements contained in this Annual Report on Form 10-K, other than statements of historical fact, including statements about management’s beliefs and expectations, are forward-looking statements and should be evaluated as such. These statements are made on the basis of management’s views and assumptions regarding future events and business performance. We use words such as “believe,” “expect,” “anticipate,” “intends,” “estimate,” “forecast,” “project,” “will,” “plan,” “should” and similar expressions to identify forward-looking statements. Forward-looking statements involve risks and uncertainties that may cause actual results to differ materially from any future results, performance or achievements expressed or implied by such statements. Potential risks and uncertainties, among others, that could cause actual results to differ materially are discussed under “Part I — Item 1A. Risk Factors” of this Annual Report on Form 10-K and include, but are not limited to:

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the effect of recent acquisitions and the divestiture of our fluid handling business (together, the “transactions”) on business relationships, operating results, and business generally, disruption of current plans and operations and potential difficulties in employee retention as a result of the transactions, diversion of management’s attention from on-going business operations in connection with the integration of recent acquisitions, the amount of the costs, fees, expenses and other charges related to the transactions, the achievement of the anticipated benefits of transactions, our ability to successfully integrate acquired businesses and realize the synergies from acquisitions, as well as a number of factors related to our business, including the sensitivity of our business to economic and financial market conditions generally and economic conditions in CECO’s service areas;

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dependence on fixed price contracts and the risks associated therewith, including actual costs exceeding estimates and method of accounting for revenue;

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the effect of growth on our infrastructure, resources and existing sales;

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the ability to expand operations in both new and existing markets;

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the potential for contract delay or cancellation as a result of on-going or worsening supply chain challenges, or other customer-driven project delays relating to supply chain challenges or other customer considerations;

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liabilities arising from faulty services or products that could result in significant professional or product liability, warranty or other claims;

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changes in or developments with respect to any litigation or investigation;

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failure to meet timely completion or performance standards that could result in higher cost and reduced profits or, in some cases, losses on projects;

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the potential for fluctuations in prices for manufactured components and raw materials, including as a result of tariffs and surcharges, and rising energy costs;

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inflationary pressures relating to rising raw material costs and the cost of labor;

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the substantial amount of debt incurred in connection with our strategic transactions and our ability to repay or refinance it or incur additional debt in the future;

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the impact of federal, state or local government regulations, including with respect to tax policy;

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our ability to repurchase shares of our common stock and the amounts and timing of repurchases, if any;

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our ability to successfully realize the expected benefits of our restructuring program;

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economic and political conditions generally;

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our ability to optimize our business portfolio by identifying acquisition targets, executing upon any strategic acquisitions or divestitures, integrating acquired businesses and realizing the synergies from strategic transactions;

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unpredictability and severity of catastrophic events, including cybersecurity threats, acts of terrorism or outbreak of war or hostilities or public health crises, as well as management’s response to any of the aforementioned factors;

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our ability to remediate our material weaknesses, or any other material weakness that we may identify in the future, that could result in material misstatements in our financial statements;

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the risk that the proposed transaction with Thermon Group Holdings, Inc. (“Thermon”) may not be completed on the anticipated terms or timeline, or at all, including as a result of the failure to obtain required regulatory or stockholder approvals;

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the risk that the announcement or pendency of the proposed transaction could disrupt our business, including our relationships with customers, suppliers and employees, and could divert management’s attention from ongoing business operations;

•

the risk that we may be unable to successfully integrate Thermon’s business or realize anticipated benefits, synergies or growth opportunities;

•

the risk that transaction-related costs and expenses may be greater than expected; and

•

the risk of litigation or regulatory proceedings arising in connection with the proposed transaction.

Many of these risks are beyond management’s ability to control or predict. Should one or more of these risks or uncertainties materialize, or should any related assumptions prove incorrect, actual results may vary in material aspects from those currently anticipated. Investors are cautioned not to place undue reliance on such forward-looking statements as they speak only to our views as of the date the statement is made. Except as required under the federal securities laws or the rules and regulations of the Securities and Exchange Commission (the “SEC”), we undertake no obligation to update or review any forward-looking statements, whether as a result of new information, future events or otherwise.