Ecovyst Inc. 10-Q

ITEM 1. FINANCIAL STATEMENTS (UNAUDITED) ECOVYST INC. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF (LOSS) INCOME (in thousands, except share and per share amounts) (unaudited) Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Sales $ 204,907 $ 153,867 $ 524,082 $ 449,428 Cost of goods sold 152,832 108,732 412,748 329,032 Gross profit 52,075 45,135 111,334 120,396 Selling, general and administrative expenses 15,658 15,178 49,768 49,846 Other operating expense, net 8,142 2,414 18,492 7,859 Operating income 28,275 27,543 43,074 62,691 Interest expense, net 8,368 7,912 24,802 27,068 Debt modification and extinguishment costs — — 960 4,560 Other (income) expense, net ( 660 ) 190 ( 300 ) 645 Income from continuing operations before income taxes 20,567 19,441 17,612 30,418 Provision for income taxes 20,195 4,602 19,974 8,029 Net income (loss) from continuing operations 372 14,839 ( 2,362 ) 22,389 Net (loss) income from discontinued operations, net of tax ( 79,627 ) ( 588 ) ( 74,504 ) 1,378 Net (loss) income $ ( 79,255 ) $ 14,251 $ ( 76,866 ) $ 23,767 Net (loss) income per share: Basic income (loss) per share - continuing operations $ — $ 0.13 $ ( 0.02 ) $ 0.19 Diluted income (loss) per share - continuing operations $ — $ 0.13 $ ( 0.02 ) $ 0.19 Basic (loss) income per share - discontinued operations $ ( 0.70 ) $ ( 0.01 ) $ ( 0.64 ) $ 0.01 Diluted (loss) income per share - discontinued operations $ ( 0.69 ) $ ( 0.01 ) $ ( 0.64 ) $ 0.01 Basic (loss) income per share $ ( 0.70 ) $ 0.12 $ ( 0.66 ) $ 0.20 Diluted (loss) income per share $ ( 0.69 ) $ 0.12 $ ( 0.66 ) $ 0.20 Weighted average shares outstanding: Basic 113,901,834 116,490,634 115,943,873 116,786,759 Diluted 114,869,273 117,187,054 115,943,873 117,425,254 See accompanying notes to condensed consolidated financial statements. 4 Table of Contents ECOVYST INC. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (in thousands) (unaudited) Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Net (loss) income $ ( 79,255 ) $ 14,251 $ ( 76,866 ) $ 23,767 Other comprehensive (loss) income, net of tax: Pension and postretirement benefits ( 1 ) 3 169 527 Net loss from hedging activities ( 1,363 ) ( 11,654 ) ( 8,077 ) ( 8,865 ) Foreign currency translation ( 1,669 ) 6,403 11,444 4,040 Total other comprehensive (loss) income ( 3,033 ) ( 5,248 ) 3,536 ( 4,298 ) Comprehensive (loss) income $ ( 82,288 ) $ 9,003 $ ( 73,330 ) $ 19,469 See accompanying notes to condensed consolidated financial statements. 5 Table of Contents ECOVYST INC. AND SUBSIDIARIES CONDENSED CONSOLIDATED BALANCE SHEETS (in thousands, except share and per share amounts) (unaudited) September 30, 2025 December 31, 2024 ASSETS Cash and cash equivalents $ 81,976 $ 131,390 Accounts receivable, net 83,272 53,204 Inventories, net 24,134 17,973 Derivative assets 2,370 6,532 Prepaid and other current assets 13,495 10,931 Current assets held for sale 91,813 83,684 Total current assets 297,060 303,714 Property, plant and equipment, net 481,197 458,684 Goodwill 326,952 326,589 Other intangible assets, net 62,076 67,700 Right-of-use lease assets 40,535 33,082 Other long-term assets 37,904 37,342 Long-term assets held for sale 489,051 575,210 Total assets $ 1,734,775 $ 1,802,321 LIABILITIES Current maturities of long-term debt $ 8,730 $ 8,730 Accounts payable 47,084 32,936 Operating lease liabilities—current 9,854 9,053 Accrued liabilities 48,714 39,825 Current liabilities held for sale 17,705 24,582 Total current liabilities 132,087 115,126 Long-term debt, excluding current portion 846,083 852,099 Deferred income taxes 114,429 105,395 Operating lease liabilities—noncurrent 30,850 23,927 Other long-term liabilities 2,809 3,146 Long-term liabilities held for sale 651 2,168 Total liabilities 1,126,909 1,101,861 Commitments and contingencies (Note 15) EQUITY Common stock ($ 0.01 par); authorized shares 450,000,000 ; issued shares 140,872,846 and 140,872,846 on September 30, 2025 and December 31, 2024, respectively; outstanding shares 114,019,414 and 116,534,803 on September 30, 2025 and December 31, 2024, respectively 1,409 1,409 Preferred stock ($ 0.01 par); authorized shares 50,000,000 ; no shares issued or outstanding on September 30, 2025 and December 31, 2024 — — Additional paid-in capital 1,105,604 1,106,792 Accumulated deficit ( 254,374 ) ( 177,508 ) Treasury stock, at cost; shares 26,853,432 and 24,338,043 on September 30, 2025 and December 31, 2024, respectively ( 240,902 ) ( 222,826 ) Accumulated other comprehensive loss ( 3,871 ) ( 7,407 ) Total equity 607,866 700,460 Total liabilities and equity $ 1,734,775 $ 1,802,321 See accompanying notes to condensed consolidated financial statements. 6 Table of Contents -ECOVYST INC. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (in thousands) (unaudited) Common stock Additional paid-in capital Accumulated deficit Treasury stock, at cost Accumulated other comprehensive loss Total Balance, December 31, 2024 $ 1,409 $ 1,106,792 $ ( 177,508 ) $ ( 222,826 ) $ ( 7,407 ) $ 700,460 Net loss — — ( 3,597 ) — — ( 3,597 ) Other comprehensive income — — — — 226 226 Tax withholdings on equity award vesting — — — ( 1,477 ) — ( 1,477 ) Stock compensation expense — 3,072 — — — 3,072 Shares issued under equity incentive plan, net of forfeitures — ( 9,519 ) — 9,519 — — Balance, March 31, 2025 $ 1,409 $ 1,100,345 $ ( 181,105 ) $ ( 214,784 ) $ ( 7,181 ) $ 698,684 Net income — — 5,986 — — 5,986 Other comprehensive income — — — — 6,343 6,343 Repurchases of common shares — — — ( 21,917 ) — ( 21,917 ) Excise tax on repurchases of common shares — — — ( 151 ) — ( 151 ) Stock compensation expense — 3,395 — — — 3,395 Shares issued under equity incentive plan, net of forfeitures — ( 212 ) — 259 — 47 Balance, June 30, 2025 $ 1,409 $ 1,103,528 $ ( 175,119 ) $ ( 236,593 ) $ ( 838 ) $ 692,387 Net loss — — ( 79,255 ) — — ( 79,255 ) Other comprehensive loss — — — — ( 3,033 ) ( 3,033 ) Repurchases of common shares — — — ( 5,540 ) — ( 5,540 ) Excise tax on repurchases of common shares — — — ( 42 ) — ( 42 ) Stock compensation expense — 2,918 — — — 2,918 Shares issued under equity incentive plan, net of forfeitures — ( 842 ) — 1,273 — 431 Balance, September 30, 2025 $ 1,409 $ 1,105,604 $ ( 254,374 ) $ ( 240,902 ) $ ( 3,871 ) $ 607,866 7 Table of Contents Common stock Additional paid-in capital Accumulated deficit Treasury stock, at cost Accumulated other comprehensive (loss) income Total Balance, December 31, 2023 $ 1,407 $ 1,102,581 $ ( 170,856 ) $ ( 226,710 ) $ ( 958 ) $ 705,464 Net income — — 1,221 — — 1,221 Other comprehensive income — — — — 2,174 2,174 Tax withholdings on equity award vesting — — — ( 1,218 ) — ( 1,218 ) Stock compensation expense — 3,674 — — — 3,674 Shares issued under equity incentive plan, net of forfeitures 2 ( 9,290 ) — 9,329 — 41 Balance, March 31, 2024 $ 1,409 $ 1,096,965 $ ( 169,635 ) $ ( 218,599 ) $ 1,216 $ 711,356 Net income — — 8,295 — — 8,295 Other comprehensive loss — — — — ( 1,224 ) ( 1,224 ) Repurchases of common shares — — — ( 5,010 ) — ( 5,010 ) Stock compensation expense — 3,827 — — — 3,827 Shares issued under equity incentive plan, net of forfeitures — ( 43 ) — 82 — 39 Balance, June 30, 2024 $ 1,409 $ 1,100,749 $ ( 161,340 ) $ ( 223,527 ) $ ( 8 ) $ 717,283 Net income — — 14,251 — — 14,251 Other comprehensive loss — — — — ( 5,248 ) ( 5,248 ) Stock compensation expense — 2,952 — — — 2,952 Shares issued under equity incentive plan, net of forfeitures — ( 340 ) — 472 — 132 Balance, September 30, 2024 $ 1,409 $ 1,103,361 $ ( 147,089 ) $ ( 223,055 ) $ ( 5,256 ) $ 729,370 See accompanying notes to condensed consolidated financial statements. 8 Table of Contents ECOVYST INC. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (in thousands) (unaudited) Nine months ended September 30, 2025 2024 Cash flows from operating activities: Net (loss) income $ ( 76,866 ) $ 23,767 Net loss (income) from discontinued operations 74,504 ( 1,378 ) Net (loss) income from continuing operations ( 2,362 ) 22,389 Adjustments to reconcile net (loss) income to net cash provided by operating activities: Depreciation 50,002 44,506 Amortization 8,014 8,014 Amortization of deferred financing costs and original issue discount 888 1,082 Debt extinguishment costs — 90 Deferred income tax provision (benefit) 18,940 ( 3,424 ) Net loss on asset disposals 4,047 832 Stock compensation 7,551 8,291 Other, net ( 7,200 ) ( 7,894 ) Working capital changes that provided (used) cash: Receivables ( 20,391 ) 1,304 Inventories ( 3,106 ) ( 233 ) Prepaids and other current assets 368 ( 1,109 ) Accounts payable 14,600 ( 3,855 ) Accrued liabilities 6,210 ( 3,998 ) Net cash provided by operating activities, continuing operations 77,561 65,995 Net cash provided by operating activities, discontinued operations 20,986 40,400 Net cash provided by operating activities 98,547 106,395 Cash flows from investing activities: Purchases of property, plant and equipment ( 51,596 ) ( 42,961 ) Business combinations ( 41,315 ) — Net cash used in investing activities, continuing operations ( 92,911 ) ( 42,961 ) Net cash used in investing activities, discontinued operations ( 15,549 ) ( 13,264 ) Net cash used in investing activities ( 108,460 ) ( 56,225 ) 9 Table of Contents Nine months ended September 30, 2025 2024 Cash flows from financing activities: Issuance of long-term debt, net of original issue discount and financing fees 870,817 870,817 Repayments of long-term debt ( 877,365 ) ( 877,500 ) Repurchases of common shares ( 27,457 ) ( 5,010 ) Tax withholdings on equity award vesting ( 1,477 ) ( 1,218 ) Other, net 456 153 Net cash used in financing activities, continuing operations ( 35,026 ) ( 12,758 ) Net cash used in financing activities, discontinued operations ( 2,433 ) ( 2,354 ) Net cash used in financing activities ( 37,459 ) ( 15,112 ) Effect of exchange rate changes on cash and cash equivalents 467 51 Net change in cash and cash equivalents ( 46,905 ) 35,109 Cash and cash equivalents at beginning of period 146,013 88,365 Cash and cash equivalents at end of period 99,108 123,474 Less: cash, cash equivalents, and restricted cash of discontinued operations ( 17,132 ) ( 23,228 ) Cash, cash equivalents and restricted cash at end of period of continuing operations $ 81,976 $ 100,246 For supplemental cash flow disclosures, see Note 19. See accompanying notes to condensed consolidated financial statements. 10 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 1. Background and Basis of Presentation: Description of Business Ecovyst Inc. and subsidiaries (the “Company” or “Ecovyst”) is a leading provider of virgin sulfuric acid and sulfuric acid regeneration services. The Company supports customers through its strategically located network of manufacturing facilities. The Company believes that its products and services contribute to improving the sustainability of the environment. The Company has a uniquely positioned specialty business, Ecoservices, which provides sulfuric acid recycling to the North American refining industry for the production of alkylate and provides high quality and high strength virgin sulfuric acid for industrial and mining applications. Ecoservices also provides chemical waste handling and treatment services, as well as ex-situ catalyst activation services for the refining and petrochemical industry. The Company’s regeneration services product group typically experiences seasonal fluctuations as a result of higher demand for gasoline products in the summer months and lower demand in the winter months. These demand fluctuations result in higher sales and working capital requirements in the second and third quarters. Basis of Presentation The condensed consolidated financial statements included herein are unaudited. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) have been condensed or omitted pursuant to such rules and regulations for interim reporting. In the opinion of management, all adjustments of a normal and recurring nature necessary to state fairly the financial position and results of operations have been included. The results of operations are not necessarily indicative of the expected results for the full year. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024. On September 10, 2025, the Company entered into a definitive agreement to sell its Advanced Materials & Catalysts business for a purchase price of $ 556,000 , subject to certain purchase price adjustments as set forth in the agreement. Upon entering into the definitive agreement, the transaction met the held for sale criteria under ASC 360 and consequently the financial results of the Advanced Materials & Catalysts business are reported in discontinued operations in the condensed consolidated financial statements for all periods presented. See Note 3 for more information on this transaction. The notes to the condensed consolidated financial statements, unless otherwise indicated, are on a continuing operations basis. 2. New Accounting Standards: Accounting Standards Recently Adopted In August 2023, the Financial Accounting Standards Board (“FASB”) issued guidance for entities that meet the definition of a joint venture or a corporate joint venture, to adopt a new basis of accounting upon the formation of the joint venture. The new guidance requires the initial measurement of contributed net assets and liabilities at fair value on the formation date, recognition of goodwill for the difference between the fair value of the joint venture’s equity and net assets, and disclosures about the nature and financial impact of the transaction. The new guidance requires prospective application and is effective for all joint ventures that are formed on or after January 1, 2025, with early adoption permitted. Joint ventures that formed before January 1, 2025 may elect to retrospectively apply the new guidance. The Company has adopted the new guidance as required on January 1, 2025 and will apply the guidance to any new joint ventures formed after the effective date. In November 2023, FASB issued guidance to improve the disclosures related to public business entities (“PBEs”) reportable segments. This new guidance requires entities to provide information regarding significant segment expenses, especially those segment expenses that are regularly reported to the Company’s chief operating decision maker (“CODM,” or the Company’s Chief Executive Officer). The guidance also requires public entities to disclose the nature, type and amounts of other segment items by reportable segment. PBEs will also have to report all annual disclosures about segments profits or losses that are required by ASC 280 on an interim basis, including the significant segment expenses and other segment items. The new guidance is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company adopted the new guidance effective December 31, 2024. 11 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) Accounting Standards Not Yet Adopted In July 2025, FASB issued guidance related to the estimation of expected credit losses for current accounts receivable and current contract assets that arise from transactions accounted for under ASC 606 . This new guidance introduces a practical expedient for entities that assumes that current conditions as of the balance sheet date do not change for the remaining life of the asset. The new guidance is effective for fiscal years beginning after December 15, 2025 and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact of this guidance. In November 2024, FASB issued guidance requiring PBEs to disclose additional information on the nature of certain expenses presented in the income statement. The new guidance requires tabular disclosure of significant expense categories and qualitative descriptions for amounts not disaggregated from relevant expense categories. PBEs are required to define selling expenses and disaggregate the components. The new guidance is effective for fiscal years beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. The requirements must be applied prospectively however PBEs have the option to apply the guidance retrospectively. The disclosure will be implemented as required for the fiscal year ended December 31, 2027. The Company is currently evaluating the impact of this guidance. In December 2023, FASB issued guidance to improve disclosures related to incomes taxes. This new guidance requires PBEs to disaggregate information on the effective tax rate reconciliation and income taxes paid to provide greater transparency. PBEs will be required to provide additional information in specified categories related to effective tax rate reconciliation in tabular form and provide income taxes paid by jurisdictions, with further disaggregation needed if amounts exceed 5% of the total. The new guidance is effective for fiscal years beginning after December 15, 2024. The disclosure will be implemented as required for the fiscal year ended December 31, 2025. The Company is currently evaluating the impact of this guidance. 12 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 3. Divestiture: Advanced Materials & Catalysts Divestiture On September 10, 2025, the Company entered into a definitive agreement to sell its Advanced Materials & Catalysts business to Technip Energies N.V. for a purchase price of $ 556,000 , subject to certain adjustments including for indebtedness, cash, working capital and transaction expenses, as set forth in the definitive agreement (the “Advanced Materials & Catalysts Sale”). The Advanced Materials & Catalysts Sale is expected to be completed in the first quarter of 2026, subject to regulatory approvals and customary closing conditions. In the third quarter of 2025, the Advanced Materials & Catalysts business met the criteria set forth in ASC 205-20 , as the sale represents a strategic shift that will have a major effect on the Company’s operations and financial results. As a result, the Company’s condensed consolidated financial statements for all periods presented reflect the Advanced Materials & Catalysts business as a discontinued operation. The Advanced Materials & Catalysts business historically represented a reportable segment of the Company. As a result of the Advanced Materials & Catalysts business meeting held for sale criteria in the third quarter of 2025, the Company is required to measure the disposal group at the lower of its carrying values or fair values less costs to sell. As such, the Company performed an impairment analysis using a fair value estimate based on the agreed upon arm's length sales price resulting in the recognition of an impairment charge for assets classified as held for sale of $ 83,898 during the three months ended September 30, 2025. This impairment charge primarily consisted of a $ 49,636 impairment charge to goodwill along with a $ 34,262 valuation allowance on assets held for sale. The final fair value estimate at the completion of the sale could vary from the current fair value estimate. The Company’s estimate of fair value will be evaluated and additional impairments or recoveries of amounts previously impaired may be recognized in future periods until the divestiture is complete. The following table summarizes the results of discontinued operations related to the Advanced Materials & Catalysts business for the three and nine months ended September 30, 2025 and 2024, respectively: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Sales $ 21,609 $ 25,308 $ 64,760 $ 73,104 Cost of goods sold 14,802 15,740 41,874 45,911 Gross profit 6,807 9,568 22,886 27,193 Selling, general and administrative expenses 4,471 4,772 14,367 14,414 Impairment of assets held for sale 83,898 — 83,898 — Other operating expense, net 4,217 798 8,298 2,128 Operating (loss) income ( 85,779 ) 3,998 ( 83,677 ) 10,651 Equity in net (income) from affiliated companies ( 2,261 ) 922 ( 13,104 ) ( 2,543 ) Interest expense, net (1) 2,801 3,393 8,494 10,541 Other (income) expense, net ( 31 ) 376 364 548 (Loss) income from discontinued operations before income taxes ( 86,288 ) ( 693 ) ( 79,431 ) 2,105 (Benefit) provision for income taxes ( 6,661 ) ( 105 ) ( 4,927 ) 727 (Loss) income from discontinued operations, net of tax $ ( 79,627 ) $ ( 588 ) $ ( 74,504 ) $ 1,378 (1) Upon the close of the Advanced Materials & Catalysts Sale and finalization of net cash proceeds, the Company will be required to provide partial repayment under its Term Loan Credit Agreement dated as of January 30, 2025 (“2025 Term Loan Facility”). As such, interest expense has been allocated to discontinued operations on the basis of the Company’s estimated mandatory partial repayment of the 2025 Term Loan Facility. 13 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) The following table summarizes the assets and liabilities of discontinued operations related to the Advanced Materials & Catalysts divestiture as of September 30, 2025 and December 31, 2024, respectively: September 30, 2025 December 31, 2024 ASSETS Cash and cash equivalents $ 17,132 $ 14,623 Accounts receivables, net 20,082 24,733 Inventories, net 47,190 39,153 Prepaid and other current assets 7,409 5,175 Current assets held for sale $ 91,813 $ 83,684 Investments in affiliated companies $ 343,783 $ 349,308 Property, plant and equipment, net 113,254 110,591 Goodwill 29,687 77,513 Other intangible assets, net 29,036 30,713 Right-of-use lease assets 830 476 Other long-term assets 6,723 6,609 Valuation allowance on assets held for sale ( 34,262 ) — Long-term assets held for sale $ 489,051 $ 575,210 LIABILITIES Accounts payable $ 5,300 $ 10,992 Operating lease liabilities—current 351 214 Accrued liabilities 12,054 13,376 Current liabilities held for sale $ 17,705 $ 24,582 Deferred income taxes $ 70 $ — Operating lease liabilities—noncurrent 479 262 Other long-term liabilities 102 1,906 Long-term liabilities held for sale $ 651 $ 2,168 The disposal group includes the Company’s investment in an affiliated company, which was historically accounted for under the equity method. The following table provides summarized financial information of the combined investments in affiliated companies that were included within the divested business unit: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Sales $ 79,128 $ 76,568 $ 237,238 $ 204,073 Gross profit 16,180 9,200 58,132 43,129 Operating income (loss) 5,803 ( 1,608 ) 28,053 10,976 Net income (loss) 5,463 ( 623 ) 29,190 11,387 Certain administrative services are provided to the affiliated company by the Company. The Company charged $ 576 and $ 1,728 for the three and nine months ended September 30, 2025 and $ 687 and $ 2,062 for the three and nine months ended September 30, 2024, respectively, which were included in selling, general and administrative expenses in the condensed consolidated statements of (loss) income. 14 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 4. Revenue from Contracts with Customers: Disaggregated Revenue The Company’s primary means of disaggregating revenue is by key end uses, which are described in the table below. Key End Uses Key Products Regeneration and treatment services • Sulfuric acid regeneration services • Hazardous waste treatment services Industrial, mining & automotive • Virgin sulfuric acid for mining • Virgin sulfuric acid derivatives for industrial production • Virgin sulfuric acid derivatives for nylon production Other • Catalyst activation • Aluminum sulfate solution • Ammonium bisulfite solution The following table disaggregates the Company’s sales by key end uses, for the three and nine months ended September 30, 2025 and 2024, respectively: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Regeneration and treatment services (1) $ 99,157 $ 91,037 $ 271,192 $ 269,721 Industrial, mining & automotive 96,430 53,291 226,641 154,165 Other 9,320 9,539 26,249 25,542 Total sales $ 204,907 $ 153,867 $ 524,082 $ 449,428 (1) As described in Note 1 to these condensed consolidated financial statements, the Company experiences seasonal s ales fluctuations to customers in the regeneration services product group. 5. Fair Value Measurements: Fair values are based on quoted market prices when available. When market prices are not available, fair values are generally estimated using discounted cash flow analyses, incorporating current market inputs for similar financial instruments with comparable terms and credit quality. In instances where there is little or no market activity for the same or similar instruments, the Company estimates fair values using methods, models and assumptions that management believes a hypothetical market participant would use to determine a current transaction price. These valuation techniques involve some level of management estimation and judgment that becomes significant with increasingly complex instruments or pricing models. Where appropriate, adjustments are included to reflect the risk inherent in a particular methodology, model or input used. The Company’s financial assets and liabilities carried at fair value have been classified based upon a fair value hierarchy. The hierarchy gives the highest ranking to fair values determined using unadjusted quoted prices in active markets for identical assets and liabilities (Level 1) and the lowest ranking to fair values determined using methodologies and models with unobservable inputs (Level 3). The classification of an asset or a liability is based on the lowest level input that is significant to its measurement. For example, a Level 3 fair value measurement may include inputs that are both observable (Levels 1 and 2) and unobservable (Level 3). The levels of the fair value hierarchy are as follows: • Level 1—Values are unadjusted quoted prices for identical assets and liabilities in active markets accessible at the measurement date. Active markets provide pricing data for trades occurring at least weekly and include exchanges and dealer markets. • Level 2—Inputs include quoted prices for similar assets or liabilities in active markets, quoted prices from those willing to trade in markets that are not active, or other inputs that are observable or can be corroborated by market data for the term of the instrument. Such inputs include market interest rates and volatilities, spreads and yield curves. 15 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) • Level 3—Certain inputs are unobservable (supported by little or no market activity) and significant to the fair value measurement. Unobservable inputs reflect the Company’s best estimate of what hypothetical market participants would use to determine a transaction price for the asset or liability at the reporting date. Fair value on a recurring basis The following tables present information about the Company’s assets and liabilities that were measured at fair value on a recurring basis as of September 30, 2025 and December 31, 2024, and indicates the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value. September 30, 2025 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Derivative assets: Interest rate caps (Note 12) $ 2,510 $ — $ 2,510 $ — Derivative liabilities: Interest rate caps (Note 12) $ 1,569 $ — $ 1,569 $ — December 31, 2024 Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Derivative assets: Interest rate caps (Note 12) $ 12,500 $ — $ 12,500 $ — Derivative liabilities: Interest rate caps (Note 12) $ 710 $ — $ 710 $ — Derivative contracts Derivative assets and liabilities can be exchange-traded or traded over-the-counter (“OTC”). The Company generally values exchange-traded derivatives using models that calibrate to market transactions and eliminate timing differences between the closing price of the exchange-traded derivatives and their underlying instruments. OTC derivatives are valued using market transactions and other market evidence whenever possible, including market-based inputs to models, model calibration to market transactions, broker or dealer quotations or alternative pricing sources with reasonable levels of price transparency. When models are used, the selection of a particular model to value an OTC derivative depends on the contractual terms of, and specific risks inherent in, the instrument as well as the availability of pricing information in the market. The Company generally uses similar models to value similar instruments. Valuation models require a variety of inputs, including contractual terms, market prices and rates, forward curves, measures of volatility, and correlations of such inputs. For OTC derivatives that trade in liquid markets, such as forward contracts, swaps and options, model inputs can generally be corroborated by observable market data by correlation or other means, and model selection does not involve significant management judgment. As of September 30, 2025, th e Company had interest rate c aps th at were fair valued using Level 2 inputs. In addition, the Company applies a credit valuation adjustment to reflect credit risk which is calculated based on credit default swaps. To the extent that the Company’s net exposure under a specific master agreement is an asset, the Company utilizes the counterparty’s default swap rate. If the net exposure under a specific master agreement is a liability, the Company utilizes a default swap rate comparable to Ecovyst. The credit valuation adjustment is added to the discounted fair value to reflect the exit price that a market participant would be willing to receive to assume the Company’s liabilities or that a market participant would be willing to pay for the Company’s assets. 16 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 6. Stockholders' Equity: Accumulated Other Comprehensive Loss The following tables present the tax effects of each component of other comprehensive (loss) income for the three and nine months ended September 30, 2025 and 2024, respectively: Three months ended September 30, 2025 2024 Pre-tax amount Tax benefit/(expense) After-tax amount Pre-tax amount Tax benefit/(expense) After-tax amount Defined benefit and other postretirement plans: Net (loss) gain $ ( 1 ) $ — $ ( 1 ) $ 11 $ ( 3 ) $ 8 Net prior service cost — — — ( 7 ) 2 ( 5 ) Benefit plans, net ( 1 ) — ( 1 ) 4 ( 1 ) 3 Net loss from hedging activities ( 1,817 ) 454 ( 1,363 ) ( 15,539 ) 3,885 ( 11,654 ) Foreign currency translation ( 1,669 ) — ( 1,669 ) 6,403 — 6,403 Other comprehensive loss $ ( 3,487 ) $ 454 $ ( 3,033 ) $ ( 9,132 ) $ 3,884 $ ( 5,248 ) Nine months ended September 30, 2025 2024 Pre-tax amount Tax benefit/ (expense) After-tax amount Pre-tax amount Tax benefit/ (expense) After-tax amount Defined benefit and other postretirement plans: Net gain $ 224 $ ( 55 ) $ 169 $ 724 $ ( 181 ) $ 543 Net prior service cost — — — ( 22 ) 6 ( 16 ) Benefit plans, net 224 ( 55 ) 169 702 ( 175 ) 527 Net loss from hedging activities ( 10,769 ) 2,692 ( 8,077 ) ( 11,820 ) 2,955 ( 8,865 ) Foreign currency translation 11,444 — 11,444 4,040 — 4,040 Other comprehensive income (loss) $ 899 $ 2,637 $ 3,536 $ ( 7,078 ) $ 2,780 $ ( 4,298 ) The following tables present the changes in accumulated other comprehensive loss (“AOCI”), net of tax, by component for the nine months ended September 30, 2025 and 2024, respectively: Defined benefit and other postretirement plans Net gain (loss) from hedging activities Foreign currency translation Total December 31, 2024 $ 1,467 $ 9,902 $ ( 18,776 ) $ ( 7,407 ) Other comprehensive income (loss) before reclassifications 172 ( 3,378 ) 11,444 8,238 Amounts reclassified from AOCI (1) ( 3 ) ( 4,699 ) — ( 4,702 ) Net current period other comprehensive income (loss) 169 ( 8,077 ) 11,444 3,536 September 30, 2025 $ 1,636 $ 1,825 $ ( 7,332 ) $ ( 3,871 ) December 31, 2023 $ 612 $ 12,546 $ ( 14,116 ) $ ( 958 ) Other comprehensive income before reclassifications 549 1,657 4,040 6,246 Amounts reclassified from AOCI (1) ( 22 ) ( 10,522 ) — ( 10,544 ) Net current period other comprehensive income (loss) 527 ( 8,865 ) 4,040 ( 4,298 ) September 30, 2024 $ 1,139 $ 3,681 $ ( 10,076 ) $ ( 5,256 ) (1) See the following table for details about these reclassifications. Amounts in parentheses indicate debits. 17 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) The following table presents the reclassifications out of AOCI for the three and nine months ended September 30, 2025 and 2024, respectively: Details about AOCI Components Amounts reclassified from AOCI (1) Affected line item where income is presented Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Amortization of defined benefit and other postretirement items: Net loss $ 1 $ — $ 4 $ 7 Other expense (2) Net prior service cost — 7 — 22 Other expense (2) 1 7 4 29 Total before tax — ( 2 ) ( 1 ) ( 7 ) Tax benefit $ 1 $ 5 $ 3 $ 22 Net of tax Gains and losses on cash flow hedges: Interest rate caps $ 2,041 $ 4,711 $ 6,266 $ 14,029 Interest expense ( 510 ) ( 1,177 ) ( 1,567 ) ( 3,507 ) Tax benefit $ 1,531 $ 3,534 $ 4,699 $ 10,522 Net of tax Total reclassifications for the period $ 1,532 $ 3,539 $ 4,702 $ 10,544 Net of tax (1) Amounts in parentheses indicate debits to profit/loss. (2) These AOCI components are components of net periodic pension and other postretirement cost (see Note 14 to these condensed consolidated financial statements for additional details). Treasury Stock Repurchases 2022 Stock Repurchase Program On April 27, 2022, the Company’s board of directors (the “Board”) approved a stock repurchase program that authorized the Company to purchase up to $ 450,000 of the Company’s common stock over the four-year period from the date of approval (the “Stock Repurchase Program”). On October 30, 2025, the Board amended the Stock Repurchase Program to remove the limitation that all repurchases must be made within the four-year period from the date of original approval. Under the plan, the Company is permitted to repurchase shares from time to time for cash in open market transactions or in privately negotiated transactions in accordance with applicable federal securities laws, with the Company determining the timing and the amount of any repurchases based on its evaluation of market conditions, share price and other factors. During the nine months ended September 30, 2025, the Company repurchased 3,536,364 shares on the open market at an average price of $ 7.74 per share, for a total of $ 27,387 , excluding brokerage commissions and accrued excise tax. During the nine months ended September 30, 2025, the Company accrued $ 193 of excise tax related to these repurchases, net of shares issued under the Company’s equity incentive program (see Note 17 to these condensed consolidated financial statements). As of September 30, 2025, $ 202,207 was available for share repurchases under the program. During the nine months ended September 30, 2024, the Company repurchased 552,081 shares on the open market at an average price of $ 9.05 per share, for a total of $ 4,998 , excluding brokerage commissions and accrued excise tax. During the nine months ended September 30, 2024, the Company did not need to accrue excise tax related to these repurchases, net of shares issued under the Company’s equity incentive program (see Note 17 to these condensed consolidated financial statements). 18 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) Tax Withholdings on Equity Award Vesting In connection with the vesting of restricted stock awards (“RSA” or “RSAs”), restricted stock units (“RSU” or “RSUs”) and performance stock units (“PSU” or “PSUs”), shares of common stock may be delivered to the Company by employees to satisfy withholding tax obligations at the instruction of the employee award holders. These transactions, when they occur, are accounted for as stock repurchases by the Company, with the shares returned to treasury stock at a cost representing the payment by the Company of the tax obligations on behalf of the employees in lieu of shares for the vesting event. There were 189,446 and 128,801 shares delivered to the Company to cover tax payments for the nine months ended September 30, 2025 and 2024, respectively, and the fair value of those shares withheld were $ 1,477 and $ 1,218 for the nine months ended September 30, 2025 and 2024, respectively. 7. Goodwill: The following table provides a summary of the changes in the carrying amount of goodwill associated with the Ecoservices segment for the nine months ended September 30, 2025: Balance as of December 31, 2024 $ 326,589 Goodwill recognized (Note 8) 363 Balance as of September 30, 2025 $ 326,952 The Company completes its annual goodwill and indefinite-lived intangible assets impairment test during the fourth quarter of each year, or more frequently if triggering events indicate a possible impairment. The Company determined the fair value of its reporting unit using both a market approach and an income, or discounted cash flow, approach. As of October 1, 2024, the date of the Company’s most recent quantitative assessments, the fair value of the Company’s reporting unit and the fair value of the Company’s indefinite-lived trade names and trademarks exceeded their respective carrying values. During the nine months ended September 30, 2025, the Company did not identify any events or circumstances that would more likely than not reduce the fair value of the Company’s reporting unit below its carrying value. 19 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 8. Acquisition: On May 6, 2025 (the “Closing Date”), the Company completed its acquisition of the sulfuric acid production assets of Cornerstone Chemical Company LLC (“Cornerstone”) located in Waggaman, Louisiana. As part of an asset purchase agreement (the “Acquisition”), the Company paid $ 41,315 in cash, consisting of the $ 35,000 purchase price plus $ 6,315 of adjustments for working capital, pursuant to the agreement. The sulfuric acid production assets will be used to increase capacity of virgin sulfuric acid and sulfuric acid regeneration services to current and future customers. The Acquisition is a business combination, therefore the acquisition method was applied. Under the acquisition method, the purchase price was allocated to the identifiable assets acquired based on the fair values of the identifiable assets acquired as of the Closing Date. The excess of the purchase price over fair values of the identifiable assets acquired was recorded to goodwill. The table below presents the provisional fair values allocated to the assets acquired. The purchase accounting and purchase price allocation for Cornerstone are preliminary and the Company continues to refine the preliminary valuation of certain acquired assets which could impact the amount of residual goodwill recorded. The Company intends to finalize the amounts recognized as it obtains the information necessary to complete the analysis, but no later than one year from the date of the acquisition. Final determination of the fair values may result in further adjustments to the values presented in the following table: Preliminary Purchase Price Allocation Cash paid $ 41,315 Recognized amounts of identifiable assets acquired: Accounts receivable $ 9,812 Inventories 3,055 Property, plant and equipment 25,000 Other intangible assets 2,390 Other long-term assets 695 Fair value of identifiable assets acquired 40,952 Goodwill 363 Total assets acquired $ 41,315 Adjustments to the preliminary amounts during the measurement period that result in changes to depreciation, amortization or other income effects will be recognized in the reporting period(s) in which the adjustments are determined. In accordance with the requirements of the purchase method of accounting for acquisitions, accounts receivable and inventories were recorded at fair market value. As of the Closing Date, the fair value of accounts receivable approximated historical cost. The gross contractual amount of accounts receivable at the Closing Date was $ 9,812 , of which there was no amount deemed uncollectible. Fair value of inventory is defined as estimated selling prices less the sum of (a) costs of disposal and (b) a reasonable profit allowance for the selling effort of the acquiring entity. Prior to the acquisition, the Company had a preexisting relationship with Cornerstone. The Company had a net payable of $ 619 for a sulfuric acid exchange balance. As part of the acquisition terms, the payable was settled at cost, which was recorded separate from the business combination. 20 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) The valuation of intangibles assets acquired and the related weighted-average amortization period are as follows: Amount Weighted-Average Expected Useful Life (in years) Intangible assets subject to amortization: Customer relationships $ 2,390 15 The Company evaluated the disclosure requirements under ASC 805 and determined the Acquisition was not considered a material business combination for purposes of disclosing the sales and earnings attributable to Cornerstone since the date of acquisition or supplemental pro forma information. Acquisition and integration costs were $ 1,315 and $ 4,070 for the three and nine months ended September 30, 2025, respectively, and are included in other operating expense, net in the Company’s condensed consolidated statements of (loss) income. The Company entered into an agreement with Cornerstone to lease the land where the acquired assets are located for a 7-year term plus renewal options. Additionally, Cornerstone will charge the Company for site services and utilities for the location. 9. Other Operating Expense, Net: A summary of other operating expense, net is as follows: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Amortization expense $ 2,130 $ 2,130 $ 6,390 $ 6,390 Transaction and other related costs 554 — 2,845 198 Restructuring, integration and business optimization costs 1,764 58 2,931 232 Net loss on asset disposals 3,630 218 4,047 832 Other, net 64 8 2,279 207 Total other operating expense, net $ 8,142 $ 2,414 $ 18,492 $ 7,859 10. Inventories, Net: Inventories, net are stated at the lower of cost or net realizable value. Cost is determined using the first-in, first-out (“FIFO”) or average cost method. The components of inventories, net consist of the following: September 30, 2025 December 31, 2024 Finished products and work in process $ 19,703 $ 15,810 Raw materials 4,431 2,163 Total inventories, net $ 24,134 $ 17,973 21 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 11. Long-term Debt: The summary of long-term debt is as follows: September 30, 2025 December 31, 2024 2025 Term Loan Facility $ 864,271 $ 870,817 ABL Facility — — Total debt 864,271 870,817 Original issue discount ( 6,484 ) ( 7,201 ) Deferred financing costs ( 2,974 ) ( 2,787 ) Total debt, net of original issue discount and deferred financing costs 854,813 860,829 Less: current portion ( 8,730 ) ( 8,730 ) Total long-term debt, excluding current portion $ 846,083 $ 852,099 Term Loan Facility In June 2024, the Company amended its Term Loan Credit Agreement dated as of June 9, 2021 to, among other things, (a) reduce the interest rate applicable to all outstanding Secured Overnight Financing Rate (“SOFR”) term loans to a rate equal to the forward-looking term rate based on SOFR as administered by the Federal Reserve Bank of New York (“Term SOFR”) plus 2.25 % per annum from a maximum of adjusted Term SOFR plus 2.75 % per annum, (b) reduce the interest rate applicable to all outstanding base rate term loans to the alternate base rate plus 1.25 % per annum from a maximum of the alternate base rate plus 1.75 % per annum and (c) extend the maturity date of all outstanding term loans to June 12, 2031. As a result of the amendment, there is no longer a credit spread adjustment of 10 basis points. In January 2025, the Company amended its Term Loan Credit Agreement dated as of June 12, 2024 to, among other things, (a) reduce the interest rate applicable to all outstanding SOFR term loans to Term SOFR plus 2.00 % per annum from a maximum of Term SOFR plus 2.25 % per annum and (b) reduce the interest rate applicable to all outstanding base rate term loans to the alternate base rate plus 1.00 % per annum from a maximum of the alternate base rate plus 1.25 % per annum. The Company evaluated the terms of the amendments in accordance with ASC 470-50 Debt - Modification and Extinguishment and determined that both amendments were a modification of debt. As a result of the January 2025 amendment, the Company recorded $ 960 of third-party financing costs within debt modification and extinguishment costs in the condensed consolidated statements of (loss) income for the nine months ended September 30, 2025. No third-party financing costs were recorded for the three months ended September 30, 2025, and no original issue discount was paid for the three and nine months ended September 30, 2025. As a result of the June 2024 amendment, the Company recorded $ 4,471 of third-party financing costs within debt modification and extinguishment costs in the condensed consolidated statements of (loss) income for the nine months ended September 30, 2024 and capitalized $ 2,183 of original issued discount within long-term debt, excluding current portion in the condensed consolidated balance sheets during the quarter ended June 30, 2024. In addition, $ 90 of previous unamortized deferred financing costs and original issue discount associated with the previously outstanding debt were written off as debt modification and extinguishment costs for the nine months ended September 30, 2024. No third-party financing costs were recorded for the three months ended September 30, 2024, and no original issue discount was paid for the three months ended September 30, 2024. The interest rate on the 2025 Term Loan Facility was 5.98 % as of September 30, 2025. ABL Facility The borrowings under the senior secured asset-based lending revolving credit facility (“ABL Facility”) bear interest at a rate equal to an adjusted Term SOFR or the base rate plus a margin of between 1.25 % to 1.75 % or 0.25 % to 0.75 %, respectively. The interest rate on the ABL Facility was 7.50 % as of September 30, 2025. 22 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) In April 2025, the Company amended its ABL credit agreement (“ABL Credit Agreement”) to, among other things, (a) reallocate all European revolving loan commitments thereunder as United States revolving loan commitments, (b) extend the maturity date with respect to borrowings under the ABL Credit Agreement by over three years to April 10, 2030 (subject to acceleration under certain circumstances), (c) reduce the interest rate applicable to outstanding revolving loans that bear interest at a rate equal to Term SOFR by removing the credit spread adjustment that was applied to Term SOFR in the ABL Credit Agreement in calculating adjusted Term SOFR, and (d) reduce the frequency of borrowing base reporting, field examinations and appraisals (subject to higher frequency under certain circumstances). As a result of the amendment, the Company capitalized $ 551 of deferred financing costs within long-term debt, excluding current portion in the condensed consolidated balance sheets during the quarter ended June 30, 2025. Fair Value of Debt The fair value of a financial instrument is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. As of September 30, 2025 and December 31, 2024, the fair value of the Company’s term loan facility was $ 862,109 and $ 874,083 , respectively. The fair value is classified as Level 2 based upon the fair value hierarchy (see Note 5 to these condensed consolidated financial statements for further information on fair value measurements). 12. Financial Instruments: The Company uses interest rate related derivative instruments to manage its exposure to changes in interest rates on its variable-rate debt instruments. The Company does not speculate using derivative instruments. By using derivative financial instruments to hedge exposures to changes in interest rates, the Company exposes itself to credit risk and market risk. Credit risk is the failure of the counterparty to perform under the terms of the derivative contract. When the fair value of a derivative contract is an asset, the counterparty owes the Company, which creates credit risk for the Company. When the fair value of a derivative contract is a liability, the Company owes the counterparty and therefore, the Company is not exposed to the counterparty’s credit risk in those circumstances. The Company minimizes counterparty credit risk in derivative instruments by entering into transactions with high quality counterparties. The derivative instruments entered into by the Company do not contain credit-risk-related contingent features. Market risk is the adverse effect on the value of a derivative instrument that results from a change in interest rates. The market risk associated with the Company’s derivative instruments is managed by establishing and monitoring parameters that limit the types and degree of market risk that may be undertaken. Use of Derivative Financial Instruments to Manage Interest Rate Risk The Company is exposed to fluctuations in interest rates on its senior secured credit facilities. Changes in interest rates will not affect the market value of such debt but will affect the Company’s interest payments over the term of the loans. Likewise, an increase in interest rates could have a material impact on the Company’s condensed consolidated statements of cash flows. The Company hedges the interest rate fluctuations on debt obligations through interest rate cap agreements. The Company records these agreements at fair value as assets or liabilities in the condensed consolidated balance sheets. As the derivatives are designated and qualify as cash flow hedges, the gains or losses on the interest rate cap agreements are recorded in stockholders’ equity as a component of other comprehensive (loss) income, net of tax. Reclassifications of the gains and losses on the interest rate cap agreements into earnings are recorded as part of interest expense in the condensed consolidated statements of (loss) income as the Company makes its interest payments on the hedged portion of its senior secured credit facilities. Fair value is determined based on estimated amounts that would be received or paid to terminate the contracts at the reporting date based on quoted market prices. The following table provides a summary of the Company’s interest rate cap agreements: Financial instrument Number of instruments In effect as of September 30, 2025 Current notional amount of instruments in effect Annuitized premium of instruments in effect Cap rate in effect for all agreements at September 30, 2025 Interest rate caps 4 3 $ 625,000 $ 35,285 1.00 % The current notional amounts of the three interest rate cap agreements in effect at September 30, 2025 are $ 250,000 , $ 175,000 and $ 200,000 . The Company entered into a $ 250,000 interest rate cap to mitigate interest rate volatility from September 2023 to October 2025, a $ 175,000 interest rate cap agreement to mitigate interest rate volatility from August 2024 to July 2026 and a $ 200,000 interest rate cap agreement to mitigate interest rate volatility from November 2024 to October 2025. The $ 200,000 interest rate cap agreement will increase to $ 450,000 to mitigate interest rate volatility from November 2025 to October 2026. 23 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) During the quarter ended September 30, 2025, the Company dedesignated a portion of its interest rate caps. With the Company’s expected prepayments on the 2025 Term Loan Facility (see Note 3 to these condensed consolidated financial statements for additional information), an estimated portion of the original forecasted interest rate payments associated with the dedesignated portion of the interest rate cap agreement may no longer be highly probable of occurring but continue to be reasonably possible of occurring. The Company will continue to amortize the loss into interest expense as long as the hedged transaction continues to be reasonably possible of occurring. If the hedged transaction is determined to be probable of not occurring, any remaining loss in AOCI will be immediately reclassified into earnings. The loss related to this portion is not material. Any future gains and losses associated with the dedesignated portion of the interest rate cap agreement through its maturity in October 2026 will be recognized in earnings. The Company also entered into a $ 200,000 forward starting interest rate cap agreement to mitigate interest volatility from August 2026 to July 2028. The fair values of derivative instruments held as of September 30, 2025 and December 31, 2024, respectively, are shown below: Balance sheet location September 30, 2025 December 31, 2024 Derivative assets Derivatives designated as cash flow hedges: Interest rate caps Prepaid and other current assets $ 1,142 $ 6,532 Interest rate caps Other long-term assets 48 5,968 1,190 12,500 Derivative not designated as hedging instrument: Interest rate caps Prepaid and other current assets 1,228 — Interest rate caps Other long-term assets 92 — Total derivative assets $ 2,510 $ 12,500 Derivative liabilities Derivatives designated as cash flow hedges: Interest rate caps Accrued liabilities $ 949 $ 235 Interest rate caps Other long-term liabilities 620 475 Total derivative liabilities $ 1,569 $ 710 24 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) The following tables show the effect of the Company’s derivative instruments designated as cash flow hedges on AOCI and the condensed consolidated statements of (loss) income for the three and nine months ended September 30, 2025 and 2024, respectively: Amount of gain (loss) recognized in OCI Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Interest rate caps $ 224 $ ( 10,828 ) $ ( 4,503 ) $ 2,209 Amount of loss reclassified from AOCI Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Interest rate caps $ ( 2,041 ) $ ( 4,711 ) $ ( 6,266 ) $ ( 14,029 ) Amount of loss reclassified into income Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Interest rate caps $ 2,041 $ 4,711 $ 6,266 $ 14,029 The following table shows the amounts in the line items presented in the condensed consolidated statements of (loss) income in which the effects of derivatives designated as cash flow hedges are recorded for the three and nine months ended September 30, 2025 and 2024, respectively: Three months ended September 30, Location and amount of gain (loss) recognized in income on cash flow hedging relationships 2025 2024 Interest rate caps Interest expense $ ( 8,368 ) $ ( 7,912 ) Nine months ended September 30, 2025 2024 Interest rate caps Interest expense $ ( 24,802 ) $ ( 27,068 ) The amount of net unrealized gains in AOCI related to the Company’s cash flow hedges that is expected to be reclassified to the condensed consolidated statements of (loss) income over the next twelve months is $ 2,489 as of September 30, 2025. 25 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 13. Income Taxes: The effective income tax rate for the three months ended September 30, 2025 was 98.2 %, compared to 23.7 % for the three months ended September 30, 2024. The effective income tax rate for the nine months ended September 30, 2025 was 113.4 %, compared to 26.4 % for the nine months ended September 30, 2024. The Company’s effective income tax rates for the three and nine months ended September 30, 2025 and 2024, respectively, fluctuated primarily due to the increased discrete tax impact relative to pre-tax book income related to a stock compensation shortfall, intraperiod allocation revaluation of deferred tax assets and liabilities including valuation allowances as a result of the Advanced Materials & Catalysts divestiture, state tax refunds associated with prior tax years and expense related to accrued penalties and interest on historical uncertain tax positions. The tax expense for the three and nine months ended September 30, 2025 includes a $ 15,620 discrete tax expense connected to intraperiod allocation associated with the revaluation of deferred tax assets and liabilities, a valuation allowance against the Company’s Kansas Investment Tax Credits, and an increase in valuation allowance against a portion of the Company’s state net operating losses. In accordance with intraperiod allocation rules, this discrete tax expense is reflected in the tax provision for continuing operations. The difference between the U.S. federal statutory income tax rate and the Company’s effective income tax rate for the nine months ended September 30, 2025 was mainly due to state and local taxes, a shortfall tax expense related to stock compensation, tax benefit related to state tax refunds associated with prior tax years, discrete tax expense related to intraperiod allocation associated with the revaluation of deferred tax assets and liabilities, a valuation allowance against the Company’s Kansas Investment Tax Credits, and a valuation allowance against a portion of the Company’s state net operating losses. The difference between the U.S. federal statutory income tax rate and the Company’s effective income tax rate for the nine months ended September 30, 2024 was mainly due to state and local taxes, a discrete shortfall tax expense related to stock compensation and a discrete tax expense associated with the recording of accrued penalties and interest on historical uncertain tax positions. During the three months ended September 30, 2025, the Company reassessed its indefinite reinvestment assertion with respect to its foreign subsidiaries as a result of the decision to divest the Advanced Materials & Catalysts business, which is now classified as held for sale. The Company no longer considers the undistributed earnings of its foreign subsidiaries to be permanently reinvested in non-U.S. operations. Accordingly, the Company considered the deferred tax impacts of the repatriation of the undistributed earnings of its foreign subsidiaries and concluded that there was no net tax impact necessary based on available information. The Company recorded a full valuation allowance offsetting a potential deferred tax asset for the excess of tax basis over the book basis of the foreign subsidiaries. Valuation allowances are provided, if, based upon the weight of available evidence, it is more likely than not that some or all the deferred tax assets will not be realized. We may release all or a portion of the valuation allowance in the near-term; however, the release of the valuation allowance will be evaluated at each reporting period until the divestiture is complete. On July 4, 2025, H.R.1, the One Big Beautiful Bill Act (“OBBBA”), was enacted in the U.S. The OBBBA includes significant provisions, such as the permanent extension of certain expiring provisions of the Tax Cuts and Jobs Act, modifications to the international tax framework and the restoration of favorable tax treatment for certain business provisions. The legislation has multiple effective dates, with certain provisions effective in 2025 and others implemented through 2027. We do not expect the OBBBA to have a material impact on our estimated annual effective tax rate in 2025. 14. Benefit Plans: The following tables present the components of net periodic expense (benefit) for the Company-sponsored defined benefit pension and postretirement plans, which cover certain employees and retirees located in the U.S.: Defined Benefit Pension Plans Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Interest cost $ 818 $ 807 $ 2,460 $ 2,421 Expected return on plan assets ( 809 ) ( 837 ) ( 2,426 ) ( 2,511 ) Settlement gain — — ( 1 ) ( 6 ) Net periodic expense (benefit) $ 9 $ ( 30 ) $ 33 $ ( 96 ) 26 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) Other Postretirement Benefit Plan Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Interest cost $ 6 $ 6 $ 19 $ 18 Amortization of prior service credit — ( 7 ) — ( 22 ) Amortization of net gain ( 1 ) — ( 3 ) ( 1 ) Net periodic expense (benefit) $ 5 $ ( 1 ) $ 16 $ ( 5 ) All components of net periodic expense (benefit) are presented within other (income) expense, net in the Company’s condensed consolidated statements of (loss) income. 15. Commitments and Contingent Liabilities: There is a risk of environmental impact in the Company’s manufacturing operations. The Company’s environmental policies and practices are designed to comply with existing laws and regulations and to minimize the possibility of significant environmental impact. The Company is also subject to various other lawsuits and claims with respect to matters such as governmental regulations, labor and other actions arising out of the normal course of business. All claims that are probable and reasonably estimable have been accrued for in the Company’s condensed consolidated financial statements. When these matters are ultimately concluded and determined, the Company believes that there will be no material adverse effect on its condensed consolidated financial position, results of operations or liquidity. 16. Segment Information: The segment information herein excludes the results of the Advanced Materials & Catalysts segment, which is reflected in held for sale and discontinued operations as described in Note 3, for all periods presented. The Company’s CODM evaluates the operating results of the segments based upon Adjusted EBITDA. The CODM uses Adjusted EBITDA to allocate resources in the annual budget and forecasting process. The CODM considers budget-to-actual variances on a monthly basis when making decisions about allocating capital and personnel to the segments. The CODM also uses segment Adjusted EBITDA to evaluate the return on assets in connection with performance evaluation and to inform the compensation for certain employees. Summarized financial information for the Company’s Ecoservices reportable segment is shown in the following table: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Sales $ 204,907 $ 153,867 $ 524,082 $ 449,428 Adjusted EBITDA (1) $ 63,631 $ 55,098 $ 141,928 $ 146,301 (1) The Company defines Adjusted EBITDA as EBITDA adjusted for certain items as noted in the reconciliation below. Management evaluates the performance and allocates resources based on several factors, of which the primary measure is Adjusted EBITDA. Adjusted EBITDA should not be considered as an alternative to net income (loss) from continuing operations as an indicator of the Company’s operating performance. Adjusted EBITDA as defined by the Company may not be comparable with EBITDA or Adjusted EBITDA as defined by other companies. 27 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) The following table presents selected financial information with respect to the Company’s Ecoservices reportable segment: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Sales $ 204,907 $ 153,867 $ 524,082 $ 449,428 Less: (1) Cost of goods sold $ 134,628 $ 92,619 $ 362,083 $ 283,589 Selling, general and administrative expenses 6,652 6,155 19,864 19,541 Other segment items ( 4 ) ( 5 ) 207 ( 3 ) Adjusted EBITDA from the Ecoservices segment $ 63,631 $ 55,098 $ 141,928 $ 146,301 Less: Interest expense, net 8,368 7,912 24,802 27,068 Depreciation and amortization 20,668 18,488 58,016 52,520 Unallocated corporate expenses 6,157 6,445 21,170 21,394 Debt modification and extinguishment costs — — 960 4,560 Net loss on asset disposals 3,630 218 4,047 832 Transaction and other related costs 554 — 2,845 198 Equity-based compensation 2,271 2,348 7,551 8,291 Restructuring, integration and business optimization expenses 1,764 58 2,931 232 Other ( 348 ) 188 1,994 788 Income from continuing operations before income taxes $ 20,567 $ 19,441 $ 17,612 $ 30,418 (1) The significant expense categories and amounts align with the segment-level information that is regularly provided to the CODM. All lines exclude depreciation, amortization and other items as noted in the above reconciliation. A reconciliation of capital expenditures for the Company’s continuing operations is shown in the following table: Nine months ended September 30, 2025 2024 Capital expenditures: Ecoservices $ 48,826 $ 42,107 Other (1) 2,770 854 Capital expenditures per the condensed consolidated statements of cash flows $ 51,596 $ 42,961 (1) Includes corporate capital expenditures, the cash impact from changes in capital expenditures in accounts payable and capitalized interest. 28 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 17. Stock-Based Compensation: The Company has an equity incentive plan under which it grants common stock awards to employees, directors and affiliates of the Company. At September 30, 2025, 7,081,030 shares of common stock were available for issuance under the plan. The Company settles these awards through the issuance of treasury shares under its equity incentive plan. The Company has granted RSAs, RSUs and PSUs as part of its equity incentive compensation program. RSU During the nine months ended September 30, 2025, the Company granted 985,551 RSUs under its equity incentive plan. Each RSU provides the recipient with the right to receive a share of common stock subject to graded vesting terms based on service, which for the awards granted during the nine months ended September 30, 2025, generally requires approximately one year of service for members of the Company’s Board and approximately three years of service for employees. The value of the RSUs granted during the nine months ended September 30, 2025 was based on the average of the high and low trading prices of the Company’s common stock on the NYSE on the preceding trading day, in accordance with the Company’s policy for valuing such awards. Compensation expense related to the RSUs is recognized on a straight-line basis over the respective vesting period. PSU 2025 Grants During the nine months ended September 30, 2025, the Company granted 508,109 PSUs (at target) under its equity incentive plan. The PSUs granted during the nine months ended September 30, 2025 provide the recipients with the right to receive shares of common stock dependent on 50 % of a Company-specific financial performance target and 50 % on the relative increase in the total shareholder return (“TSR”) goal (“the Performance measures”). The Performance measures are measured independently of each other, but achievement of both metrics is measured on the same three-year performance period from January 1, 2025 through December 31, 2027 (“Performance period”). Depending on the Company’s performance relative to the Performance measures, each PSU award recipient is eligible to receive a percentage of the target number of shares granted to the recipient, ranging from zero to 200 %. The PSUs, to the extent earned, will vest on the date the Compensation Committee of the Company’s Board (“Compensation Committee”) certifies the achievement of the Performance measures for the Performance period, which will occur subsequent to the end of the Performance period and after the Company files its annual consolidated financial statements for the year ending December 31, 2027. Achievement of the Company-specific financial performance target is measured based on the actual three-year cumulative results across the Performance period. The TSR goal is based on the Company’s actual TSR performance against companies in the S&P 1500 Specialty Chemicals Index over the Performance period. The TSR goal, which determines how much of the 50 % of the PSUs granted during 2025 may be earned, is considered a market condition as opposed to a vesting condition. Because a market condition is not considered a vesting condition, it is reflected in the grant date fair value of the award and the associated compensation cost based on the fair value of the award is recognized over the Performance period, regardless of whether the Company actually achieves the market condition or the level of achievement, as long as service is provided by the recipient. The Company used a Monte Carlo simulation to estimate the $ 10.80 weighted average fair value of the awards granted, subject to the TSR goal during the nine months ended September 30, 2025, with the following weighted average assumptions: Expected dividend yield — % Risk-free interest rate 4.19 % Expected volatility 40.39 % Expected term (in years) 2.90 2022 Grants In February 2025, the Compensation Committee certified the achievement of the performance metrics for the three-year period ended December 31, 2024, related to the PSUs granted during the year ended December 31, 2022. The PSUs granted during the year ended December 31, 2022 provide the recipients with the right to receive shares of common stock dependent on the achievement of a TSR goal and are generally subject to the provision of service through the vesting date of the award. The TSR goal was based on the Company’s actual TSR percentage increase over the performance period. The awards vested during the nine months ended September 30, 2025 with no percentage of the TSR goal earned. 29 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) Award Activity The following table summarizes the activity for the Company’s RSUs and PSUs for the nine months ended September 30, 2025: Restricted Stock Units Performance Stock Units Number of units Weighted average grant date fair value (per share) Number of units Weighted average grant date fair value (per share) Nonvested as of December 31, 2024 1,977,373 $ 9.37 1,353,409 (1) $ 11.10 Granted 985,551 $ 7.76 508,109 $ 9.28 Vested ( 1,053,456 ) $ 9.53 — $ — Forfeited ( 222,182 ) $ 8.77 ( 268,935 ) $ 9.64 Nonvested as of September 30, 2025 1,687,286 $ 8.41 1,592,583 (1) $ 10.77 (1) Based on target. During the nine months ended September 30, 2025, the Company did not grant any RSAs. Cash proceeds received by the Company from the exercise of stock options were not material for the nine months ended September 30, 2025. Stock-Based Compensation Expense For the three months ended September 30, 2025 and 2024, stock-based compensation expense for the Company included in continuing operations was $ 2,271 and $ 2,348 , respectively. The associated income tax benefit based on the applicable statutory rate recognized in the condensed consolidated statements of (loss) income for the three months ended September 30, 2025 and 2024 was $ 620 and $ 576 , respectively. For the nine months ended September 30, 2025 and 2024, stock-based compensation expense for the Company included in continuing operations was $ 7,551 and $ 8,291 , respectively. The associated income tax benefit based on the applicable statutory rate recognized in the condensed consolidated statements of (loss) income for the nine months ended September 30, 2025 and 2024 was $ 2,063 and $ 2,033 , respectively. As of September 30, 2025, unrecognized compensation cost of $ 6,439 for RSUs and $ 4,876 for PSUs are considered probable of vesting and the weighted-average period over which these costs are expected to be recognized at September 30, 2025 was 1.66 years for the RSUs and 1.89 years for the PSUs. 18. Earnings per Share: Basic earnings per share is calculated as income available to common stockholders, divided by the weighted average number of common shares outstanding during the period. The weighted average number of common shares outstanding during the period for the computation of basic earnings per share excludes RSAs that have legally been issued but are nonvested during the period, as the sale of these shares is prohibited pending satisfaction of certain vesting conditions by the award recipients in order to earn the rights to the shares. Diluted earnings per share is calculated as income available to common stockholders, divided by the weighted average number of common and potential common shares outstanding during the period, if dilutive. Potential common shares reflect (1) unvested RSAs and RSUs with service vesting conditions, (2) PSUs with vesting conditions considered probable of achievement and (3) options to purchase common stock, all of which have been included in the diluted earnings per share calculation using the treasury stock method. 30 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) The reconciliation from basic to diluted weighted average shares outstanding is as follows: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Weighted average shares outstanding – Basic 113,901,834 116,490,634 115,943,873 116,786,759 Dilutive effect of unvested common shares and RSUs with service conditions, PSUs considered probable of vesting and assumed stock option exercises and conversions 967,439 696,420 — 638,495 Weighted average shares outstanding – Diluted 114,869,273 117,187,054 115,943,873 117,425,254 We utilize the control number concept in the computation of diluted earnings per share to determine whether potential common stock equivalents are dilutive. The control number used is income from continuing operations. The control number concept requires that the same number of potentially dilutive securities applied in computing diluted earnings per share from continuing operations be applied to all other categories of income or loss, regardless of their anti-dilutive effect on such categories. The Company reported a net loss from continuing operations for the nine months ended September 30, 2025, and therefore excluded the dilutive effect of 521,803 shares, which consisted of unvested common shares, RSUs with service conditions, PSUs considered probable of vesting and assumed stock option exercises and conversions from the computation of weighted average diluted shares outstanding. Basic and diluted income per share are calculated as follows: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Numerator: Net (loss) income $ ( 79,255 ) $ 14,251 $ ( 76,866 ) $ 23,767 Denominator: Weighted average shares outstanding – Basic 113,901,834 116,490,634 115,943,873 116,786,759 Weighted average shares outstanding – Diluted 114,869,273 117,187,054 115,943,873 117,425,254 Net (loss) income per share: Basic (loss) income per share $ ( 0.70 ) $ 0.12 $ ( 0.66 ) $ 0.20 Diluted (loss) income per share $ ( 0.69 ) $ 0.12 $ ( 0.66 ) $ 0.20 The table below presents the details of the Company’s weighted average equity-based awards outstanding during each respective period that were excluded from the calculation of diluted earnings per share: Three months ended September 30, Nine months ended September 30, 2025 2024 2025 2024 Anti-dilutive RSUs and PSUs 725,217 920,355 596,900 419,315 Anti-dilutive stock options 367,100 367,100 367,100 367,100 Certain stock options to purchase shares of common stock were excluded from the computation of diluted earnings per share for the respective periods because the options’ exercise price was greater than the average market price of the common shares. These stock options and anti-dilutive awards are not included in the dilution calculation, as their inclusion would have the effect of increasing diluted income per share. 31 Table of Contents ECOVYST INC. AND SUBSIDIARIES NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Dollars in thousands, except share and per share amounts) (unaudited) 19. Supplemental Cash Flow Information: The following table presents supplemental cash flow information for the Company, which includes activity from both continuing and discontinued operations, except for operating leases which is continuing operations only: Nine months ended September 30, 2025 2024 Cash paid during the period for: Income taxes, net of refunds $ 9,957 $ 20,832 Interest (1) 34,643 36,982 Non-cash investing activity: Capital expenditures acquired on account but unpaid as of the period end 1,491 2,358 Non-cash financing activity: Accrued excise tax on share repurchases (Note 6) 193 — Right-of-use assets obtained in exchange for new lease liabilities (non-cash): Operating leases 15,094 8,044 (1) Cash paid for interest is shown net of capitalized interest and includes the cash received or paid on the Company’s interest rate cap agreements designated as cash flow hedges for the periods presented (see Note 12 to these condensed consolidated financial statements for details). 20. Subsequent Events: T he Company has evaluated subsequent events since the balance sheet date and determined that there are no additional items to disclose. 32 Table of Contents