CFO — Michael Feehan: The CFO is departing without cause but is being immediately succeeded by a named external hire with a structured transition plan, indicating an orderly succession rather than a sudden loss.

Results of Operations and Financial Condition. On August 5, 2026, Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter ended June 30, 2026. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the Securities Excha…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information contained in

on Form 8-K that are not otherwise defined herein have the meanings ascribed to such terms in the Credit Agreement or Fourth Amendment, as applicable. The Fourth Amendment provides for an additional $100.0 million first lien term loan (the “Incremental Term Loan”) as a fungible increase to the existing Initial Term Loans and makes certain other changes to the Existing Credit Agreement. The Incremental Term Loan will bear interest at the same variable rate as the Initial Term Loans, which is,…

Other Events On June 30, 2026, Ecovyst Inc. (the “Company”), through its wholly owned subsidiaries New Structure Subco Inc. (the “US Purchaser”) and EV Industrial Chemical Subsidiary Holdings Inc. (the “Canadian Purchaser” and, together with the US Purchaser, the “Purchasers”), completed the previously announced acquisition of the entire issued share capital of the US Target and the Canadian Target pursuant to the Share Purchase Agreement (the “Purchase Agreement”), dated as of May 1, 2026, b…

Results of Operations and Financial Condition. On May 5, 2026, Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter ended March 31, 2026. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchang…

Entry into a Material Definitive Agreement. On May 1, 2026, Ecovyst Inc. (the “Company”), through its wholly owned subsidiaries New Structure Subco Inc. (the “US Purchaser”) and EV Industrial Chemical Subsidiary Holdings Inc. (the “Canadian Purchaser” and, together with the US Purchaser, the “Purchasers”), entered into a Share Purchase Agreement (the “Purchase Agreement”) with INEOS Calabrian Holdings Limited (the “US Seller”) and INEOS Calabrian Canada Holdings Limited (the “Canadian Seller”…

Results of Operations and Financial Condition. On February 26, 2026 , Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter and year ended December 31, 2025. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the…

Vice President and President, Advanced Materials & Catalysts — Paul Whittleston: Departure of Paul Whittleston from his roles due to the closing of a transaction.

Triggering Events That Accelerate or Increase a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement. The closing of the Transaction discussed in

Completion of Acquisition or Disposition of Assets. On December 31, 2025, Ecovyst, Inc. ("Ecovyst" or the "Company") completed the previously announced sale of its Advanced Materials & Catalysts business to Technip Energies N.V. (the “Purchaser”), pursuant to a Stock Purchase Agreement (the “Purchase Agreement”), dated September 10, 2025, by and between Ecovyst Inc. and the Purchaser, for a purchase price of $556 million in cash, subject to certain adjustments specified therein, including for…

Paul Whittleston: A supplemental bonus grant was approved for Paul Whittleston as part of a retention bonus program.

Results of Operations and Financial Condition. On November 4, 2025, Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter ended September 30, 2025. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the Securitie…

Entry into a Material Definitive Agreement. On September 10, 2025, Ecovyst Inc. (the “Company”) entered into a Stock Purchase Agreement (the “Purchase Agreement”) with Technip Energies N.V. (the “Purchaser”), pursuant to which the Company will divest its Advanced Materials & Catalysts business to the Purchaser (the “Transaction”). The Company and the Purchaser will provide each other with certain transition services for a period of up to 13 months from the date of the closing of the Transacti…

CFO — George L. Vann, Jr.: Mr. Vann's departure is involuntary and includes severance benefits.

Results of Operations and Financial Condition. On August 7, 2025, Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter ended June 30, 2025. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the Securities Excha…

Results of Operations and Financial Condition. On May 1, 2025, Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter ended March 31, 2025. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchang…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth above under

Entry into a Material Definitive Agreement. On April 10, 2025, Ecovyst Catalyst Technologies LLC (“Ecovyst LLC”), an indirect, wholly owned subsidiary of Ecovyst Inc., entered into a fifth amendment agreement (the “ABL Amendment”) among Ecovyst LLC, Ecovyst Catalyst Technologies UK Limited (“Ecovyst UK” and together with Ecovyst LLC, collectively, the “Borrowers”), Ecovyst Midco II Inc. (“Holdings”), the guarantors party thereto, the replacement lenders party thereto and Citibank, N.A., as ad…

Results of Operations and Financial Condition. On February 27, 2025 , Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter and year ended December 31, 2024. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth above under

Entry into a Material Definitive Agreement. On January 30, 2025 (the “Third Amendment Effective Date”), Ecovyst Catalyst Technologies LLC (“Ecovyst”) and Eco Services Operations Corp. (“Eco Services”, and together with Ecovyst, collectively, the “Borrowers”), each an indirect, wholly owned subsidiary of Ecovyst Inc., entered into a third amendment agreement (the “Amendment”) among the Borrowers, Ecovyst Midco II Inc., UBS AG, Stamford Branch, as administrative agent, and the lenders party the…

The filing describes a retention bonus program for certain employees, including the Vice President and President – Advanced Materials and Catalysts.

Results of Operations and Financial Condition. On October 31, 2024, Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter ended September 30, 2024. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the Securitie…

Results of Operations and Financial Condition. On August 1, 2024, Ecovyst Inc. issued a press release announcing the reporting of its financial results for the quarter ended June 30, 2024. A copy of the press release is furnished with this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in this Current Report on Form 8-K (including the exhibit attached hereto) shall not be deemed “filed” for the purposes of Section 18 of the Securities Excha…