Business Description

NOTE 1—ORGANIZATION AND BUSINESS ACTIVITIES Organization Trinseo PLC (“Trinseo,” and together with its subsidiaries, the “Company”) is a public limited company existing under the laws of Ireland. On October 8, 2021, the Company’s former publicly-traded parent entity, Trinseo S.A., was merged with and into Trinseo PLC, with Trinseo PLC as the surviving entity. As a result of the merger, all of Trinseo S.A.’s outstanding ordinary shares, excluding treasury shares, were exchanged on a one-for-one basis for newly issued ordinary shares of Trinseo PLC. Prior to the formation of Trinseo S.A., the Company’s business was wholly owned by The Dow Chemical Company (together with its affiliates, “Dow”). In 2010, the Styron business was sold by Dow to investment funds advised or managed by affiliates of Bain Capital Partners, LP (the “Dow Separation”). In 2016, Bain Capital Partners, LP fully divested its ownership in the Company. Potential Restructuring of Our Indebtedness We have been reviewing a number of potential alternatives regarding our outstanding indebtedness. These alternatives include refinancings, exchange offers, consent solicitations, the issuance of new indebtedness, amendments to the terms of our existing indebtedness and/or other transactions. We are currently in active discussions with holders of our indebtedness and have engaged outside advisors with respect to these alternatives. Additionally, the Company has appointed two new board members with significant experience in debt restructuring and strategic transactions. Among these alternatives is a restructuring that would, on a consensual basis, seek to modify the terms of substantially all of our outstanding indebtedness, including through the use of an in-court or out-of-court process. We may offer to exchange the indebtedness under our 2028 Refinance Term Loans, 2028 Term Loan B, or 2029 Refinance Senior Notes for new debt and/or equity securities of our parent and/or subsidiary companies. In conjunction with any such transactions, we may seek consents to amend the documents governing our indebtedness to amend or eliminate certain covenants or collateral provisions. Because the terms of any such transactions will be subject to negotiations with the holders of our indebtedness, they may differ materially from those described above and are, to a large extent, outside of our control. There can be no assurance that we will be able to complete any such transactions, and, as no decision with respect to the terms of any such transactions has been made, we may decide not to pursue any such transactions. If we are unable or elect not to complete any such transactions, or if the Company is unable to obtain additional necessary waivers or amendments and its debt is accelerated, there can be no assurance that the Company would be able to obtain replacement financing or to satisfy its obligations, in which case the Company may pursue a process to restructure its indebtedness through an in-court or out-of-court process. We continue to focus on our initiatives to drive operational performance, maintain safe manufacturing processes, retain talent in our organization and continue our objective to become a specialties materials provider. These accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates realization of assets and satisfaction of liabilities in the ordinary course of business. As such, they do not include any adjustments to the recoverability and reclassification of recorded amounts that might be necessary should the Company be unable to continue as a going concern. Refer to Note 2 and Note 16 for additional information. New York Stock Exchange Delisting Notification On March 2, 2026, we received written notice (the “Notice”) from the New York Stock Exchange (the “NYSE”) that they determined to commence proceedings to delist the Company’s ordinary shares and will file a Form 25 with the SEC to delist the Company’s ordinary shares from the NYSE upon completion of applicable procedures. The delisting will be effective 10 days after the filing of the Form 25. As stated in the Notice, the NYSE reached its decision to delist the Company’s securities pursuant to Section 802.01B of the NYSE Listed Company Manual because the Company had fallen below the NYSE continued listing standard requiring listed companies to maintain an average market capitalization over a 30-trading day period of at least $15.0 million.…