Regulation FD Disclosure (Form 8-K)

ITEM 7.01 Regulation FD Disclosure.

Amendments and Limited Waivers

On March 19, 2026, the Company and certain of its subsidiaries entered into amendments and limited waivers (collectively, the "Limited Waivers") with lenders under certain of the Company's credit facilities.

Trinseo Luxco S.à r.l. ("Trinseo Luxco"), Trinseo Holding S.à r.l. ("Trinseo Holding"), and Trinseo Materials Finance, Inc. (together with Trinseo Holding, the "Borrowers"), entered into amendments and limited waivers under the Company's super-priority revolving credit facility dated January 17, 2025 (as amended, the "SuperPriority Revolver") and the Credit Agreement dated as of September 6, 2017 (as amended, the "Senior Credit Agreement"). Trinseo NA Finance LLC, Trinseo LuxCo Finance SPV S.à r.l. ("LuxCo Finance SPV"), and Trinseo NA Finance SPV LLC entered into an amendment and limited waiver under the Credit Agreement dated as of September 8, 2023 (as amended, the "Refinance Credit Agreement"). Trinseo Ireland Global IHB Limited, Trinseo Holding and Styron Receivables Funding Designated Activity Company entered into an amendment and limited waiver under the Company's accounts receivable securitization facility (the "Accounts Receivable Securitization Facility").

Pursuant to the Limited Waivers, the requisite lenders under each facility agreed to, among other things, temporarily waive certain acceleration and collateral enforcement rights and remedies (until April 30, 2026 under the SuperPriority Revolver, Senior Credit Agreement, and Refinance Credit Agreement, and until April 2, 2026 under the Accounts Receivable Securitization Facility) as a result of the nonpayment of interest or principal beyond applicable grace periods under the Senior Credit Agreement, Refinance Credit Agreement, and the indenture governing LuxCo Finance SPV's 7.625% second lien secured notes due 2029 (the "2L Notes" and such indenture, the "2L Notes Indenture"), and other related notice and cross-defaults. In addition, an amendment to the SuperPriority Revolver removed the anti-cash hoarding provisions and minimum liquidity financial covenant thereunder. In connection with certain of the Limited Waivers, the borrowers thereunder agreed to pay consent fees in-kind to certain lenders.

Expiration of Interest Payment Grace Periods; Events of Default; Intercreditor Agreement

On March 19, 2026, following the lapse of the 30-day grace period, LuxCo Finance SPV elected not to make scheduled interest payments due under the 2L Notes Indenture in the amount of approximately $10 million. On March 19, 2026, following the lapse of the contractual grace period, the Borrowers also elected not to make a scheduled interest payment due under the Senior Credit Agreement in the amount of approximately $12 million. The decisions not to make such interest payments were made in connection with the Company's ongoing discussions with its financial stakeholders regarding its capital structure.