BASIS OF PRESENTATION (Policies)	6 Months Ended
Jun. 30, 2026
BASIS OF PRESENTATION
Basis of Presentation	The unaudited interim condensed consolidated financial statements of Trinseo PLC and its subsidiaries (the “Company”) as of and for the periods ended June 30, 2026 and 2025 were prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and reflect all adjustments, consisting only of normal recurring adjustments, which, in the opinion of management, are considered necessary for the fair statement of the results for the periods presented. Because they cover interim periods, the statements and related notes to the financial statements do not include all disclosures normally provided in annual financial statements, and therefore, these statements should be read in conjunction with the 2025 audited consolidated financial statements included within the Company’s Annual Report on Form 10-K (“Annual Report”) filed with the Securities and Exchange Commission (“SEC”) on March 13, 2026. The Company’s condensed consolidated financial statements presented herein reflect the latest estimates and assumptions made by management that affect the reported amounts and related disclosures as of and for the period ended June 30, 2026. However, actual results could differ from these estimates and assumptions. The December 31, 2025 condensed consolidated balance sheet data presented herein was derived from the Company’s December 31, 2025 audited consolidated financial statements but does not include all disclosures required by GAAP for annual periods.
Going Concern	Going Concern In accordance with ASC 205-40, Going Concern, the Company evaluated whether conditions and events raise substantial doubt about its ability to continue as a going concern within one year after the issuance of these condensed consolidated financial statements. The condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As of June 30, 2026, the Company had liquidity of $186.7 million and an accumulated deficit of $1,574.8 million and used cash in operations of $348.2 million during the six months ended June 30, 2026. The Company expects continued operating losses and significant cash outflows from operating activities in the near term. Current macroeconomic and geopolitical conditions, including inflation, and ongoing conflicts (such as the Russia-Ukraine war and military conflict in Iran), continue to create significant uncertainty in the broader business environment. These external factors have contributed to weaker demand in many of our end markets, significant volatility in raw material prices, and supply chain disruptions that are expected to continue to have a material adverse effect on the Company's financial performance and liquidity forecasts. Absent the consummation of the Chapter 11 Restructuring Transactions, significant debt maturities would occur in 2028, including the 2028 Refinance Term Loans, the 2028 Term Loan B, the A/R Facility, and the OpCo Super-Priority Revolver. As a result of these factors, the Company concluded that substantial doubt about its ability to continue as a going concern existed as of the issuance of the prior Form 10-K and continues to exist within one year after the issuance of these condensed consolidated financial statements.

BASIS OF PRESENTATION (Policies)

6 Months Ended

Jun. 30, 2026

The unaudited interim condensed consolidated financial statements of Trinseo PLC and its subsidiaries (the “Company”) as of and for the periods ended June 30, 2026 and 2025 were prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and reflect all adjustments, consisting only of normal recurring adjustments, which, in the opinion of management, are considered necessary for the fair statement of the results for the periods presented. Because they cover interim periods, the statements and related notes to the financial statements do not include all disclosures normally provided in annual financial statements, and therefore, these statements should be read in conjunction with the 2025 audited consolidated financial statements included within the Company’s Annual Report on Form 10-K (“Annual Report”) filed with the Securities and Exchange Commission (“SEC”) on March 13, 2026.

The Company’s condensed consolidated financial statements presented herein reflect the latest estimates and assumptions made by management that affect the reported amounts and related disclosures as of and for the period ended June 30, 2026. However, actual results could differ from these estimates and assumptions.

The December 31, 2025 condensed consolidated balance sheet data presented herein was derived from the Company’s December 31, 2025 audited consolidated financial statements but does not include all disclosures required by GAAP for annual periods.

Going Concern

Going Concern

In accordance with ASC 205-40, Going Concern, the Company evaluated whether conditions and events raise substantial doubt about its ability to continue as a going concern within one year after the issuance of these condensed consolidated financial statements.

The condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As of June 30, 2026, the Company had liquidity of $186.7 million and an accumulated deficit of $1,574.8 million and used cash in operations of $348.2 million during the six months ended June 30, 2026. The Company expects continued operating losses and significant cash outflows from operating activities in the near term. Current macroeconomic and geopolitical conditions, including inflation, and ongoing conflicts (such as the Russia-Ukraine war and military conflict in Iran), continue to create significant uncertainty in the broader business environment. These external factors have contributed to weaker demand in many of our end markets, significant volatility in raw material prices, and supply chain disruptions that are expected to continue to have a material adverse effect on the Company's financial performance and liquidity forecasts.

Absent the consummation of the Chapter 11 Restructuring Transactions, significant debt maturities would occur in

2028, including the 2028 Refinance Term Loans, the 2028 Term Loan B, the A/R Facility, and the OpCo Super-Priority Revolver.

As a result of these factors, the Company concluded that substantial doubt about its ability to continue as a going concern existed as of the issuance of the prior Form 10-K and continues to exist within one year after the issuance of these condensed consolidated financial statements.