{"schema_version":"secwatch.filing_event.v1","accession":"0001558370-25-004485","form_type":"8-K","ticker":"TSEOF","cik":"0001519061","company_name":"Trinseo PLC","filed_at":"2025-04-04T23:59:59+00:00","discovered_at":"2026-05-14T18:02:48.582543+00:00","generated_at":"2026-05-23T20:57:55.130533+00:00","sec_items":["5.02","9.01"],"event_type":"other_material","sentiment":"neutral","materiality_score":0.45,"calibrated_materiality_score":0.45,"confidence":"high","headline":"Trinseo board members De Leener and Tomkins retire; board to shrink to nine","bullets":["Pierre-Marie De Leener and Mark Tomkins will retire at 2025 AGM and not stand for reelection.","Board size will decrease to nine members following the annual general meeting.","De Leener served since Trinseo's 2014 IPO; Tomkins served since 2019.","Retirements not due to any disagreement with the company on operations or policies."],"urls":{"canonical":"https://secwatch.observer/filing/0001558370-25-004485","json":"https://secwatch.observer/filing/0001558370-25-004485.json","markdown":"https://secwatch.observer/filing/0001558370-25-004485.md","text":"https://secwatch.observer/filing/0001558370-25-004485.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1519061/000155837025004485/0001558370-25-004485-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1519061/000155837025004485/tse-20250403x8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-23T20:57:55.130533+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[{"claim_id":"44f7f9ab1a","claim":"Mark Tomkins departed as Director at Trinseo PLC.","evidence_excerpt":"Pierre-Marie De Leener and Mark Tomkins, two members of the Board of Directors (the “Board”) of Trinseo PLC (the “Company”), notified the Company of their decision to retire from the Board and not stand for reelection at the Company’s 2025 annual general meeting of shareholders.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1519061/000155837025004485/0001558370-25-004485-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"retire"},{"label":"Role","value":"Director"}]},{"claim_id":"6652382019","claim":"Pierre-Marie De Leener departed as Director at Trinseo PLC.","evidence_excerpt":"Pierre-Marie De Leener and Mark Tomkins, two members of the Board of Directors (the “Board”) of Trinseo PLC (the “Company”), notified the Company of their decision to retire from the Board and not stand for reelection at the Company’s 2025 annual general meeting of shareholders.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1519061/000155837025004485/0001558370-25-004485-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"retire"},{"label":"Role","value":"Director"}]}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}