Environmental Tectonics Corporation reported that on June 7, 2023, the Chairman of the Board of Directors of the Company received notification from Mr. Roger Colley that Mr. Colley will retire from the ETC Board of Directors as of the date of the Company's upcoming 2023 annual meeting of shareholders. Mr. Colley has served as the Chairman of the Audit Committee since 2011 and is currently a member of the Nominating and Compensation Committees. Mr. Colley's decision was not due to any disagreement with the Company on any matter relating to the Company's operations, policies or practices.