On November 21, 2022, Andrew Currie notified Ecovyst Inc., that he would be resigning from the Company's Board of Directors (the “Board”), effective December 31, 2022. Mr. Currie, a director of INEOS Group, has served on its Board since 2008. On November 22, 2022, Mark McFadden notified the Company that he would also be resigning from the Board effective December 31, 2022.

Mr. McFadden, the co-managing partner of CCMP Capital Advisors, has served on its Board since 2016.