KAISER ALUMINUM CORP

In January 2025, in connection with the retirement of Jack A. Hockema from our board, Mr. Harvey, our President and CEO was appointed Chairman. Mr. Arnold serves as the Lead Independent Director of our board. We believe Mr. Harvey's substantial experience with our company and its business, the independence of the other directors, our governance structure and the interaction between and among Messrs. Harvey and Arnold and the other directors make our board leadership structure the most appropriate for our company and our stockholders.

Our corporate governance guidelines and governance structure require a Lead Independent Director to be selected by a majority of the independent directors when the position of CEO and Chairman of the board are combined or the Chairman of the board is otherwise not an independent director, thereby ensuring that there is independent leadership within our board of directors and allowing our independent directors to function as a body distinct from management and evaluate the performance of our CEO and management independently and objectively. The responsibilities of our Lead Independent Director include:

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establishing the agenda for executive sessions;

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calling a meeting of independent directors upon the request of a majority of independent directors;

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serving as a liaison between our independent directors and Mr. Harvey;

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presiding at meetings of our independent directors;

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soliciting advice and input from our independent board members; and

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routinely meeting and conferring with Mr. Harvey to address comments, issues and areas of interest expressed or identified by our independent directors, to assess the governance of our board of directors and our company, and to review board responsibilities, meeting schedules, meeting agenda and information requested or otherwise provided to our directors routinely or in connection with meetings of our board of directors.

Each of the audit, compensation, nominating and corporate governance and sustainability committees consists solely of independent directors. The chair of each committee serves as a liaison to keep our full board of directors and our CEO apprised of the work performed by their respective committees at each of our regularly scheduled board meetings and as otherwise required. Finally, under our bylaws, special meetings of our board of directors may be called by the Chairman, our CEO or a majority of our board members.

Under our corporate governance guidelines, each member of our board of directors may submit items to be included on the agenda for any meeting of our board of directors and raise topics that are not on the agenda at any meeting of our board of directors. In addition, our independent directors, representing nine of our 10 directors, are required to meet at least quarterly in executive sessions at which only independent directors are present. Additionally, we encourage direct communication among our directors and with our CEO before, during and after formal board and committee meetings and facilitate those communications around all of our meetings. Our directors also have full access to our officers, employees and advisors.