Tex. Nat. Res. Code § 32.0123

An officer, employee, or paid consultant of a statewide or national trade association in the oil and gas or mining industry may not be a member or employee of the board, nor may a person who cohabits with or is the spouse of an officer, managerial employee, or paid consultant of a statewide or national trade association in the oil and gas or mining industry be a member of the board or an employee of the board grade 17 and over, including exempt employees, according to the position classification schedule under the General Appropriations Act.