Tex. Lab. Code § 21.053
A labor organization commits an unlawful employment practice if because of race, color, disability, religion, sex, national origin, or age the labor organization:
(2) limits, segregates, or classifies a member or an applicant for membership or classifies or fails or refuses to refer for employment an individual in a manner that would:
Acts 1993, 73rd Leg., ch. 269, Sec. 1, eff. Sept. 1, 1993.