Amend Floor Amendment No. 24 (second reading) to CSSB 5, by striking paragraph (c) of Chapter 401.013 of the Labor Code, and adding a new paragraph (c) to read as follows: (c) Upon the voluntary introduction into the body of any substance listed under subsection (a)(2)(b), based upon a blood test or urinalysis, it is a rebuttable presumption that a person is intoxicated and not having the normal use of mental or physical faculties.