Tex. Natural Resources Code § 81.091: INCRIMINATING TESTIMONY.

If a witness fails or refuses to appear on being summoned, to answer any question he is asked, or to produce any record or data required by subpoena, the claim that the testimony may tend to incriminate the person giving it does not excuse the witness from testifying or producing the records and data, but the evidence or testimony may not be used against the person on the trial of any criminal proceeding.

Acts 1977, 65th Leg., p. 2510, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977.