A person shall not be excused from attending and testifying or producing any books, papers, or other documents before a court or magistrate upon an investigation, proceeding, or trial for a violation of this chapter on the ground that the testimony or evidence may tend to degrade or incriminate the person. Truthful testimony, evidence, or other truthful information compelled under this section and any information derived directly or indirectly from that truthful testimony, evidence, or other truthful information shall not be used against the witness in a criminal case, except for impeachment purposes or in a prosecution for perjury or otherwise failing to testify or produce evidence as required.