Food & Agr. Code, § 18908

No person shall be excused from attending and testifying, or from producing books, papers, schedules of charges, contracts, agreements, or other documentary evidence before the director or in obedience to the subpoena of the director, whether such subpoena be signed or issued by him or his delegate, or in any cause or proceeding, criminal or otherwise, based upon or growing out of any alleged violation of this chapter, on the ground or for the reason that the testimony or evidence, documentary or otherwise, required of him or it may tend to incriminate him or it or subject him or it to a penalty or forfeiture. No individual shall be prosecuted or subjected to a penalty or forfeiture for, or on account of any transaction, matter, or thing concerning which he is compelled, after having claimed his privilege against self-incrimination, to testify or produce evidence, documentary or otherwise, except that any individual so testifying shall not be exempt from prosecution and punishment for perjury committed in so testifying.