California Code, Code of Civil Procedure - CCP § 1297.371

(a) Evidence of anything said or of any admission made in the course of the conciliation is not admissible in evidence, and disclosure of any such evidence shall not be compelled, in any civil action in which, pursuant to law, testimony may be compelled to be given. However, this subdivision does not limit the admissibility of evidence if all parties participating in conciliation consent to its disclosure.

(b) In the event that any such evidence is offered in contravention of this section, the arbitration tribunal or the court shall make any order which it considers to be appropriate to deal with the matter, including, without limitation, orders restricting the introduction of evidence, or dismissing the case without prejudice.

(c) Unless the document otherwise provides, no document prepared for the purpose of, or in the course of, or pursuant to, the conciliation, or any copy thereof, is admissible in evidence, and disclosure of any such document shall not be compelled, in any arbitration or civil action in which, pursuant to law, testimony may be compelled to be given.