(1) When a dispute exists between a public employer and a labor organization over the meaning, interpretation or application of an existing collective bargaining agreement, the parties may request grievance mediation. The board, in its discretion, may designate a qualified labor mediator to mediate the dispute under the following conditions:

(a) the parties mutually agree to the request;

(b) the parties mutually agree to the conditions set by the board; and

(c) the parties mutually agree to waive the applicable time limitations in the collective bargaining agreement's grievance procedure.

(2) Matters disclosed to the mediator by the parties during the course of mediation shall be confidential and shall not be divulged unless approved by both parties to the dispute.

(3) In the event the dispute goes to arbitration, the mediator may not be called as a witness or otherwise called to divulge information or settlement offers which may have been discussed during mediation.