RCW 7.05.170: Competence of arbitral tribunal to rule on its own jurisdiction.

(1) The arbitral tribunal may rule on its own jurisdiction, including any objections with respect to the existence or validity of the arbitration agreement. For that purpose, an arbitration clause which forms part of a contract shall be treated as an agreement independent of the other terms of the contract. A decision by the arbitral tribunal that the contract is null and void shall not entail ipso jure the invalidity of the arbitration clause. (2) A plea that the arbitral tribunal does not have jurisdiction shall be raised not later than the submission of the statement of defense. A party is not precluded from raising such a plea by the fact that the party has appointed, or participated in the appointment of, an arbitrator. A plea that the arbitral tribunal is exceeding the scope of its authority shall be raised as soon as the matter alleged to be beyond the scope of its authority is raised during the arbitral proceedings. The arbitral tribunal may, in either case, admit a later plea if it considers the delay justified. (3) The arbitral tribunal may rule on a plea referred to in subsection (2) of this section either as a preliminary question or in an award on the merits. If the arbitral tribunal rules as a preliminary question that it has jurisdiction, any party may request, within thirty days after having received notice of that ruling, the court specified in RCW 7.05.070 to decide the matter, which decision shall be subject to no appeal. While such a request is pending, the arbitral tribunal may continue the arbitral proceedings and make an award.