Wash. Rev. Code § 51.52.100
Hearings shall be held in the county of the residence of the worker or beneficiary, or in the county where the injury occurred, at a place designated by the board. Such hearing shall be de novo and summary, but no witness' testimony shall be received unless he or she shall first have been sworn to testify the truth, the whole truth and nothing but the truth in the matter being heard, or unless his or her testimony shall have been taken by deposition according to the statutes and rules relating to superior courts of this state. The department shall be entitled to appear in all proceedings before the board and introduce testimony in support of its order. The board shall cause all oral testimony to be stenographically reported and thereafter transcribed, and when transcribed, the same, with all depositions, shall be filed in, and remain a part of, the record on the appeal. Such hearings on appeal to the board may be conducted by one or more of its members, or a duly authorized industrial appeals judge, and depositions may be taken by a person duly commissioned for the purpose by the board.
Members of the board, its duly authorized industrial appeals judges, and all persons duly commissioned by it for the purpose of taking depositions, shall have power to administer oaths; to preserve and enforce order during such hearings; to issue subpoenas for, and to compel the attendance and testimony of, witnesses, or the production of books, papers, documents, and other evidence, or the taking of depositions before any designated individual competent to administer oaths, and it shall be their duty so to do to examine witnesses; and to do all things conformable to law which may be necessary to enable them, or any of them, effectively to discharge the duties of his or her office.
If any person in proceedings before the board disobeys or resists any lawful order or process, or misbehaves during a hearing or so near the place thereof as to obstruct the same, or neglects to produce, after having been ordered so to do, any pertinent book, paper or document, or refuses to appear after having been subpoenaed, or upon appearing refuses to take oath as a witness, or after having the oath refuses to be examined according to law, the board or any member or duly authorized industrial appeals judge may certify the facts to the superior court having jurisdiction in the place in which said board or member or industrial appeals judge is sitting; the court shall thereupon, in a summary manner, hear the evidence as to the acts complained of, and, if the evidence so warrants, punish such person in the same manner and to the same extent as for a contempt committed before the court, or commit such person upon the same conditions as if the doing of the forbidden act had occurred with reference to the proceedings, or in the presence, of the court.
RCW 51.52.100