Wash. Rev. Code § 43.21A.160
Whenever any records or other information furnished under the authority of this chapter to the director, the department, or any division of the department, relate to the processes of production unique to the owner or operator thereof, or may affect adversely the competitive position of such owner or operator if released to the public or to a competitor, the owner or operator of such processes or production may so certify, and request that such information or records be made available only for the confidential use of the director, the department, or the appropriate division of the department. The director shall give consideration to the request, and if such action would not be detrimental to the public interest and is otherwise within accord with the policies and purposes of this chapter, may grant the same.
RCW 43.21A.160