Wash. Rev. Code § 18.64.470
Every proprietor or manager of a health care entity shall keep readily available a suitable record of drugs, which shall preserve for a period of not less than two years the record of every drug used at such health care entity. The record shall be maintained either separately from all other records of the health care entity or in such form that the information required is readily retrievable from ordinary business records of the health care entity. All recordkeeping requirements for controlled substances must be complied with. Such record of drugs shall be for confidential use in the health care entity, only. The record of drugs shall be open for inspection by the commission, who is authorized to enforce chapter 18.64, 69.41, or 69.50 RCW.
RCW 18.64.470