Wash. Rev. Code § 69.40.055
It shall be unlawful for any person to sell at retail or furnish any repackaged poison drug or product without affixing or causing to be affixed to the bottle, box, vessel, or package a label containing the name of the article, all labeling required by the Food and Drug Administration and other federal or state laws or regulations, and the word "poison" distinctly shown with the name and place of the business of the seller.
This section shall not apply to the dispensing of drugs or poisons on the prescription of a practitioner.
The pharmacy quality assurance commission shall have the authority to promulgate rules for the enforcement and implementation of this section.
Every person who shall violate any of the provisions of this section shall be guilty of a misdemeanor.
RCW 69.40.055