Wash. Rev. Code § 69.58.100
Nitrous oxide—Sale or distribution prohibited—Penalty—Exceptions
(1) Every person who sells, furnishes, administers, distributes, gives away, or offers to sell, furnish, administer, distribute, or give away a device, canister, tank, or receptacle either exclusively containing nitrous oxide or flavored nitrous oxide or exclusively containing a chemical compound mixed with nitrous oxi…