Wash. Rev. Code § 70.74.230
If any manufacturer of explosives or dealer therein shall have shipped any explosives into another state, and the laws of such other state shall designate an officer or agency to regulate the possession, receipt or storage of explosives, and such officer or agency shall so require, such manufacturer shall, at least once each calendar month, file with such officer or agency of such other state a report giving the names of all purchasers and the amount and description of all explosives sold or delivered in such other state. Dealers in explosives shall keep a record of all explosives purchased or sold by them, which record shall include the name and address of each vendor and vendee, the date of each sale or purchase, and the amount and kind of explosives sold or purchased. Such records shall be open for inspection by the duly authorized agents of the department of labor and industries and by all federal, state and local law enforcement officers at all times, and a copy of such record shall be furnished once each calendar month to the department of labor and industries in such form as said department shall prescribe.
RCW 70.74.230