Every person engaging in the business of keeping or storing of explosives shall pay an annual license fee for each magazine maintained, to be graduated by the department of labor and industries according to the quantity kept or stored therein, of fifty dollars. The director of labor and industries may adjust the amount of the license fee to reflect the administrative costs of the department. The fee shall not exceed four hundred dollars.
Said license fee shall accompany the application and shall be transmitted by the department to the state treasurer.