73 Pa. Stat. § 159
After January first, one thousand nine hundred and thirty-eight, every person storing or in possession of explosives shall be required to have a license for each magazine used for the storing or placing of explosives, which license shall be issued on a form prepared and furnished by the Department of Labor and Industry. The application for license shall be accompanied by the proper license fee, which shall be prescribed by the department, according to the quantity of explosives which are to be stored or placed in the magazine, and shall not be less than three dollars and fifty cents ($3.50) nor more than fifty dollars ($50). Such license shall be kept posted conspicuously in or about the magazine for which issued. Licenses shall expire annually on the thirty-first day of December, and shall be renewed annually upon payment of the fee as specified in this section.
73 P.S. § 159