S.C. Code Ann. § 58-13-730: Railroads and others transporting passengers shall not transport unmarked explosive compound.

No railroad corporation or other person engaged in the transportation of passengers within this State shall knowingly transport within the territorial limits of this State or transport into such limits, for sale, storage or use therein, any explosive compound in quantities exceeding the amounts fixed by the rules hereinafter referred to in any vehicle containing passengers, or in any vehicle attached to any railroad train or vehicle conveying passengers nor in any case, unless such explosive compound be plainly and legibly marked with the name of such compound and the words "Explosive - Dangerous." The Public Service Commission, from time to time, shall make such rules fixing the maximum amounts of various explosive compounds which may be so carried in any public vehicle, in a railroad train containing passengers or in a vehicle attached to such train. Such rules shall also define the method of packing such compounds to ensure the greatest safety and shall prescribe how they shall be carried as freight on railroads and steamboats and by common carriers generally.