552.12 Transportation of explosives without license prohibited; exceptions.—No person shall transport any explosive into this state or within the boundaries of this state over the highways, on navigable waters or by air, unless such person is possessed of a license or permit; provided, there is excepted from the effects of this sentence common, contract and private carriers, as mentioned in the next succeeding sentence. Common carriers by air, highway, railroad, or water transporting explosives into this state, or within the boundaries of this state (including ocean-plying vessels loading or unloading explosives in Florida ports), and contract or private carriers by motor vehicle transporting explosives on highways into this state, or within the boundaries of this state, and which contract or private carriers are engaged in such business pursuant to certificate or permit by whatever name issued to them by any federal or state officer, agency, bureau, commission or department, shall be fully subject to the provisions of this chapter; provided, that in any instance where the Federal Government, acting through the 1Interstate Commerce Commission or other federal officer, agency, bureau, commission or department, by virtue of federal laws or rules or regulations promulgated pursuant thereto, has preempted the field of regulation in relation to any activity of any such common, contract or private carrier sought to be regulated by this chapter, such activity of such a carrier is excepted from the provisions of this chapter.