The premises in which small arms nitro-compound or fireworks or gun powder or safety fuse is kept shall be used only for possession and sale of such explosives and for no other purposes when small arms nitro-compound or fireworks or gun powder or safety fuse is stored :
Provided that the premises may be used for other purposes except for inflammable and dangerous substances when small arms nitro-compound or fireworks or gun powder or safety fuse are not stored in the premises.