M.O. Industries has the solution for you. The Muller patented drum closing system as shown is the answer. The closing system has been tested and proven effective in protecting highly sensitive substances. This system replaces the air in the drum with nitrogen and provides a tight closing of the drum. M.O. Industries supplies the closing system, the drums; the total system. If your product is valuable and needs air protection, then you need the Air Protected Drum Closing System.