It was MY impression that it was filled with a water/glycerine-filled containers (anti-freeze) and evaporation didn't occur. ~ Jeff

(7) The use of any fluids (water, antifreeze compound, or ammudamp) in ammunition box cans has been discontinued. All ammudamp cans will be completely drained of ammudamp fluid.

Where the ammunition racks can be removed easily, remove the rack, unscrew the filler and drain plugs from the cans, and pour out the fluid. In other locations where it may be impracticable to remove the racks, siphon the fluid from the cans by use of a suction type oil gun fitted with three nipples, straight tee, and rubber hose. Bring the free end of the rubber hose to the ammunition can, remove the filler and drain plug, and insert the hose to the lowest portion of the can. To start the fluid flowing, hold a finger tightly over the outlet nipple, pull the suction gun handle completely out, and then release the finger from the nipple.

After all the fluid has been drained, thoroughly dry the ammunition boxes and ammudamp cans. After the cans have dried, replace the filler and drain plugs. Discard the ammudamp fluid drained from the cans. Remove from the ammunition boxes those ammudamp cans that have deteriorated to such an extent that they are no longer suitable for use as separators or barriers for the ammunition. Cut and shape well seasoned wooden blocks (procure wood locally) to the shape of the ammudamp cans that were removed. Fit the blocks into position in the ammunition boxes. Treat the wooden blocks with synthetic wood filler and apply two coats of paint before use. Paint filler and drain plugs black to indicate that the ammudamp cans have been drained of all fluid.