Vermiculite will not react dangerously with any substance or any packaging material. Place the inner packaging together with a volume of vermiculite in a plastic bag. After sealing the plastic bag, place it in the outer packaging. This method is better than placing vermiculite around the plastic bag containing the inner packaging. According to U.S. Air Force regulation 71-4, the volume of vermiculite required to absorb 1 litre of liquid substance, you will need a 50.8mm (2 in) bed of vermiculite under the inner packaging, build a 25.4mm (1 in) wall around the inner packaging, and place 50.8mm (2 in) layer of vermiculite on the top of the inner packaging. This volume is needed to absorb 1 litre of liquid substance.