1/Pentene Flammable liquid stored in a metal cylinder. Due to its peculiar shape and size, we had to pack into our largest possible UN Fibreboard box. Additionally, we had to ensure that we pack the sample into “intermediate packaging”. This means that each primary package needs to be packed into a secondary, leak proof package (in this case, due the cylinder size and shape), a plywood box. This in turn had to be filled with vermiculite and then packed into the final outer UN fibreboard box.