Combination packaging
These consist of an outer manufactured from wood, fiberboard, plastic or metal, containing inner packaging of metal, plastic, glass, earthenware, paper or fiberboard usually packed in absorbent or cushioning material according to the individual packing requirements.
Single packaging
These require on outer packaging for protection and are manufactured from steel, aluminium, plastic or other permitted materials, for example, a drum. It is recommended that when single steel or aluminium packaging are to be transported in narrow-bodied aircraft, they should be over packed, palletized or have the bottom head and chime protected in some other way. Also small single packaging, with a capacity of 2L or less, should be over packed to facilitate handling and to permit adequate securing aboard the aircraft.
Combination packaging and/or single packaging may be enclosed to form a single handling unit. This is called an Overpack.