Either the primary receptacle or the secondary packaging must be capable of withstanding an internal pressure of 95 kPa (0.95 bar).
The complete triple package must be capable of passing a 1.2 m drop test, to prove that it is of an appropriate strength and quality.
As the name suggests, any triple packaging system used to contain an infectious substance must comprise three layers:

A primary receptacle;
A second, watertight and leak-proof or sift proof packaging to enclose and protect the primary receptacle; and
A third, outer layer of packaging that is used to protect the secondary packaging from physical damage while in transit.