When a pack breaks, two events happen together: cooling capacity falls and the filling may have touched the goods. The filling varies by product, and instant cold packs use, for example, calcium ammonium nitrate, so it is identified from the label and SDS, not guessed.

At delivery the external leakage, time and temperature indication are recorded before the box is opened; once it is opened in a safe area, the position of the broken pack and the contacted goods are photographed. Appearance or feeling cold by hand is no reason to accept. The root cause is traced too: trapping against a sharp corner, top load, freezer adhesion or ageing. A damaged pack does not return to the pool and does not go into general waste before its contents are known.