Banks Use Exploding Dye Packs

Banks defend against robberies using dye packs hidden inside stacks of bills at teller stations. The packs remain unarmed while resting on a magnetic plate but activate when removed. Once a robber carries the money past a transmitter at the door, the dye pack explodes, reaching temperatures of about 400°F, and staining the cash with permanent ink.

Previous Fact Next Fact