If it is the wrong metal, or wrong enough alloy, merely by touching the things it is in contact with can cause a galvanic reaction. Several airplanes have crashed due to damage caused by galvanic corrosion. The FAA is frequently called a "tombstone agency" because they tend to only take action after a bunch of people die.
https://en.wikipedia.org/wiki/Galvanic_corrosion
Mercury versus aluminum: https://www.youtube.com/watch?v=IrdYueB9pY4
In an earlier life, I shipped items requiring this particular hazmat label on packaging: https://www.safetyemporium.com/12332