Often there are nails, screws, pop rivet stems, box cutter blades, etc. that wind up on the floor and sometimes end up in a tire or maybe in your foot. I learned this the hard way with a pop rivet stem on my motorcycle tire. That was a 40$ lesson plus my time. As a rule, I keep a sealable container at the bench to put all of these sharps in. After the container is full, it's sealed, disposed of responsibly and safely.