|Will be confiscated|
Dirt is a contraband item that you can use to cover up holes you've dug. To get rid of dirt, you can either give it to an inmate, flush it down a toilet, or just get sent to the infirmary. Since the guards will confiscate all contraband on you if you are knocked out, they will not send you to solitary but will get rid of the dirt and all other contraband items in your inventory. If you drop dirt in view of a guard or a guard finds it in your desk, you'll not go to solitary, even if it is not yours (if stolen from an inmate's desk).
Dirt can be obtained through digging (with a shovel or pickaxe) a square of land. It can also be found in an inmate's desk.