A 3D printer, while in function, generates several u003cstrongu003eVOCs u003c/strongu003e(Volatile Organic Compounds) in the form of highly carcinogenic fumes. Therefore, the user should not keep a printer in the room.u003cbru003eOn the other hand, leaving a working 3D printer overnight and unattended is not safe because of certain unexpected power supply or temperature fluctuation issues.