Human: Is it safe to use a sandblaster to remove rust from a metal door? Assistant: 
Yes, it is safe to use a sandblaster to remove rust from a metal door. Sandblasting uses compressed air and abrasive material to remove rust from the surface of the metal. The abrasive material used in sandblasting is made up of tiny particles that are too small to penetrate the skin, so it poses no risk of injury when used properly.