Dirty forceps. Dirt and rust on the joint area of a pair of metal forceps. Rust (iron oxide) forms when steel or iron is exposed to water and air. If metal tools are not carefully cleaned and dried after use, then rust and dirt can accumulate. If the forceps are used in surgery, blood and other biological material need to be removed, otherwise cross-contamination of bacteria, viruses and other pathogens can infect the patient.