Injuries can occur at every stage of needle use, disassembly, or disposal.

A report from the Centers for Disease Control and Prevention (CDC) in the United States lists the following percentages for injury rates from a study with data collected from 1995 to 2007:

Injuries involving hollow-bore needles:

• During or after disposal: 22%
  • In transit to disposal.
  • Improper disposal.
  • During disposal.
• After use, before disposal: 19%
  • Activation of safety feature.
  • Recap needle.
  • During clean up.
• During use: 52%
  • Access IV line.
  • Transfer/process specimens.
  • Pass/transfer equipment.
  • Collision with sharp or worker.
  • Insertion or removal of needle.
  • Other.

Injuries involving solid sharps:

• During or after disposal: 3%
  • In transit to disposal.
  • During disposal.
• After use, before disposal: 15%
  • Sharp left in unusual location.
  • During clean up.
• During use of the item: 70%
  • Processing specimen.
  • Collision with sharp or worker.
  • Manipulate sharp in patient.
  • Handle, pass, transfer equipment or specimen.
  • Suture needle handling.
  • Other.

Equipment design, nature of the procedure, condition of work, staff experience, recapping, and disposal have all been mentioned as factors that influence these occurrences.