What are the three instrument classifications that used to determine method of sterilization?

The three instrument classifications that used to determine method of sterilization are:

1. Critical: These instruments are used to penetrate sterile tissue or the vascular system. They require the highest level of sterilization, which is typically achieved by steam under pressure (autoclaving). Examples include surgical instruments, needles, and implants.

2. Semi-critical: These instruments come into contact with mucous membranes or non-intact skin. They require a high level of sterilization, which can be achieved by steam under pressure, chemicals, or radiation. Examples include endoscopes, laryngoscopes, and speculums.

3. Non-critical: These instruments come into contact with intact skin but do not penetrate it. They require a low level of sterilization, which can be achieved by cleaning with soap and water, disinfectants, or wipes. Examples include stethoscopes, blood pressure cuffs, and thermometers.