Decontamination, Disinfection, and Sterilization
These three terms are not interchangeable, and questions test the distinction. Decontamination reduces or removes contaminants so items are safe to handle; disinfection kills most pathogenic microorganisms on inanimate surfaces but not necessarily spores; sterilization destroys all microbial life, including spores. Know the Spaulding classification (critical, semicritical, noncritical items) and that only sterilization is appropriate for critical items entering sterile tissue.
Candidates should understand the major methods: autoclaving (moist heat, typically 121°C at 15 psi for 15–30 minutes, validated with biological indicators such as Geobacillus stearothermophilus spores), chemical disinfectants (chlorine, quaternary ammonium, glutaraldehyde, hydrogen peroxide), and filtration or irradiation for heat-sensitive items. Contact time and concentration are the operative variables - a disinfectant used at the wrong dilution or wiped off too soon fails. Organic load reduces efficacy, so surfaces are cleaned before disinfection.
Traps: assuming 70% ethanol sterilizes; confusing sanitization with disinfection; forgetting that prions require special protocols (e.g., prolonged high-concentration hypochlorite or extended autoclave cycles) because standard cycles may not inactivate them.
Rule of thumb: if it will contact sterile tissue or blood, it must be sterile; if it touches intact skin, disinfection is usually enough.
Worked example: A reusable surgical instrument is cleaned, wrapped, and autoclaved at 121°C/15 psi for the validated cycle, with a biological indicator confirming spore kill.