CBET Sterilization and Infection Control Equipment 1 — Questions and Answers
Question 1: What is the standard sterilization temperature and time for a gravity displacement steam autoclave at 121°C?
- 15 minutes (Correct answer)
- 30 minutes
- 45 minutes
- 60 minutes
Correct answer: 15 minutes
Gravity displacement autoclaves operating at 121°C (250°F) require a minimum of 15 minutes at that temperature to achieve sterilization.
Question 2: Which Spaulding classification category requires sterilization rather than just high-level disinfection?
- Noncritical items
- Semicritical items
- Critical items (Correct answer)
- General-use items
Correct answer: Critical items
Critical items enter sterile tissue or the vascular system and must be sterilized to eliminate all microorganisms including spores.
Question 3: What is the primary biological indicator used to validate steam sterilization processes?
- Bacillus subtilis spores
- Geobacillus stearothermophilus spores (Correct answer)
- Clostridium sporogenes spores
- Bacillus cereus spores
Correct answer: Geobacillus stearothermophilus spores
Geobacillus stearothermophilus is the most resistant organism to moist heat and is the standard biological indicator for steam sterilization validation.
Question 4: A BIOMED technician is testing an EtO (ethylene oxide) sterilizer. Which parameter is NOT critical to monitor during the EtO cycle?
- Gas concentration
- Temperature
- Humidity
- UV light exposure (Correct answer)
Correct answer: UV light exposure
EtO sterilization depends on gas concentration, temperature, humidity, and exposure time — UV light plays no role in this chemical sterilization process.
Question 5: What does a positive result on a Bowie-Dick test indicate?
- Successful sterilization of the load
- Air removal failure in the pre-vacuum autoclave (Correct answer)
- Biological indicator growth detected
- Chemical indicator color change failed
Correct answer: Air removal failure in the pre-vacuum autoclave
A positive (failed) Bowie-Dick test indicates that air was not properly removed from the chamber, which would prevent steam penetration and sterilization.
Question 6: Which sterilization method is most appropriate for heat-sensitive endoscopes?
- Steam autoclave at 134°C
- Dry heat oven at 160°C
- Low-temperature hydrogen peroxide plasma (Correct answer)
- Ethylene oxide at 60°C
Correct answer: Low-temperature hydrogen peroxide plasma
Low-temperature hydrogen peroxide gas plasma sterilization operates below 50°C and is compatible with heat-sensitive devices like flexible endoscopes.
Question 7: When performing preventive maintenance on an autoclave, what should the BIOMED technician check first after a reported cycle abort?
- The biological indicator results
- The printout or cycle log for the fault code (Correct answer)
- The chemical indicators in the last load
- The door gasket for wear
Correct answer: The printout or cycle log for the fault code
The cycle log or printout provides the specific fault code and the point of failure, which is the most efficient starting point for diagnosing an autoclave abort.
CBET Sterilization and Infection Control Equipment 1
What is the standard sterilization temperature and time for a gravity displacement steam autoclave at 121°C?