CIC Cleaning, Disinfection, & Sterilization 5 — Questions and Answers
Question 1: Which packaging material is NOT compatible with ethylene oxide (EtO) sterilization?
- Nonwoven polypropylene wrap
- Nylon pouches (Correct answer)
- Paper/plastic peel pouches
- Muslin textile wrap
Correct answer: Nylon pouches
Nylon is impermeable to EtO gas and is therefore not a suitable packaging material for EtO sterilization.
Question 2: When preparing a diluted bleach solution for disinfecting surfaces contaminated with C. difficile spores, the recommended concentration is:
- 100 ppm (1:500 dilution)
- 500 ppm (1:100 dilution)
- 1,000–5,000 ppm (1:50 to 1:10 dilution) (Correct answer)
- 10,000 ppm (undiluted)
Correct answer: 1,000–5,000 ppm (1:50 to 1:10 dilution)
EPA-registered bleach solutions at 1,000–5,000 ppm (approximately 1:10 dilution of household bleach) are required for C. difficile spore inactivation.
Question 3: Which statement best describes the difference between disinfection and sterilization?
- Disinfection eliminates all microbial life including spores; sterilization does not
- Sterilization destroys all microbial life including spores; disinfection reduces but may not eliminate spores (Correct answer)
- Disinfection and sterilization are interchangeable terms in the Spaulding system
- Sterilization applies only to liquid-immersion processes
Correct answer: Sterilization destroys all microbial life including spores; disinfection reduces but may not eliminate spores
Sterilization destroys all forms of microbial life including bacterial spores, while disinfection reduces microbial load but typically does not reliably eliminate spores.
Question 4: A surgical instrument set is found to contain a used instrument that was mistakenly included in a sterile wrapped tray. What is the most appropriate action?
- Remove the used instrument and use the remaining instruments
- Consider the entire tray contaminated and return it for reprocessing (Correct answer)
- Wipe the instrument with an alcohol swab and proceed
- Document the error and continue the procedure using that instrument
Correct answer: Consider the entire tray contaminated and return it for reprocessing
Sterility is package-based; any breach of tray integrity — including inclusion of a used item — renders the entire tray non-sterile and requires reprocessing.
Question 5: The Bowie-Dick test is used specifically to detect failures in which component of a prevacuum steam sterilizer?
- Temperature recording devices
- Air removal and steam penetration (Correct answer)
- Biological indicator validity
- Chamber pressure sensors
Correct answer: Air removal and steam penetration
The Bowie-Dick test detects air pockets and inadequate steam penetration in prevacuum (dynamic-air-removal) steam sterilizers.
Question 6: Which factor has the LEAST influence on the efficacy of chemical disinfectants?
- Contact time
- Concentration of the disinfectant
- Ambient humidity levels (Correct answer)
- Presence of organic material
Correct answer: Ambient humidity levels
While humidity is a factor for gaseous agents like EtO, ambient humidity has the least direct impact on liquid chemical disinfectant efficacy compared to contact time, concentration, and organic burden.
Question 7: Which organization's standards are most commonly referenced for sterilization validation and quality assurance in US healthcare facilities?
- WHO (World Health Organization)
- AAMI (Association for the Advancement of Medical Instrumentation) (Correct answer)
- OSHA (Occupational Safety and Health Administration)
- NIOSH (National Institute for Occupational Safety and Health)
Correct answer: AAMI (Association for the Advancement of Medical Instrumentation)
AAMI standards (particularly ANSI/AAMI ST79) are the primary guidance documents for steam sterilization practices in US healthcare facilities.
CIC Cleaning, Disinfection, & Sterilization 5
Which packaging material is NOT compatible with ethylene oxide (EtO) sterilization?