Sterilization Methods Flashcards
7 cards from real CRCST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Sterilization Methods flashcards as text
What is the primary mechanism by which ethylene oxide (EtO) achieves sterilization?
Answer: Alkylating DNA and proteins
EtO sterilizes by alkylating the DNA and proteins of microorganisms, preventing reproduction and causing cell death.
Which parameter is NOT part of the EtO sterilization cycle?
Answer: UV exposure
UV exposure is not a parameter in EtO sterilization; the key parameters are gas concentration, humidity, temperature, and exposure time.
Hydrogen peroxide gas plasma sterilization is contraindicated for items made of which material?
Answer: Cellulose-based materials
Cellulose-based materials (paper, linen, cotton) absorb hydrogen peroxide and are incompatible with H2O2 gas plasma sterilization.
What does the term 'D-value' represent in sterilization science?
Answer: The time needed to reduce a microbial population by 90%
The D-value (decimal reduction time) is the time required to reduce a microbial population by one log (90%) at a given set of conditions.
Which biological indicator organism is the standard for validating steam sterilization cycles?
Answer: Geobacillus stearothermophilus
Geobacillus stearothermophilus spores are the standard biological indicator for steam sterilization because of their high heat resistance.
When using dry heat sterilization at 160°C, what is the standard minimum exposure time?
Answer: 120 minutes
Dry heat sterilization at 160°C requires a minimum exposure time of 120 minutes to achieve sterilization.
Which sterilization method is most appropriate for prion-contaminated instruments?
Answer: Extended gravity steam at 134°C for 18 minutes
Prions are highly resistant; extended prevacuum steam cycles at 134°C for a minimum of 18 minutes are recommended by the WHO for prion decontamination.