CABT Sterilization and Infection Control 2 — Questions and Answers
Question 1: High-level disinfection (HLD) differs from sterilization in that HLD:
- Eliminates all microorganisms including all spore concentrations
- Kills only gram-positive vegetative bacteria
- Eliminates all microorganisms except high numbers of bacterial spores (Correct answer)
- Is used only for non-critical environmental surfaces
Correct answer: Eliminates all microorganisms except high numbers of bacterial spores
High-level disinfection eliminates all microorganisms except high concentrations of bacterial spores, whereas sterilization destroys all forms of microbial life.
Question 2: Which class of chemical indicator provides the most reliable evidence that all critical parameters of a sterilization cycle were met?
- Class 1 process (exposure) indicators
- Class 4 multi-variable indicators
- Class 5 integrating indicators (Correct answer)
- Class 2 Bowie-Dick test indicators
Correct answer: Class 5 integrating indicators
Class 5 integrating indicators respond to all critical sterilization parameters (time, temperature, and sterilant) and provide the highest chemical indicator assurance level.
Question 3: According to OSHA's Bloodborne Pathogen Standard, what practice must biomedical technicians follow when handling potentially contaminated equipment?
- Using only gloves when decontaminating visibly soiled items
- Following Standard Precautions with appropriate PPE for all potentially infectious material (Correct answer)
- Discarding all used instruments after a single-use procedure
- Applying low-level disinfection to all biomedical equipment regardless of contact type
Correct answer: Following Standard Precautions with appropriate PPE for all potentially infectious material
OSHA's Bloodborne Pathogen Standard mandates Standard Precautions — appropriate PPE must be used whenever handling equipment potentially contaminated with blood or body fluids.
Question 4: Which water type is recommended for use in steam sterilizers to prevent mineral scaling and equipment damage?
- Standard municipal tap water
- Softened water treated with sodium chloride
- Filtered but not deionized water
- Distilled or deionized water (Correct answer)
Correct answer: Distilled or deionized water
Distilled or deionized water is recommended because it lacks minerals found in tap water that cause scaling deposits in sterilizer chambers and on instrument surfaces.
Question 5: When storing sterile packages after processing, which factor is most critical for maintaining sterility?
- Storing in a temperature-controlled refrigerator below 20°C
- Maintaining packaging integrity and protecting from moisture and physical damage (Correct answer)
- Re-sterilizing packages stored for more than 30 days regardless of condition
- Keeping packages in a humidity-controlled environment above 60% RH
Correct answer: Maintaining packaging integrity and protecting from moisture and physical damage
Sterility is event-related; it depends on the integrity of the packaging rather than time, so intact, undamaged, dry packaging preserves sterility indefinitely.
Question 6: Glutaraldehyde (2%) used as a high-level disinfectant requires a minimum immersion contact time of approximately:
- 5 minutes at room temperature
- 20–45 minutes for high-level disinfection (Correct answer)
- 3 hours for complete inactivation of all pathogens
- 10 hours to achieve full sterilization of immersed instruments
Correct answer: 20–45 minutes for high-level disinfection
2% glutaraldehyde requires approximately 20–45 minutes of immersion contact time to achieve high-level disinfection and inactivate all non-spore microorganisms.
Question 7: What is the primary purpose of the Bowie-Dick test performed in pre-vacuum steam sterilizers?
- It verifies that the required kill temperature was reached throughout the entire load
- It confirms that biological indicators were successfully inactivated
- It detects air leaks and inadequate air removal that could impair steam penetration (Correct answer)
- It measures the concentration of residual ethylene oxide after sterilization
Correct answer: It detects air leaks and inadequate air removal that could impair steam penetration
The Bowie-Dick test detects air leaks and inadequate air removal in pre-vacuum sterilizers, since retained air prevents steam from penetrating and achieving sterilization.
CABT Sterilization and Infection Control 2
High-level disinfection (HLD) differs from sterilization in that HLD: