CRCST Quality Assurance 3 — Questions and Answers
Question 1: Which action should be taken first when a sterilizer load fails a biological indicator (BI) test?
- Immediately release the load and document the failure
- Quarantine all items from that load and investigate the cause (Correct answer)
- Re-run the BI test to confirm results before acting
- Notify only the department manager without quarantining
Correct answer: Quarantine all items from that load and investigate the cause
When a BI fails, all items from that load must be recalled or quarantined immediately, and an investigation into the root cause must be initiated before any items are used.
Question 2: What does 'D-value' mean in the context of sterilization quality assurance?
- The dose of sterilant required to kill all organisms in a load
- The time or dose required to reduce the microbial population by 90% (1 log) (Correct answer)
- The depth of penetration of sterilant into a package
- The drying time needed after a sterilization cycle
Correct answer: The time or dose required to reduce the microbial population by 90% (1 log)
The D-value (decimal reduction value) is the time or radiation dose required to reduce the number of microorganisms by 90%, or one logarithmic unit.
Question 3: Which sterilization quality record must be retained to allow for instrument tracking in the event of a recall?
- Sterilizer operator's personal notes
- Load content records linking items to a specific sterilization cycle (Correct answer)
- General equipment maintenance logs only
- Annual competency records for central service staff
Correct answer: Load content records linking items to a specific sterilization cycle
Load content records that link specific instruments or implants to a sterilization cycle number are essential for effective traceability and recall management.
Question 4: How often should mechanical/physical parameters (time, temperature, pressure) of a sterilizer be reviewed for each cycle?
- Weekly during routine audits
- Only when biological indicators are used
- For every sterilization cycle run (Correct answer)
- Monthly during preventive maintenance
Correct answer: For every sterilization cycle run
Mechanical monitoring of sterilizer parameters must be reviewed for every cycle to ensure the equipment is functioning within acceptable ranges before items are released.
Question 5: What is the significance of the '12D concept' in sterilization?
- Sterilization must achieve 12 log reductions of Clostridium botulinum spores (Correct answer)
- The cycle must run for a minimum of 12 minutes
- 12 biological indicators must be used per load
- Instruments must be decontaminated in 12 steps
Correct answer: Sterilization must achieve 12 log reductions of Clostridium botulinum spores
The 12D concept, originating from food canning, requires achieving a 12-log reduction of the most resistant organism (Clostridium botulinum) to ensure safety.
Question 6: A package is found wet after a steam sterilization cycle. What quality concern does this represent?
- The package will dry faster due to residual moisture
- Wet packs may compromise sterility and are considered non-sterile (Correct answer)
- Minor moisture is acceptable if the chemical indicator passed
- Wet packs only need to be re-dried before use
Correct answer: Wet packs may compromise sterility and are considered non-sterile
Wet packs are considered a sterilization failure because moisture can wick microorganisms through packaging material, compromising the sterile barrier.
Question 7: Which sterilization method is most commonly validated using Bacillus atrophaeus (formerly B. subtilis) spore strips as biological indicators?
- Steam sterilization
- Hydrogen peroxide gas plasma sterilization
- Ethylene oxide (EtO) sterilization (Correct answer)
- Dry heat sterilization
Correct answer: Ethylene oxide (EtO) sterilization
Bacillus atrophaeus spores are the standard biological indicator for ethylene oxide sterilization due to their high resistance to EtO.
CRCST Quality Assurance 3
Which action should be taken first when a sterilizer load fails a biological indicator (BI) test?