Large scale sterilization equipment MCQs With Answer

Large scale sterilization equipment MCQs With Answer is an essential resource for B.Pharm students focused on pharmaceutical manufacturing, quality control, and aseptic processing. This concise, SEO-friendly introduction emphasizes large-scale sterilization equipment topics such as steam autoclaves, dry heat, ethylene oxide, hydrogen peroxide, gamma irradiation, filtration, validation (IQ/OQ/PQ), biological indicators, D- and Z-values, F0 concept, and sterility assurance. These MCQs are designed to deepen conceptual understanding, link theory to GMP practice, and improve exam and interview readiness. Each question includes clear answers and brief rationales to aid retention. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the standard sterilization temperature and time often used as a reference for F0 calculations in moist heat sterilization?

• 121°C for 15 minutes
• 134°C for 3 minutes
• 115°C for 30 minutes
• 160°C for 2 hours

Correct Answer: 121°C for 15 minutes

Q2. Which biological indicator microorganism is most commonly used to monitor steam sterilization?

• Bacillus subtilis spores
• Bacillus stearothermophilus spores
• Geobacillus stearothermophilus spores
• Staphylococcus aureus

Correct Answer: Geobacillus stearothermophilus spores

Q3. What does SAL (Sterility Assurance Level) of 10^-6 signify?

• One in a million probability of a non-sterile unit
• One in a thousand probability of a non-sterile unit
• Zero chance of contamination
• Sterilization achieved at 121°C

Correct Answer: One in a million probability of a non-sterile unit

Q4. Which sterilization method is recommended for heat-sensitive injectable solutions?

• Steam autoclaving
• Ethylene oxide gas
• Membrane filtration (0.22 µm)
• Dry heat sterilization

Correct Answer: Membrane filtration (0.22 µm)

Q5. In a gravity displacement autoclave cycle, how is air removed from the chamber?

• Pre-vacuum pump removes air before steam
• Air is displaced downward by incoming steam
• Compressed air purge forces air out
• Vacuum is created during cooling

Correct Answer: Air is displaced downward by incoming steam

Q6. What is the primary purpose of a Bowie-Dick test?

• To verify sterility of a load
• To detect residual ethylene oxide
• To assess air removal and steam penetration in pre-vacuum sterilizers
• To measure dry heat oven efficiency

Correct Answer: To assess air removal and steam penetration in pre-vacuum sterilizers

Q7. Which parameter represents the time required at a given temperature to reduce the microbial population by one log (90%)?

• Z-value
• D-value
• F0-value
• SAL

Correct Answer: D-value

Q8. What does the Z-value indicate in thermal inactivation studies?

• Temperature increase to achieve a tenfold change in D-value
• Time to achieve sterilization at 121°C
• pH dependence of heat resistance
• Number of spores surviving a cycle

Correct Answer: Temperature increase to achieve a tenfold change in D-value

Q9. Which sterilization method is most suitable for decontaminating plastic disposable syringes at industrial scale?

• Dry heat sterilization
• Gamma irradiation
• Autoclave steam sterilization
• Ethylene oxide gas sterilization

Correct Answer: Gamma irradiation

Q10. What is the main advantage of pre-vacuum (prevac) steam sterilizers over gravity displacement sterilizers?

• Lower capital cost
• Better steam penetration into porous loads and packaged items
• No need for biological indicators
• They operate at lower temperatures

Correct Answer: Better steam penetration into porous loads and packaged items

Q11. For dry heat depyrogenation, which temperature-time combination is commonly used for glassware?

• 160°C for 2 hours
• 180°C for 30 minutes
• 250°C for 30 minutes
• 121°C for 15 minutes

Correct Answer: 250°C for 30 minutes

Q12. Which indicator provides immediate visual confirmation of exposure to sterilization conditions but not sterility?

• Biological indicator
• Chemical indicator
• Sterility test
• Endotoxin test

Correct Answer: Chemical indicator

Q13. Which of the following is a critical part of sterilizer validation?

• Only IQ (Installation Qualification)
• IQ, OQ (Operational Qualification), and PQ (Performance Qualification)
• Only daily biological indicator runs
• Random equipment cleaning records

Correct Answer: IQ, OQ (Operational Qualification), and PQ (Performance Qualification)

Q14. Ethylene oxide sterilization is most suitable for which type of materials?

• Heat- and moisture-sensitive medical devices
• Endotoxin removal from water
• Glass ampoules for terminal sterilization
• Sterilizing bulk powders at high temperature

Correct Answer: Heat- and moisture-sensitive medical devices

Q15. What is the typical pore size of a sterilizing-grade membrane filter used for aqueous pharmaceutical solutions?

• 0.45 µm
• 0.22 µm
• 0.8 µm
• 1.2 µm

Correct Answer: 0.22 µm

Q16. Which parameter is most directly increased to achieve higher lethality in a steam sterilization cycle?

• Decrease chamber pressure
• Reduce temperature
• Increase temperature or time (F0 increase)
• Increase load density

Correct Answer: Increase temperature or time (F0 increase)

Q17. What is the purpose of using biological indicators (BIs) during sterilization validation?

• To measure pH changes during sterilization
• To provide a resistant test organism to demonstrate microbial kill
• To indicate steam exposure visually
• To test filter integrity

Correct Answer: To provide a resistant test organism to demonstrate microbial kill

Q18. Which sterilization method can inactivate endotoxins (pyrogens) effectively?

• Steam sterilization at 121°C
• Dry heat depyrogenation at high temperature
• Filtration through 0.22 µm filters
• Gamma irradiation at low dose

Correct Answer: Dry heat depyrogenation at high temperature

Q19. During steam sterilization, what is condensate and why is it important?

• Condensate is evaporated steam and it cools the load
• Condensate is liquid formed from steam; excessive condensate can reduce sterilization effectiveness by creating cold spots
• Condensate is chemical residue that indicates sterilant failure
• Condensate increases chamber pressure to aid sterilization

Correct Answer: Condensate is liquid formed from steam; excessive condensate can reduce sterilization effectiveness by creating cold spots

Q20. What does the term “overkill” approach in sterilization validation imply?

• Using the smallest possible cycle that achieves sterility
• Applying a sterilization regime that provides a large margin of safety beyond the minimum required to achieve sterility
• Sterilizing only a fraction of the production batch
• Using chemical indicators instead of biological indicators

Correct Answer: Applying a sterilization regime that provides a large margin of safety beyond the minimum required to achieve sterility

Q21. Which test is essential to confirm the integrity of sterilizing-grade membrane filters after filtration?

• Bowie-Dick test
• Bubble point or pressure-hold integrity test
• Endotoxin test
• F0 calculation

Correct Answer: Bubble point or pressure-hold integrity test

Q22. What is the typical biological indicator organism used for ethylene oxide sterilization validation?

• Geobacillus stearothermophilus spores
• Bacillus atrophaeus (formerly Bacillus subtilis var. niger) spores
• Escherichia coli
• Pseudomonas aeruginosa

Correct Answer: Bacillus atrophaeus (formerly Bacillus subtilis var. niger) spores

Q23. What does a failed Bowie-Dick test indicate in a pre-vacuum sterilizer?

• Excessive chamber temperature
• Inadequate air removal or steam penetration
• Excessive vacuum level
• Proper sterilizer performance

Correct Answer: Inadequate air removal or steam penetration

Q24. Which parameter is most relevant when validating dry heat sterilization for depyrogenation?

• Moisture content in the oven
• Holding time at specified high temperature to achieve required endotoxin reduction
• Steam quality
• Use of biological indicators for vegetative bacteria

Correct Answer: Holding time at specified high temperature to achieve required endotoxin reduction

Q25. What role does temperature mapping play in sterilizer qualification?

• Determines thermal uniformity and identifies cold spots in the chamber and loads
• Measures humidity only
• Checks filter pore size
• Calculates SAL directly

Correct Answer: Determines thermal uniformity and identifies cold spots in the chamber and loads

Q26. Which is a critical control parameter for ethylene oxide sterilization cycles?

• Relative humidity and temperature during exposure
• Chamber steam pressure only
• Bubble point of filters
• Gamma dose distribution

Correct Answer: Relative humidity and temperature during exposure

Q27. Why is aeration required after ethylene oxide sterilization?

• To dry the load
• To allow residual EO and by-products to dissipate to acceptable levels
• To cool the chamber
• To increase sterilization efficacy

Correct Answer: To allow residual EO and by-products to dissipate to acceptable levels

Q28. Which instrument is commonly used to monitor steam quality (presence of non-condensable gases) in an autoclave?

• Thermocouple mapping only
• Bowie-Dick test pack
• Bubble point tester
• pH meter

Correct Answer: Bowie-Dick test pack

Q29. What is F0 value in sterilization terminology?

• The equivalent minutes at 121°C delivered by a moist heat cycle
• The pH required for sterilization
• The filter rating in micrometers
• The number of surviving organisms after sterilization

Correct Answer: The equivalent minutes at 121°C delivered by a moist heat cycle

Q30. In industrial sterilization, what does “load configuration” influence most directly?

• Sterilizer color
• Steam penetration and heat transfer to the product
• Filter integrity tests
• Biological indicator selection

Correct Answer: Steam penetration and heat transfer to the product

Q31. Which of the following is a limitation of membrane filtration for sterilization?

• It removes endotoxins effectively
• It cannot remove viruses or mycoplasma reliably depending on pore size and filter type
• It inactivates spores efficiently
• It is suitable for opaque suspensions

Correct Answer: It cannot remove viruses or mycoplasma reliably depending on pore size and filter type

Q32. What is the primary safety concern with ethylene oxide sterilizers that necessitates strict controls?

• EO is non-flammable and inert
• EO is toxic, carcinogenic, and flammable requiring exposure and environmental controls
• EO generates excessive steam
• EO degrades metal instruments

Correct Answer: EO is toxic, carcinogenic, and flammable requiring exposure and environmental controls

Q33. Which sterilization technology uses low-temperature vaporized hydrogen peroxide for equipment and room decontamination?

• Gamma irradiation
• VH2O2 (vaporized hydrogen peroxide) sterilization
• Dry heat depyrogenation
• Ultraviolet sterilization only

Correct Answer: VH2O2 (vaporized hydrogen peroxide) sterilization

Q34. For sterilizing lyophilized pharmaceuticals in sealed glass vials, which method is most commonly applied industrially?

• Filtration of vials
• Terminal steam sterilization of filled vials (if formulation permits) or aseptic processing with sterile filtration
• Dry heat depyrogenation of filled vials
• Gamma irradiation of filled vials always

Correct Answer: Terminal steam sterilization of filled vials (if formulation permits) or aseptic processing with sterile filtration

Q35. During sterilizer PQ, what is the purpose of placing biological indicators in the most challenging locations?

• To shorten cycle times
• To ensure the cycle achieves required lethality even in worst-case positions
• To save on the number of indicators used
• To validate chemical indicators only

Correct Answer: To ensure the cycle achieves required lethality even in worst-case positions

Q36. Which parameter does a chemical integrator indicator measure in sterilization packs?

• Bioburden count
• Exposure to a combination of sterilization parameters (time, temperature, steam) indicating process exposure
• Filter porosity
• Endotoxin levels

Correct Answer: Exposure to a combination of sterilization parameters (time, temperature, steam) indicating process exposure

Q37. What is a common sterility test performed to detect viable microorganisms in a finished pharmaceutical product?

• F0 calculation
• Membrane filtration sterility test or direct inoculation methods described in pharmacopeias
• Bowie-Dick test
• Bubble point test

Correct Answer: Membrane filtration sterility test or direct inoculation methods described in pharmacopeias

Q38. Which term describes the reduction in microbial population achieved by a sterilization process?

• Bioburden increase
• Lethality or microbial log reduction
• Filter validation
• Residual toxicity

Correct Answer: Lethality or microbial log reduction

Q39. What is the role of load challenge studies in sterilization validation?

• To test only empty chamber performance
• To simulate the most difficult-to-sterilize product configurations and confirm process robustness
• To calibrate thermocouples only
• To measure residual moisture after sterilization

Correct Answer: To simulate the most difficult-to-sterilize product configurations and confirm process robustness

Q40. Which regulatory guidance is often referenced for sterilization validation and documentation in pharmaceutical manufacturing?

• ICH Q7 and relevant pharmacopeia chapters such as USP <1211> and ISO standards where applicable
• Only local building codes
• Food labeling regulations
• Clinical trial protocols

Correct Answer: ICH Q7 and relevant pharmacopeia chapters such as USP <1211> and ISO standards where applicable

Q41. What is the typical effect of increased load density on sterilization cycle performance if not compensated?

• Improved steam penetration automatically
• Poorer heat transfer leading to potential cold spots and under-processing
• No effect at all
• Instant sterilization

Correct Answer: Poorer heat transfer leading to potential cold spots and under-processing

Q42. Why are sterility assurance levels important in risk-based decision making?

• They define the acceptable probability of a non-sterile unit, guiding process design and validation to manage patient risk
• They set the color code for sterilizers
• They are only relevant for hospital laundry services
• They replace biological indicators

Correct Answer: They define the acceptable probability of a non-sterile unit, guiding process design and validation to manage patient risk

Q43. Which sterilization method relies on ionizing radiation to inactivate microorganisms?

• Autoclaving
• Gamma irradiation or electron beam sterilization
• Ethylene oxide only
• Dry heat at 160°C

Correct Answer: Gamma irradiation or electron beam sterilization

Q44. What is the main consideration when selecting sterilization method for a biopharmaceutical product?

• Only cost of equipment
• Product stability, container-closure compatibility, and required sterility assurance
• Color of packaging
• Facility location

Correct Answer: Product stability, container-closure compatibility, and required sterility assurance

Q45. Which of the following is a sign of incomplete sterilization in an autoclave load?

• All chemical indicators show expected change and BIs are inactivated
• Localized wetness or unprocessed cold spots and positive biological indicators
• Decreased chamber pressure beyond limits
• Shorter cycle time with full sterilization guaranteed

Correct Answer: Localized wetness or unprocessed cold spots and positive biological indicators

Q46. What is the significance of “sterile barrier system” in aseptic processing?

• It is unrelated to sterilization
• The system of packaging and components that maintains sterility after a sterilization or during aseptic assembly
• A test for endotoxins
• An instrument to measure autoclave pressure

Correct Answer: The system of packaging and components that maintains sterility after a sterilization or during aseptic assembly

Q47. How is gamma irradiation dose typically measured for sterilization purposes?

• In degrees Celsius
• In kilograys (kGy)
• In minutes at 121°C
• In atmospheric pressure units

Correct Answer: In kilograys (kGy)

Q48. Which of the following best describes sterilant residual concerns for hydrogen peroxide vapor sterilization?

• No residues form and no aeration is required
• Residual hydrogen peroxide must be removed or decomposed to safe levels before product release
• Residues are always beneficial
• Residues are only an issue for gamma irradiation

Correct Answer: Residual hydrogen peroxide must be removed or decomposed to safe levels before product release

Q49. What is the purpose of using process challenge devices (PCDs) in sterilization validation?

• To validate HVAC systems only
• To simulate product with defined challenge to verify sterilant penetration and lethality
• To replace biological indicators entirely
• To measure endotoxin concentrations

Correct Answer: To simulate product with defined challenge to verify sterilant penetration and lethality

Q50. Which monitoring practice is essential for routine control of large-scale sterilizers in a GMP environment?

• Random undocumented cycles
• Routine use of chemical indicators, scheduled biological indicator testing, cycle recording and review, and periodic requalification
• Only annual visual inspection
• Discarding biological indicator results

Correct Answer: Routine use of chemical indicators, scheduled biological indicator testing, cycle recording and review, and periodic requalification

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com