Advanced sterile manufacturing – environmental control MCQs With Answer

Introduction

Advanced sterile manufacturing – environmental control MCQs With Answer is designed for M.Pharm students preparing for advanced topics in sterile production. This quiz-focused post covers critical concepts such as cleanroom classifications, airflow patterns, HEPA filtration, environmental monitoring (viable and non-viable), gowning and personnel practices, HVAC design considerations, and regulatory expectations (ISO 14644 and Annex 1 principles). Questions probe practical understanding and decision-making in controlling particulate and microbial contamination, filter integrity testing, and contamination control strategies. Use these MCQs to test knowledge depth, identify gaps, and reinforce best practices essential for maintaining aseptic processing environments in modern pharmaceutical manufacturing.

Q1. What is the primary objective of environmental control in advanced sterile manufacturing?

• To eliminate all microorganisms from the production area
• To maintain conditions that minimize particulate and microbial contamination risks to products
• To reduce energy consumption of HVAC systems
• To increase personnel comfort during long shifts

Correct Answer: To maintain conditions that minimize particulate and microbial contamination risks to products

Q2. Which ISO cleanroom class is generally equivalent to EU GMP Grade A for aseptic operations?

• ISO 3
• ISO 5
• ISO 7
• ISO 9

Correct Answer: ISO 5

Q3. What is the commonly stated efficiency of a HEPA filter at the most penetrating particle size (0.3 µm)?

• 90% removal of 0.3 µm particles
• 99% removal of 0.3 µm particles
• 99.97% removal of 0.3 µm particles
• 100% removal of 0.3 µm particles

Correct Answer: 99.97% removal of 0.3 µm particles

Q4. Which airflow pattern is most effective at minimizing cross-contamination in the critical filling zone?

• Turbulent mixing airflow
• Counter-current airflow
• Unidirectional (laminar) downward airflow
• Intermittent pulsed airflow

Correct Answer: Unidirectional (laminar) downward airflow

Q5. Typical target face velocity for a vertical laminar flow hood (downflow) used at the point of use is approximately:

• 0.05 m/s
• 0.45 m/s
• 2.0 m/s
• 5.0 m/s

Correct Answer: 0.45 m/s

Q6. In a contamination control pressure cascade, airflow should move from:

• Less clean to more clean areas
• Clean to less clean areas
• Equal pressure between all rooms
• Outside to inside only when doors are open

Correct Answer: Clean to less clean areas

Q7. The primary rationale for strict gowning procedures in aseptic areas is to:

• Keep personnel warm and comfortable
• Reduce shedding of skin scales and fibers that carry microorganisms and particles
• Identify staff by role and seniority
• Reduce static electricity in equipment only

Correct Answer: Reduce shedding of skin scales and fibers that carry microorganisms and particles

Q8. Which environmental monitoring method provides quantitative assessment of airborne viable microorganisms?

• Non-viable particle counter
• Settle plates only (passive monitoring)
• Active air sampling using an impactor or slit-to-agar sampler
• Surface ATP swab without incubation

Correct Answer: Active air sampling using an impactor or slit-to-agar sampler

Q9. For sterile production, the recommended environmental monitoring approach for critical (Grade A) zones is:

• Periodic non-viable monitoring monthly and no viable monitoring
• Continuous non-viable particle monitoring plus frequent viable monitoring and spot checks
• No monitoring if HVAC is validated
• Only personnel monitoring is required

Correct Answer: Continuous non-viable particle monitoring plus frequent viable monitoring and spot checks

Q10. Increasing air changes per hour (ACH) in a cleanroom primarily results in:

• Higher microbial growth rates due to turbulence
• Faster removal of airborne particulates and shorter recovery time after disturbance
• Increased particulate generation from filters
• Reduced need for gowning

Correct Answer: Faster removal of airborne particulates and shorter recovery time after disturbance

Q11. Which test is commonly used to perform HEPA filter integrity verification in-situ using an aerosol challenge and photometer?

• Bacterial endotoxin test
• PAO (or equivalent) challenge photometer test
• Pressure decay test without aerosol
• Microbial culture test downstream

Correct Answer: PAO (or equivalent) challenge photometer test

Q12. In cleanroom qualification, the term “recovery time” refers to:

• The time taken for HVAC to restart after a shutdown
• The time required for particle levels to return to specified limits after a deliberate disturbance
• The time necessary to clean surfaces between batches
• The lag time for personnel to don gowning

Correct Answer: The time required for particle levels to return to specified limits after a deliberate disturbance

Q13. The primary purpose of performing media fill (aseptic process simulation) is to:

• Validate the sterility of the final product directly
• Demonstrate the aseptic process, personnel technique, and environmental controls are effective in preventing contamination
• Replace routine environmental monitoring
• Measure HEPA filter efficiency

Correct Answer: Demonstrate the aseptic process, personnel technique, and environmental controls are effective in preventing contamination

Q14. Terminal HEPA filtration in an aseptic workstation is located:

• Upstream in the HVAC plant only
• At the final point of air delivery above the critical zone (point-of-use)
• Only in the return air duct
• Outside the building for pre-filtration

Correct Answer: At the final point of air delivery above the critical zone (point-of-use)

Q15. Which property is most desirable in cleanroom garments used for sterile manufacturing?

• Highly absorbent natural fibers
• Low particle shedding, non-linting, and easy to decontaminate
• Elastic stretch to fit closely and trap particles
• Bright colors for visual identification

Correct Answer: Low particle shedding, non-linting, and easy to decontaminate

Q16. The most penetrating particle size (MPPS) for HEPA filters, at which removal is most challenging, is approximately:

• 10 µm
• 5 µm
• 0.3 µm
• 0.01 µm

Correct Answer: 0.3 µm

Q17. For critical HVAC components in sterile manufacturing, the term “N+1 redundancy” means:

• There are no backups and all systems are single train
• At least one additional (backup) component is provided beyond the required capacity
• All components must be duplicated exactly (2N)
• Systems operate with negative redundancy to save energy

Correct Answer: At least one additional (backup) component is provided beyond the required capacity

Q18. Which airflow orientation is generally preferred for minimizing contamination at the filling nozzle during aseptic filling?

• Horizontal turbulent airflow across the nozzle
• Vertical unidirectional downflow over the nozzle
• Upward airflow from the floor toward the nozzle
• No directed airflow to avoid drafts

Correct Answer: Vertical unidirectional downflow over the nozzle

Q19. A commonly specified differential pressure between adjacent cleanrooms to maintain the cascade is approximately:

• 0–2 Pa
• 5–7 Pa
• 10–15 Pa
• 100–150 Pa

Correct Answer: 10–15 Pa

Q20. According to ISO 14644-1 particle limits, the maximum allowed concentration of particles ≥0.5 µm for an ISO 5 cleanroom is closest to:

• 3,520,000 particles per m³
• 352,000 particles per m³
• 35,200 particles per m³
• 3,520 particles per m³

Correct Answer: 3,520 particles per m³

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