Control of contamination in pharmaceutical plants MCQs With Answer is an essential study area for B. Pharm students that focuses on contamination control strategies, cleanroom operation, and GMP compliance. This introduction covers microbial contamination sources, airborne particles, personnel hygiene, HVAC and HEPA filtration, gowning and aseptic technique, cleaning, disinfection and sterilization methods, and environmental monitoring. It emphasizes validation, risk-based controls, cross-contamination prevention, water systems (WFI), and regulatory standards like ISO 14644 and Annex 1. Practical knowledge of sampling, corrective actions, and documentation prepares students for manufacturing roles and inspections. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary purpose of contamination control in pharmaceutical plants?
- To reduce production costs
- To increase product shelf life only
- To ensure product quality, safety, and regulatory compliance
- To maximize production speed
Correct Answer: To ensure product quality, safety, and regulatory compliance
Q2. Which of the following is the most common route for microbial contamination in aseptic processing?
- Raw material intrinsic contamination
- Contaminated water for injection (WFI)
- Personnel handling and poor gowning practices
- Packaging material defects
Correct Answer: Personnel handling and poor gowning practices
Q3. What does HEPA stand for in contamination control?
- High Efficiency Particulate Air
- High Energy Particle Absorber
- High Efficiency Particle Arrestor
- High Efficiency Process Air
Correct Answer: High Efficiency Particulate Air
Q4. Which ISO standard is most directly related to cleanroom classification?
- ISO 9001
- ISO 14644
- ISO 22716
- ISO 13485
Correct Answer: ISO 14644
Q5. In cleanroom terminology, what does “ACH” stand for and why is it important?
- Air Change per Hour; controls particle and microbial dilution
- Air Contamination Hazard; measures contamination risk
- Atmospheric Control Humidity; maintains humidity
- Airflow Control Heuristics; optimizes HVAC algorithms
Correct Answer: Air Change per Hour; controls particle and microbial dilution
Q6. Which of the following disinfectants is most commonly used for routine surface disinfection in pharmaceutical cleanrooms?
- 70% isopropyl alcohol (IPA)
- Hydrogen peroxide vapor only
- Sodium hypochlorite 0.1% for all surfaces
- Phenolic compounds for sterile zones
Correct Answer: 70% isopropyl alcohol (IPA)
Q7. What is the recommended order of gowning to enter a Grade A/B aseptic area?
- Shoe covers → gloves → gown → face mask
- Face mask → gown → gloves → shoe covers
- Hand hygiene → gown → mask → gloves
- Hand hygiene → shoe covers → gown → gloves → face mask
Correct Answer: Hand hygiene → gown → mask → gloves
Q8. Which environmental monitoring method provides quantitative airborne particle counts?
- Settle plates
- Active air sampling with volumetric particle counter
- Contact plates
- Surface swabbing
Correct Answer: Active air sampling with volumetric particle counter
Q9. What is the main role of a laminar airflow (LAF) hood in aseptic processing?
- To sterilize products using UV light
- To provide unidirectional HEPA-filtered air to protect product from particles
- To store sterile supplies
- To control humidity near processing equipment
Correct Answer: To provide unidirectional HEPA-filtered air to protect product from particles
Q10. Which biological indicator is commonly used to validate steam sterilization (autoclave) cycles?
- Escherichia coli spores
- Geobacillus stearothermophilus spores
- Bacillus subtilis vegetative cells
- Staphylococcus aureus spores
Correct Answer: Geobacillus stearothermophilus spores
Q11. What is the purpose of a segregation (airlock) between cleanroom gowning and production areas?
- To serve as a storage area for raw materials
- To provide an intermediate pressure and contamination barrier to reduce ingress of contaminants
- To house HVAC equipment
- To allow staff to take breaks
Correct Answer: To provide an intermediate pressure and contamination barrier to reduce ingress of contaminants
Q12. Which water quality is required for terminal sterilization rinse and critical manufacturing steps?
- Tap water
- Purified water
- Water for Injection (WFI)
- Deionized water only
Correct Answer: Water for Injection (WFI)
Q13. What does Annex 1 (EMA/ICH) primarily address in pharmaceutical manufacturing?
- Medical device classification
- Guidance on sterile medicinal product manufacture and aseptic processes
- Labeling requirements for over-the-counter drugs
- Clinical trial design
Correct Answer: Guidance on sterile medicinal product manufacture and aseptic processes
Q14. During environmental monitoring, which method is best for detecting surface microbial contamination?
- Active air sampling
- Surface contact plates (RODAC)
- Particle counting
- Temperature logging
Correct Answer: Surface contact plates (RODAC)
Q15. Which factor most influences the effectiveness of a disinfectant in a cleanroom?
- Color of the disinfectant
- Contact time, concentration, and presence of organic load
- Manufacturer brand name only
- Room temperature only
Correct Answer: Contact time, concentration, and presence of organic load
Q16. What is cross-contamination in the context of pharmaceutical plants?
- The transfer of biological hazards to the environment
- The unintended transfer of material (active ingredients, excipients, microbes) between products or processes
- Intentional mixing of products for new formulations
- Contamination of HVAC filters only
Correct Answer: The unintended transfer of material (active ingredients, excipients, microbes) between products or processes
Q17. Which particle size is most critical to control because it can carry microorganisms into sterile products?
- Particles >10 µm only
- Submicron particles (<0.1 µm)
- Particles in the 0.5–5.0 µm range
- Only visible dust particles
Correct Answer: Particles in the 0.5–5.0 µm range
Q18. What is the main advantage of sterilizing filtration for heat-sensitive solutions?
- It removes endotoxins completely
- It removes particulate and microbial contaminants without heat
- It inactivates viruses chemically
- It increases product viscosity
Correct Answer: It removes particulate and microbial contaminants without heat
Q19. Which monitoring practice helps detect slow-developing microbial trends in a production area?
- Single-point air sampling once a year
- Routine environmental monitoring with trend analysis
- Only visual inspection
- Intermittent temperature checks
Correct Answer: Routine environmental monitoring with trend analysis
Q20. Why are gowning qualification and periodic retraining important?
- To reduce laundry costs
- To ensure personnel continue to follow procedures that minimize contamination risk
- To increase staff turnover
- To validate HVAC systems
Correct Answer: To ensure personnel continue to follow procedures that minimize contamination risk
Q21. What is a typical corrective action when an environmental sample exceeds alert or action limits?
- Ignore the result if production is on schedule
- Investigate root cause, perform cleaning/disinfection, review procedures, and re-sample
- Immediately discard all finished products without investigation
- Replace personnel without investigation
Correct Answer: Investigate root cause, perform cleaning/disinfection, review procedures, and re-sample
Q22. Which HVAC parameter is crucial to maintain to prevent inward contamination of a Grade A zone?
- Negative pressure relative to adjacent areas
- Positive pressure relative to less clean adjacent areas
- Equalized pressure with adjacent corridors
- High humidity only
Correct Answer: Positive pressure relative to less clean adjacent areas
Q23. Which of the following is an appropriate use for settle plates in monitoring?
- Quantitative airborne particle measurement
- Passive assessment of deposition risk over a defined exposure period
- Measuring viable counts on high-touch surfaces only
- Determining endotoxin levels
Correct Answer: Passive assessment of deposition risk over a defined exposure period
Q24. What is the role of qualification and validation in contamination control?
- To provide training materials only
- To demonstrate systems and processes perform consistently and meet predefined acceptance criteria
- To certify personnel academically
- To eliminate the need for routine monitoring
Correct Answer: To demonstrate systems and processes perform consistently and meet predefined acceptance criteria
Q25. Which cleaning agent is preferred to remove proteinaceous residue before disinfection?
- Alcohol-based disinfectant alone
- Enzymatic or detergent cleaners followed by disinfectant
- Sterile water rinse only
- Sodium chloride solution
Correct Answer: Enzymatic or detergent cleaners followed by disinfectant
Q26. In a contamination control strategy, what is “zoning” used for?
- Scheduling maintenance activities
- Separating areas by cleanliness requirements to limit contamination spread
- Allocating office space
- Designing ergonomic workstations
Correct Answer: Separating areas by cleanliness requirements to limit contamination spread
Q27. Which microbial test is specifically used to detect endotoxin contamination?
- Membrane filtration sterility test
- Limulus Amebocyte Lysate (LAL) test
- ATP bioluminescence for surface ATP
- Gram staining
Correct Answer: Limulus Amebocyte Lysate (LAL) test
Q28. During media fill (aseptic process simulation), what is the main acceptance criterion?
- No visible particulate in product
- No microbial growth in incubated filled containers above allowed limits
- Correct fill volume only
- Operator comfort and ergonomics
Correct Answer: No microbial growth in incubated filled containers above allowed limits
Q29. What is the significance of particle size distribution measurement in cleanrooms?
- It helps assess source of particles and compliance with cleanroom class limits
- It only measures humidity
- It is used to count personnel in the room
- It replaces microbial monitoring entirely
Correct Answer: It helps assess source of particles and compliance with cleanroom class limits
Q30. Which practice best reduces contamination risk when transferring materials into a clean area?
- Bringing items through the main corridor unlocked
- Using double-door pass-throughs or transfer hatches with appropriate cleaning and decontamination
- Handing items directly without wiping
- Opening windows to ventilate during transfer
Correct Answer: Using double-door pass-throughs or transfer hatches with appropriate cleaning and decontamination
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.
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