Air-based hazards: sources and types MCQs With Answer

Air-based hazards: sources and types MCQs With Answer

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Air-based hazards: sources and types MCQs With Answer

This quiz set is designed for M.Pharm students to deepen understanding of airborne hazards relevant to pharmaceutical practice, sterile manufacturing and occupational safety. It covers particulate and gaseous contaminants, bioaerosols, nanoparticles, monitoring methods, exposure limits and control strategies such as ventilation, HEPA filtration, containment and personal protective equipment. Questions emphasize practical applications—cleanroom classifications, aerosol generation during handling of potent APIs, deposition in the respiratory tract and emergency responses to accidental releases. Use these MCQs to test knowledge needed for safe drug production, regulatory compliance and risk assessment when managing air-based hazards in laboratory and manufacturing environments.

Q1. Which airborne particulate fraction is most likely to reach the alveolar region and pose the highest systemic absorption risk for pharmaceutical aerosols?

  • Particles >10 µm
  • Particles 2.5–10 µm
  • Particles <2.5 µm (PM2.5)
  • Fibres >50 µm

Correct Answer: Particles <2.5 µm (PM2.5)

Q2. In a sterile pharmaceutical cleanroom, which contaminant is primarily controlled by HEPA filtration rated at 99.97% for 0.3 µm particles?

  • Gaseous VOCs
  • Bioaerosols and fine particulates
  • Large droplets from coughing (>100 µm)
  • Odorous compounds

Correct Answer: Bioaerosols and fine particulates

Q3. Which monitoring device provides real-time measurements of airborne particle counts in different size channels commonly used for cleanroom classification?

  • Gravimetric filter sampler
  • Optical particle counter (OPC)
  • Impactor plate culture sampler
  • Diffusive passive badge

Correct Answer: Optical particle counter (OPC)

Q4. Which gas is colorless, highly toxic at low concentrations, produced by incomplete combustion and poses an acute inhalation risk in workplaces?

  • Ammonia (NH3)
  • Carbon monoxide (CO)
  • Sulfur dioxide (SO2)
  • Ozone (O3)

Correct Answer: Carbon monoxide (CO)

Q5. For highly potent active pharmaceutical ingredients (HPAPIs), what primary engineering control is recommended to minimize operator exposure during weighing and dispensing?

  • Local exhaust ventilation within a containment isolator or glovebox
  • Open bench operations with general room ventilation
  • Personal air-supplied respirators only
  • Use of only administrative controls

Correct Answer: Local exhaust ventilation within a containment isolator or glovebox

Q6. Which term describes airborne biological particles including bacteria, fungi, viruses and endotoxin-containing fragments relevant to pharmaceutical processes?

  • Bioaerosols
  • VOCs
  • Particulate matter (PM10)
  • Inert dusts

Correct Answer: Bioaerosols

Q7. Which occupational exposure limit is typically a recommended guideline set by ACGIH to prevent adverse health effects from inhalation in the workplace?

  • PEL (Permissible Exposure Limit)
  • TWA (Time-Weighted Average) TLV
  • LC50 environmental limit
  • NOAEL community standard

Correct Answer: TWA (Time-Weighted Average) TLV

Q8. Which mechanism predominantly governs deposition of ultrafine nanoparticles (<0.1 µm) in the respiratory tract?

  • Inertial impaction
  • Gravitational settling
  • Brownian diffusion
  • Electrostatic attraction only

Correct Answer: Brownian diffusion

Q9. When sampling airborne endotoxins in a pharmaceutical facility, which sampling method is commonly used to collect inhalable bioaerosol fractions for endpoint analysis?

  • Cascade impactor for size-selective culture only
  • Filter-based personal inhalable samplers
  • Direct-reading VOC monitors
  • Gas detector tubes

Correct Answer: Filter-based personal inhalable samplers

Q10. Which of the following control strategies most effectively reduces cross-contamination by airborne powders in multiproduct pharmaceutical manufacturing?

  • Strict gowning without zoning
  • Dedicated suites with closed transfer systems and negative/positive pressure cascades
  • Intermittent cleaning only
  • Relying on operator awareness and training

Correct Answer: Dedicated suites with closed transfer systems and negative/positive pressure cascades

Q11. Which volatile organic compound class is commonly emitted during solvent-based pharmaceutical manufacturing and contributes to inhalation and flammability hazards?

  • Alkanes and aromatic solvents (e.g., toluene, methanol)
  • Inert noble gases
  • Metal vapours only
  • Non-volatile salts

Correct Answer: Alkanes and aromatic solvents (e.g., toluene, methanol)

Q12. Which respiratory protective device provides a higher level of protection and is often used for handling high-potency powders compared with an N95 respirator?

  • Surgical mask
  • Half-mask elastomeric respirator with HEPA P100 cartridges
  • Cloth mask
  • Face shield without respirator

Correct Answer: Half-mask elastomeric respirator with HEPA P100 cartridges

Q13. Which environmental parameter, when improperly controlled in a cleanroom, can increase airborne particle resuspension from garments and surfaces?

  • Temperature only
  • Relative humidity extremes and high turbulent airflow
  • CO2 concentration
  • Lighting intensity

Correct Answer: Relative humidity extremes and high turbulent airflow

Q14. Which statement best describes a Class ISO 5 cleanroom (formerly ISO Class 100) in terms of particle concentration?

  • Allows up to 3,520,000 particles ≥0.5 µm per m3
  • Allows up to 3520 particles ≥0.5 µm per m3
  • Allows unlimited particles
  • Is equivalent to an open non-sterile laboratory

Correct Answer: Allows up to 3520 particles ≥0.5 µm per m3

Q15. Which primary sampling instrument is used for measuring mass concentration of respirable dust for regulatory compliance (gravimetric method)?

  • Real-time OPC directly reporting mass
  • Filter cassette with respirable cyclone and gravimetric weighing
  • Photoionization detector (PID)
  • Thermoanemometer

Correct Answer: Filter cassette with respirable cyclone and gravimetric weighing

Q16. In the event of an accidental powder spill that may become airborne, what immediate action minimizes aerosol generation?

  • Use dry sweeping with a broom
  • Vacuum with an appropriate HEPA-filtered industrial vacuum or damp cleanup
  • Increase room air turbulence to dilute the aerosol
  • Ask multiple people to scoop it quickly

Correct Answer: Vacuum with an appropriate HEPA-filtered industrial vacuum or damp cleanup

Q17. Which air pollutant produced during sterilization with ethylene oxide poses both acute and chronic inhalation hazards and requires strict exposure controls?

  • Ethylene oxide (EtO)
  • Hydrogen peroxide in solution only
  • Chlorine dioxide in trace amounts
  • Carbon dioxide residual

Correct Answer: Ethylene oxide (EtO)

Q18. Which deposition mechanism causes large droplets (>10 µm) to deposit in the upper respiratory tract and be trapped by mucus?

  • Brownian motion
  • Inertial impaction
  • Diffusive deposition
  • Electrostatic suspension

Correct Answer: Inertial impaction

Q19. Which concept describes the combined likelihood of exposure and severity of health effect used to prioritize controls for airborne pharmaceutical hazards?

  • Air exchange rate
  • Risk assessment / risk ranking
  • Particle size distribution only
  • Odour threshold

Correct Answer: Risk assessment / risk ranking

Q20. For continuous protection of sterile products from airborne contamination, which airflow pattern within a filling isolator is preferred to sweep particles away from the product and operator?

  • Turbulent mixing flow
  • Unidirectional (laminar) downward or horizontal flow
  • Bi-directional oscillating flow
  • Random recirculating flow

Correct Answer: Unidirectional (laminar) downward or horizontal flow

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