Introduction: Mechanical, electrical, thermal, and process hazards MCQs With Answer is designed for M.Pharm students preparing for exams and working in pharmaceutical industries. This quiz collection focuses on common hazards encountered in drug manufacturing — from rotating tablet presses and conveyors to electrical faults, steam sterilization, and reactive process upsets. Questions emphasize hazard recognition, prevention strategies (such as guarding, lockout–tagout, grounding, pressure relief), regulatory practices, and safety engineering controls applicable to pharmaceutical settings. By practicing these focused MCQs, students will strengthen their understanding of practical safety measures, risk assessment methods, and incident mitigation approaches relevant to laboratory and production environments.
Q1. Which of the following is the most effective engineering control to prevent entanglement injuries on a rotating tablet press?
- Regular operator training on safe operation
- Fixed mechanical guarding that prevents access to rotating parts
- Providing workers with non-slip footwear
- Posting warning signs near the machine
Correct Answer: Fixed mechanical guarding that prevents access to rotating parts
Q2. What does a residual current device (RCD) primarily protect against in a pharmaceutical production area?
- Overheating of electrical motors
- Imbalance in three-phase supply
- Ground fault leading to electric shock
- Voltage spikes from the utility
Correct Answer: Ground fault leading to electric shock
Q3. In the context of process safety, what is a “runaway reaction”?
- A reaction that proceeds without proper documentation
- A self-accelerating chemical reaction leading to uncontrolled temperature and pressure rise
- A reaction that stops unexpectedly due to catalyst poisoning
- A reaction performed at a higher-than-planned yield
Correct Answer: A self-accelerating chemical reaction leading to uncontrolled temperature and pressure rise
Q4. Which thermal hazard is most relevant when working with steam sterilizers (autoclaves) in a sterile manufacturing line?
- Risk of electrical shock from control panels
- Risk of thermal burns and scalding during door opening and load handling
- Risk of inhalation of solvent vapors
- Risk of mechanical entrapment by moving shelves
Correct Answer: Risk of thermal burns and scalding during door opening and load handling
Q5. Which lockout–tagout (LOTO) practice is essential before performing maintenance on a vacuum dryer in a pharmaceutical plant?
- Isolating electrical power only
- Isolating all energy sources including electrical, pneumatic, hydraulic, and thermal and verifying zero energy state
- Asking the operator to stop machine and leaving a sign
- Turning off the main building power
Correct Answer: Isolating all energy sources including electrical, pneumatic, hydraulic, and thermal and verifying zero energy state
Q6. Which of the following is a primary sign of imminent mechanical failure in rotating process equipment?
- Stable operating temperature
- Increased vibration and unusual noise
- Decreased power consumption with steady output
- Cleaner surfaces around the equipment
Correct Answer: Increased vibration and unusual noise
Q7. What is the primary purpose of a pressure relief valve on a reactor vessel used in pharmaceutical synthesis?
- To prevent product contamination
- To maintain reaction temperature
- To protect the vessel from overpressure by venting excess pressure
- To filter vapors before discharge
Correct Answer: To protect the vessel from overpressure by venting excess pressure
Q8. Which personal protective equipment (PPE) is most important when handling hot molten excipient during capsule manufacturing?
- Disposable nitrile gloves only
- Flame-resistant apron, heat-resistant gloves, and face shield
- Standard lab coat and safety glasses
- Dust mask and safety boots
Correct Answer: Flame-resistant apron, heat-resistant gloves, and face shield
Q9. What hazard does a punctured compressed gas cylinder primarily present in a cleanroom compounding area?
- Increased humidity affecting formulations
- Projectile hazard and rapid release of stored energy
- Minor temperature fluctuations
- Noise disturbance only
Correct Answer: Projectile hazard and rapid release of stored energy
Q10. In a HAZOP study for a batch reactor, which guide word would be most relevant to identify hazards related to reduced cooling capacity?
- More
- Less
- Reverse
- None
Correct Answer: Less
Q11. Which electrical safety measure reduces the risk of equipment causing fires due to insulation failure in pharmaceutical HVAC systems?
- Using higher voltage supply
- Regular insulation resistance testing and earthing (grounding)
- Limiting maintenance to annual intervals
- Installing more lighting fixtures
Correct Answer: Regular insulation resistance testing and earthing (grounding)
Q12. What is the main cause of thermal runaway in exothermic pharmaceutical reactions carried out in stirred tank reactors?
- Excessive catalyst activity leading to uncontrolled heat generation combined with insufficient heat removal
- Using inert atmosphere instead of air
- Operating at very low reactant concentration
- Frequent operator interventions
Correct Answer: Excessive catalyst activity leading to uncontrolled heat generation combined with insufficient heat removal
Q13. Which of the following best describes a BLEVE (Boiling Liquid Expanding Vapor Explosion) risk in pharmaceutical storage?
- Explosion due to ignition of powdered solids
- Sudden rupture and violent release of a vessel containing liquid above its boiling point when heated externally
- Slow leak of compressed gases into ventilated area
- Corrosion of packaging materials over time
Correct Answer: Sudden rupture and violent release of a vessel containing liquid above its boiling point when heated externally
Q14. For electrical classification in areas handling flammable solvents, what is the primary goal of area classification (hazardous area zoning)?
- To determine HVAC filter efficiency
- To specify lighting color schemes
- To identify zones where explosion-proof or intrinsically safe equipment is required
- To schedule preventive maintenance
Correct Answer: To identify zones where explosion-proof or intrinsically safe equipment is required
Q15. Which process safety instrumented function (SIF) action is typically used to control overpressure in a pressurized pharmaceutical crystallizer if the primary control fails?
- Automated controlled venting or emergency shutdown triggered by high-pressure trip
- Manual inspection by operator
- Increase feed rate to dilute the system
- Change condenser coolant without authorization
Correct Answer: Automated controlled venting or emergency shutdown triggered by high-pressure trip
Q16. What is the main thermal hazard associated with freeze–thaw cycles in liquid pharmaceutical formulations stored in refrigerated vessels?
- Increased microbial contamination
- Expansion leading to container rupture and possible release of product and pressure shock
- Reduction in pH only
- Evaporation of volatile ingredients
Correct Answer: Expansion leading to container rupture and possible release of product and pressure shock
Q17. Which inspection practice helps prevent electrical arcing hazards in motor control centers used for process pumps?
- Painting motor control centers regularly
- Periodic infrared thermography and tightening of electrical connections
- Keeping doors open to ventilate heat
- Replacing motors annually regardless of condition
Correct Answer: Periodic infrared thermography and tightening of electrical connections
Q18. In process hazard analysis, what is the key objective of conducting a Layer of Protection Analysis (LOPA)?
- To write operating procedures for batch recipes
- To estimate risk and determine if existing independent protection layers reduce risk to tolerable levels
- To design the plant layout
- To select personal protective equipment for operators
Correct Answer: To estimate risk and determine if existing independent protection layers reduce risk to tolerable levels
Q19. Which mechanical hazard control is most appropriate to prevent falling loads when using a hoist to lift drums of raw material in a warehouse?
- Using slings without inspection
- Regular inspection of hoist and use of load-rated slings and secondary restraints
- Allowing only one worker to guide the load
- Relying solely on operator experience
Correct Answer: Regular inspection of hoist and use of load-rated slings and secondary restraints
Q20. When managing process hazards involving toxic inhalation in a solvent-handling area, which hierarchy of control measure is most effective?
- Use of respirators by all staff without other controls
- Elimination or substitution of the toxic solvent, engineering controls (local exhaust ventilation), then PPE
- Posting warning signs and limiting access
- Relying on administrative controls such as training only
Correct Answer: Elimination or substitution of the toxic solvent, engineering controls (local exhaust ventilation), then PPE
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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