Safety Engineer — 50 MCQs
Toggle each question to reveal the correct answer and a short explanation. Topics: fire extinguisher, near miss, hazards, and general safety engineering.
Which class of fire extinguisher should be used on ordinary combustibles like wood and paper?
Answer: B. Class A
Class A extinguishers are for ordinary combustibles (wood, paper, cloth). Water or foam types are commonly used. Always confirm by checking the extinguisher label.
What does the term “near miss” refer to in safety reporting?
Answer: C. An event that could have caused harm but did not
Near misses are important leading indicators — they reveal weaknesses in controls without the cost of injuries; reporting them helps prevent actual incidents.
Which one is the best first action when discovering a small fire that you can safely tackle?
Answer: B. Use the correct extinguisher following PASS
PASS: Pull the pin, Aim low, Squeeze handle, Sweep side to side. Ensure you have a clear exit and the fire is small and controllable.
What is a “hazard”?
Answer: B. A source with potential to cause harm
Hazard = anything with potential to cause harm (chemicals, energy, behavior). Risk is the likelihood and severity of harm.
Which extinguisher is suitable for electrical fires?
Answer: B. Class C (CO₂ or dry chemical)
Electrical fires require non-conductive agents like CO₂ or dry chemical. Water can conduct electricity and worsen the hazard.
Which of the following is the highest level in the hierarchy of controls?
Answer: C. Elimination/substitution
Hierarchy: elimination, substitution, engineering controls, administrative controls, PPE. Elimination removes the hazard entirely — most effective.
What is the main purpose of a near-miss reporting system?
Answer: B. Capture events to prevent future incidents
Near-miss reporting identifies hazards and weak controls early so corrective actions can prevent actual harm.
Which document gives hazard and first-aid information for chemicals?
Answer: C. Safety Data Sheet (SDS)
SDS (formerly MSDS) provides hazards, handling, PPE, exposure limits, and first-aid measures for chemicals.
What does the acronym “PPE” stand for?
Answer: A. Personal Protective Equipment
PPE includes helmets, gloves, eye protection, hearing protection, respirators — used when hazards cannot be eliminated.
Which tool is typically used to identify steps and hazards for a specific task?
Answer: B. Job Safety Analysis (JSA) / Job Hazard Analysis (JHA)
JSA/JHA breaks a task into steps, identifies hazards, and prescribes controls for each step.
Which class of fire involves flammable liquids (gasoline, oil)?
Answer: B. Class B
Class B fires involve flammable liquids. Foam, dry chemical, or CO₂ extinguishers are commonly used depending on the situation.
What is the correct sequence of PASS when using an extinguisher?
Answer: A. Pull, Aim, Squeeze, Sweep
PASS is the universal mnemonic for portable extinguisher operation: Pull the pin, Aim at base, Squeeze, Sweep side-to-side.
Which of these is a leading safety indicator?
Answer: B. Number of safety observations completed
Leading indicators (proactive) include audits, inspections, training completion, and near-miss reports; lagging indicators measure outcomes after incidents.
What is the purpose of lockout-tagout (LOTO)?
Answer: B. To isolate energy sources and prevent accidental startup
LOTO ensures machinery cannot be energized during maintenance — securing energy sources and tagging for awareness.
Which fire class is for cooking oils and fats?
Answer: C. Class K (or F)
Class K (US) or Class F (Europe) extinguishers are for cooking oils/grease — wet chemical agents cool and saponify the oil.
Which of the following best describes “risk”?
Answer: A. The probability and consequence of harm
Risk combines likelihood and severity of adverse outcomes. Risk assessment evaluates both to prioritize controls.
What is the minimum monthly visual inspection for portable fire extinguishers aimed at?
Answer: B. Ensure extinguisher is present, accessible and not obviously damaged
Monthly checks confirm physical condition, pressure gauge, and accessibility; full maintenance is periodic by trained personnel.
Which action best reduces the hazard from noisy machinery?
Answer: B. Eliminate or enclose the source and use engineering controls
Engineering solutions (enclosures, dampers) are preferred; PPE is last resort when elimination isn’t feasible.
What should you do after discovering a near miss?
Answer: B. Report it, document circumstances, and apply corrective action
Reporting near misses enables investigation, root cause analysis, and fixes to prevent real incidents.
Which is NOT part of a fire triangle?
Answer: D. Electricity
The fire triangle is fuel + oxygen + heat. Electricity can be a source of heat/ignition but isn’t one of the three basic elements.
Which of the following is a typical control for chemical exposure?
Answer: D. All of the above
Controls include engineering (ventilation), administrative (work practices), and PPE (respirators) depending on exposure level.
What is a common sign that a near miss reporting culture is strong?
Answer: C. Many near misses reported and acted upon
A positive reporting culture encourages reporting and ensures corrective actions are taken, demonstrating proactive safety management.
Which extinguisher is typically used for metal fires (e.g., magnesium)?
Answer: B. Class D (dry powder)
Metal fires require specialized dry powders that smother and absorb heat; water can react dangerously with some burning metals.
What does HAZOP stand for?
Answer: A. Hazard and Operability Study
HAZOP is a structured technique to identify hazards and operability problems in process systems using guide words and nodes.
Which inspection frequency is typically required for fire extinguishers by many standards?
Answer: B. Monthly visual inspection and annual maintenance
Common practice: monthly quick checks, annual professional inspection, and periodic hydrostatic testing per manufacturer/standard.
Which of these is an example of an administrative control?
Answer: B. Rotating shifts to limit exposure time
Administrative controls change work practices or schedules to reduce exposure, such as training, signage, or rotation.
What is an appropriate immediate action if a coworker receives an electrical shock?
Answer: B. Turn off the power source before touching and call for help
Do not touch a person still in contact with electricity. Isolate power first, then assess and provide first aid/EMT as needed.
Which item is commonly included in a spill response kit for oils and fuels?
Answer: A. Absorbent pads and booms
Spill kits typically include absorbents, PPE, disposal bags, and tools to contain and clean spilled liquids safely.
What is the recommended safe procedure before entering a confined space?
Answer: B. Obtain a confined space permit, test atmosphere, and ventilate
Confined spaces require permits, atmospheric testing (oxygen, flammables, toxic gases), rescue plan, and trained entrants.
What is the correct place to store full and empty compressed gas cylinders?
Answer: B. Secure upright with caps on and segregate flammables
Cylinders must be stored upright, secured to prevent tipping, valve protection caps on, and separated by gas type and hazards.
Which is the best way to prevent slips, trips and falls?
Answer: A. Keep good housekeeping and mark hazards
Good housekeeping, lighting, non-slip surfaces, and signage significantly reduce slip/trip hazards.
What is the typical response if a portable extinguisher is found discharged or missing?
Answer: B. Replace or recharge it and investigate why it was used/missing
Empty or missing extinguishers must be restored promptly and any usage investigated to understand the cause and prevent recurrence.
Which concept focuses on finding the underlying reason an incident occurred?
Answer: A. Root Cause Analysis
Root cause analysis investigates contributing factors to address systemic causes rather than only symptoms.
Which of the following is a common sign of heat stress?
Answer: B. Muscle cramps and faintness
Heat stress signs include cramps, heavy sweating, nausea, dizziness — respond by moving to cool area and hydrating; severe cases need medical help.
What is the most appropriate fire response if the fire is large or spreading?
Answer: B. Evacuate area and call emergency services
Large or rapidly spreading fires require evacuation, alarm activation and professional firefighting response; do not attempt if unsafe.
Which of these is a common cause of near misses?
Answer: B. Unsafe acts or conditions
Near misses often stem from unsafe acts (shortcuts) or unsafe conditions (poor maintenance, poor housekeeping) that should be corrected.
Which color is commonly used for fire safety signs and equipment labels?
Answer: C. Red
Red is commonly associated with fire equipment and alarms to attract attention to emergency firefighting equipment and alarms.
Which practice helps reduce flammable vapor ignition in storage areas?
Answer: B. Provide ventilation and grounding/bonding
Ventilation reduces vapor concentration; grounding and bonding prevent static sparks when transferring flammable liquids.
Which emergency equipment should be readily available near hot work (welding)?
Answer: A. Fire extinguisher and fire watch
Hot work requires permits, fire extinguishers nearby, and often a fire watch during and after work to detect smoldering fires.
What is the best immediate action when you discover a hazardous spill with fumes?
Answer: B. Evacuate area, isolate and alert emergency responders
Fumes can be toxic; evacuate, ventilate if safe, and call trained response teams with proper PPE and monitoring equipment.
Which is a primary objective of incident investigation?
Answer: B. Identify root causes and corrective actions
Investigations focus on learning, preventing recurrence and improving systems rather than assigning blame.
What is the proper distance to maintain between an extinguisher and a potential fire source before discharging (general guidance)?
Answer: A. 1–2 meters (3–6 feet) depending on extinguisher
Most portable extinguishers are operated from a few feet away; follow manufacturer instructions for safe operating distance.
Which practice improves near-miss reporting rates?
Answer: B. Anonymous, simple reporting and positive feedback
Encouraging reporting with no blame, easy tools and visible corrective action increases near-miss reports and safety engagement.
What is the main hazard when using water on a flammable liquid fire?
Answer: B. Water can spread the burning liquid and worsen the fire
Water can float and spread flammable liquids; proper agents (foam, dry chemical) are used for Class B fires.
Which of these best describes “safety culture”?
Answer: B. The shared values, beliefs and behaviors regarding safety
Safety culture influences how people prioritize safety — leadership commitment and employee involvement are key.
Which is the most appropriate fuel source control for a potential ignition source during maintenance?
Answer: A. Remove fuel or isolate it
Removing or isolating fuel sources eliminates the possibility of combustion; it’s a higher-level control than administrative measures.
Which best practice applies to storing flammable liquids inside a building?
Answer: A. Use approved flammable storage cabinets and limit quantities
Approved cabinets reduce vapor release and fire spread; follow quantity limits and keep containers sealed.
What should a fire watch do after hot work is completed?
Answer: B. Continue observation for a specified period to ensure no smoldering fires
Fire watch duties include monitoring during and after hot work (often 30–60 minutes) to detect smoldering embers.
Which of the following is true about PPE?
Answer: B. PPE reduces exposure when higher-level controls are not feasible
PPE is the last line of defense; it does not eliminate hazards but minimizes exposure when engineering or other controls are not possible.
Which practice helps ensure effectiveness of emergency exits during an evacuation?
Answer: B. Keep exit routes clear, well-lit and signed
Clear, marked and unobstructed exits enable fast and safe evacuation during emergencies; obstructed exits increase risk.