Chemical hazards – sources and types MCQs With Answer

Chemical hazards – sources and types MCQs With Answer

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Chemical hazards – sources and types MCQs With Answer

This short quiz package is designed specifically for M.Pharm students to deepen understanding of chemical hazards: their sources, classification and practical implications in pharmaceutical laboratories and manufacturing. The questions cover physical, health and environmental hazard types, routes of exposure, hazard communication (GHS/SDS), exposure metrics (LD50/LC50, TLV/PEL, IDLH), incompatibilities, control strategies and emergency care. Each MCQ emphasizes applied knowledge you will need for safe handling, risk assessment and regulatory compliance in pharmaceutical practice. Attempt these questions to test conceptual clarity and decision-making skills critical for hazard prevention, incident response and maintaining a safe workplace in the pharmaceutical sector.

Q1. What are the primary sources of chemical hazards in a pharmaceutical laboratory and manufacturing facility?

  • Only raw materials and finished products
  • Laboratory operations, industrial processes, storage, transport and waste disposal
  • Only equipment malfunctions and fires
  • Natural disasters only

Correct Answer: Laboratory operations, industrial processes, storage, transport and waste disposal

Q2. Which of the following lists correctly identifies the major routes of occupational chemical exposure?

  • Inhalation, dermal contact and ingestion
  • Inhalation only
  • Injection, ingestion and external radiation
  • Dermal contact only

Correct Answer: Inhalation, dermal contact and ingestion

Q3. Chemical hazards are commonly classified into which three broad categories relevant to pharmaceutical safety?

  • Combustible, edible and aesthetic hazards
  • Physical hazards, health hazards and environmental hazards
  • Mechanical, electrical and thermal hazards
  • Biological, nutritional and psychological hazards

Correct Answer: Physical hazards, health hazards and environmental hazards

Q4. Which physicochemical properties are most important in determining the inhalation hazard of a volatile chemical?

  • Melting point and color
  • Vapor pressure and vapor density
  • Optical rotation and refractive index
  • Boiling point only

Correct Answer: Vapor pressure and vapor density

Q5. How are LD50 and LC50 best defined in toxicology?

  • LD50 is lethal concentration in air for 50% of animals; LC50 is lethal dose per kg body weight
  • LD50 is lethal dose producing 50% mortality (mg/kg) and LC50 is lethal concentration producing 50% mortality (ppm or mg/L)
  • Both LD50 and LC50 are time to onset of symptoms
  • LD50 and LC50 refer to non-lethal toxicity endpoints

Correct Answer: LD50 is lethal dose producing 50% mortality (mg/kg) and LC50 is lethal concentration producing 50% mortality (ppm or mg/L)

Q6. Which GHS pictogram represents corrosive hazards that can damage skin and metals?

  • A skull and crossbones
  • Test tube pouring onto hand and metal (corrosion)
  • Flame over circle (oxidizer)
  • Exploding bomb

Correct Answer: Test tube pouring onto hand and metal (corrosion)

Q7. In flammability terms, what do LEL and UEL stand for and indicate?

  • Lower Emission Limit and Upper Emission Limit for air pollutants
  • Lower Explosive Limit and Upper Explosive Limit: the lowest and highest concentrations of vapor in air that will burn or explode
  • Liquid Evaporation Level and Ultimate Evaporation Level
  • Light Emission Limit and Ultrasonic Emission Limit

Correct Answer: Lower Explosive Limit and Upper Explosive Limit: the lowest and highest concentrations of vapor in air that will burn or explode

Q8. What does the occupational term IDLH mean and why is it important for emergency planning?

  • Immediate Dose Likely Harmful — a non-regulatory guideline for ingestion risk
  • Immediately Dangerous to Life or Health — a concentration posing an immediate threat to life, irreversible health effects, or escape impairment
  • Industrial Dose Limit Heterogeneity — a measurement variability index
  • Inhalation Dose Limit History — historical exposure data

Correct Answer: Immediately Dangerous to Life or Health — a concentration posing an immediate threat to life, irreversible health effects, or escape impairment

Q9. Chronic health effects such as carcinogenicity, mutagenicity and teratogenicity most commonly result from which exposure pattern?

  • Single, high-dose acute exposure only
  • Repeated or prolonged low-level exposures over time
  • Exposure to inert gases only
  • Short-term exposure below detection limits

Correct Answer: Repeated or prolonged low-level exposures over time

Q10. Which sequence correctly lists the hierarchy of controls from most to least effective in preventing chemical exposures?

  • PPE → Administrative controls → Engineering controls → Substitution → Elimination
  • Elimination → Substitution → Engineering controls → Administrative controls → Personal protective equipment (PPE)
  • Administrative controls → PPE → Engineering controls → Substitution → Elimination
  • Substitution → PPE → Administrative controls → Engineering controls → Elimination

Correct Answer: Elimination → Substitution → Engineering controls → Administrative controls → Personal protective equipment (PPE)

Q11. Which routine chemical incompatibility is correctly paired with the hazardous product formed?

  • Mixing bleach (sodium hypochlorite) with acids can release chlorine gas
  • Mixing ethanol with water produces highly unstable peroxides
  • Storing sodium metal with dry organic solvents prevents reactivity
  • Mixing potassium permanganate with water neutralizes all hazards

Correct Answer: Mixing bleach (sodium hypochlorite) with acids can release chlorine gas

Q12. Under the Globally Harmonized System (GHS), how many standardized sections does a Safety Data Sheet (SDS) contain?

  • 8 sections
  • 12 sections
  • 16 sections
  • 24 sections

Correct Answer: 16 sections

Q13. For controlling airborne exposures to volatile pharmaceutical solvents, which ventilation strategy is most effective at the source?

  • General room dilution ventilation only
  • Local exhaust ventilation (e.g., fume hood or capture hood)
  • Relying solely on administrative limits
  • Personal handheld fans for workers

Correct Answer: Local exhaust ventilation (e.g., fume hood or capture hood)

Q14. Which glove material is generally recommended for handling concentrated strong acids in a lab?

  • Cotton gloves
  • Neoprene or butyl rubber chemical-resistant gloves
  • Latex surgical gloves only
  • Leather gloves

Correct Answer: Neoprene or butyl rubber chemical-resistant gloves

Q15. How do flash point and autoignition temperature differ for flammable chemicals?

  • Flash point is higher than autoignition temperature for all chemicals
  • Flash point is the lowest temperature that gives off ignitable vapors with an external ignition source; autoignition is the temperature at which a substance ignites without an external source
  • They are interchangeable terms
  • Autoignition refers only to liquids while flash point refers only to solids

Correct Answer: Flash point is the lowest temperature that gives off ignitable vapors with an external ignition source; autoignition is the temperature at which a substance ignites without an external source

Q16. Which statement correctly distinguishes OSHA PELs and ACGIH TLVs?

  • OSHA PELs are legally enforceable exposure limits; ACGIH TLVs are recommended guideline values based on health data
  • Both OSHA PELs and ACGIH TLVs are legally enforceable worldwide
  • ACGIH TLVs are limits for noise exposure only
  • OSHA PELs represent environmental emission limits, not worker exposure

Correct Answer: OSHA PELs are legally enforceable exposure limits; ACGIH TLVs are recommended guideline values based on health data

Q17. Which scenario best exemplifies a reactive chemical hazard due to spontaneous decomposition or secondary hazardous formation?

  • Formation of peroxides in ethers upon prolonged exposure to air and light
  • Boiling water to remove impurities
  • Dilution of acids with water following correct procedure
  • Storage of table salt at room temperature

Correct Answer: Formation of peroxides in ethers upon prolonged exposure to air and light

Q18. Which chemical property most directly promotes environmental bioaccumulation in aquatic organisms?

  • High water solubility and rapid biodegradability
  • High lipid solubility (high octanol–water partition coefficient, Kow) and persistence
  • High vapor pressure and low molecular weight
  • Strong color and odor

Correct Answer: High lipid solubility (high octanol–water partition coefficient, Kow) and persistence

Q19. In inhalation toxicology reporting, an LC50 value is typically expressed as which type of unit?

  • Mass dose per body weight (mg/kg)
  • Concentration in air, for example ppm or mg/m3 over a specified exposure duration
  • Percentage of total body water
  • Electrical conductivity

Correct Answer: Concentration in air, for example ppm or mg/m3 over a specified exposure duration

Q20. What is the immediate first aid action following a chemical splash to the skin in a laboratory?

  • Wait for symptoms to develop before acting
  • Remove contaminated clothing and flush the affected skin with copious water for at least 15 minutes, then seek medical attention
  • Neutralize with a strong acid regardless of the chemical
  • Cover the area with a plastic sheet and continue work

Correct Answer: Remove contaminated clothing and flush the affected skin with copious water for at least 15 minutes, then seek medical attention

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