Laboratory Science Lab Safety and Equipment 2 — Questions and Answers
Question 1: What is the correct technique for pipetting a caustic chemical to prevent accidental ingestion?
- Mouth pipetting
- Mechanical pipette aid or bulb (Correct answer)
- Thumb-capping
- Finger aspiration
Correct answer: Mechanical pipette aid or bulb
Mechanical pipette aids or bulbs must always be used; mouth pipetting is strictly prohibited in any laboratory setting.
Question 2: Which autoclave cycle parameter is standard for sterilizing aqueous solutions?
- 121°C for 15 minutes at 15 psi (Correct answer)
- 100°C for 30 minutes at 1 atm
- 134°C for 3 minutes at 30 psi
- 150°C for 10 minutes at 20 psi
Correct answer: 121°C for 15 minutes at 15 psi
Standard autoclave sterilization uses 121°C (250°F) at 15 psi for 15 minutes to ensure destruction of all microbial life including spores.
Question 3: What does SDS stand for in laboratory chemical safety?
- Standard Dilution Sheet
- Safety Data Sheet (Correct answer)
- Solvent Disposal Summary
- Sterilization Directive Schedule
Correct answer: Safety Data Sheet
A Safety Data Sheet (SDS) provides detailed information about a chemical's properties, hazards, handling, storage, and emergency procedures.
Question 4: When using a centrifuge, what is the most important safety precaution?
- Run at maximum speed always
- Balance opposing tubes with equal mass (Correct answer)
- Keep the lid open during operation
- Never use with biological samples
Correct answer: Balance opposing tubes with equal mass
Balancing opposing tubes with equal mass prevents rotor imbalance, which can cause vibration, mechanical failure, or catastrophic rotor destruction.
Question 5: Which waste container is appropriate for disposing of sharps in a clinical laboratory?
- Regular trash bin
- Red biohazard bag
- Rigid puncture-resistant sharps container (Correct answer)
- Chemical waste drum
Correct answer: Rigid puncture-resistant sharps container
Sharps must be disposed of in rigid, puncture-resistant sharps containers to prevent needlestick injuries during handling and transport.
Question 6: What is the minimum eye wash station flush time recommended by ANSI standards after a chemical eye exposure?
- 1 minute
- 5 minutes
- 15 minutes (Correct answer)
- 30 minutes
Correct answer: 15 minutes
ANSI Z358.1 requires a minimum of 15 minutes of continuous eye flushing to adequately dilute and remove chemical contaminants.
Laboratory Science Lab Safety and Equipment 2
What is the correct technique for pipetting a caustic chemical to prevent accidental ingestion?