CMLA REE CMLA Laboratory Safety & Procedures 2 — Questions and Answers
Question 1: Which class of fire extinguisher is appropriate for electrical equipment fires in the laboratory?
- Class A
- Class B
- Class C (Correct answer)
- Class D
Correct answer: Class C
Class C extinguishers are designed for electrical fires and use non-conductive agents that won't cause electrocution.
Question 2: A sharps container should be sealed and disposed of when it is:
- Completely full
- Three-quarters full (Correct answer)
- Half full
- After each shift regardless of fill level
Correct answer: Three-quarters full
Sharps containers should be sealed and replaced when they reach three-quarters full to prevent overfilling and needlestick injuries.
Question 3: What does the NFPA 704 diamond's blue quadrant indicate?
- Flammability hazard
- Reactivity hazard
- Health hazard (Correct answer)
- Special hazard
Correct answer: Health hazard
The blue (left) quadrant of the NFPA 704 diamond represents the health hazard rating on a scale of 0–4.
Question 4: When centrifuging potentially infectious specimens, which safety measure is mandatory?
- Opening the lid immediately after stopping
- Using safety-capped centrifuge tubes or sealed rotors (Correct answer)
- Centrifuging at maximum speed to reduce time
- Wearing only gloves with no additional PPE
Correct answer: Using safety-capped centrifuge tubes or sealed rotors
Safety-capped tubes or sealed rotors contain aerosols and prevent release of infectious particles if a tube breaks during centrifugation.
Question 5: A chemical spill of a corrosive acid on the skin should FIRST be treated by:
- Applying a neutralizing base immediately
- Rinsing with large amounts of water for at least 15 minutes (Correct answer)
- Covering with a sterile dressing
- Notifying the supervisor before any treatment
Correct answer: Rinsing with large amounts of water for at least 15 minutes
Immediate and prolonged water rinsing (≥15 minutes) dilutes and removes the acid before it causes further tissue damage.
Question 6: Which biosafety level (BSL) is required when working with agents that pose a moderate hazard and are associated with human disease transmitted by ingestion or mucous membrane contact?
- BSL-1
- BSL-2 (Correct answer)
- BSL-3
- BSL-4
Correct answer: BSL-2
BSL-2 is appropriate for moderately hazardous agents associated with human disease, requiring standard precautions plus face protection and restricted access.
Question 7: Laboratory specimens should be transported within the facility in containers that are:
- Labeled only with the patient name
- Leak-proof with a secondary containment bag (Correct answer)
- Left open for rapid access by receiving personnel
- Wrapped in paper toweling to absorb spills
Correct answer: Leak-proof with a secondary containment bag
Specimens must be in leak-proof primary containers placed inside a secondary containment bag to prevent exposure if the primary container leaks.
CMLA REE CMLA Laboratory Safety & Procedures 2
Which class of fire extinguisher is appropriate for electrical equipment fires in the laboratory?