CMLA REE CMLA Laboratory Safety & Procedures 4 — Questions and Answers
Question 1: In the laboratory chain of custody for forensic or legal specimens, which step is most critical?
- Rapid processing to avoid degradation
- Continuous documentation of specimen handling from collection to reporting (Correct answer)
- Storing specimens at room temperature
- Processing specimens in batches to save time
Correct answer: Continuous documentation of specimen handling from collection to reporting
Chain of custody requires unbroken documentation of every person who handles a specimen to maintain its integrity for legal purposes.
Question 2: Which personal protective equipment (PPE) is required when handling specimens with potential aerosol generation?
- Gloves only
- Gloves and lab coat
- Gloves, lab coat, and face shield or splash goggles (Correct answer)
- No PPE required if working in a hood
Correct answer: Gloves, lab coat, and face shield or splash goggles
Aerosol-generating procedures require gloves, lab coat, and face/eye protection to prevent mucous membrane exposure.
Question 3: Which is the correct order of donning (putting on) PPE before entering a patient isolation room?
- Gloves → Gown → Mask → Goggles
- Gown → Mask/Respirator → Goggles → Gloves (Correct answer)
- Mask → Gloves → Gown → Goggles
- Goggles → Gloves → Gown → Mask
Correct answer: Gown → Mask/Respirator → Goggles → Gloves
CDC recommends donning in the order: gown, mask/respirator, goggles/face shield, then gloves last to avoid contaminating other PPE.
Question 4: According to OSHA, which document must be readily accessible to laboratory employees for every hazardous chemical in the workplace?
- Procedure manual
- Safety Data Sheet (SDS) (Correct answer)
- Manufacturer's invoice
- Laboratory director's approval form
Correct answer: Safety Data Sheet (SDS)
OSHA's Hazard Communication Standard (29 CFR 1910.1200) requires Safety Data Sheets to be immediately accessible to employees for every hazardous chemical.
Question 5: A newly received chemical reagent should be labeled with:
- Only the manufacturer's original label
- Expiration date and date received (Correct answer)
- The supervisor's initials only
- Nothing additional if the original label is present
Correct answer: Expiration date and date received
Laboratories must add the date received and expiration date to chemical containers to track shelf life and ensure reagent validity.
Question 6: What is the function of a fume hood's sash?
- Increases airflow velocity into the hood
- Acts as a physical barrier protecting the user from splashes and fumes (Correct answer)
- Filters chemical vapors before they enter the room
- Maintains humidity inside the hood
Correct answer: Acts as a physical barrier protecting the user from splashes and fumes
The sash serves as a physical barrier between the worker and chemical hazards, containing splashes and providing a shield during reactions.
Question 7: In the event of a needlestick injury involving a potentially HIV-positive source, post-exposure prophylaxis (PEP) should ideally be started within:
- 72 hours (Correct answer)
- 1 week
- 24 hours
- 2 hours
Correct answer: 72 hours
PEP is most effective when initiated within 72 hours of exposure, though starting within 2 hours is ideal when feasible.
CMLA REE CMLA Laboratory Safety & Procedures 4
In the laboratory chain of custody for forensic or legal specimens, which step is most critical?