MLS Safety & Infection Control 2 — Questions and Answers
Question 1: A medical laboratory scientist receives a specimen with a broken tube and blood on the outside of the transport bag. What is the FIRST action to take?
- Process the specimen immediately to avoid degradation
- Don gloves and other appropriate PPE before handling (Correct answer)
- Discard the specimen and request a redraw
- Notify the supervisor before touching anything
Correct answer: Don gloves and other appropriate PPE before handling
PPE must be donned before handling any potentially contaminated specimen to protect against bloodborne pathogen exposure.
Question 2: Which OSHA standard specifically governs occupational exposure to bloodborne pathogens in the clinical laboratory?
- 29 CFR 1910.1200
- 29 CFR 1910.1030 (Correct answer)
- 29 CFR 1910.1450
- 29 CFR 1910.132
Correct answer: 29 CFR 1910.1030
29 CFR 1910.1030 is OSHA's Bloodborne Pathogens Standard, which requires exposure control plans and PPE for laboratory workers.
Question 3: When using a biosafety cabinet (BSC), a laboratory scientist should avoid placing materials near the front grille because:
- It blocks the UV light used for decontamination
- It disrupts the inward airflow that protects the worker (Correct answer)
- It damages the HEPA filter located beneath the grille
- It creates an aerosol that contaminates reagents
Correct answer: It disrupts the inward airflow that protects the worker
The front grille maintains the inward airflow barrier that prevents aerosols from escaping the cabinet and protects the operator.
Question 4: A laboratory worker sustains a needlestick injury from a patient known to be HIV-positive. Which action should be taken FIRST?
- Report immediately to employee health
- Begin post-exposure prophylaxis within 2 hours
- Wash the wound thoroughly with soap and water (Correct answer)
- Draw blood from the source patient for baseline testing
Correct answer: Wash the wound thoroughly with soap and water
Immediate wound washing with soap and water is the first step to reduce the inoculum before any reporting or treatment.
Question 5: 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 use non-conductive agents and are rated for energized electrical equipment fires.
Question 6: Under Standard Precautions, which of the following body fluids requires the SAME level of precaution as blood?
- Sweat
- Tears
- Cerebrospinal fluid (Correct answer)
- Nasal secretions
Correct answer: Cerebrospinal fluid
Cerebrospinal fluid is listed under Standard Precautions as a body fluid posing infectious risk similar to blood.
Question 7: Which chemical hazard label system is used in US laboratories to communicate hazard information on secondary containers?
- UN GHS pictograms only
- NFPA 704 diamond only
- OSHA HazCom GHS-aligned Safety Data Sheets and labels (Correct answer)
- ISO 7010 safety signs
Correct answer: OSHA HazCom GHS-aligned Safety Data Sheets and labels
OSHA's Hazard Communication Standard (HazCom 2012) aligned with GHS requires standardized labels and SDSs for hazardous chemicals in US workplaces.
MLS Safety & Infection Control 2
A medical laboratory scientist receives a specimen with a broken tube and blood on the outside of the transport bag.
What is the FIRST action to take?