MLS Safety & Infection Control 3 — Questions and Answers
Question 1: A laboratory finds that multiple staff members are developing respiratory symptoms after working in the same section. The MOST appropriate initial investigation is to:
- Administer antibiotics prophylactically to all exposed staff
- Review the chemical inventory and ventilation in that work area (Correct answer)
- Close the laboratory and fumigate immediately
- Conduct serology testing on all staff members
Correct answer: Review the chemical inventory and ventilation in that work area
Reviewing the chemical inventory and HVAC ventilation is the logical first step to identify a potential chemical or biological environmental source.
Question 2: Which biosafety level (BSL) is required when working with agents that pose a HIGH risk of life-threatening disease transmitted via aerosol for which no vaccine or therapy exists?
- BSL-1
- BSL-2
- BSL-3
- BSL-4 (Correct answer)
Correct answer: BSL-4
BSL-4 facilities handle the most dangerous agents with no available countermeasures, requiring full pressure suits or cabinet lines.
Question 3: What is the correct disposal method for used sharps in the clinical laboratory?
- Place in a puncture-resistant, leak-proof sharps container at the point of use (Correct answer)
- Recap the needle and place in a red biohazard bag
- Place uncapped in a rigid labeled box at the end of the shift
- Bend the needle before placing in a standard trash bin
Correct answer: Place in a puncture-resistant, leak-proof sharps container at the point of use
Sharps must be discarded immediately after use into a puncture-resistant, leak-proof container located at the point of use to prevent needlestick injuries.
Question 4: An autoclave used for steam sterilization should be validated using biological indicators containing spores of:
- Clostridium sporogenes
- Geobacillus stearothermophilus (Correct answer)
- Bacillus atrophaeus
- Staphylococcus aureus
Correct answer: Geobacillus stearothermophilus
Geobacillus stearothermophilus spores are the standard biological indicator for steam (moist heat) sterilization validation due to their high heat resistance.
Question 5: Which personal protective equipment is required when handling concentrated acids in the clinical chemistry laboratory?
- Surgical gloves and lab coat only
- Nitrile gloves, chemical splash goggles, and acid-resistant apron (Correct answer)
- Face shield alone with standard lab coat
- Double latex gloves with standard safety glasses
Correct answer: Nitrile gloves, chemical splash goggles, and acid-resistant apron
Concentrated acids require chemical-resistant nitrile gloves, splash goggles (not standard glasses), and an acid-resistant apron to protect against splashes and vapor.
Question 6: The purpose of the eyewash station in the laboratory is to flush chemicals from the eyes for a minimum of:
- 1 minute
- 5 minutes
- 10 minutes
- 15 minutes (Correct answer)
Correct answer: 15 minutes
ANSI Z358.1 requires a minimum of 15 minutes of continuous flushing of chemical splashes to the eyes to adequately dilute and remove hazardous material.
Question 7: In the laboratory's exposure control plan, which element defines which employees are at risk for occupational exposure to bloodborne pathogens?
- Post-exposure evaluation procedures
- Methods of compliance section
- Exposure determination (Correct answer)
- Hepatitis B vaccination records
Correct answer: Exposure determination
The exposure determination section of the exposure control plan identifies job classifications and tasks where occupational exposure may occur.
MLS Safety & Infection Control 3
A laboratory finds that multiple staff members are developing respiratory symptoms after working in the same section.
The MOST appropriate initial investigation is to: