CMLA REE CMLA Laboratory Safety & Procedures 5 — Questions and Answers
Question 1: Which of the following best describes the purpose of using 70% isopropyl alcohol rather than 100% for surface disinfection?
- 100% is too expensive for routine use
- The water in 70% solutions allows longer contact time and better protein denaturation (Correct answer)
- 70% is less toxic to laboratory workers
- 100% alcohol leaves a residue that contaminates specimens
Correct answer: The water in 70% solutions allows longer contact time and better protein denaturation
The water component in 70% isopropyl alcohol slows evaporation and enhances protein coagulation in microbial cells, making it more effective as a disinfectant.
Question 2: A laboratory receives a specimen with a cracked tube and no secondary containment. The FIRST step is to:
- Process the specimen immediately to avoid further delay
- Don appropriate PPE before handling the package (Correct answer)
- Discard the specimen and order a recollect without notification
- Contact the physician for verbal results
Correct answer: Don appropriate PPE before handling the package
PPE must be donned before handling any potentially contaminated or damaged specimen to protect the worker from exposure.
Question 3: Which type of laboratory waste requires incineration or autoclaving before disposal?
- Empty reagent bottles
- Biohazardous cultures and stocks of infectious agents (Correct answer)
- Expired non-hazardous reagents
- Used paper towels with non-infectious material
Correct answer: Biohazardous cultures and stocks of infectious agents
Cultures and stocks of infectious agents must be decontaminated by autoclaving or incineration prior to disposal per federal and state regulations.
Question 4: What does 'universal precautions' require laboratory personnel to assume about all patient specimens?
- Only specimens labeled 'infectious' require precautions
- All blood and body fluid specimens are potentially infectious regardless of diagnosis (Correct answer)
- Precautions apply only to HIV and hepatitis B samples
- Precautions are optional for vaccinated employees
Correct answer: All blood and body fluid specimens are potentially infectious regardless of diagnosis
Universal precautions mandate treating all human blood and certain body fluids as potentially infectious, eliminating reliance on patient diagnosis for risk assessment.
Question 5: Which action should be taken when a laboratory worker's lab coat becomes heavily contaminated with blood?
- Continue working until the end of the shift to avoid waste
- Remove the coat immediately and place it in a biohazard laundry bag (Correct answer)
- Rinse the coat in the sink and return it to a locker
- Spray with 70% alcohol and continue wearing it
Correct answer: Remove the coat immediately and place it in a biohazard laundry bag
Heavily contaminated PPE must be removed immediately and handled as biohazardous laundry to prevent exposure and cross-contamination.
Question 6: In laboratory quality control, a Levey-Jennings chart is used to:
- Track inventory of reagents over time
- Monitor analytical precision and detect instrument drift visually (Correct answer)
- Schedule preventive maintenance of equipment
- Document employee training completion
Correct answer: Monitor analytical precision and detect instrument drift visually
Levey-Jennings charts plot QC results over time against control limits, allowing visual detection of trends, shifts, and random error.
Question 7: Which regulation governs laboratory-developed tests and quality standards for clinical laboratories in the United States?
- HIPAA
- CLIA (Clinical Laboratory Improvement Amendments) (Correct answer)
- OSHA Bloodborne Pathogens Standard
- FDA 510(k) clearance
Correct answer: CLIA (Clinical Laboratory Improvement Amendments)
CLIA establishes quality standards for all laboratory testing performed on human specimens, covering personnel, QC, proficiency testing, and inspections.
CMLA REE CMLA Laboratory Safety & Procedures 5
Which of the following best describes the purpose of using 70% isopropyl alcohol rather than 100% for surface disinfection?