CSMLS Laboratory Quality Assurance & Safety Protocols — Questions and Answers
Question 1: What is the purpose of running quality control (QC) samples in a medical laboratory?
- To verify that analytical instruments and reagents are producing accurate and reliable results (Correct answer)
- To test new equipment before purchase
- To train new laboratory technologists on procedures
- To reduce the cost of reagent consumption
Correct answer: To verify that analytical instruments and reagents are producing accurate and reliable results
Quality control samples with known values are analyzed alongside patient specimens to detect errors in the analytical process, ensuring that patient results are accurate and clinically reliable.
Question 2: According to WHMIS 2015, what does a pictogram showing a flame over a circle represent?
- Oxidizing hazard (Correct answer)
- Flammable material
- Explosive material
- Compressed gas
Correct answer: Oxidizing hazard
The flame over circle pictogram indicates an oxidizing substance that can intensify fire or cause combustion by providing oxygen, a critical hazard in laboratories storing multiple chemical types.
Question 3: What Westgard rule violation occurs when a single QC result falls outside 3 standard deviations from the mean?
- 1-3s rule violation (Correct answer)
- 2-2s rule violation
- R-4s rule violation
- 4-1s rule violation
Correct answer: 1-3s rule violation
The 1-3s rule flags when one control observation exceeds ±3 standard deviations, indicating a random error. This is typically considered an immediate rejection criterion requiring investigation.
Question 4: What is the correct order for removing personal protective equipment (PPE) after working with potentially infectious specimens?
- Gloves, gown, eye protection, mask (Correct answer)
- Mask, eye protection, gown, gloves
- Gown, mask, gloves, eye protection
- Eye protection, gloves, mask, gown
Correct answer: Gloves, gown, eye protection, mask
Gloves are removed first because they are the most contaminated item. The gown follows, then eye protection and mask, minimizing the risk of self-contamination during removal.
Question 5: What is the primary purpose of proficiency testing (PT) in a clinical laboratory?
- To assess laboratory performance by comparing results with other laboratories analyzing the same samples (Correct answer)
- To train new staff on instrument operation
- To calibrate instruments to manufacturer specifications
- To determine how many samples can be processed per hour
Correct answer: To assess laboratory performance by comparing results with other laboratories analyzing the same samples
Proficiency testing involves analyzing unknown samples provided by an external organization and comparing results with peer laboratories, serving as an external check on laboratory accuracy and competency.
Question 6: What class of biological safety cabinet (BSC) is most commonly used for routine work with Risk Group 2 organisms in Canadian laboratories?
- Class II Type A2 (Correct answer)
- Class I
- Class III
- Laminar flow hood
Correct answer: Class II Type A2
Class II Type A2 BSCs provide both personnel and product protection through HEPA-filtered vertical laminar airflow, making them suitable for routine work with moderate-risk biological agents in clinical laboratories.
CSMLS Laboratory Quality Assurance & Safety Protocols
What is the purpose of running quality control (QC) samples in a medical laboratory?