MLPAO - Medical Laboratory Professionals Association of Ontario Laboratory Safety and Quality Questions and Answers 2 — Questions and Answers

Question 1: According to CMLTO standards, which class of fire extinguisher is appropriate for electrical equipment fires in a medical laboratory?

Class A
Class B
Class C (Correct answer)
Class D

Correct answer: Class C

Class C extinguishers are designed for electrical fires and use non-conductive agents, making them safe for use on energized electrical equipment found in laboratories.

Class C fire extinguishers contain non-conductive extinguishing agents such as carbon dioxide or dry chemical, making them appropriate for fires involving electrical equipment. Using water (Class A) or foam on an electrical fire would create an electrocution hazard. Class B is for flammable liquids and Class D is for combustible metals. In Ontario medical laboratories, correct fire extinguisher selection is a critical safety competency tested on the CMLTO registration examination.

Question 2: A medical laboratory technologist receives a specimen with a label discrepancy. What is the most appropriate first action?

Process the specimen and note the discrepancy in the report
Discard the specimen immediately
Contact the requesting clinician or unit to clarify and relabel (Correct answer)
Run the test and hold results pending label correction

Correct answer: Contact the requesting clinician or unit to clarify and relabel

Specimen label discrepancies must be resolved before processing. Contacting the source for clarification and proper relabeling ensures patient safety and result integrity.

CMLTO standards and accreditation requirements mandate that specimen identification discrepancies be resolved prior to analysis. Processing an improperly labelled specimen risks misidentification of results, which can cause patient harm. The appropriate action is to contact the requesting unit, confirm patient identity, and obtain a properly labelled specimen or relabel per laboratory policy. Simply noting the discrepancy or holding results without resolution is not acceptable practice under Ontario quality standards.

Question 3: What is the purpose of a biological safety cabinet (BSC) Class II Type A2 in a medical laboratory?

Protection of personnel only from aerosols
Protection of the product and environment only
Protection of personnel, product, and environment from biohazardous aerosols (Correct answer)
Containment of radioactive materials

Correct answer: Protection of personnel, product, and environment from biohazardous aerosols

A Class II Type A2 BSC provides triple protection: personnel protection, product protection, and environmental protection by recirculating and exhausting HEPA-filtered air.

Class II Type A2 biological safety cabinets use a combination of HEPA filtration and laminar airflow to protect laboratory workers from aerosol exposure, protect the specimen or culture from contamination, and protect the laboratory environment by exhausting filtered air. They are used for Biosafety Level 2 work with infectious agents in Ontario medical laboratories. Class I cabinets protect personnel and environment but not the product. Class III cabinets are for BSL-4 work. Proper BSC use and certification is a laboratory safety requirement under Ontario regulations.

Question 4: In a proficiency testing program, a laboratory's result falls outside the acceptable performance criteria. According to quality management principles, what is the required response?

Report the discrepancy to the Ministry of Health only
Investigate root cause, implement corrective action, and document findings (Correct answer)
Repeat the proficiency test until acceptable results are achieved
Suspend testing for that analyte until the next PT cycle

Correct answer: Investigate root cause, implement corrective action, and document findings

Unacceptable proficiency testing results require formal root cause analysis, corrective action, and documentation as part of a quality management system.

When a laboratory receives unacceptable proficiency testing (PT) results, quality management principles require a systematic response: identify the root cause of the failure (equipment malfunction, reagent issue, procedural error, etc.), implement appropriate corrective action, document the investigation and actions taken, and monitor for effectiveness. This process is required by accreditation bodies such as IQMH in Ontario. Simply repeating the PT sample is not acceptable as it does not address the underlying problem that may affect patient results.

Question 5: Which of the following is an example of a pre-analytical error in laboratory quality?

Incorrect calibration of the analyzer
Hemolysis due to improper venipuncture technique (Correct answer)
Transcription error in result reporting
Failure of quality control to detect reagent deterioration

Correct answer: Hemolysis due to improper venipuncture technique

Pre-analytical errors occur before specimen analysis, including specimen collection issues such as hemolysis from poor venipuncture technique.

Laboratory errors are categorized as pre-analytical (before testing), analytical (during testing), and post-analytical (after testing). Pre-analytical errors are the most common category and include issues with test ordering, patient preparation, specimen collection (hemolysis, wrong tube), labelling, transport, and storage. Hemolysis from improper venipuncture technique is a pre-analytical error that can interfere with many analytes including potassium, LDH, and AST. Incorrect calibration is an analytical error, transcription errors are post-analytical, and QC failure is an analytical quality issue.

Question 6: Under WHMIS 2015 (GHS), what does a pictogram showing a flame over a circle represent?

Flammable material
Oxidizing material (Correct answer)
Explosive material
Corrosive material

Correct answer: Oxidizing material

The WHMIS 2015 flame over circle pictogram indicates oxidizing materials that can intensify fires or cause combustion of other materials.

Under WHMIS 2015, which aligns with the Globally Harmonized System (GHS), the flame over circle pictogram identifies oxidizing gases, liquids, and solids. Oxidizers can react with other materials to cause or intensify fire or explosion. In medical laboratories, oxidizing agents such as hydrogen peroxide, potassium permanganate, and sodium hypochlorite carry this symbol. A plain flame symbol (without circle) indicates flammable materials. Ontario laboratory workers must be trained to recognize all WHMIS 2015 pictograms as part of workplace hazardous materials training.

MLPAO - Medical Laboratory Professionals Association of Ontario Laboratory Safety and Quality Questions and Answers 2

According to CMLTO standards, which class of fire extinguisher is appropriate for electrical equipment fires in a medical laboratory?