CMLA REE CMLA Laboratory Safety & Procedures 3 — Questions and Answers
Question 1: Which action is NOT acceptable when working in a laboratory with open flames?
- Tying back long hair
- Removing flammable solvents from the area
- Wearing loose-fitting synthetic clothing (Correct answer)
- Using a flame-resistant lab coat
Correct answer: Wearing loose-fitting synthetic clothing
Loose-fitting synthetic fabrics ignite easily and melt onto the skin, creating severe burn injuries near open flames.
Question 2: An eyewash station must be activated and flushed for how long during an eye chemical exposure?
- 1–2 minutes
- 5 minutes
- 10 minutes
- 15–20 minutes (Correct answer)
Correct answer: 15–20 minutes
ANSI Z358.1 requires continuous flushing of the eyes for a minimum of 15 minutes to adequately remove chemical contaminants.
Question 3: What is the purpose of a biological safety cabinet (BSC) Class II Type A2?
- Protects only the product from contamination
- Protects personnel, product, and the environment (Correct answer)
- Provides chemical fume protection only
- Protects personnel only, not the environment
Correct answer: Protects personnel, product, and the environment
Class II Type A2 BSCs provide triple protection — personnel, product, and environment — through HEPA-filtered inflow and exhaust.
Question 4: Which waste stream is used for blood-soaked materials and cultures of infectious agents?
- Regular municipal waste
- Recycling bin
- Regulated medical/biohazardous waste (red bag) (Correct answer)
- Chemical waste container
Correct answer: Regulated medical/biohazardous waste (red bag)
Blood-soaked materials and infectious cultures are regulated medical waste and must be placed in red biohazard bags for proper disposal.
Question 5: OSHA's Bloodborne Pathogen Standard requires that employers offer hepatitis B vaccination to at-risk employees:
- Within 10 working days of initial assignment (Correct answer)
- Within 30 days of hire
- After the first needlestick incident
- Only if requested by the employee after 6 months
Correct answer: Within 10 working days of initial assignment
OSHA 29 CFR 1910.1030 mandates that Hep B vaccination be offered within 10 working days of initial assignment to at-risk employees.
Question 6: When pipetting corrosive or infectious liquids, laboratory personnel must use:
- Mouth pipetting for precision
- Mechanical pipetting devices only (Correct answer)
- Any available pipette without restrictions
- Pipettes rinsed with distilled water only
Correct answer: Mechanical pipetting devices only
Mouth pipetting is absolutely prohibited; mechanical pipetting devices (bulbs, electronic pipettors) must always be used to prevent ingestion or inhalation.
Question 7: A laboratory worker notices a gas odor near a Bunsen burner. The FIRST action should be to:
- Light the burner to burn off the gas
- Turn off the gas supply and ventilate the area (Correct answer)
- Continue working while investigating the source
- Pour water on the burner area
Correct answer: Turn off the gas supply and ventilate the area
Immediately shutting off the gas supply and ventilating prevents accumulation of flammable gas and eliminates ignition risk.
CMLA REE CMLA Laboratory Safety & Procedures 3
Which action is NOT acceptable when working in a laboratory with open flames?