MRS HEPA Filtration & Air Scrubbing 2 — Questions and Answers
Question 1: What does the acronym HEPA stand for?
- High Efficiency Particulate Air (Correct answer)
- High Energy Purification Apparatus
- Heavy Element Particle Absorber
- Hazardous Environmental Protection Array
Correct answer: High Efficiency Particulate Air
HEPA stands for High Efficiency Particulate Air, a filtration standard defined by the US Department of Energy.
Question 2: When operating a negative air machine in a mold remediation containment, where should the exhaust be directed?
- Recirculated back into the containment area
- Into an adjacent occupied room
- Outside the building or to an unaffected area (Correct answer)
- Through the HVAC return duct
Correct answer: Outside the building or to an unaffected area
Exhaust from negative air machines must be directed outside the building or to an uncontaminated area to prevent cross-contamination.
Question 3: How many air changes per hour (ACH) is the minimum recommended for a mold remediation containment zone?
- 2–4 ACH
- 4–6 ACH
- 6–12 ACH (Correct answer)
- 15–20 ACH
Correct answer: 6–12 ACH
Industry guidelines recommend a minimum of 6–12 air changes per hour in remediation containment zones to maintain adequate negative pressure and particle control.
Question 4: A HEPA air scrubber pre-filter is primarily designed to:
- Remove odors and VOCs from the air
- Capture large particles to extend HEPA filter life (Correct answer)
- Generate negative pressure in the containment
- Eliminate bacteria and viruses
Correct answer: Capture large particles to extend HEPA filter life
Pre-filters capture larger dust and debris particles before they reach the HEPA filter, prolonging its service life and maintaining efficiency.
Question 5: Which of the following best describes 'negative pressure' in a mold remediation containment?
- Air pressure inside the containment is higher than outside
- Air pressure inside the containment is lower than outside (Correct answer)
- Air pressure is equal on both sides of the barrier
- Pressure fluctuates based on temperature differences
Correct answer: Air pressure inside the containment is lower than outside
Negative pressure means air pressure inside the containment is lower than the surrounding area, causing air to flow inward and preventing mold spores from escaping.
Question 6: Which filter stage in a multi-stage air scrubber is responsible for removing gaseous contaminants and odors?
- HEPA filter
- Pre-filter
- Activated carbon filter (Correct answer)
- Electrostatic precipitator
Correct answer: Activated carbon filter
Activated carbon filters use adsorption to capture gaseous contaminants, VOCs, and odors that HEPA filters cannot trap.
Question 7: What is the minimum negative pressure differential typically maintained in a mold remediation containment relative to adjacent areas?
- -0.001 inches water column (WC)
- -0.02 inches water column (WC) (Correct answer)
- -0.5 inches water column (WC)
- -1.0 inches water column (WC)
Correct answer: -0.02 inches water column (WC)
A minimum differential of -0.02 inches water column (approximately -5 Pa) is the standard recommended by IICRC S520 to ensure proper containment integrity.
MRS HEPA Filtration & Air Scrubbing 2
What does the acronym HEPA stand for?