CPR Mold Assessment & Abatement 3 — Questions and Answers
Question 1: A restorer discovers mold in an HVAC system. Per IICRC S520, what is the recommended first step?
- Shut down the HVAC system to prevent spore distribution before beginning work (Correct answer)
- Run the HVAC system at maximum speed to dilute the spore concentration
- Spray antifungal solution into the return air plenum while the system operates
- Install HEPA filters on the supply registers before any other action
Correct answer: Shut down the HVAC system to prevent spore distribution before beginning work
Shutting down the HVAC system immediately prevents further distribution of mold spores throughout the building via ductwork.
Question 2: Which type of respirator provides the minimum acceptable protection for workers in a small mold remediation area (10–100 sq ft) per EPA guidelines?
- Half-face respirator with N-95 or better particulate filter (Correct answer)
- Surgical mask rated for biological agents
- Full-face supplied-air respirator (SCBA)
- Paper dust mask rated N-80
Correct answer: Half-face respirator with N-95 or better particulate filter
EPA guidance recommends at minimum an N-95 half-face respirator for small mold remediation areas of 10–100 square feet.
Question 3: Post-remediation verification (PRV) sampling should be conducted under what conditions?
- After containment is in place and the work area is visually clean but before containment is removed (Correct answer)
- Before any remediation work begins to establish a baseline
- Immediately after applying biocide while surfaces are still wet
- Only if the client requests it in writing
Correct answer: After containment is in place and the work area is visually clean but before containment is removed
PRV sampling is most valid when performed after visible cleanup, while containment remains in place to reflect work area conditions.
Question 4: What is 'hyphae' in the context of mold biology?
- The thread-like filaments that make up the body (mycelium) of a mold (Correct answer)
- Airborne reproductive particles shed by mature mold colonies
- The spore-producing structures on the mold surface
- Chemical signals mold uses to communicate between colonies
Correct answer: The thread-like filaments that make up the body (mycelium) of a mold
Hyphae are the microscopic filaments that form the vegetative body of a mold organism, collectively called mycelium.
Question 5: Which moisture reading on a pin-type meter in drywall paper typically indicates active mold growth risk?
- Above 16–17% moisture content (Correct answer)
- Above 5% moisture content
- Any reading above 0%
- Above 30% moisture content only
Correct answer: Above 16–17% moisture content
Most mold species can begin to colonize porous building materials once moisture content exceeds approximately 16–17%.
Question 6: What is the purpose of a 'clearance test' at the conclusion of mold remediation?
- To confirm that mold levels in the work area have returned to normal background conditions (Correct answer)
- To certify that all biocide products used are safe for re-occupancy
- To document that the contractor met the contract scope of work
- To satisfy insurance requirements for claim payment
Correct answer: To confirm that mold levels in the work area have returned to normal background conditions
A clearance test verifies that remediated areas have mold levels comparable to or better than unaffected reference areas.
Question 7: A technician finds mold on the back side of drywall that was not visible from the room side. What does this scenario indicate?
- Moisture infiltration likely came from behind the wall cavity, not the room side (Correct answer)
- The mold was painted over by a previous contractor
- Surface mold migrated through the drywall by capillary action
- The sampling strategy was flawed and must be restarted
Correct answer: Moisture infiltration likely came from behind the wall cavity, not the room side
Mold on the back of drywall typically indicates moisture intrusion from within the wall cavity, such as a pipe leak or exterior water penetration.
CPR Mold Assessment & Abatement 3
A restorer discovers mold in an HVAC system.
Per IICRC S520, what is the recommended first step?