CPR Microbial Remediation Protocols 3 — Questions and Answers
Question 1: During microbial remediation, what is the purpose of maintaining negative air pressure inside the containment zone?
- To speed up the drying of wet materials
- To prevent contaminated air from escaping into clean areas (Correct answer)
- To increase the effectiveness of HEPA filtration
- To reduce humidity levels inside the work area
Correct answer: To prevent contaminated air from escaping into clean areas
Negative pressure ensures that airflow moves inward through containment barriers, preventing mold spores and contaminated air from migrating to unaffected spaces.
Question 2: What is the recommended dwell time for most EPA-registered biocides applied to mold-contaminated non-porous surfaces?
- 30 seconds
- 1–2 minutes
- 10–15 minutes (Correct answer)
- 30–60 minutes
Correct answer: 10–15 minutes
Most EPA-registered disinfectants require a dwell time of 10–15 minutes to achieve the stated log-reduction of microbial populations on hard, non-porous surfaces.
Question 3: A restorer encounters a 150 sq ft area of mold growth in a commercial building. According to IICRC S520, what remediation level does this most likely require?
- Level 1 – Small isolated area
- Level 2 – Mid-sized isolated area
- Level 3 – Full containment remediation (Correct answer)
- Level 4 – Extensive remediation
Correct answer: Level 3 – Full containment remediation
IICRC S520 Level 3 applies to mold contamination between 100 and 1,000 square feet, requiring full containment and negative air pressure.
Question 4: Which of the following correctly describes the role of an Industrial Hygienist (IH) in a large-scale mold remediation project?
- To apply biocides and clean contaminated surfaces
- To develop the remediation work plan and conduct clearance testing (Correct answer)
- To operate the negative air machines during remediation
- To dispose of contaminated materials at an approved facility
Correct answer: To develop the remediation work plan and conduct clearance testing
An IH develops the scope of work, oversees sampling protocols, and conducts independent post-remediation clearance testing to verify successful remediation.
Question 5: Mycotoxins associated with certain mold species are concerning because they:
- Are easily destroyed by standard HEPA filtration
- Can remain hazardous on materials even after mold cells are dead (Correct answer)
- Only affect individuals with pre-existing respiratory conditions
- Are only produced outdoors in agricultural environments
Correct answer: Can remain hazardous on materials even after mold cells are dead
Mycotoxins are secondary metabolites that can persist on building materials after mold is killed, continuing to pose health risks even after remediation of live mold.
Question 6: When disposing of mold-contaminated porous materials, what is the IICRC-recommended method for bagging debris inside containment?
- Single-layer 3-mil polyethylene bags sealed with duct tape
- Double-layer 6-mil polyethylene bags, misted before sealing (Correct answer)
- Single-layer 6-mil bags transported immediately to a dumpster
- Cardboard boxes sealed with biohazard tape
Correct answer: Double-layer 6-mil polyethylene bags, misted before sealing
Double-bagging in 6-mil polyethylene bags with misting to suppress airborne spores before sealing minimizes cross-contamination during transport out of the containment.
Question 7: A post-remediation air sample shows elevated Aspergillus/Penicillium counts indoors compared to the outdoor reference. What should the restorer do?
- Declare remediation complete since counts are below 1,000 spores/m³
- Resume remediation activities to address the remaining contamination source (Correct answer)
- Apply a second coat of encapsulant to all treated surfaces
- Notify the EPA and request a regulatory inspection
Correct answer: Resume remediation activities to address the remaining contamination source
Elevated indoor counts relative to outdoor baseline indicate incomplete remediation; the restorer must re-evaluate and continue removal or cleaning procedures.
CPR Microbial Remediation Protocols 3
During microbial remediation, what is the purpose of maintaining negative air pressure inside the containment zone?