CMA Mold Remediation & Safety Standards 2 — Questions and Answers
Question 1: According to the EPA and IICRC S520 standard, what is the minimum recommended air pressure differential that must be maintained in a mold remediation containment zone relative to adjacent areas?
- -0.02 inches water column (negative pressure) (Correct answer)
- +0.02 inches water column (positive pressure)
- Zero differential (neutral pressure)
- -0.10 inches water column (strong negative pressure)
Correct answer: -0.02 inches water column (negative pressure)
Negative pressure of at least -0.02 inches water column prevents contaminated air from migrating out of the containment area.
Question 2: Which respirator class is the minimum level of protection required when disturbing mold-contaminated materials during a large remediation project (>100 sq ft) per OSHA guidelines?
- N95 filtering facepiece respirator
- Half-face air-purifying respirator with P100 filters (Correct answer)
- Powered air-purifying respirator (PAPR)
- Full-face supplied-air respirator
Correct answer: Half-face air-purifying respirator with P100 filters
OSHA and IICRC S520 recommend a minimum of a half-face air-purifying respirator with P100 particulate filters for large mold remediation projects.
Question 3: A post-remediation verification (PRV) air sample result shows 350 spores/m³ of Aspergillus/Penicillium in the remediated room and 400 spores/m³ outdoors. How should this result be interpreted?
- Remediation failed because indoor counts exceed 200 spores/m³
- Remediation passed because indoor levels are lower than or comparable to outdoor levels (Correct answer)
- Remediation failed because Aspergillus/Penicillium should be zero indoors
- Result is inconclusive and a second air sample must be taken
Correct answer: Remediation passed because indoor levels are lower than or comparable to outdoor levels
Post-remediation success is judged by comparing indoor spore counts to outdoor baseline levels; indoor counts equal to or lower than outdoor counts indicate successful remediation.
Question 4: During remediation, workers discover asbestos-containing ceiling tiles mixed with mold-contaminated materials. What is the FIRST correct action?
- Continue mold remediation using enhanced PPE for both hazards simultaneously
- Stop work, secure the area, and notify a licensed asbestos abatement contractor (Correct answer)
- Remove visible mold from tiles using wet wiping and HEPA vacuum, then dispose as mold waste
- Apply encapsulant over tiles to seal both mold and asbestos before removal
Correct answer: Stop work, secure the area, and notify a licensed asbestos abatement contractor
When asbestos is discovered, work must stop immediately and a licensed asbestos abatement professional must handle removal before mold remediation resumes.
Question 5: Which disposal method is required for mold-contaminated porous building materials removed during remediation per most state and EPA guidelines?
- Double-bagged in 6-mil polyethylene bags sealed before transport through clean areas (Correct answer)
- Labeled hazardous waste drums transported by a licensed hazardous material carrier
- Standard construction dumpster without special bagging requirements
- Incinerated on-site to eliminate spore contamination
Correct answer: Double-bagged in 6-mil polyethylene bags sealed before transport through clean areas
Mold-contaminated materials must be double-bagged in 6-mil poly bags and sealed before being transported through clean areas to prevent cross-contamination.
Question 6: What is the primary purpose of a critical barrier in a mold remediation containment setup?
- To support the weight of negative air machines attached to poly sheeting
- To completely seal HVAC registers and return air ducts within the containment zone
- To isolate the work area from unaffected building spaces and prevent cross-contamination (Correct answer)
- To provide a decontamination chamber for workers exiting the remediation zone
Correct answer: To isolate the work area from unaffected building spaces and prevent cross-contamination
A critical barrier physically separates the contaminated work area from clean building spaces, preventing the spread of mold spores during remediation activities.
Question 7: A remediation contractor proposes applying a biocide to mold-contaminated drywall as the sole remediation method without physical removal. Which statement best describes this approach?
- This is acceptable because EPA-registered biocides kill mold and render the drywall safe
- This is insufficient because dead mold spores still pose an allergen risk and physical removal is required (Correct answer)
- This meets IICRC S520 standards if the biocide is applied twice with a 24-hour drying period
- This is appropriate only for Category 1 water damage with surface mold below 10 sq ft
Correct answer: This is insufficient because dead mold spores still pose an allergen risk and physical removal is required
Dead mold spores retain allergenic and potentially toxic properties, so physical removal of contaminated porous materials is required, not just biocide application.
CMA Mold Remediation & Safety Standards 2
According to the EPA and IICRC S520 standard, what is the minimum recommended air pressure differential that must be maintained in a mold remediation containment zone relative to adjacent areas?