MRS Mold Remediation Techniques and Procedures 2 — Questions and Answers
Question 1: When remediating a large mold-contaminated area (>100 sq ft), what type of containment is typically required?
- Passive containment with plastic sheeting only
- Full containment with negative air pressure and airlock entry (Correct answer)
- Source containment with a single layer of poly sheeting
- No containment is necessary for large areas
Correct answer: Full containment with negative air pressure and airlock entry
Large mold remediation projects require full containment with negative air pressure and an airlock entry to prevent cross-contamination to unaffected areas.
Question 2: Which HEPA vacuum filter efficiency is required for mold remediation work?
- 85% efficiency at 0.3 microns
- 95% efficiency at 0.3 microns
- 99.97% efficiency at 0.3 microns (Correct answer)
- 99.5% efficiency at 1.0 microns
Correct answer: 99.97% efficiency at 0.3 microns
HEPA filters used in mold remediation must capture 99.97% of particles at 0.3 microns to effectively capture mold spores.
Question 3: After physically removing mold-contaminated materials, what is the next critical step before applying antimicrobial treatments?
- Immediately seal all surfaces with encapsulant
- Damp wipe and HEPA vacuum all affected surfaces (Correct answer)
- Apply bleach solution and allow to dry
- Install new building materials
Correct answer: Damp wipe and HEPA vacuum all affected surfaces
Damp wiping and HEPA vacuuming removes residual mold spores and debris from surfaces before any antimicrobial treatment is applied.
Question 4: What does a negative air machine do during mold remediation containment?
- Adds moisture to prevent static electricity
- Creates positive pressure to push contaminated air out
- Creates negative pressure to pull air through HEPA filters before exhausting (Correct answer)
- Circulates biocide-treated air throughout the work area
Correct answer: Creates negative pressure to pull air through HEPA filters before exhausting
A negative air machine creates negative pressure inside the containment zone, drawing air through HEPA filters before exhausting it outside, preventing spore migration.
Question 5: When demolishing mold-contaminated drywall, workers should use which cutting technique to minimize spore dispersal?
- Dry cutting with a circular saw at high speed
- Scoring and snapping after misting with water (Correct answer)
- Grinding the surface to remove the paper facing
- Using a heat gun to loosen the drywall compound
Correct answer: Scoring and snapping after misting with water
Scoring and snapping drywall after misting with water minimizes dust and aerosolized spore dispersal compared to power cutting.
Question 6: What is the correct method for disposing of mold-contaminated materials removed during remediation?
- Place in open dumpsters for standard waste removal
- Double-bag in 6-mil polyethylene bags and seal before disposal (Correct answer)
- Leave on the property for later pickup
- Burn the materials on-site to eliminate mold spores
Correct answer: Double-bag in 6-mil polyethylene bags and seal before disposal
Mold-contaminated materials must be double-bagged in 6-mil polyethylene bags, sealed, and disposed of as regulated waste to prevent further contamination.
Question 7: Which parameter must be controlled to prevent mold recurrence after remediation of a water-damaged building?
- Indoor CO2 levels below 800 ppm
- Relative humidity maintained below 60% (Correct answer)
- Indoor temperature kept above 75°F
- Air pressure maintained at positive levels
Correct answer: Relative humidity maintained below 60%
Maintaining relative humidity below 60% (ideally below 50%) is the primary environmental control that prevents mold regrowth after remediation.
MRS Mold Remediation Techniques and Procedures 2
When remediating a large mold-contaminated area (>100 sq ft), what type of containment is typically required?