A technical overview of the IICRC S520 Standard for mold remediation, defining when to clean it yourself and when to call a certified abatement team.
Discovering mold in your home triggers an immediate urge to “kill it.” However, most internet advice (like “spray it with bleach”) contradicts established industrial hygiene standards.
The goal of remediation is not to kill the mold; it is to remove the mold. Dead spores contain the same allergenic and toxigenic properties as live spores. This guide outlines the correct protocols based on EPA and IICRC guidelines.
1. The Decision Matrix: DIY vs. Pro
Before you touch the mold, you must determine the size of the infestation. The Environmental Protection Agency (EPA) provides a clear threshold for safety.
If the total affected area is less than 10 square feet (roughly 3ft x 3ft), you can handle the cleanup yourself using proper PPE.
If the area is larger than 10 sq ft, or if the mold is caused by sewage water (Category 3), EPA standards require professional remediation.
2. The “Kill vs. Remove” Myth
Many homeowners believe that if they spray a chemical and the mold turns white, the problem is solved. This is false.
- Live Spores: Release mycotoxins and cause allergies.
- Dead Spores: Still release mycotoxins and cause allergies.
Successful remediation requires physical removal of the fungal structure (hyphae) and the material it is growing on (if porous, like drywall). You cannot “clean” mold out of drywall; you must cut it out.
3. The 4-Step DIY Protocol
If your infestation is under 10 sq ft, follow this abbreviated version of the IICRC S520 Standard:
Seal the room with 6-mil plastic sheeting. Tape over vents to prevent spores from entering the HVAC system.
Wear an N95 respirator mask, non-porous gloves, and goggles. Do not touch mold with bare skin.
Bag moldy porous materials (drywall/carpet) before carrying them through the house. Scrub non-porous surfaces (tile/wood) with antifungal solution.
After cleaning, vacuum the entire room with a HEPA-rated vacuum to capture microscopic spores that settled during cleaning.
4. Deep Dive Resources
Select a specific topic below for a detailed technical breakdown.
Why the EPA advises AGAINST using bleach on drywall, and the chemistry behind why it fails.
The science of acetic acid. Does it actually penetrate the cell membrane of the spore?
How to spot a scammer. The essential licenses and certifications to ask for.
Are Home Depot petri dishes accurate? Comparing DIY plates vs. ERMI lab tests.