ANSI/IICRC S520
Mold remediation is not mold cleaning — it is a controlled, science-driven process that eliminates the source, contains the colony, and confirms clearance through independent testing. DRR follows ANSI/IICRC S520 from initial sampling through final third-party air clearance.
What We Do
Environmental Relative Moldiness Index sampling identifies species present and contamination levels, providing a defensible scientific baseline before remediation begins and a benchmark for clearance comparison.
Critical barriers and negative air pressure containment prevent cross-contamination during remediation. Our containment protocols are sized and constructed according to the S520 standard for the confirmed contamination level.
Mold cannot be remediated without addressing the moisture source. We identify and eliminate the water intrusion pathway before any remediation begins — preventing recurrence and protecting your investment.
HEPA air scrubbers run continuously throughout the remediation process, capturing airborne spores displaced during material removal and surface cleaning, and maintaining negative air pressure within the containment zone.
EPA-registered antimicrobial agents are applied to affected substrates following physical removal of mold colonies, inhibiting regrowth on surfaces that cannot be fully removed or that are adjacent to affected areas.
Every remediation closes with a third-party air sample collected by an independent industrial hygienist. Clearance is not issued by DRR — it is issued by an independent laboratory, protecting you from liability.
Why DRR
We never skip clearance testing. Every remediation closes with a third-party air sample. This is not optional — it is the only scientifically valid way to confirm that remediation was successful. Any contractor who skips clearance testing is leaving you with unverified results and potential liability.
What To Do First
If you've found visible mold, the most damaging mistake is to disturb it. These steps preserve containment until a certified remediation crew can establish negative-air conditions per IICRC S520.
Brushing, wiping, or attempting to clean mold releases millions of spores into the air and across surrounding rooms. Containment must be set up under IICRC S520 protocol before any disturbance.
A running air handler will distribute mold spores to every connected room within minutes. Shut off central HVAC at the thermostat or breaker until containment and HEPA filtration are established.
Mold needs liquid water — leaking pipe, roof failure, condensation, or flood event. Identifying and stopping the source is required by IICRC S520 itself; remediation without source control will recur.
Bleach does not penetrate porous materials where mold roots live. Treatment without proper containment, HEPA filtration, and source-of-moisture control is cosmetic only and frequently makes the loss worse.
Tell us the affected square footage of visible growth, how long moisture has been present, and which materials are involved (drywall, carpet, wood framing, HVAC components). DRR is IICRC S520-certified across the Phoenix metro.
Mold Remediation — Standards & Equipment
ANSI/IICRC S520
Defines Condition 1/2/3 contamination levels, containment requirements, removal methods, and post-remediation verification (PRV). DRR remediates only to S520 — including the PRV step many cheaper firms skip.
EPA Mold Remediation Guide
EPA's consensus guidance for sizing remediation scope (≤10 sq ft homeowner / ≤30 sq ft mid / >30 sq ft full containment + IH oversight). DRR uses these thresholds as a floor, not a ceiling.
OSHA 1910.134
Mold remediation crews work in N95+ minimum (often APR with HEPA cartridges) per OSHA's respiratory protection standard. Fit testing documented annually.
HEPA-filtered negative-pressure scrubbers establish containment so spores can't escape during demolition. Pressure-differential monitoring documented continuously.
6-mil poly with zipper-door entry, decon chamber, and HEPA-filtered exhaust create the containment envelope S520 requires for Condition 3 work.
True HEPA-rated wet/dry vacs (not shop-vacs with HEPA bag accessories) for spore-laden surface cleaning post-removal.
EPA-registered antimicrobials applied per label after physical removal — never as a substitute for removal.
Independent industrial hygienist coordination for pre- and post-remediation air sampling. PRV based on third-party data, not contractor self-attestation.
FAQ
ANSI/IICRC S520 is the consensus standard for professional mold remediation. It defines containment (negative-pressure barriers), HEPA filtration, removal procedures, and post-remediation verification. We perform every mold job to S520 — both because it produces durable results and because most insurance carriers require it.
Sometimes. Mold caused by a covered water loss (e.g., a sudden burst pipe) is usually covered, often with a sub-limit specific to mold. Long-term humidity, maintenance issues, or undiscovered slow leaks are typically excluded. We document the underlying cause and provide an S520-compliant scope so the carrier has what they need to make a coverage decision.
We build sealed containment with 6-mil poly, run negative pressure with HEPA-filtered air scrubbers, and use airlock entries. Spores stay inside the containment, not in your living or working space. PPE and decontamination chambers are standard for Condition 3 work.
Yes. We coordinate with an independent industrial hygienist for clearance sampling — air samples and surface samples compared against outdoor and unaffected baselines. We don't tear down containment until clearance comes back passing.
The popular concern is around Stachybotrys chartarum, but health risk depends on exposure, individual sensitivity, and concentration — not just color. Our scope follows S520 regardless of species: any visible mold or condition 2/3 contamination gets removed under containment with HEPA filtration. We don't use scare language to upsell scope.
A small bathroom or closet typically runs 2–4 days. Whole-room or multi-room remediation runs 5–10 days. Add time for clearance results and reconstruction (drywall, paint, flooring) on the back end.
Both. Mold without a moisture source comes back. Our scope includes identifying and addressing the underlying water issue — leak repair, drainage, ventilation, or building-envelope work — before clearance. Skipping this step is the most common reason remediation fails.
Yes. We don't sample our own work — that's a conflict of interest the standard explicitly warns against. An independent industrial hygienist or environmental consultant handles pre- and post-remediation sampling. We coordinate scheduling and provide them full access.
Technical References
Phoenix Mold Resources
