IICRC S520 Reference Guide: IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide

About this source

The restoration industry's consensus reference for professional mold remediation, widely written into contracts and insurance scopes. Not law in Texas; where it differs from TDLR's rules, the rules control.

Copyrighted by the IICRC. We summarize it in our own words, with chapter and page citations and only brief quotations; we never reproduce its text. Buy the standard from the IICRC to read it.

Chapters and where we cover them

We don't reproduce this standard. These topics explain each chapter in our own words, with page citations.

• Intro: Introduction: how the Reference Guide relates to the S520 Standard p. 8
  Covered in: The five principles behind IICRC mold remediation
• Ch. 1: Principles of Mold Remediation pp. 9–12
  Covered in: The five principles behind IICRC mold remediation; Condition 1, 2 and 3: how R520 classifies a space; The indoor environmental professional (IEP); Post-remediation evaluation and independent verification
• Ch. 2: The Fungal Biology of Indoor Environments pp. 13–17
  Covered in: How mold grows indoors: spores, hyphae and shifting ecology; Water activity, humidity and the moisture levels mold needs
• Ch. 3: Health Effects from Indoor Exposure to Mold in Water/Moisture-Impacted Buildings pp. 18–32
  Covered in: What health agencies conclude about damp buildings; Allergy, toxins and infection: how mold may affect health; Occupant health, relocation and remediation worker risk
• Ch. 4: Building and Material Science pp. 33–49
  Covered in: How air, moisture and heat move through a house; Building envelopes, climate and how materials handle water
• Ch. 5: Equipment, Tools and Materials pp. 50–69
  Covered in: Moisture meters, thermal cameras and other inspection tools; Source, local and full containment; Negative pressure, HEPA air filtration and air changes; HEPA vacuums, sanding and blasting; Misting, drying and dehumidification during remediation; Biocides and antimicrobials: limits and legal rules; Mold-resistant coatings, encapsulants and other shortcuts
• Ch. 6: Safety and Health pp. 70–79
  Covered in: Respirators and protective gear for mold work; Job-site safety: OSHA, asbestos, lead, confined spaces
• Ch. 7: Administrative Procedures, Documentation, and Risk Management pp. 80–92
  Covered in: Contracts, communication and project records; Mold and insurance: exclusions and coverage gaps
• Ch. 8: Inspection and Preliminary Determination pp. 93–100
  Covered in: Condition 1, 2 and 3: how R520 classifies a space; The remediator's inspection and preliminary determination; Job-site safety: OSHA, asbestos, lead, confined spaces
• Ch. 9: Limitations, Complexities, Complications and Conflicts pp. 101–104
  Covered in: When a job is limited: complications and conflicts; Mold and insurance: exclusions and coverage gaps
• Ch. 10: Indoor Environmental Professionals and Assessments pp. 105–108
  Covered in: The indoor environmental professional (IEP)
• Ch. 11: Structural Remediation pp. 109–126
  Covered in: Condition 1, 2 and 3: how R520 classifies a space; The indoor environmental professional (IEP); Source, local and full containment; Negative pressure, HEPA air filtration and air changes; Respirators and protective gear for mold work; Job-site safety: OSHA, asbestos, lead, confined spaces; Removing moldy materials: what goes and how to take it out; HEPA vacuums, sanding and blasting; Misting, drying and dehumidification during remediation; Final cleaning, leaving containment and disposing of debris; Biocides and antimicrobials: limits and legal rules; Mold-resistant coatings, encapsulants and other shortcuts; Post-remediation evaluation and independent verification
• Ch. 12: HVAC Remediation pp. 127–133
  Covered in: How HVAC systems spread or prevent mold; Cleaning coils, blowers and ducts; chemicals in HVAC systems
• Ch. 13: Contents Remediation pp. 135–150
  Covered in: Final cleaning, leaving containment and disposing of debris; Mold-resistant coatings, encapsulants and other shortcuts; Post-remediation evaluation and independent verification; Contents: deciding what to restore, dispose of or preserve; Cleaning clothing, furniture, papers and valuables
• Back matter: Industry Acronyms pp. 151–152
• Back matter: Glossary of Terms pp. 153–186
• Back matter: Conversion Charts p. 187
• Back matter: Sources and Source Acknowledgements pp. 188–189
• Back matter: Index pp. 191–194

Topics that cite this source

• The five principles behind IICRC mold remediation R520 opens with five principles that every later chapter builds on. In short: protect the people doing the work and the people living there; keep records of what was... Best practice
• Condition 1, 2 and 3: how R520 classifies a space R520 does not describe mold problems by square footage or by species. It sorts a space, a system or an item into one of three Conditions. Condition 1 is a normal... Best practice
• How mold grows indoors: spores, hyphae and shifting ecology Molds are microscopic fungi that feed on dead organic material. They spread as spores too small to see. When a spore lands somewhere with enough moisture and a... Best practice
• Water activity, humidity and the moisture levels mold needs R520 explains mold's moisture needs with water activity (aw): how much free water a material offers, which roughly matches the relative humidity the material would... Best practice
• What health agencies conclude about damp buildings Chapter 3 reviews what national and international bodies had concluded about damp, moldy buildings and health. R520 reports that the Institute of Medicine found... Best practice
• Allergy, toxins and infection: how mold may affect health R520 describes three ways mold exposure may affect people. Allergy affects only people who are already sensitized, and it explains runny nose, watery eyes and asthma... Best practice
• Occupant health, relocation and remediation worker risk When people in a building report symptoms, R520 recommends a physician experienced with indoor air problems, ideally brought in before or alongside the building... Best practice
• How air, moisture and heat move through a house Chapter 4 asks remediators to understand basic building physics, because a fix that ignores it can create the next problem. The core rules: heat moves toward cold,... Best practice
• Building envelopes, climate and how materials handle water The envelope (roof, walls, foundation, windows and doors) keeps out rain and ground water and controls heat and moisture flow. R520 identifies poorly flashed windows,... Best practice
• Moisture meters, thermal cameras and other inspection tools R520 lists the instruments used to find and track moisture, along with the limits of each. A thermo-hygrometer records temperature and humidity; the same unit should... Best practice
• The remediator's inspection and preliminary determination In R520, a mold job starts with an inspection: gathering facts and walking the property for moisture and possible mold. Background includes what prompted the call,... Best practice
• The indoor environmental professional (IEP) R520 uses "indoor environmental professional" as a general label for the person who assesses mold rather than removing it. The IEP designs a sampling plan, collects... Best practice
• Source, local and full containment Containment separates the work area from the rest of the building so spores and dust released during removal stay put. R520 describes a range. Source containment... Best practice
• Negative pressure, HEPA air filtration and air changes Containment works best when air leaks into the work area rather than out of it. R520 calls for keeping contaminated areas under negative pressure relative to clean... Best practice
• Respirators and protective gear for mold work OSHA requires employers to provide the protective equipment a job calls for, and R520 explains what that means for mold. Respirators are worn whenever ventilation and... Best practice
• Job-site safety: OSHA, asbestos, lead, confined spaces No federal standard is written specifically for mold, but R520 points out that general OSHA rules still apply. Remediation firms work under both the general industry... Best practice
• Removing moldy materials: what goes and how to take it out What happens to a moldy material depends on how porous it is. R520's rule of thumb: porous materials with actual growth, such as drywall, insulation and ceiling tile,... Best practice
• HEPA vacuums, sanding and blasting HEPA vacuuming is the workhorse of mold cleaning. R520 specifies professional units that actually filter 99.97% of particles at 0.3 microns. It warns that some... Best practice
• Misting, drying and dehumidification during remediation Misting means spraying a fine water mist to keep dust down. R520 calls it controversial in mold work. Some practitioners use it routinely, but research cited in the... Best practice
• Final cleaning, leaving containment and disposing of debris After demolition, the area is cleaned until dust is gone. R520's method is HEPA vacuuming followed by damp wiping with as little water as possible, repeated in rounds... Best practice
• Biocides and antimicrobials: limits and legal rules R520 is clear that chemicals are not a substitute for removal. Killing mold does not remove what makes it a problem, because dead spores and fragments can still... Best practice
• Mold-resistant coatings, encapsulants and other shortcuts Fungicidal and mold-resistant coatings are paints or sealers with a bound antimicrobial. R520 says they are meant to discourage future growth on surfaces that have... Best practice
• Post-remediation evaluation and independent verification R520 describes two checks at the end of a job. First, the remediator performs a post-remediation evaluation as internal quality control. It includes a visual... Best practice
• How HVAC systems spread or prevent mold Heating and cooling systems control the conditions that cause condensation, and they also move air through the whole house. R520 says this makes them both a cause and... Best practice
• Cleaning coils, blowers and ducts; chemicals in HVAC systems Once the system has been assessed and any mechanical fixes made, cleaning follows the NADCA ACR standard. If the Condition of the system is unclear, an IEP with HVAC... Best practice
• Contents: deciding what to restore, dispose of or preserve Contents are sorted by what they are made of and what Condition they are in. Porous items such as clothing, upholstery and mattresses soak up moisture and support... Best practice
• Cleaning clothing, furniture, papers and valuables Contents in Condition 2 or 3 are cleaned outdoors at a safe distance from people and air intakes, or in a multi-stage cleaning chamber. Most processes start and end... Best practice
• Contracts, communication and project records Chapter 7 treats paperwork as part of the job. R520 recommends a written contract that names who pays and how, what happens on default or termination, whether an... Best practice
• When a job is limited: complications and conflicts Chapter 9 gives names to the things that get in the way of a job done by the book. A limitation is a restriction imposed by others, such as a budget cap, a ban on... Best practice
• Mold and insurance: exclusions and coverage gaps R520 recounts how a surge of mold claims around 2001 and 2002 led insurers to add mold exclusions and lower limits across homeowners, commercial and professional... Best practice