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IICRC S520 Checklist: A Field-Ready Guide for Mold Remediators

July 27, 20268 min read

A working checklist mold remediation crews can actually run, mapped to the ANSI/IICRC S520 standard, from pre-remediation assessment through post-verification.

The ANSI/IICRC S520 standard is the industry reference for professional mold remediation. It's also 200-plus pages that nobody reads in the field. Here's the working checklist we run, mapped to S520 sections, that keeps a job defensible without burying the crew in paperwork.

1. Pre-remediation assessment

  • Visual inspection with moisture readings at multiple wall and floor locations
  • Photograph every visible mold location, tagged to the room
  • Air samples: indoor affected, indoor unaffected, outdoor reference
  • Document HVAC involvement and contamination pathways

2. Containment and engineering controls

  • Poly containment with negative air; log AMU model and serial
  • HEPA filtration in place before removal starts
  • PPE per Condition 2/3 requirements, logged per shift

3. Removal and cleaning

  • Porous materials removed and bagged inside containment
  • Semi-porous surfaces HEPA-vacuumed and damp-wiped
  • Structural drying documented daily until below dry standard

4. Post-remediation verification (PRV)

  • Visual inspection: no visible mold, no dust, no debris
  • Moisture readings back to reference
  • Analytical clearance: air samples reviewed against S520 criteria

For general safety context, cross-reference OSHA guidance on mold and the EPA's guide to mold and moisture. For the workflow to actually run this in the field, see our mold remediation toolkit.

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