The Institute of Inspection, Cleaning and Restoration Certification published the seventh edition of the ANSI/IICRC S500 Standard for Professional Water Damage Restoration in January 2026, introducing significant updates to documentation requirements for Category 3 water losses and new guidance on emerging contaminants.
Category 3 water — defined as grossly contaminated water that may contain pathogenic, toxigenic, or other harmful agents — includes sewage backflows, floodwater from rivers and streams, and water from beyond the toilet trap. The seventh edition requires contractors to document the source of contamination, the extent of affected materials, and the specific decontamination protocols used.
The new edition also introduces guidance on emerging contaminants, including PFAS (per- and polyfluoroalkyl substances) compounds that may be present in floodwater from industrial or agricultural areas. The standard recommends that contractors assess the potential for PFAS contamination in Category 3 losses and consult with industrial hygienists when contamination is suspected.
Other key changes include updated psychrometric drying standards, revised guidance on the use of antimicrobial treatments, and new requirements for post-remediation verification testing in Category 3 losses.
The seventh edition maintains the three-category water classification system (Category 1: clean water; Category 2: gray water; Category 3: black water) and the three-class drying system (Class 1-4) that have been the foundation of the standard since its initial publication.
Contractors are encouraged to review the full text of the seventh edition, available through the IICRC, and to update their standard operating procedures to reflect the new requirements.
