Water category & class reference
Cat-1/2/3, Class 1-4.
IICRC S500 water categories (contamination) and classes (amount of water / evaporation load).
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Cat-1/2/3, Class 1-4.
IICRC S500 water categories (contamination) and classes (amount of water / evaporation load).
Category 1 | Clean / sanitary source (broken supply line, rainwater). | |
|---|---|---|
Category 2 | Grey — significant contamination (appliance overflow, sump pump). | |
Category 3 | Black — grossly contaminated (sewage, ground / surface water). |
Class 1 | Least water; low porosity; <~5% of the area affected. | |
|---|---|---|
Class 2 | Large amount; wicking up walls <24 in. | |
Class 3 | Greatest amount; from overhead; wicking >24 in. | |
Class 4 | Specialty / low-evaporation (hardwood, plaster, concrete). |