Assessment & Testing
Condition 1, 2 and 3: how R520 classifies a space
In plain English
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 fungal ecology: some settled spores or traces of growth are expected in any building. Condition 2 means the area is mainly contaminated by spores and fragments that drifted in from a growth site. Condition 3 means actual growth is present, whether active or dormant, visible or hidden.
The Conditions drive the rest of the process. Remediation aims to return every affected area to Condition 1, and containment is there to keep Condition 1 areas from becoming Condition 2 while work goes on. R520 notes that growth (Condition 3) can usually be found by looking and smelling, though hidden pockets may require opening up materials under containment. Telling Condition 2 apart from Condition 1, however, generally takes sampling by an indoor environmental professional (IEP).
Texas note: Texas law uses its own terms. It regulates by the area of visible mold (25 contiguous square feet or more), and the licensed Mold Assessment Consultant defines the work area in the protocol. The Condition framework is a useful way to think about a job, but it is not the Texas legal test.
“an indoor environment contaminated with the presence of actual mold growth, associated spores, and fungal fragments”
Key points
- Condition 1: normal background for a similar, well-kept building.
- Condition 2: settled spores or fragments that came from a growth area.
- Condition 3: actual growth, active or dormant, seen or hidden.
- The goal of remediation is a verified return to Condition 1.
- Separating Condition 2 from Condition 1 usually requires an IEP's sampling.
Official text
This topic is covered in our own words because the standard behind it is copyrighted; we cite it below rather than reproduce it.
Citations
- IICRC S520 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 1, p. 10. Best practice
- IICRC S520 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 8, p. 98. Best practice
- IICRC S520 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 11, p. 119. Best practice