Indoor/Outdoor Spore Ratio Clearance Screen
The indoor/outdoor spore ratio that reads as a post-remediation mold clearance.
Example
You enter
- Indoor spore concentration (spores/m³) 800
- Outdoor control (spores/m³) 1500
You get
- Indoor/outdoor ratio 0.5333
- Clearance screen Supportable -- indoor at/below outdoor, no marker
Details, formula, and sources
The everyday mold clearance read: post-remediation indoor airborne spore concentration should sit at or below the outdoor control (ratio at or under 1), with no indoor-dominant water-damage marker genera (Stachybotrys, Chaetomium) elevated inside. Computes the indoor/outdoor ratio and screens the marker flag. A screen, not a clearance certificate; an independent environmental professional interprets the genera and the full criteria (ANSI/IICRC S520).
io_ratio = indoor_spores_m3 / outdoor_spores_m3; pass when io_ratio <= 1 and no indoor-elevated water-damage marker (indoor_marker == 0).
Indoor/outdoor airborne-spore comparison and the marker-genera (Stachybotrys / Chaetomium) principle of ANSI/IICRC S520, by name. Not edition-bound.
The indoor/outdoor ratio is public arithmetic; the comparison and marker-genera principle are named in the published ANSI/IICRC S520.
Estimate. AHJ and licensed professional govern.
Field names used by the API: indoor_spores_m3, outdoor_spores_m3, io_ratio, pass
- Outdoor control the outdoor sample establishes the baseline genera and concentration for the comparison and must be positiveANSI/IICRC S520
- Marker genera indoor-dominant water-damage markers (Stachybotrys, Chaetomium) elevated inside fail the screen regardless of the ratioANSI/IICRC S520