Standards for Mold Levels

NAMM Standards for Mold Levels

Permissible or Acceptable Standards

Source: Inspectapedia and Environmental Analysis Associates


  • 200 cfu/m3 (per cubic meter)

If assessment is focusing only on “colony-forming-units” (that is, viable mold that will grow) it is not a very reliable way to check out a building because according to the “Field Guide for Determination of Biological Contaminants in Environmental Samples”

 QUOTE:  “This is because the vast majority (90% or more) of airborne fungal spores are non-culturable or non-viable and thus are undetectable by culture analysis. “ END QUOTE


  • 1,000 – 2,000 spores/m3
  • May be acceptable for healthy person
  • Extremely sensitive individuals may experience symptoms

Action Level


  • Greater than 200 cfu/m3 of non-pathogenic species
  • More than 50 cfu/m3 of a pathogenic species
  • At 1,000 cfu/m3 or greater investigation is needed


  • Total spore levels above 1,300 and greater than control sample outdoors warrants investigation

Evacuation Level


  • Greater than 10,000 cfu/m3


  • Greater that 25,000 spores/m3

Post Remediation Verification (PRV) Levels

  • A visual and olfactory inspection verifying that all moisture/mold issues have been resolved
  • Less than 1300 spores at the completion of the remediation project
  • If using the EMLab P&K MoldScore lab report, the MoldScore must be below 150

* These are baseline mold levels. In some cases, even lower counts can indicate a serious indoor mold growth problem. The presence of any marker spores inside a structure can indicate a moisture/mold problem. The lab report should be reviewed by a professional in conjunction with the visual inspection.

Disclaimer: Every effort to include a complete literature and peer review has been made to insure the accuracy, or completeness of this information. Such materials have been compiled from a variety of sources and are subject to change