IEP Committee ERMI Score Consensus Statement

The ISEAI Indoor Environmental Professional (IEP) Committee recommends that ERMI and HERTSMI-2 scores should not typically be used as the sole basis for patients to make major life or financial decisions, such as moving, selling a home, or beginning remediation.  

While the scores may have value, they are not designed to directly identify or locate any sources of mold.

Therefore, detailed interpretation of the ERMI and HERTSMI-2 raw data, ideally by an indoor environmental professional, is much more valuable and appropriate to the patient or building’s individual context than the score alone. 


The Environmental Relative Moldiness Index (ERMI) is a research tool developed by EPA scientists for estimating mold contamination. Note that the EPA mentions “ERMI has been peer reviewed for research purposes but has not been validated for non-research purposes.”

Several commercial laboratories offer “ERMI tests”, which use Mold-Specific Quantitative PCR (MSQPCR) technology to analyze dust (typically collected on a dry Swiffer cloth, or via vacuum). MSQPCR is a detection system based on unique DNA sequences.

The test results provided by commercial laboratories typically include 1) valuable raw data for each individual mold species and 2) an “ERMI score” involving a complex calculation.

Who created this statement?

The ISEAI Indoor Environmental Professional Committee is a group of highly credentialed and experienced indoor environmental professionals who have specialized experience with medically-sensitive patients. The Committee reports to the ISEAI Board of Directors and provides education to clinicians and the public on topics of mold, indoor air quality and contaminants.

> Also see our Mold Testing Guide and other resources.