If you’ve ever wondered what an ERMI test looks like—and how to understand the results—this post will walk you through a real-life example using lab data from a de-identified Dwellness client case.
We’ve taken a snapshot of the lab’s key output and added the interpretation tables to help you understand how these scores relate to mould levels in your home and their potential health impacts.
🧬 What Is an ERMI Test?
The Environmental Relative Moldiness Index (ERMI) is a DNA-based lab test that analyses dust from your home to identify and quantify 36 mould species using qPCR (quantitative polymerase chain reaction).
These species are grouped into:
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Group 1 (Water-damage indicator moulds) – These are the moulds often associated with water damage and indoor contamination.
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Group 2 (Common indoor moulds) – Typically found in homes without significant moisture problems.
The final ERMI score is calculated as:
Group 1 score – Group 2 score = ERMI value
🔍 Sample Lab Report Snapshot
In this case study, the ERMI lab detected elevated DNA counts of multiple Group 1 moulds, including:
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Aspergillus penicillioides
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Aspergillus versicolor
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Chaetomium globosum
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Wallemia sebi
The resulting ERMI Score was 13.2 — putting this home in Q4 (High Relative Moldiness).
📊 According to the ERMI interpretation table:
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Q1 = Low relative moldiness
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Q4 = High relative moldiness
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Scores above 5 are cause for concern, especially for mould-sensitive individuals.
🧠 Why ERMI Alone Isn’t Enough: Enter HERTSMI-2
ERMI is a broad index of mould DNA, but when a client is chronically ill or has been diagnosed with CIRS (Chronic Inflammatory Response Syndrome), we also calculate the HERTSMI-2 score from the same data.
HERTSMI-2 focuses on five particularly toxic moulds known to trigger immune dysregulation in sensitive individuals. Each is weighted by its risk level.
In this case, the HERTSMI-2 Score was 22, which falls into Level 3 – Unsafe for those with CIRS.
📉 Interpretation:
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<11 = Low risk; likely safe for re-entry
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11–15 = Borderline; needs further remediation
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>15 = High risk for those with CIRS or mould-related illness
📸 What the Lab Report Tells Us (in Plain English)
This report helps answer questions like:
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Is there hidden mould in my home even if I don’t see it?
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How “bad” is the mould exposure, really?
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Is my environment safe for someone with asthma, CIRS, or MCAS?
Without a visible water leak or mould patch, you may still have dangerous levels of mycotoxin-producing mould species trapped in dust.
That’s why we interpret ERMI and HERTSMI-2 results alongside an in-home inspection and moisture mapping—to provide clear, actionable guidance.