ERMI DNA Panel

What ERMI Tests For — And When It Adds Value

ERMI uses DNA analysis to screen for 36 mold species from a single dust sample. Because it reads settled dust, it reflects months or years of accumulation — not just what is in the air right now. Inspectors recommend it when a long-term historical screen adds information that air sampling alone cannot provide.

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How It Works

ERMI: DNA Analysis on Settled Dust

One composite dust sample. Thirty-six species screened by DNA. A single score that reflects long-term mold accumulation in the home.

01

Dust sample collected

A vacuum with a specialized HEPA filter sweeps a measured area of carpet or hard flooring in a representative room. Settled dust traps mold DNA released over months and years of growth — giving the sample its historical depth.

02

DNA extracted and quantified

The AIHA-accredited lab extracts DNA from the dust and applies MSQPCR — mold-specific quantitative polymerase chain reaction. This identifies and counts DNA from each of the 36 target species without relying on visual microscope identification.

03

ERMI score calculated

The lab groups the 36 species into water-damage-associated (Group 1, 26 species) and common background species (Group 2, 10 species). The ERMI score subtracts the Group 2 sum from the Group 1 sum. Higher scores indicate a greater relative burden of water-damage-indicator mold.

ERMI and Air Sampling Answer Different Questions

Air sampling captures a snapshot: the mold spores that are suspended in the air at the moment of collection. It is the right tool for detecting active amplification — mold that is currently producing and releasing spores into the space you breathe. But it only sees what is in the air on the day of the inspection.

ERMI reads settled dust, which accumulates mold DNA over the life of the home. A high ERMI score tells you that water-damage-associated mold has been present and active at some point in the past — even if air counts look normal today, because a past event has resolved but left mold DNA in the carpet. A normal ERMI score in a home with elevated air counts suggests the mold source may be recent or isolated.

Used together, the two tests build a more complete picture: what is happening now (air) and what has happened over time (ERMI). Your inspector will recommend ERMI when that historical dimension is worth understanding — for example, in a home with unexplained symptoms and no obvious visible mold, or when verifying the effectiveness of past remediation.

Why Choose Us

The Fast Mold Testing Difference

See how we compare with traditional mold inspection.

Fast Mold Testing Co.

Days, Not Weeks

Lab-backed reports typically 1-2 business days after inspection

Test-Only, No Upsells

We don't sell remediation — no incentive to inflate findings

Interactive Web Report

Modern, mobile-friendly, and easy-to-understand with AI assistance

Air Quality Assessment

Complete indoor air quality analysis included

Traditional Inspectors

Report in 7-14 Days

Long wait times for written report with laboratory results

Remediation Conflict

Same company tests AND remediates — incentive to find more mold

PDF Report Only

Complex technical documents with limited guidance

No Air Quality Testing

Limited to basic mold inspection only

Why Choose Us

Why Choose Fast Mold Testing co.?

Leading the industry with AI-powered mold detection and superior service quality at competitive prices.

AI-Powered Analysis

Our proprietary AI technology processes samples faster and more accurately than traditional methods.

Rapid Results

Get your results within hours of analysis, not days or weeks like traditional labs.

Certified Expertise

InterNachi and AIHA-EMPAT certified inspectors with 15+ years of experience.

Advanced Equipment

State-of-the-art tools including thermal imaging and automated microscopy.

Industry Leading

Pioneer in combining AI with traditional inspection methods for superior results.

Test-Only, Conflict-Free

We don't sell remediation, so our findings are never influenced by what would be most profitable to find. Independent results you can trust.

Our Certifications

Industry Recognition & Expertise

Our commitment to excellence is backed by industry-leading certifications and partnerships.

ASTM International

ASTM International

Active member contributing to industry standards development

AIHA

AIHA

Certified for environmental microbiology testing

PAT

PAT

Proficiency in analytical testing program participant

InterNACHI

InterNACHI

Certified professional mold inspection certification

Berkeley SkyDeck

Berkeley SkyDeck

Accelerator program alumni

Part of a Full Inspection

Other Testing Methods Used in Your Inspection

ERMI is one tool. Your inspector combines it with these methods based on what they find.

Air Sampling

Captures airborne mold spores at the moment of collection — including hidden mold inside walls and HVAC systems.

Surface Sampling

Identifies the exact mold species on a visible surface using swabs and tape-lifts.

Full Mold Inspection

The complete inspection — visual, thermal, air sampling, surface sampling, and lab analysis.

Frequently Asked

Questions About ERMI Testing

What homeowners and buyers ask most often about the ERMI DNA panel.

What is ERMI and what does it measure?
ERMI stands for Environmental Relative Moldiness Index. It is a DNA-based test developed by the U.S. Environmental Protection Agency (EPA) that screens a dust sample for 36 specific mold species using a method called MSQPCR (mold-specific quantitative polymerase chain reaction). The 36 species are divided into two groups: 26 species associated with water-damaged buildings (Group 1) and 10 species commonly found in homes without water damage (Group 2). The ERMI score is calculated by subtracting the log sum of Group 2 from the log sum of Group 1. Higher scores indicate a greater burden of water-damage-associated mold relative to the background level.
How is the dust sample collected for an ERMI test?
ERMI uses a composite dust sample collected from the floor of a representative room — typically the room of greatest concern or a main living area. A vacuum with a specialized collection filter sweeps a measured area of carpet or hard flooring. Settled dust accumulates mold DNA over months and years, so the sample reflects long-term mold history rather than a snapshot of current airborne levels. This is the key difference from air sampling, which captures only what is suspended in the air at the moment of collection.
When does the inspector recommend an ERMI test?
ERMI is most useful in specific situations: when a home has unexplained health symptoms but no visible mold and normal-looking air sample results; when a past water-damage event or remediation needs to be evaluated for residual mold DNA; when a buyer wants a comprehensive baseline screen before purchasing a home; or when a homeowner wants to understand cumulative mold history over time. ERMI does not replace air sampling — it answers a different question. Air sampling tells you what is in the air right now; ERMI tells you what has accumulated in the settled dust over the long term.
What does a high ERMI score mean?
ERMI scores typically range from about -10 to +20. Scores below 0 suggest a low mold burden relative to the reference population. Scores above 5 are generally considered elevated and associated with a higher probability of water-damage-associated mold growth somewhere in the home. A high score does not tell you where the mold is or which surface it is growing on — it tells you that significant mold DNA has accumulated in the dust, which warrants further investigation. Your inspector interprets the score in context with the visual walkthrough and any air or surface sample results.
Is ERMI included in the standard full inspection?
ERMI is an add-on test, not a standard component of every inspection. Air sampling and surface sampling (when warranted) are the core testing methods in a Fast Mold Testing full inspection. Your inspector will recommend ERMI if the situation calls for a long-term historical screen — for example, if air results are borderline but the home has a history of water events, or if a buyer wants a comprehensive pre-purchase baseline. The decision is made on-site based on what the visual walkthrough reveals.

Need a Comprehensive Mold Screen?

Your inspector will recommend ERMI if the history of your home warrants it. Book a full inspection and we will determine the right testing approach on-site.

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