The ERMI DIY Mold Test
The ERMI (Environmental Relative Moldiness Index) test was developed by the EPA to estimate possible mold contamination. This DNA-based method of testing, using mold-specific quantitative polymerase chain reaction (MSQPCR), identifies and quantifies 36 molds and calculates an index number for comparison with a database of reference homes.
Then, Researchers analyze the DNA from mold found in dust samples and compare the sample to the ERMI’s scale. This national database from 1096 homes across the U.S. was part of the 2006 HUD American Healthy Home Survey.
Proper ERMI testing requires careful sampling and interpretation of the lab report for best results. The ERMI score is not always the best indicator of what is happening inside a home; more often, the different species identified on the sample tell the story.
ERMI Dust Sampling – Do’s and Don’ts
✅ DO:
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Use disposable gloves to avoid contaminating the sample.
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Use the Swiffer cloth provided in the test kit to collect dust.
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Swipe several areas within the space you want to test using the cloth.
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Wipe in one direction only—do not scrub back and forth or in circles.
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Collect dust from a variety of cleanable surfaces throughout the home, such as:
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Tops of interior door frames
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Entertainment centers
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Shelves
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Dressers and nightstands
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Ceiling fan blades
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HVAC return vents
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Sample 10 or more different surfaces in the space for the most accurate results.
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Stop swiping when the cloth is visibly dirty (gray). If it’s still white, keep sampling until enough dust is collected.
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Fold the cloth in half with the dusty sides touching, place it in the plastic bag, and seal it.
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Complete the Chain of Custody (CoC) form included in your kit:
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Write the sample location(s) under “Location.”
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If collecting more than one sample, label both the bag and the form with matching location names.
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Purchase the test online using this LINK. Code HHZONE saves you 10%
❌ DO NOT:
- Do not scrub or wipe in a circular or back-and-forth motion.
Do not sample directly from visible mold.
Do not collect from floors, baseboards, or window ledges.
Do not sample from areas with:
Rust
Clay or drywall dust (especially from recent construction)
High-heat sources like stoves or heaters (these may alter the sample or produce false negatives)
Do not rely solely on kitchen or bathroom samples—these areas don’t provide a full picture of the home’s mold status.
When you receive your results, contact us to schedule a Virtual Session to determine what your next steps are.
If you have a large home or want to narrow down testing areas, please consider purchasing multiple tests and using several kits for “zone testing” ” i.e. upstairs and downstairs or for specific bedrooms.
If you have urine mycotoxin testing or serious health issues, then please use the contact us to send a list of your concerns and we will send you instructions on how to purchase a CUSTOM ERMI specific to your needs.
Have questions?
Kit is a Florida Licensed Mold Inspector! License number: MRSA5292
Kit Brucker,
Building Biologist & Council Certified Indoor Environmentalist
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