HERTSMI Testing for Mold (and ERMI)

air qualityMany Lyme and mold doctors recommend the HERTSMI-2 test from Mycometrics

It shows a direct connection between health and 5 toxic molds.  It's a good gauge to see where your building stands in compared to other buildings and whether

The HERTSMI-2 or HERTSMI detects 5 of the indoor toxic molds that grow in varying amounts of moisture. These 5 molds give a realistic educated guess of whether mold is a problem in a home or building.

There is a grading system or a “scorecard” to plug the numbers into and you get a good idea of how moldy a place is compared to other homes and whether or not a building is sick enough to make people sick.

“Only the ERMI and HERTSMI have been associated with sequential activation of innate immune responses, not air testing.” ~Dr. Shoemaker. Meaning it is the only test that he found that is consistently in line with lab results for CIRS, despite its drawbacks.

Buy a new box of unscented swiffer cloths from the drugstore.
This is important as an opened box that may be stored in your house may
be collecting mold toxins while sitting. Take one swiffer cloth from the
middle of the box – just in case the store was moldy – it's more likely
that the middle cloths are not cross-contaminated.

Inside the building you want to test, use a clean swiffer to collect dust
from as many as ten sites, trying to get dust from the locations most
likely to have collected dust with mold in it.

Old dust may be a better indicator of what you want to find out than new
dust will be, if you are testing somewhere to see if you can live there…
or if someone is getting sick.

Put the swiffer in a ziploc and send that, the Mycometrics Chain of Custody Form, and
$155 to the address on the chain of custody form.

You will receive the result via email five days after they receive it. You
can get faster results by paying extra, and you can overnight the sample
and form to speed up the process. Mycometrics is in New Jersey.

Make sure you check the HERTSMI box!
The HERTSMI costs $155 and can be ordered from Mycometrics.com

If you order it directly from mycometrics, they send you the kit which includes the dust cloth, zip lock bag and the Chain of Custody sheet.  It costs $5 for them to send you the kit and you have to wait a few days.  

If you don't have a printer, and you can wait for the testing kit than when you order the HERTSMI  “Dust Cloth” kit – you will pay $55 and when you send in your sample, you will pay the additional $105.  

When you get the results back by email and/or snail mail plug your numbers in the HERTSMI scorecard:

The HERTSMI “Scorecard”

We use a point system. Units are Spore E/mg.
10 points are assigned for
Aspergillus penicilloides >500      
Aspergillus versicolor >500      
Chaetomium globosum >125      
Stachybotrys chartarum >125      
Wallemia sebi >2500      
6 points are assigned for
Aspergillus penicilloides 100-499      
Aspergillus versicolor 100-499      
Chaetomium globosum 25-124      
Stachybotrys chartarum 25-124      
Wallemia sebi 500-2499      
4 points are assigned for
Aspergillus penicilloides 10-99      
Aspergillus versicolor 10-99      
Chaetomium globosum 5-24      
Stachybotrys chartarum 5-24      
Wallemia sebi 100-499      
Interpretation of HERTSMI-2 Score        
<11 Statistically safe for re-entry for those with CIRS      
11-15 Borderline; clean first and re-test before re-entry      
>15 Dangerous for those with CIRS. Do not enter.      
HERTSMI-2 is a building index. No one HERTSMI-2 can possibly show all areas of a given building.
HERTSMI-2 does not replace careful observation of symptoms and lab results obtained following re-exposure

If you have already done an ERMI and you want to use the HERTSMI scorecard, just pull the values for the 5 molds in the HERTSMI and plug the values into the scorecard above.


If you do the HERTSMI and you get the results and you decide you want to upgrade to the ERMI, you can pay the difference and they will do an anylization of all 36 molds.

If you want a more detailed report that looks for 36 molds instead of just 5 of the most toxic molds… The Environmental Relative Moldiness Index or ERMI has been a highly valuable tool for many practitioners and patients alike in evaluating the potential of ongoing mold exposure in the indoor environment.

It is not uncommon for an air testing sample to return negative results in the same environment where an ERMI is highly positive.

Given that some toxic molds are not readily airborne, air sampling is generally not an effective tool for indoor air quality; thus dust sample testing using the ERMI may be a better option.

Dust is a sampling of the air over a longer period of time… while air testing shows a snap shot in time.

This panel, developed by the United States EPA, includes a total of 36 fungal species/clusters that are broad enough to help address the mold problems of water-damaged indoor environments and to help assess the risk of mold exposure.

The ERMI gives a ratio of indoor and outdoor molds and I will advise you to pull the five molds measured in the HERTSMI-2 and follow the “scorecard” for evaluting both the ERMI and the HERTSMI tests.

The ERMI costs $285-$290 from Mycometrics – you save $5 if you use your own swiffer cloth and ziploc bag as described above for the HERTSMI. The swiffer kit or the vacuum kit can be ordered from Mycometrics.com Some people have gone to other labs for the ERMI testing but I recommend Mycometrics 100%. We have found inconsistent and unreliable results from other labs.

No test is absolute. If even one person is sick in a home or a building, and your HERTSMI comes back low… that person can be reacting to low amounts of mold. I have known people who are still reacting to mold when their HERTSMI is a ZERO! The more immune-compromised we are, the more sensitive we are.

Other things to look into if your HERTSMI is low and you still suspect the environment:

  • Radon
  • VOC's
  • formaldehyde
  • pet dander
  • microbial fragments
  • Electro-magnetic frequencies
  • smart meters
  • water
  • food

There is a home air test for mold that I talk about on this page — scroll down below the HERTSMI instructions which are basically a repeat of this page!

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2 thoughts on “HERTSMI Testing for Mold (and ERMI)”

  1. I didn’t realize that the ERMI test can show or look for 36 different types of molds instead of the standard 5 most toxic molds. My husband and I just bought an older home a few weeks ago. I’ve noticed that some of my kids are coughing a lot. I’m curious to know if this could be the result of mold. It might be worth it to get a mold assessment done.

    1. I think everyone should do a mold assessment before buying or renting a home and if anyone has any kind of illness from allergies to cancer. Sick buildings make sick people, pets and plants. I used to think I did not have a green thumb because house plants would die – it was the air in my home. It was making all living things sick.

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