Mold Remediation Blog

Are ERMI Tests Really Accurate?

lab tech with blue gloves gathering mold sample for testing

Mold in the home is NEVER a good thing, that is something we can all agree on. The first step towards cleansing your home of mold once and for good is to first identify which type of mold you are living with along with the severity of growth. 

While many mold testing companies have their own set of tests and procedures, we here at Valor mold only entrust the very best for our clients. 

We typically opt for the 100% successful InstaScope technology for our testing procedures as it provides instant results on the outcome. 

Because this piece of machinery is unobtainable by other mold testing companies for a variety of reasons, ERMI tests are the next best thing. 

What Is An ERMI Test?

If there are no visible signs of mold growth in your home, having an ERMI test done on your home will confirm once and for all if mold is a concern. The abbreviation “ERMI” stands for Environmental Relative Moldiness Index, a standardized sequencing procedure that utilizes dust from around the home as its test sample.  

ERMI was developed by the Environmental Protection Agency (EPA) as the end all be all mold testing techniques. Although, to this day the EPA is adamant about the fact that results from an ERMI test should be used for research purposes only.


Because of the natural design of an ERMI test, having a negative ERMI test does not always mean there is no mold within the home.

How An ERMI Test Works

As we mentioned before, an ERMI test first begins with collecting dust from around the home. The dust sample is then observed using mold-specific quantitative polymerase chain reaction (MSQPCR), which breaks down the DNA sequence of the collected dust. 

This DNA sequence helps scientists identify the EXACT mold that has been living in your home. Unlike air quality tests, the ERMI test focuses on lingering mold spores that have a history of using your home as a breeding ground. 

As of today, an ERMI test can isolate and identify the DNA structure of 36 different species of mold commonly associated with internal water damage of the home, along with ten different species of mold that typically stick to the outdoors.

Accuracy Levels Of ERMI Tests

ERMIs give the mold history of the tested area, while other tests only determine whether or not there is airborne mold in the home at the specific time of testing. An airborne test could come back negative for mold, while an ERMI test utilizing dust samples can give a whole different story. 

The same goes for airborne tests! If you keep your home nice and tidy or have recently had a cleaning crew or mold removal team working in your home, the chance of collecting a decent dust sample is quite slim.

In this case, an airborne mold test would give a more accurate reading. 

As far as accuracy levels go, tests with a decent dust sample to DNA sequence have astonishing results: up to 99.9% accurate! 

But, as we mentioned before, an ERMI test done after a mold removal company has given it their best shot will not nearly be as accurate. 

ERMI tests are most accurate at the very start of the mold identification and removal process.

Types Of Mold Identified By ERMI Tests

ERMI tests can identify 46 different types of mold from the indoors and outdoors combined, with a major focus on indoor mold species. The following types of mold DNA sequences can be accurately identified with an ERMI test:


  • Aspergillus (flavus/oryzae, fumigatus, niger, ochraceus, penicillioides, restrictus, sclerotium, sydowii, unguis, & versicolor) 
  • Aureobasidium pullulans 
  • Chaetomium globosum
  • Cladosporium Sphaero Serum
  • Eurotium Aspergillus amstelodami
  • Paecilomyces variotii
  • Penicillium (brevicompactum, corylophilum, crustosum, purpurogenum, spinulosum, & variabile)
  • Scopulariopsis (brevicaulis/fusca & chartarum)
  • Stachybotrys chartarum  
  • Trichodermaviride 
  • Wallemia sebi 


  • Acremonium strictum 
  • Alternaria alternata 
  • Aspergillus Ustus 
  • Cladosporium (cladosporioides 1, cladosporioides 2, herbarum) 
  • Epicoccum nigrum 
  • Mucor amphibiorum 
  • Penicillium chrysogenum
  • Rhizopus stolonifer

Ready To Schedule Your At-Home Mold Test?

With all of the potential health risks mold poses to healthy and at-risk individuals, regularly testing your home for mold is an important chore to remember throughout the year. 

Often, mold can grow rampant in the home unbeknownst to the homeowner or inhabitants due to an internal leak, cracks in the home’s foundation, or other avenues that allow excess moisture to enter the home. 

Whether you know for a fact you have a mold problem, or you just have your suspicions, give us a call! 

Here at Valor Mold, we take our job very seriously and work diligently to test and treat your home as if it were our own. 

We can be reached Monday-Friday at our home office by calling (703) 897-7121 or by giving us a visit in Springfield, VA! 

Why Choose Us

We remove mold the right way… and it would be an honor to hear from you.

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96% Success Rate

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Instant Mold Testing

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300+ Happy Clients

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