Mold Testing Myths: Why ERMI and HERTSMI Might Not Be the Answer

The ERMI (Environmental Relative Moldiness Index) and HERTSMI (Health Effects Roster of Type-specific Formers of Mycotoxins and Inhalants) tests are commonly used to assess mold contamination in homes, but they have some limitations that can make them less reliable for identifying mold-related issues. Here’s why they might not be the best options for detecting problems in a home:

1. They Focus on Specific Mold Species

• Both tests are based on identifying specific mold species (usually Aspergillus, Penicillium, and a few others) that are linked to health issues or moldiness. However, not all molds that can cause health problems are included in these tests. There are many other species of mold that may also be harmful but are not part of the ERMI or HERTSMI panels.
• The ERMI test, for example, looks at 36 different mold species, which means it does not look for any of the other hundreds of potential molds that can be found in a home. These other molds can cause health problems and can give the tester an idea of what is going on in the home based upon the type of mold that is found.

2. They Don’t Measure Mold Viability

• Both ERMI and HERTSMI tests typically measure mold DNA through air or surface sampling. However, just because mold DNA is present doesn’t mean the mold is active or producing mycotoxins. A sample might show DNA from a mold species, but it doesn’t necessarily indicate that the mold is actively growing or releasing harmful spores into the air.
• In other words, the tests might not reflect the current risk of exposure to active mold problems.

3. Limited Scope of Testing

• These tests are often conducted with air or dust samples, which may not capture the full extent of mold contamination, especially if the mold is hidden inside walls, ceilings, or other inaccessible areas. Mold can grow in places where these tests don’t sample effectively, like behind drywall, under carpeting, or in HVAC systems.
• Therefore, these tests may give you a false sense of security if they don’t find much mold, even though the actual problem could be hidden.
• ERMI and HERTSMI do not look at humidity and water damage molds. Some mold can grow from high levels of humidity (can be caused by ventilation issues or an incorrectly sized HVAC system)
• In addition, another big failure is the inability to determine a historical issues vs an active issue.
• The score does not pinpoint where the issue is coming from. Because of the fact that only 36 molds are looked at for the ERMI, this means that the picture of what is going on in the home is incomplete. For example, it does not look for a mold called Scopulariopsis. This mold can cause VOC type odors and is allergenic. It is also typically found in homes that have high humidity. The ERMI would fail to find this issue, and someone may think there is not a problem, when there definitely is.

4. The Tests Can Be Expensive

• These tests can be costly, and depending on the results, you might still need to hire an expert to perform more comprehensive inspections or remediation. This can create additional financial burdens without guaranteeing actionable results.

5. Over-reliance on Test Results

• Mold issues in a home are often more complex than a test result can capture. The ERMI and HERTSMI tests focus on specific mold species, but mold problems can also be influenced by moisture levels, building materials, ventilation, and other environmental factors that aren’t directly assessed by these tests.
• Mold remediation requires a more holistic understanding of the environment in the home, something these tests may not fully reflect.

6. Confounding Factors

• The presence of mold species listed in ERMI and HERTSMI may not necessarily correlate with actual health risks for the occupants. People’s reactions to mold can vary greatly depending on their sensitivities, allergies, and overall health, and these tests don’t capture this nuance.

7. False Positives/Negatives

• ERMI and HERTSMI results may also be impacted by sampling errors, contamination during testing, or improperly handled samples. This could lead to false positives (showing mold that isn’t really there) or false negatives (failing to detect mold that is).
• The sampling protocol was created and the results that are obtained are based upon that specific sampling method. I know for a fact that many companies do not follow that specific sampling method. In fact, many companies are now using swifter mops to obtain samples. This means that those results cannot be compared to the chart with any accuracy.

It is also important to note the EPA itself has stated since 2013 that these tests are not to be used for residences, schools and workplaces. Here is a link to the fact sheet. Please note the red paragraph.  https://drive.google.com/file/d/1J3GEd7D_vm5gcSFEw4eGyDKbY7LwRzCt/view?usp=sharing

There have been several instances since 2013 where the EPA has said that these tests are not to be used as a diagnostic tool outside of a research setting. The fact is that this test is expensive and companies make money on it. You do not want a company that is going to come in and gouge you for testing that will not get you closer to answers. You need a company that works with you to help figure out the issue.

What Are Better Alternatives?

If you are concerned about mold in your home, it is better to:
• Get a comprehensive mold testing from a certified professional who can assess the entire property, including hidden areas.
• Conduct moisture inspection/testing to identify areas prone to mold growth.
• Consider testing for mycotoxins in the air if you suspect serious health effects, as this might give a better sense of whether mold is actively producing harmful substances.
• Consider VOC testing as mold will put off their own version of a voc called an mvoc while it is actively growing.
A combination of testing, professional evaluation, and environmental assessment is often necessary to get a complete picture of a mold problem. If you or someone you love is having issues in their home and mold/moisture may be a concern, contact Environmental Consultants of Ohio for a free consultation. 

Text 614.286.5229 and let Laura know that you have a mold issue and need help.