JANUARY BLOG: What is ERMI Testing?

East Bay Indoor Environmental

The indoors is OUR Environment!

January Newsletter:

What is ERMI testing?

Hello All!

Thank you for taking time out of your busy schedules to spend a few moments with us. East Bay Indoor Environmental is your resource for all matters of creating a healthier indoor environment. Like every month, we strive to give our readers a kernel or two of information to improve and maintain a healthy live/work space. This month comes from the field. When the rain comes, mold concerns increase. Mold is naturally occurring, but when dampness, odors, and damaged building materials occur we must find and remove the source as best we can. There are a few different sampling methods in the marketplace. ERMI testing is probably the most “famous” of the group but as you’ll learn fame does not always equate to application.

The ERMI or The Environmental Relative Moldiness index (ERMI) was developed by the U.S. Environmental Protection Agency, Office of Research and Development (ORD) as a research tool to investigate mold contamination in homes. Dust samples are collected in a home and DNA from mold in the dust is analyzed. The sample is then compared to the ERMI, an index or scale, which was developed for use in the U.S. The analysis can be used by researchers to estimate the amount of mold in a home as well as indicate some of the types of mold that are present.



The Institute of Medicine report, Damp Indoor Spaces and Health (2004), recommended the development of “More rapid measurement methods for specific microorganisms that use DNA-based and other technology.” This report also indicated that the “Application of the new or improved methods will allow more valid exposure assessment of microorganisms and their components, which should facilitate more-informed risk assessments.” After ten years of research, EPA patented such a method called mold specific quantitative PCR (MSQPCR). MSQPCR is a DNA based method for quantifying molds. The “application” of the MSQPCR technology has resulted in the development of the ERMI.

Essentially, there was a point in time where and national index was to be created where homes, schools, and other buildings can be sampled and compared to the national index. Are you starting to see the potential for accuracy issues? There is mold everywhere, in every home, school, and building but are you breathing it? Are there damaged materials? How is the domestic hygiene? What’s the average relative humidity in the space? What time of year did the issue present itself?

ERMI on the rise…

A number of years ago a booked called Surviving Mold got the world of health, wealthness, and indoor air quality in an uproar. CFS or chronic fatigue syndrome was being linked to mold exposure. One of the most famous name is the “Mold-o-sphere” is Dr. Ritchie Shoemaker. Shoemaker’s website discusses mold-induced chronic inflammatory response syndrome (CIRS) ad nauseum. This disease encompasses a gamut of vague symptomatology, defined as “an acute and chronic, systemic inflammatory response syndrome” in response to mold, bacteria, and other “pro-inflammatory” exposures. The scientific evidence to back up CIRS is severely lacking, and if you search for more details on specific clinical descriptors, you will end up empty-handed, according to TheDailyBeast, Though the EPA does not recommend ERMI for public use it is one of the methods of choice. Fortunately, Shoemaker offers to train (for a fee) other physicians with his “Shoemaker Protocol,” a program to help them detect and treat CIRS. Online memberships are offered for all website visitors, ranging in price from $19.50 per month to $175 for a 12-month subscription. The memberships offer screening tools, email consultations with Shoemaker, and other “Surviving Mold” materials.

Are there any advantages to ERMI?

The simplicity of taking only one sample, the ERMI offers several advantages over traditional mold screening methods. Carpet dust acts as a reservoir for mold spores and is more representative of mold levels over time versus short-term air samples. The use of MSQPCR for this test allows for increased precision as it is based on a biochemical assay using calibrated instrumentation. Further research is being conducted and published that will link the ERMI assessing health risks for susceptible individuals. This information along with the national database will be invaluable in providing an objective and standardized method for screening homes for mold.

Where does it fall short?

Well, it tells you on the label. “As research continues, the index will be refined. At this point in its development, the ERMI should be used only for research. The ERMI has not been validated for routine public use in homes, schools, or other buildings. EPA does not recommend that homes routinely be tested or sampled for mold. Testing may be done for research. Testing may also be useful to help characterize or identify mold problems in some buildings. Physical inspection for water damage and mold is a key part of current EPA mold remediation guidance.”

For the best evaluation of your indoor space and more importantly the air that you and your loved one’s are breathing, sampling via bioaerosol sampling cassette submitted to an accredited 3rd party laboratory is still the best method. Contact your local indoor air quality company and or reputable mold and odor mitigation company near you for more information.


Want to do some research?

The Environmental Protection Agency

Understanding and Applying ERMI



Why is the internet so obsessed with “toxic mold”


If you’re curious about your indoors, send us a question and we may select your topic for our next newsletter! Info@ebindoors.com

See you next month for next topic!