ERMI – what it is and isn’t

Update Sept.24, 2019 - We had such high hopes for tenants suffering from uncorrected mold problems when this law was passed. The reality is the San Francisco Building Department seldom issues a Notice of Violation for Mold - even when it looks like this photo. They say they don't have the trained staff to perform the inspections. We can assure you the few NOVs for mold that we have seen were definitely not prepared by anyone with any toxic mold training.  ... heavy sigh...Please contact your Supervisor and request help based on this Bill.

house-dustERMI testing measures composite dust in your home, office, or vehicle. The results will tell you and your medical team about your historical exposure risks.

ERMI is a composite dust sample and can’t identify the source of water intrusions that created a mold problem, or how to fix the mold problem. You need non-viable mold air sampling to do that. This is a direct quote from the EPA website: “the ERMI should be used only for research.  The ERMI has not been validated for routine public use in homes, schools, or other buildings.”

The EPA (Environmental Protection Agency) created the Environmental Relative Moldiness Index (ERMI). This test is still considered to be most appropriate for research. To create a baseline, EPA sent techs out into the low-income housing projects to measure mold without regard to the condition of the building, nor the housekeeping: only consideration of the levels of mold spores in the dust that were found. The baseline had been determined. Now, whenever an ERMI test is performed in an environmental lab, the results are theoretically integrated into the EPA’s ERMI database.

ERMI testing requires approximately 1 tbs. of dust. An ERMI test cannot tell if the mold spores in the dust came from outside of from a mold reservoir behind the refrigerator.

At American Air Testing we measure the levels of mold spores that are in your breathing zone and settled on your contents. This way we can give your directions to clean up your living and work areas.

For more information on how our testing differs from ERMI, call us at 415-337-2923.

We can’t give house or work cleanup instructions from ERMI or MARIA dust testing alone.

[wpforms id=”11259″]

Share This Post

Share on facebook
Share on linkedin
Share on twitter
Share on email

More To Explore

dust mite


We test the dust in your home, office, or car to find your allergy triggers identified by your allergist. MARIA dust testing will show the

graphic how many asbestos samples


The number of asbestos bulk samples needed to determine if asbestos fibers are present in building materials depends on how large the area is of