Testing Your Home for Mold

Testing your home or workplace for excessive levels of mold is an easy task and, if performed using the proper steps, can minimize unnecessary expenses.

ERMI (Environmental Relative Moldiness Index):

This test can be used as an initial screening test of your environment. This test involves collecting dust samples yourself and having them analyzed for fungal DNA.

The ERMI does allow you to compare the amount and types of mold in your environment with the labs national database of approximately a thousand homes, however, since their database has not been standardized, their “ERMI Score” may not be a reliable indicator. The ERMI test does, however, give you a reasonably accurate identification of the mold species found.

Note that certain species of mold do not easily show up on ERMI testing. The ERMI score is simply the difference in the log transformed total of the two groups. Make sure that you use EPA ERMI testing.

Traditional mould analysis compared to a DNA-based method of mould analysis article

“Traditional mould analysis compared to a DNA-based method of mould analysis” (PDF). Critical Reviews in Microbiology, 2010, 1–10,
Early Online ERMI article by Lin/Shoemaker

Instructions for completing your Mycometrics ERMI sample

Home Inspection:

Inspection by a Certified Mold Expert or Industrial Hygienist is the next step if your ERMI score is elevated or you are strongly suspicious and have chosen to forego the ERMI. It is important for you to decide that remediation is the route you have chosen (as opposed to moving out permanently) before starting a inspection by a mold expert as their findings once completed become public knowledge.

Please note that there can be a world of difference between someone with 20-30 years of experience in the field versus someone who was “certified” after attending a weekend course. Choose carefully.

The following websites may also be helpful:

  • IICRC (Institute of Inspection, Cleaning and Restoration Certification. http://iicrc.org/

  • ACAC (American Council for Accredited Certification)—a certifying body that is third-party accredited. www.acac.org/

As mentioned earlier, since water damaged buildings can harbor mold, bacteria, actinomycetes, mold spores, mycotoxins, endotoxins, and microbial VOCs, among others, the testing should be comprehensive enough to reflect this. Make sure it includes the following:

  • Air Sampling

  • Bulk Sampling (such as pieces of baseboards, wall paper, dry wall and other areas with suspicious growth)

  • Testing for gram positive and gram negative bacteria.

  • Testing for toxins from microbial growth (mycotoxins, endotoxins, beta D glucan, ...)

  • Moisture evaluation of walls, floors and other areas with a moisture meter.

  • A thorough, visual inspection of the home, including the attic, crawl space, and roof.

John Banta, RestCon Environmental logo

Locally, John Banta of RestCon Environmental is a useful resource for home inspections. Phone: 1-888-617-3266 - www.restconenvironmental.com

Proper Decontamination of Your Home