Mold test kits are unreliable and here is why. A mold test kit is simply a petri dish, so named after a German bacteriologist by the name of J.R. Petri. The dish contains moisture and nutrient and is used in laboratories for culturing bacteria and other microorganisms.
Mold, known by its scientific name as fungus, is a microorganism found everywhere in nature. Its purpose in life is to help dead organic material to decay. It needs a surface to grow on, food, and moisture in order to grow.
Mold reproduces by sending spores into the air. These microscopic seeds then float through the air and settle on surfaces. When they happen to land in a good environment with food and moisture, they grow. Petri dish type mold test kits provide a very good environment for mold growth, thus
…any airborne spores can land and
grow on mold test kits!
As mold inspectors, we receive many calls from people who are alarmed after seeing things growing on their petri type mold test kits. We explain that all it means is that one or more spores landed on the petri dish and grew, but that does not mean that they have a mold problem in their house. In most cases, after testing the air, we find normal levels of mold spores for all species compared to the outside control.
The only reliable mold test we know is to test the air for mold spores by collecting one or more indoor air samples and collecting an outside air sample as a control. If a mold contamination is present, excess mold spores will be in the air. An air test is both qualifying and quantifying. It tells us the species that are present and also their amounts.
In conclusion, these types of mold test kits are totally unreliable
for testing indoor air quality in relation to mold.
If you believe you may have a mold problem, hire a professional mold assessor to collect air samples. Lastly, make sure this mold assessor does not also perform mold remediation, which could lead to conflict of interest, and make sure he is a seasoned mold assessor who knows how to interpret mold reports.