Mold Testing Services
Mold Testing -- Sioux Falls, South Dakota
Home Test Kits (Settle Plates)
Low cost home test kits for mold are in wide use (about $10/plate). These are “settle plates” where growth media is placed in a petri plate. The bottom of the plate should be labeled as to the date and room tested. The cover is lifted for a certain amount of time (often an hour) and mold spores present in the air settle out onto the plate. Some of these mold spores will grow. The cover is put back and the petri plate incubated (kept in a paper bag) for 3-4 days. After a few days, visible mold colonies (spots) will occur on the plate. These tests are MUCH less reliable than standard airborne mold tests. Because a pump is not used, there is no way to calibrate the amount of air the plate was exposed to. These tests often fail to detect the most common forms of problem indoor molds.

However, especially for persons with limited means, such tests may sometimes provide a crude indicator as to whether an obvious airborne mold problem exists. Such tests may justify more detailed assessment. See MTS handout on home test kits in the Documents section. It is important to take a number of tests in different rooms and compare them to each other. Photos and/or tape lifts can be taken of the plates. Time is critical as it takes 3-4 days to notice the mold colonies but after about 5-7 days, some of the mold colonies have completely overgrown the plate, making it impossible to count the individual colonies.

MTS sometimes offer assistance to persons who have used home test kits. We are willing to look at digital photos of the plates e-mailed to us. We do not consider home tests kits reliable.