Once you have decided to have your home or office tested for mold it is important to understand the different types of mold testing that are available and their limitations.

#1: "Tape” or “surface” testing is accomplished by placing a special tape onto a flat surface to measure the amount of mold within a given surface area. The tape samples are then sent to a laboratory for analysis. Typically, results are given in terms of “low”, “moderate”, or “high” but do not tell you how much you are breathing in. Some insurance companies require this type of sampling to verify cleanliness after a mold abatement company has completed their work. Because nothing is known of the area before any contamination took place it is impossible to determine what is “clean” and therefore results are subjective.

#2: “Agar” or “plate” testing can be accomplished by purchasing an agar plate(s) at a local “big box” store, opening the lid for a certain amount of time, and then sending the sealed plate(s) to a lab for analyses. The biggest benefit of this type of testing is cost as it can be performed by anyone without special equipment. However, results are subjective as only the mold spores that randomly fall on the agar plate are identified.

#3: The third type of testing used to determine if mold contamination is present is “air testing”. This process is typically performed by an individual who has been trained as specialized equipment is needed and calculations are usually necessary to interpret results. The hygienist should typically inspect the suspect area looking for visible mold growth, areas of water infiltration, and other sources that may be contributing to the amount of mold in the air. The air sampling is typically done using a vacuum pump. Mold spores in the air will be deposited on agar plates or tape cassettes which are sent to a laboratory for analyses. The location of the air coming into the potentially contaminated area must also be tested to make sure that the mold found on the samples is not from the outside. The biggest limitation of this type of testing is the cost. The hygienist will charge for his/her time as well as the cost of the analyses. Make sure that any hygienist you hire has “Professional Liability Insurance” and that the laboratory performing the analyses is accredited. Insist on seeing proof of both before work starts.

Part three of this series will deal with the interpretation of testing results and identification of different types of mold.

Fungus "Amungus": There's a Water Leak in My Home or Business. Now What? -Part I
Fungus "Amungus": There's a Water Leak in My Home or Business. Now What? -Part III

Posted ByStephen Badger, CSP, OHST, WCP®