My Take on Professional Mold Testing: Test and Method Comparisons and Best Practices

Let’s talk professional mold testing. I get so many questions on the blog about it—almost daily questions. Thus, this post is for you! It is a brief rundown of my take on professional mold testing in your home. I will go over various tests and test methods and compare some of the most popular ways that professionals test the air and surfaces in your home for mold. I will also discuss best practices for sample collection. This is by no means an exhaustive list of all of the options. It is just an overview.

(Note: These are all just my insights and opinions given from my perspective and my experience. I am not a mold remediation professional, nor am I a doctor or licensed building biologist. Take all of this information at face value and consult a professional prior to any mold testing you decide to do on your home.)

First and foremost, I cannot launch into this post without mentioning the EC3 Mold Testing Plates. These plates are the simplest, most cost-effective way for you to take the reins and test the air and surfaces to see if you have a mold issue in your home or office. These plates are not a laboratory diagnostic test; however, they are the most trustworthy source to determine if mold is present and whether it is at unmanageable levels. These plates enable you to test and to also keep testing your environment and things on a regular basis to see if you have a mold issue, if what you are doing to clean for mold in your home is working, if something you are bringing into your home has mold, etc. The list can go on. The most important takeaway for you is to know that the EC3 Mold Test Plates put you in the driver’s seat, so that you do not have to wait or rely on a professional to confirm that your home or office has a mold problem. That is what makes these DIY test plates invaluable.

Doing these tests is important in my life to staying well. With them, I do not need to call a professional to do a simple test. I can do it myself, take my results and proceed accordingly, either moving ahead with what I am doing, consulting a professional for help fixing or remediating something, or getting rid of something entirely, if it has mold in it. For me, the EC3 Mold Test Plates are like mold security, because there is no reason not to test and not to know. These test plates also serve as a jumping off point for many, because, armed with what the plates reveal, they can proceed with professional testing and with finding the correct medical professionals, if what they are being affected by is, indeed, mold.

As far as diagnostic testing is concerned, MicroBalance Health Products also offers laboratory diagnostic testing kits on their site from ImmunoLytics. The diagnostic tests become important when you are interested in doing more in-depth testing to determinee what specific types of molds are present, at what concentrations and whether or not they are mycotoxin-producing molds. These tests are invaluable for all of the information that they can provide. Once you send the plates in, the lab will contact you with your results. You can discuss the results with scientists in the lab, in addition to having the results for a consultation with your doctor or mold remediation professional on next steps. This information is sometimes more conclusive than other methods professional mold inspectors use, which, for many people is a big selling point.

That being said, what I really want to breakdown for you in the remainder of this post are the particulars of some of the kinds of testing that can be done when you call a professional out to your home for help with a known mold issue, or an as yet undiscovered and possible mold issue. This usually occurs if and when people in the home start to become sick, and/or visible mold or musty smells occur.

First off, most really good folks who do this line of work want to do a visual inspection BEFORE doing any types of testing. If a mold inspector comes to your home and does not do a visual inspection, you have not hired the right person. Sometimes the visual inspection of your home is the most important thing that can be done. A seasoned professional will want to walk all around the interior and exterior of your home to see what is growing on surfaces, to see if there is any visible mold growth anywhere, to smell the inside of the home for mustiness, and to look for clues. Of equal importance is looking for dampness and moisture on surfaces and in the air. They will sometimes use a moisture meter to do this and will sometimes touch and feel walls, windows, etc.

Someone who truly knows what they are doing also knows that any air testing for mold spores is merely a snapshot of what is in the air at that exact time. Air tests try to capture what is there, but don’t always do that, because at the instant of testing, lots of factors can be at play, which I will discuss later. As a matter of fact, I have found air testing to be most valuable at the end of a remediation job to see what is still there before reconstruction begins. That way, if spore counts in the air are still high, things are still opened up and better accessible to being fixed. Not having to demo things and start over is good for everyone’s sanity.

One very popular type of air testing is ERMI (Environmental Relative Moldiness Index) Testing. An ERMI provides statistical analysis to create a single number people can look at to tell if the air in their home or office is moldier than most. In my opinion, while this can be beneficial information, there are many fundamental problems with testing based on comparison, especially when climate differences in different states cause the mold levels to vary tremendously. One simple way to illustrate this is just to think about the variance in outdoor spore counts on a seasonal basis—when outdoor spores are really high, like in the fall, an unsafe indoor space could look really good, in terms of mold counts.

ERMI Testing is also based on group 1 and 2 organisms, meaning that if a mold crosses over into more than one group, it is not necessarily picked up correctly for the purpose of determining a home’s or building’s health. For example, if a water-damaged building has extremely high mold levels, but that mold is only classified as one type by the ERMI, the ERMI comes back as low, even though the building is unsafe for human health, due to mold contamination. Also, the ERMI only tests for 36 organisms. This does save clients money, but many organisms are not being identified, and if you want to know what is there, you may be coming up short.

If you are looking to know more about the molds present in your home, PCR-DNA Analysis Tests are the way to go. This testing can look at specific molds that are present and can tell a lot about what is going on inside the home. For example, do we have molds that require a lot of water for a long period of time, like Stachybotrys, or is the mold we have a more quick-growing mold? In this way, taking culturable samples is ideal, because you can test for more than one organism in a single sample. You can also test mold to see if it is alive or dormant. This will tell you more about whether or not you have an active water source, or have a contaminated piece of furniture or an old leak that was fixed, but never properly remediated for mold. Again, this information can serve as valuable pieces to the puzzle about why your indoor mold levels are unsafe and how you should tackle fixing them.

Some professionals perform the HRTSMI-2 mold subset of testing that was made popular by Dr. Ritchie Shoemaker, one of the most well-known mold pioneers. His protocols informed the way mold illness and mold toxicity was first treated and still are looked to today for insight and guidance. It is a test that can be done in lieu of a full ERMI to test for only the molds that have been found to be the most reactionary for human health. It is a 5 organism panel of subset 1 of the ERMI, so, of course, it will not identify all of your issues. Since the test is designed from the medical perspective, not a building biology perspective, it doesn’t show you the most complete picture of what is going on in the indoor environment. For example, with a limited panel, you won’t always know if the molds present are water-loving, cooler climate molds, bacteria-loving molds, or molds that are more associated with condensation. All of this information helps a remediator find and solve the problem. I have also talked to many doctors with patients who have done only the HRTSMI-2 and had results that came back as ok, in other words, their environments did not contain one of the 5 molds on the test, but whose homes were contaminated with other molds and were making them sick. There are always outliers, but it seems to me, that if you are in the market for this type of species testing, you should just go ahead and do something a bit more complete and potentially enlightening.

Now, once the professional gets to the sample and air testing part of things, where should you have them test to get the most viable samples and results?

Well, if a professional is doing the vacuum dust method of collection and you have wall-to-wall carpet, then the carpet is definitely the best to place test, because the rooms in your home with carpet and carpet dust have been shown to accumulate the most mold as well. A test that I read about recently that illustrates this wonderfully is as follows:

When 50 square yards of 10-year-old carpet were vacuumed with a clean vacuum bag, 3 ounces of dirt were collected. Then, after the carpet and padding were pulled up, the floor underneath was again vacuumed using a clean vacuum bag. This yielded 3 pounds of dirt. When both dirt samples were analyzed and compared, the same amount of mold and types of mold were present above and below the carpet. Thus, even though the carpet had a smaller amount of dirt on top, it was not a barrier to the mold and contained just as much mold as the dirtier floor beneath it.

Takeaway: Test for mold, and then get rid of your carpet!

If you do not have carpet, your next best areas to collect samples are rugs, and upholstery.

If the professional is doing the wipe method of testing, it is best to have them wipe objects that are not as high up. I say this, because some of the heavier mold spores, like Stachybotrys take 5-8 minutes to settle out of the air, once disturbed. This means, that if Stachybotrys is present, it may not get high enough into the air to settle on a windowsill or on top of a refrigerator. Also, you want to make sure the wipe testing is done methodically and not in more than one place per sample. If you wipe all over the place, and find lots of mold, you have no idea where it came from when you are trying to figure out how to solve the problem. Of course, doing lots of samples is best, but is also very expensive, so you need to be judicious about where and what you test to get the best picture of what is going on in your home.

Some inspectors prefer to use the particle collection method of testing. In my opinion, this is not the best method. If you are paying someone to do this, the vacuum dust method and home inspections are the worth paying for. For particle counts, just purchase the Diagnostic Test Kit. It can yield much of the same information and more for less money.

Finally, do NOT have the professional take samples where you KNOW that a mold problem exists. I know, I know, this seems a little strange for me to say, but think about it this way: If you had a pipe leak and visible mold is growing as a result, then you KNOW you have a mold problem in that area, and  it needs to be fixed. Save your money on that area and have the professional test the air and surfaces in the surrounding rooms. You want to know how far the spores are spreading and at what concentration or gradient they are spreading to help guide your remediation.

Does this information help you? It is definitely a cursory summation of a LOT of material, so if you have a particular interest in one or more of the topics discussed in this post, please write to me and let me know. I can do a more in-depth post on that subject later on.