Home Cleaning Tips How Much Mold Is REALLY Being Tracked Into Your Home? The White Towel Test, Take #2

How Much Mold Is REALLY Being Tracked Into Your Home? The White Towel Test, Take #2

by Catherine

Hi, guys. Today I want to address a reader’s comment about “The White Towel Test.” She didn’t feel the post addressed how much mold was REALLY being tracked into her home. The reader wrote,

“Of course the towel is going to get dirty. That’s a ‘duhhhh!’ How do you know there’s mold on the towel? I have a pet that can come and go at will, have used towels on my carpet on the high traffic areas for years, then wash them & use them again. I don’t see what this test is telling me other than we have dirty feet. Sorry. I was hoping for more.”

Reading the comment, of course, deflated me a bit, but I get it. She really was hoping for more information on mold specifically.

Before I address her question, I do want to say that the White Towel Test is only meant to create awareness, rather than a definitive diagnosis of the amount of mold that is tracked into your home each day. Putting the white towel down and consciously stepping onto it before entering your home causes you to pause and consider that every speck and micro-organism that ends up on that towel is also ending up inside of your home. Whether that is dirt, a leaf, a bug, whatever, each of those things has the potential to bring mold and bacteria with it. My thought in posting about the test was that sometimes, seeing a concept with a solid, undeniable picture helps people to make changes. That was the purpose of the experiment. Before I did it for the first time, we were not a family who took their shoes off at the door. I had always thought that was silly and a little OCD on the cleanliness scale. After doing the test myself, and seeing what came in on our shoes, we made the across-the-board decision to take our shoes off before entering our home.  It is just one of the many practical and FREE solutions we instituted in our home for lessening our mold exposure.

Back the reader’s desire to know more about the amount of mold being tracked into her home. To address her concern, I could think of no better way, than to perform an additional, more scientific test. This time, not only will I perform and document the white towel test, but I will TAP test the towel for mold prior to us walking on it for 2 days, and then, at the end of the 2 days, when it is dirty with footprints. My hope is that the second TAP test will show the difference. This will present a clear visual of what, in terms of mold, is happening when you wear your shoes outside and then walk all through your home.

TAP Test # 1

(Note: For detailed information on TAP Testing and where to purchase the EC3 Mold Screening Test Plates that I used for this post, click HERE.)

On Day 1, I took a clean, white towel down from our garage shelf. (Note: I used one of our “car wash” towels, because I really didn’t want to contaminate a towel we would ever be using on our faces or bodies for this test.) I placed it on the kitchen floor and got out my EC3 Mold Screening Test Plates and supplies for TAP Testing. I performed a TAP Test on the clean towel, sealed and covered the test plate with aluminum foil and placed in a drawer to incubate.

Then, I placed the clean towel in front of our back door, so that we could all step onto it as we entered and exited our home for the next 2 days.

After TAP testing the clean towel, it is ready to be stepped on in front of the back door.

TAP Test # 2

Two days after putting the clean towel down, I was ready to see how much mold it had accumulated. So, I took my second EC3 Mold Screening Test Plate and used it to TAP Test the dirty towel. I sealed and covered the test plate with aluminum foil, wrote the test date on it, and placed it in a drawer to incubate.


Here is my watch with the “clean” towel test plate. I collected the sample on 8/17 and my watch is shown to display the date that I recorded my results, today, 8/22. This is 5 days of incubation time for this plate.

I collected the “dirty” towel test sample on 8/19, 2 days after I put the towel down for us to walk on. Because I recorded the results today, 8/22, this plate only had 4 days to incubate.

TAP Test #1 of the clean towel cultured 2 mold colonies over the 5 day incubation period. According to the test key that comes with the plates, this result equals a “low risk of inflammation.”

The 2 mold colonies are pretty clear. One is the green mold circle with the white perimeter and the other is the white circle under the “e” of towel. I had to take the picture pretty close and sharpen it quite a bit for both to clearly show.

To tell you the truth, I was quite disappointed that the “clean” towel cultured any mold at all. I wanted to show a totally clear test, but I also want to be totally honest and transparent on the blog. I did use one of our “car wash” towels that lives out in the garage–I stated why I did this above, which might explain why it had some mold spores on it at all. I do not use the EC3 Laundry Additive on these towels, because we don’t typically use them inside our home, or on our bodies. I think I’m going to have to start periodically cleaning them for mold, though. It looks like they need it, especially if they are to ever come inside again. So, in a way, this test is telling me that unless I am actively cleaning things that leave my home for mold, things like towels, clothing, etc., are going to pick up mold spores and potentially bring them inside. Most people would not be bothered health-wise by this level of mold spores as indicated by the test results, but anyone who is mold-sensitive, or allergic to mold would get sick from using this towel. Just something to consider…

TAP Test #2 of the towel after we walked over it with our dirty shoes for 2 days cultured 16+ mold colonies after only 4 days of incubation! (I had to cut this test one day short to get the results posted this week on the blog.) As you can see by the pictures, there are 16 definite round circles of mold, and many additional tiny dots that will eventually grow out. They are so small, though, that they are too difficult to count. According to the test key that comes with the plates, this result equals a “Risk to ALL persons / Causes autoimmune diseases (also called TNTC – Too Numerous to Count).”

The 16+ colonies of mold that grew out on the dirty towel TAP test are difficult to see in the photograph. Some were located underneath the tape. The black center of one of the colonies indicates the possibility of a mycotoxin-producing mold.

I took this picture of the other side of the plate and sharpened it, so that you can better see all of the mold growth. Another important fact to remember about this “dirty towel” plate is that these are the results after only 4 days of incubation.

Also significant to show you in this test is the black center of one of the colonies. According to the test plate literature, these dark and black colonies are evidence of mycotoxin-producing mold spores. This result is alarming and also pretty gross, right? Not only, could you be tracking in mold, but mold that has the potential to expose dangerous toxins to your body. I also want you to remember that this test is just showing mold, and only showing it after 2 days. Imagine what gets tracked inside, in terms of mold, bacteria, dirt, etc. in a year’s time! Time to rethink wearing your shoes inside and cleaning them for mold, right?

Anyway, I hope that this testing gives you a better visual representation of how much mold you track into your home on a daily basis. Next week, I have a great post on the top 5 ways to prevent mold from being tracked inside. I hope you will tune in.

Please write to me or comment with any questions.

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