What is a False Negative Mold Test?

It’s actually pretty easy to get a false negative indoor air mold test. 

False negative results can give you a false sense of security, and all the while, your family could be in contact with high levels of mold, experiencing a myriad of symptoms. 

Let’s look at some things that can lead to a false negative mold test and ways to ensure that you get accurate results from professional mold testing. 

What Leads to a False Negative Mold Test?

When you’re paying for professional services, you expect to get accurate results. There’s no harm in getting a second opinion about mold test results, but by following the guidelines below, you should be able to rely on your first results. 

• Hire a qualified, experienced mold specialist. Make sure the team you choose is staying informed about the latest mold testing techniques and they keep the best equipment for the job on hand. Pure Air Solutions offers mold testing in the Bowling Green area.
• Take a representative sample. Room air testing is a representation of the air quality at a given moment, so these results can vary greatly even when samples were taken just a few minutes apart. There are multiple factors that can affect air quality from one moment to the next. A sample from the living room may give passing results, while mold is rampant in the bathroom or basement. 
• Employ more than one testing method. Because it’s hard to get a representative sample based only room air, professionals should use more than one mold testing method, including tap tests, swabs, and dust samples. 
• Consider the time of year. Summer is the worst time for mold due to the warm temps and moist air, but it isn’t the only time mold can be an issue. During warmer months, it will be easier to get a true positive, but during the fall and winter when it’s colder outside, mold growth can slow (but not stop altogether), making it harder to get a positive result, even though the same amount of mold is present. 
• Ensure proper conditions. When mold testing is done, you should keep the conditions in your home as close to normal as possible. For example, vacuuming right before the testers come can skew results. Another example is ceiling fans. If they usually run, leave them on during testing. 
• Use common sense.  A good mold removal team may be able to use nothing but their own senses to search for indoor mold. They know exactly what mold smells like, and upon visual inspection, they may not need to test your home at all. If you have had a water leak, that’s another red flag for mold.  

Indoor Air Sample Testing 

Air tests for mold aren’t bad, but they do have some limitations. They can be unreliable based on any of the factors above. 

As long as you’ve followed the guidelines above, you should be all set to get an accurate reading within your home. 

Should it be used at all? 

With that in mind, it begs the question of whether or not indoor air testing is an appropriate way to test for mold. Yes, it is still an accepted method used by professionals all over the U.S. As long as air testing is used in conjunction with other testing methods, it will yield a comprehensive picture of the mold content in your home. 

Here are a few of the other testing methods your mold company may use: 

• Tap test – This method is used for upholstery and drapes that are suspected to have mold growing on them. 
• Swab – A swab test is generally reserved for harder surfaces. 
• Tape – A tape test can be used on virtually any surface. A mold removal pro will know which tapes can be used on specific fabrics to protect them. 
• Bulk testing – This method involves collecting materials from the home and testing them back at the lab. 
• Intrusive – In worst-case scenarios, it’s necessary to cut out building materials to find the source of the mold problem.  

You mold company will take multiple samples from each test they perform for the most accurate results.

Improve Your Chances of an Accurate Reading 

As you prepare for your professional mold test, follow these steps so there’s less chance of getting a false negative. 

• Do tests more frequently

Having your home tested for mold regularly will give you and the testing company a clearer picture of mold content in your home. And if there’s an issue, you will know more precisely when it started.  

• Open interior doors. 

One of the worst things you can do is close off parts of your home during testing. Open them up so air flows freely throughout the home. 

• Close exterior doors and windows. 

In contrast, you need to close all the doors and windows that lead outside. There is mold in the air outside in varying levels, so you don’t want the natural outdoor mold to interfere with your indoor testing results. 

• Leave your HVAC system and overhead fans running as usual. 

When you turn off the HVAC and ceiling fans, mold spores have a chance to settle. If you are only using air testing, there won’t be any mold in the air, but as soon as you turn the fans and HVAC back on, they will stir up and circulate freely again. 

• Don’t clean right before air testing. 

We discussed vacuuming in a previous section, but the same goes for other cleaning. It can be hard to resist the urge to clean when any sort of guests will be in your home, but by not cleaning, you’ll get the most accurate mold test results. 

If there’s any question about the presence of mold, have thorough testing done by Pure Air Solutions to eliminate the possibility of a false negative.