If you’re ready to learn about all things related to mold cross contamination, you’ve come to the right place. 

Whether you built a new home and the building materials were exposed to heavy rain, or live in an old home with a musty basement and mold problem in that attic, toxic mold can occur.

We’ve lived in a moldy home and helped many clients overcome mold toxicity. We understand the adverse health effects mold can have and can help you learn how to have a clean environment to avoid long-term mold damage or illness. 

This post will discuss how mold cross contamination occurs, why it’s a problem, how to prevent mold cross-contamination, and how to remedy mold contamination if exposed. 

What is Mold Cross Contamination

Mold cross contamination occurs when an individual or object has been contaminated with mold, and that mold transfers to the next object, location etc.

Mold spores are unbelievably tiny and pervasive. Their microscopic size and weight, in combination with the air currents and vibrations, is why they can travel easily from one destination to the next. 

So, if your clothing, furniture, toys, gym bag, etc. have been exposed to mold in your current home or while you’re at work or the gym, the spores will transfer to your next destination.

This can be problematic because, depending on the strains of mold plus your genetic ability to detoxify, you and your family may be at risk for serious health consequences. 

Issues like asthma, autoimmunity, food allergies, and cancer do not magically appear without a cause. Most commonly, disease occurs from chronic inflammation and cellular damage after the body spends years ineffectively working around the clock to detoxify biotoxins like mold.

The scariest part? It’s possible to live in mold even if your hired mold specialist did not see anything (we’ve been there). Plus, contrary to popular belief, mold can also grow in a brand new place. Brand new homes and apartments are at high risk for mold growth because of exposure of the building materials. to moisture. Every indoor environment is at risk!

Mold cross contamination in a closet.

Common Scenarios of When Mold Cross Contamination is a Problem

There are a multitude of situations where mold cross contamination is a problem, but here are some of the situations we see most commonly in our functional nutrition practice:

  • Working in an office with leaks and the spores get in their clothes and on their shoes, and they track it into their home
  • Working in an environment where the individual is constantly subjected to mold (farm= bales of hay/barns are full of mold,  working as a custodian, commercial realtor inspecting old buildings for purchase, etc.)
  • Moving from an old house that contained mold and if clothes, furniture, toys, etc. are not properly handled, spores will transfer to the next location.
  • Basement mold gets into the HVAC system.
  • Mold has been detected in the home, but remediation was done incorrectly without proper containment.
  • Foods in a fridge can acquire mold, especially in the fruit container, and if not cleaned properly, it gets on other fruit added back in. If not washed properly, it may get consumed. 
  • Bruised areas of fruits and vegetables that quickly grow mold were not cut out before being consumed.
  • When building a new home due to exposure of the building materials to rain, snow, and high humidity during the building process. 

Oh and speaking of edible mold, did you know coffee tends to be one of the moldiest products on the planet? If you are a coffee lover, be sure to check out our post on the best mold free coffee options!!

Why Mold Cross Contamination Can Be a Problem

Mold cross contamination can be a problem when you are genetically susceptible. However, this is a tricky topic because mold exposure, even in the most minor amounts, can cause extreme illness for some. For others, it rarely causes a problem unless they have prolonged exposure, such as in their bedroom. 

For those in the ~25% of people whose bodies cannot detox from mold, even a 10-minute exposure may provoke symptoms like headache or fatigue.😣

Others may not notice much, if anything at all. 

Therefore, if you are a part of ~25% of the population with a genetic predisposition to be affected by mold, cross contamination will cause significant problems.

Explicitly speaking, those carrying the HLA-DR gene can make it more challenging to clear mold and similar biotoxins.

Mycotoxin Illness and Free Radicals

One of the major issues with black mold and other types of mold with prolonged exposure is the amount of oxidative stress that occurs from free radicals.

We’ve all heard about antioxidants and know they’re good for us. 

But why?

The reason antioxidants are so helpful is that they help get rid of free radicals.  Antioxidants bind to free radicals and neutralize them to remove them from the body. 

With prolonged exposure of black mold and other type of mold we experience inflammation and the immune system is overwhelmed, leading to a build-up of free radicals in the body. This is one of the reasons we wrote an entire post on supplementing with quercetin for mold, one of the strongest antioxidant supplements available.

Quercetin is a great choice to help in recovery once you’ve started a comprehensive mold detox supplement routine.

We have extensive experience in helping clients detox from mold and wrote an entire post on the 13 Best Supplements for Mold Detox.

Making sure to eat a lot of colorful foods that are high in antioxidants and drinking lots of water with electrolytes is the firs place to start in your recovery. From there, consider using a powerful quercetin supplement in combination with detox binders in your comprehensive mold detox routine to help our bodies fight free radicals and oxidative stress. 

Remember that recovering from mold and battling free radicals is not a one-size-fits-all approach.  Working one-on-one with a functional nutrition coach on our team who has experience helping clients overcome mold illness can speed up your recovery. 

What are the Potential Health Risks Associated with Mold Cross Contamination?

Each individual will exhibit slightly different symptoms after exposure to mold and their associated mycotoxin particles. There are a number of factors that play into the situation, such as lifestyle habits, diet, genetics, and gut health.

However, generally speaking, the short-term health impact of these particles tend to include the following symptoms:

  • Headache
  • Fatigue
  • Dry Cough
  • Shortness of breath
  • Sinus congestion or constant running
  • Muscle aches/joint aches
  • Constant urination
  • Food sensitivities
  • New, unexplained gut issues.

Intrigued? We have an even longer symptom list in our article about biotoxin illness and how to overcome it quickly.

Are you curious if mold is inside your home? Here are the key signs that mold might be living inside your home.

If left untreated, potential long-term health complications from mold cross-contamination include but are not limited to:

  • Autoimmune disease
  • Asthma
  • Severe allergies (food and environmental)
  • Skin issues like eczema or psoriasis
  • Cancer (Particularly those more hormonal in nature, affecting more sensitive parts of the body such as ovaries and testicles)

Curious how to test if you have mold toxins in your body? Here is everything you need to know about how to test your body for mycotoxins.

Also, if you’d like to learn more about how long mycotoxins stay in the body and what to expect in recovery from mold illness, we have all the dirty details here.

Mold contamination near the HVAC system.
The mold developed from water damage in the utility closet and was next to the HVAC system.

Why Microscopic Mold Spores Can Get Everywhere

Mycotoxins are the toxic spores given off from different types of mold. It’s how they spread and stay alive. 

The issue is that airborne mold spores are super-super small and can infiltrate everywhere. 

It doesn’t matter if you live in a massive house with 7,000 square feet of space. A minor mold problem will make its way into your home’s airflow and infiltrate nearly every part of the house. Pair a moist environment from summer humidity or a small leak with air movement from your home’s HVAC system; you could have a situation that could make you extremely ill. 

How to Know if Mold Spores Are in Your Air Flow

One method to check if mold and mycotoxins are in your air flow is to have a specialists take air samples.

This can be expensive and we’ve gone through this process. The results were not conclusive for us and thankfully, we kept searching until we found the source in our attic space.

Alternatively, you can also use a got mold? test kit which has quickly become the best way to DIY home air testing for mold. If you’re willing to do it yourself, you can save a lot of $$$.

How to Prevent Mold Cross Contamination

Here are some of the best ways to prevent mold cross contamination and improve indoor air quality: 

  • Take off your shoes when entering your home
  • Wipe down lunch bags and coolers
  • Wipe down inside of the fridge where moldy or overripe fruits and vegetables are stored
  • Keep a constant eye on the rubber interior of your washing machine. Keep it open when not in use and clean mold growth as soon as you see it.
  • Change furnace and car air filters regularly
  • Run Superstratum bomb in your car with HVAC running every few years to clean and prevent mold from forming in the air system.
  • Keep indoor humidity below 50-55% and use dehumidifiers to limit mold from developing in a basement or other parts of your home. Our favorite dehumidifier is the Midea Cube which has won several awards.. We have 2 of these.
  • Consider using an air filter for your bedroom.
  • Put the bathroom fans on wall switch timers and set them to run for an hour after showers. Or, replace your fans with one that includes a humidistat that will run the fan until the humidity drops below a certain level. We used the humidistat fan in our kids bathroom and the timer in our owners bath.  
  • Consider an ERV to constantly bring fresh air into your home instead of allowing the same air to be recirculated. We have the Panasonic Intelli-balance 100.

Cleaning & Remediation – Steps to Take if. Mold Cross Contamination Occurs

Next up is possibly the most important information in this article. Here are our steps to take when mold cross contamination occurs:

If Contamination is a Part of Your Home Environment / Structure:

1. If possible, create a containment. This can be done with plastic drop cloths and tape found in the painting section of a hardware store.

2. When possible, crack a window in the area of the contamination to bring fresh air in.

3. If you’ve suffered from mold illness in the past, contract a specialist to perform the remediation and, whenever possible, ask that they REMOVE/REPLACE the affected materials instead of cleaning them (i.e. tear out drywall, remove insulation, etc.). If they say they plan to clean with bleach, find a new specialist. Be sure that they set up a second containment zone outside of the entire area they’re working so the rest of the home does not become contaminated with mold spores. 

4. If you insist on doing the work yourself, be sure to wear a respirator to avoid breathing in mold spores and a disposable hazmat suit for protective gear to limit cross contamination when you leave the containment area. 

Wearing mold protective gear and respirator to remediate mold.

5. For the items you cannot remove from your home i.e. studs, ceiling joist, etc. visibly try to clean the area with the non-toxic upertratum Everyday Cleaner to remove surface mold. For DEEP-rooted mold that is hard to clean, consider the Superstratum dot Deep Mold Stain Remover. Sand when possible to remove mold that has penetrated, then treat again with Supertratum Everyday Cleaner. If Superstratum is unavailable Concrobium Mold Control Spray is another great option that we’ve used. Both of these products are safer and cleaner alternatives to traditional shower mold and tile cleaners that are loaded with chemicals.  Just check the EWG Skin Deep database to check the harmful chemicals in your products.  

6. Treat the work area and local airflow with a Superstratum Remediation Bomb to kill mold spores and Mycotoxins in the air. 

7. Spray a mold-minimizing polymer coating with Superstratum Smart Polymer Coating to limit future mold It lasts 10 weeks in showers, 2 years outside, and up to 10 years in low-traffic areas like attics. 

Mold cross contamination containment example.
An example containment we set up at a rental home due to a roof leak in a rental we were in while building our house.

If Contamination is a Part of Your Furniture and Goods

1. Wipe down non-porous items like tables with vinegar and water or hydrogen peroxide solution. 

2. Wash clothes in an extra long cycle in hot water and add Borax which kills mold. This is the borax detergent booster we used. 

3. Dipose/trash porous items you’re unable to clean like couches or mattresses. 

If Contamination is in Your Car Air System

1. Back your car out into an open-air area where it can safely run for 20-60 minutes. 

2. Turn on your car air conditioner or heater on full speed and select the recycle air button to recirculate air in the cabin. 

3. Buy a Superstratum Remediation Bomb and place it in the center of the car.

​4. Quickly exit once you have the remediation bomb set up and let the car run/recirculate the air from the remediation bomb.

5. After 20-60 minutes. Turn off the car and let the car sit overnight. In the morning, open the windows and let the car air out.  A chlorine-like smell may linger for up to a week. 

Cleaning Mold Cross Contamination with Hydrogen Peroxide

When it comes to cleaning mold, we’ve personally found Superstratum and Concrobium to be the most effective products. They’re also safe for humans and pets. 

Two other popular cleaning solutions that are also safe for humans are hydrogen peroxide and vinegar.

You may mix water and 5% vinegar or 3% hydrogen peroxide with water in a spray bottle to wipe things down if you already have. the supplies and would prefer not to buy Superstratum or Concrobium.

DIY vs. Professional Help

There are 3 common situations when you should consider professional help:

1. When you or someone else living in the house have been showing signs of fatigue or mold illness or have suffered from mold illness. 

2. The amount of mold in the affected area is one that you cannot quickly remediate and may be a lengthy project. When possible, hire a contractor that can complete the work in as short an amount of time as possible. 

3. You’re unsure of the extent of the mold and all the areas affected. Experienced mold specialists know all the places to look for mold you may not think of. 

If you feel poorly in your own home, but you are having trouble identifying the source, we highly recommend hiring a professional.

Also, if you have a mold problem and someone tries to tell you that mold between walls, such as in an attic space, cannot make you sick, find someone else because this is absolutely not true!

Common Myths and Misconceptions – Debunking Myths About Mold

It’s time to debunk some of the biggest myths and misconceptions about mold. The confusion around this topic is often what prevents an individual from fully healing. 

Myth #1: It’s not possible to be sick from mold (mycotoxins) if you can’t see or smell it.

FALSE. Mold can make you sick even if it is trapped behind walls with zero residue hanging around anywhere. This is why someone can be living in it despite mold professionals coming in to say that your home is not full of mold.

These spores are so microscopic they can find their way to you through outlets, cracks, vents etc.

Myth #2: If I am feeling fine, there’s no way my family member could be sick from mold if we live under the same roof.

FALSE. Genetics and gut health play a significant role in detoxifying mold. If you are a part of the ~25% of the population that cannot filter and detox mold efficiently, you will feel horrible, while your spouse, child, etc. may not feel much of anything but a bit of fatigue or nasal congestion. 

Myth #3: I know I used to live in mold, but I haven’t lived there for 3 years, so I should be fine now.

FALSE. More often than not, steps need to be taken to remove the mold from your body, as it often does not clear on its own. Again, genetics play a major role in this equation. Removing yourself from the source is critical, but you will likely have to work with a trained professional, and detoxify with professional grade binders, saunas, and supplements like glutathione etc. to truly heal.

Myth #4. A brief mold exposure isn’t a big deal.

FALSE. Unfortunately, for plenty of individuals, this is not true. I’ve had clients who could not even drive their car for a 5-minute trip because of the mold in their air vents. I’ve had clients who could not shovel hay for 10 minutes because the mold in their barn was so offensive to their immune system.

Now, yet again, genetics plays a role here, too. Plenty will struggle, and plenty will deal with it just fine. 

Our Real-Life Examples of Mold Cross Contamination

Sad but true, we are sitting here speaking from first-hand experience. Unfortunately, we were exposed to extreme mold on three different occasions, two of which we will highlight here. The two worst situations were before we knew what we know now and occured when we lived in a remodeled apartment complex downtown and built a new townhome.

Let us be the ones to tell you that mold was present even when we couldn’t see it with the naked eye. As a result of all the hidden water damage, we experienced severe long-term mold damage and illness.

Black mold in new home attic space with water damage
This was the mold in our new home just above the drywall in our bedroom.

When we finally realized what was happening and realized it was time to move on to a new location, we took a major steps to stop mold cross contamination in its tracks.

  1. When it was in our new home, we immediately moved out and moved in with family members.🙏
  2. We washed all of our laundry in Borax to remove the spores and not have to buy an entirely new wardrobe. We recommend using the steam cycle on your washer if available.
  3. We threw away everything porous, such as pillows and mattresses. Stuff that cannot easily be wiped down and completely sanitized must go.
  4. Hard objects like books and tables were saved and wiped down with a white vinegar solution or Concrobium spray. The old-school approach is to just bleach everything out but that can be incredibly toxic and does not always kill the mold – the last thing your immune system needs after being exposed to mycotoxins is more toxins, so stay away from bleach and other harmful cleaners.

Back in my days working at the Cleveland Clinic Center for Functional Medicine, certain docs would tell their patients to throw away absolutely everything porous – this meant even birth certificates and marriage licenses. 

We usually do not recommend going that far unless someone is incredibly sensitive and extremely ill. And even in those cases, we often recommend the prized possessions be stored in an airtight container away from the individual’s main living space and using gloves when handling them if someone must while they’re still recovering.

It’s also important to remember that when an individual is appropriately detoxed from mold and other biotoxin illnesses, many of these contaminated objects will no longer pose such a threat. This is especially true when a proper biotoxin binder is utilized under the direction of a trained professional. 


In summary, mold cross contamination is a very real issue. However, it typically only affects highly sensitive or chronically ill people. Often, these two issues go hand in hand.

If you feel that mold cross contamination might be causing you to feel poorly, schedule a free 15-minute strategy call with one of our dietitians. We have several functionally trained dietitians on staff who specialize in creating individualized nutrition and supplement plans to combat mold exposure. 

Our team can help you strategize when it comes to preventing mold cross contamination at home and work. We can also help direct you toward foods less likely to contain mold. We’d even be willing to share details regarding our personal mold remediation projects.


  1. https://pubmed.ncbi.nlm.nih.gov/12762072/
  2. https://www.jacionline.org/article/S0091-6749(03)02676-9/fulltext
  3. https://www.mdpi.com/2072-6651/14/3/189
  4. https://err.ersjournals.com/content/27/148/170137