The term toxic mold is a bit misleading as it suggests that certain types of molds themselves are toxic. In reality, a very narrow set of molds produce secondary metabolites that produce toxins. These are known as mycotoxins.
Studies show that more than 50% of homes and more than 85% of commercial buildings in the U.S. have water damage and mold. Many experts say every home has some detectable amount of mold.
This is concerning since there is a strong likelihood that every water damaged building also has the presence of mycotoxins. This is why mold prevention and leak prevention are critical.

What Are Mycotoxins?
If you were to look up the definition of mycotoxins you would learn that mycotoxins are the toxic chemical substances that certain types of molds produce. These fungal toxins are volatile organic compounds amongst other things.
Mycotoxins are as small as 0.1 microns. For reference, mold spores are between 1 and 20 microns.
Mycotoxins typically replicate on and attach to floors or walls in humid and confined environments or on certain foods. However, mycotoxins can be found on any type of surface or material.
Why Are Mycotoxins Produced?
Mycotoxins are thought to possibly play a role in helping to prepare the substrate on which the molds exist for digestion. They have also been found to act as defense mechanisms. Mycotoxins may be produced when the organisms are under stress, which could be related to competition/defense, or simply due to inhospitable environmental conditions.
Which Types Of Mold Produce Mycotoxins?
Remember that there are many species of mold found within each main type of mold. Not every species of a type of mold will produce mycotoxins. It should be noted that not all mold genera have been tested for toxins, nor have all species within a genus necessarily been tested.

The most common and dangerous mycotoxin producing molds are:
- Alternaria
- Aspergillus
- Chaetomium
- Cladosporium
- Fusarium
- Myrothecium
- Penicillium
- Stachybotrys
- Trichoderma
- Thrichothecium
What Are The Types Of Mycotoxins?
There are over 400 mycotoxins, most of which are cytotoxic (toxic to living cells). There are 6 specific mycotoxins which are considered the most dangerous to humans.
Aflatoxins

Aflatoxins are one of the most potent carcinogens known to humans. Aflatoxins are produced by different species of Aspergillus, particularly Flavus, Oryzae, Fumigatus and Parasiticus, as well as members of the genera Penicillium. Strains of Aspergillus Flavus and Parasiticus produce mycotoxins under favorable conditions.
The most important aflatoxin mycotoxins are B1, B2, G1, G2 and M1.
B1 is the most abundant aflatoxin mycotoxin. It is also the most toxic and carcinogenic. M1 is a mycotoxin that comes from animals after the animals have eaten feed contaminated with aflatoxin mycotoxins. For example, M1 can be in cows milk after cows have eaten aflatoxin mycotoxins.
While aflatoxin mycotoxins mainly affect agriculture, they are frequently found in water damaged buildings.
A few important facts about aflatoxins
- Aflatoxins are present in the food chain.
- Aflatoxins are mutagenic, carcinogenic, teratogenic and immunosuppressive.
- Aflatoxin B1 can cause mutations to both nuclear and mitochondrial DNA meaning they can cause mitochondrial damage.
- Aflatoxins cause aflatoxicosis which is characterized by liver damage in both humans and animals.
- Aflatoxins cause an increase in circulating alpha tumor necrosing factor, suggesting that these mycotoxins are also immunotoxic in humans. In animals, immunosuppression does occur in a variety of different species.
- They have been found in human cord blood and sera and apparently can enter the developing fetus in humans and animals.
- Aflatoxins have been found in human breast milk, infant formula, cow’s milk, and dairy products.
Fumonisins

Fumonisins are produced by species of Fusarium.
In the U.S., the ingestion of moldy corn was first associated with adverse health effects in farm animals.
In humans, Fumonisins have been associated with esophageal cancer from ingested contaminated corn. Fumonisins are liver and kidney toxins and carcinogenic in rodents. They are also known neurotoxins.
More recently, they have been implicated in birth defects (neural tube) in humans and animals.
Ochratoxins

Ochratoxins are a mycotoxin produced by species of Eurotium, Aspergillus, Fusarium and Penicillium. There are three generally recognized Ochratoxins, designated A, B and C. Ochratoxin A (OTA) is chlorinated and is the most toxic, followed by OTB and OTC.
Ochratoxins are found in many food crops, including cereals, beer, wine, coffee, cocoa, grape juice, dried vine fruits, poultry, and milk.
A few facts about ochratoxins
- Ochratoxin is damaging to the kidneys and liver and is also a suspected carcinogen. There is also evidence that it impairs the immune system.
- Ochratoxins have been implicated in urinary tract tumors in humans.
- OTA is mutagenic, carcinogenic, teratogenic and immunosuppressive in a variety of animal species and in humans.
- It is a mitochondrial poison causing mitochondrial damage, oxidative burst, lipid peroxidation and interferes with oxidative phosphorylation. In addition, OTA increases apoptosis in several cell types.
- OTA causes immunosuppression following prenatal, postnatal and adult-life exposures.
- OTA has been found in human and cow milk. It is also present in human blood.
T-2 Toxin

T-2 Toxin is a tricothecene produced by species of Fusarium and is one of the more deadly toxins. If ingested in sufficient quantity, T-2 toxin can severely damage the entire digestive tract and cause rapid death due to internal hemorrhage.
T-2 has been implicated in the human diseases alimentary toxic aleukia and pulmonary hemosiderosis. Damage caused by T-2 toxin is often permanent.
Trichothecenes

The trichothecenes are a large family of metabolites (over 60) produced by several species of molds including Fusarium, Myrothecium, Trichoderma, Trichothecium, Cephalosporium, Verticimonosporium and Stachybotrys. All trichothecenes are considered mycotoxins and are one of the most toxic types.
Some of the trichothecene mycotoxins are deoxynivalenol, nivalenol, vomitoxin, HT-2 and T-2 mycotoxin. T-2 mycotoxins are defined as mononocyclic and have been used in biological warfare.
They are remarkably stable under different environmental conditions, including typical cooking temperatures.
A few facts about Trichothecenes
- All trichothecenes are toxic to humans, other mammals (domestic and research), birds, invertebrates, plants and eukaryote cells.
- They are more toxic via the lungs verses other means of exposure.
- Trichothecene mycotoxins suppress the immune system.
- Trichothecenes are potent inhibitors of protein synthesis. They bind to ribosomes, inhibiting protein and, subsequently, RNA and DNA synthesis. Rapidly proliferating tissues (intestines and bone marrow) are most adversely affected.
- They are lipid soluble, crossing cell membranes, causing lipid peroxidation with mitochondrial and cellular membrane.
- Trichothecenes cause increased cell death (apoptosis) by inhibiting cell division in a variety of cell types via mitochondrial and non-mitochondrial mechanisms.
- Trichothecenes readily cross the placenta.
- Trichothecene mycotoxins are found both in water damaged buildings and on crops.
- Trichothecene mycotoxins are also very resilient and stable and not easily removed. They have a life span of a decade or more.
Zearalenone

Zearalenone is also a mycotoxin produced by Fusarium molds. Zearalenone toxin is similar in chemical structure to the female sex hormone estrogen and targets the reproductive organs. It affects the male reproductive system as well.
Are Mycotoxins Dangerous?
Yes. The toxic effect of mycotoxins on animal and human health is referred to as mycotoxicosis.
Mycotoxins have four basic kinds of toxicity: acute, chronic, mutagenic and teratogenic. In addition to these, mycotoxins can be carcinogenic, estrogenic, hemorrhagic, immunotoxic, nephrotoxic, hepatotoxic, dermatoxic and neurotoxic. (Milićević et al., 2010).
Molecular structures of mycotoxins vary widely, so their effects on human and animal health also vary widely. The extent of adverse effects of mycotoxins on human or animals health mainly depends on the extent of exposure (dosage and period), type of mycotoxins, physiological and nutritional status as well as possible synergistic effects of other chemicals to which the animals or humans are exposed.
Mycotoxins can affect all organ systems, but individual mycotoxins usually target specific organ systems. Species differences are generally related to severity of effect, although in some cases target organs may differ according to species. Some mycotoxins cause primarily acute and highly reversible effects, others cause irreversible organ damage, and still others cause both acute and chronic effects, depending upon exposure levels, time course, and other circumstances.
The most commonly induced diseases include liver cancer, kidney failure, and effects on the brain or nervous system.
Some people are more susceptible to getting mycotoxicosis than others, and this is due to the pharmacogenetic variability where specific gene mutations such as cytochrome p450 (CYP 450) genes could either increase or decrease the metabolic activity (cytotoxicity) of the challenging mycotoxins (Sun et al., 2016).
In addition, about 25% of Americans also carry a gene called HLA-DR (human leukocyte antigen) that makes it more difficult for them to excrete mycotoxins. In people with the HLA-DR gene, their body is unable to recognize toxins as a foreign invader, so they don’t produce the antibodies needed to remove mycotoxins. This population is also more likely to develop Chronic Inflammatory Response Syndrome (CIRS), an out-of-control inflammatory response to toxins.
Aside from the fact that mycotoxins are known inhibitors of DNA, RNA, and protein synthesis, they have the ability to destroy human health (mentally and physically), and never appear in an autopsy. This is why they are used in biological warfare.
Frequently, mycotoxicosis remain unrecognized by medical professionals.
How Do Mycotoxins Get Into The Body?
Mycotoxins may enter the human and animal system in one of three ways. Ingestion, dermal, or inhalation.
When mycotoxins are ingested, they enter the body either by indirect or direct contamination. Direct contamination occurs when a food or feed becomes infected with a toxigenic fungus with subsequent toxin formation.
In contrast, indirect contamination can take place when an ingredient of a process has previously been contaminated with toxin-producing fungi and while the fungus itself may be killed or removed during processing, the mycotoxin will mostly remain in the final product. And example of this is cereal.
Mycotoxins can enter the body through the skin (dermal) or the eyes. The eyes are actually the easiest and most direct way that mycotoxins enter the body systems. If mycotoxins enter the body through the skin, this is most likely because your body was in direct, recurring contact with a contaminated source (clothing, linens, furniture, car). Typically this is the least common entry point for mycotoxins.
Mycotoxins are present in the air and therefore easily inhaled. They make their way through the sinuses or mouth and into the body.
How Do You Test For Mycotoxins?
While there are a couple of ways to test for mycotoxins in the home, the preferred and most accurate method is through dust sampling.
The Environmental Mold And Mycotoxin Assessment (EMMA) is available through Real Time Labs. It is the mycotoxin test that I rely on and have used with success in the past. The EMMA test uses sensitive molecular detection technology to look for the presence of 10 of the most toxigenic molds. It determines their presence and determines their relative abundance. EMMA also tests directly for 15 of the most poisonous Mycotoxins using its patented Mycotoxin detection test. Testing is simple, only requiring small amounts of dust or material from AC or heater filters.
The other option is to find a local environmental hygienist or mold inspector who has a relationship with a lab where they offer direct sampling. The downside of this is that you are testing a specific object of piece of your home and this may not reflect what is occurring throughout the building.
If you are looking to test yourself for mycotoxin exposure, you can have this done via a urine sample.
The only laboratory I recommend for mycotoxin testing of urine is RealTime. It is the only laboratory licensed by the College of American Pathology and CLIA for urine mycotoxin tests. Go to the website for RealTime Laboratories for further information.
The other lab that offers mycotoxin urine testing is Great Plains Laboratory. I haven’t used them personally but they have a good reputation.
How Long Are Mycotoxins Toxic For?
Mycotoxins are toxic for a very long time. According to experts, trichothecene mycotoxins can remain toxic for several years. Dr. Jack Thrasher a leading toxicicolgist (who I personally worked with) has suggested that trichothecene can remain toxic for over a decade. Trichothecenes are probably the most long lasting mycotoxin.
How Do You Kill Mycotoxins?
Mycotoxins aren’t actually alive like mold spores. So when we talk about killing mycotoxins it really means breaking down mycotoxins and their toxicity so they are no longer dangerous to humans.
It takes fire at 500 degrees Fahrenheit (260 degrees Celsius) for half an hour or fire at 900 degrees Fahrenheit (482 degrees Celsius) for 10 minutes to destroy trichothecene mycotoxins. Those mycotoxins don’t have any desire to be eradicated.
Ozone is supposed to kill most or all mycotoxins. However the level of ozone you need to kill mycotoxins is not safe for humans. So if you use an ozone generator there must be no one in the house.
Things like ultraviolet light or freezing temperatures do not have much effect on mycotoxins.
HEPA air filters are not effective at removing mycotoxins. Activated carbon filters can remove mycotoxins from the air however.
Mycotoxins do eventually break down and lose their toxicity after some time. But like I mentioned above, trichothecene mycotoxins are among the most resilient and can take years to break down.
There are a couple of products on the market that I have used and had great success with. EC3 Mold Concentrate and EC3 Candles.

These products have been subjected to independent lab testing, performed by RealTime Laboratories, Inc, against a range of molds and their toxins. The lab concluded that EC3 Mold Solution Concentrate will “eliminate aflatoxins, ochratoxins, and tricothecenes at concentrations of 1000 ppb if the solution is diluted no more than 1:40.” Note: The instructions on the bottle will guide you for proper dilution, so that this won’t be a problem.) The EC3 Candles whose mechanism is to aerosolize the citrus extracts into the air as they burn, were found to decrease known concentrations of mycotoxins in the air at 500 and 1000 parts per billion by 90% in 3 hours burn time. Mycotoxins in the 250 parts per billion range were completely eliminated in 3 hours.
So how do they work?
Citrus seed extracts (part of the proprietary blend of ingredients in EC3 products) were found to control the growth of food-borne fungi and to prevent mycotoxin biosynthesis. When mycotoxin biosynthesis is halted, molds become inert and much less of a health threat.
This information spurred testing of citrus seed extracts as possible solutions for the treatment of indoor molds and mycotoxins. Low concentrations of citrus extracts, when applied to the tested molds resulted in changes of the cell structure, inhibiting respiration and changing the permeability of the cell membrane, whereas high concentrations lead to severe membrane damage, loss of homeostasis and cell death.
Science also shows that the fungitoxic effects of citrus seed extracts is a consequence of hydrogen bonds forming between hydroxyl groups of phenolic compounds and active sites of cellular enzymes. The active components cause loss of integrity of the cell wall, and thus the loss of cytoplasmic constituents from the mold hyphae. This is important, because when the hyphae are damaged, the mold cannot take root, spread, or reproduce.

I highly recommended the EC3 Mold Solution Concentrate both as part of a monthly mold prevention protocol but also to remove and kill mycotoxins.
If you would like to read a more in depth post about the EC3 product line, check out Do EC3 Products Really Work.
What Foods Are Mycotoxins Found In?

It is now widely agreed that approximately 25% of the world’s food crops are affected each year by variable levels of mycotoxins which can have considerable economic consequences for the crop, livestock producers, grain handlers, processors, consumers and national economies. It has been conservatively estimated that annual losses in the US and Canada, as a result of mycotoxin occurrence, to the feed and livestock industries alone can be in the region of $5 billion.
Most disturbing is that since mycotoxins greatly resist decomposition or being broken down in digestion, they remain in the food chain in meat and dairy products. Even temperature treatments, such as cooking and freezing, do not destroy some mycotoxins.
10 foods highly contaminated with aflatoxins are:
- Coconut
- Corn
- Dairy products (most readily from cow’s milk – sheep and goat milk products are usually saf)
- Grains (including grain based baked goods, breads, cereal, crackers, and pasta)
- Grapes
- Maple Syrup
- Nuts and Nut Butters
- Orange Juice
- Wheat
- Wine
Food highly contaminated with other mycotoxins include:
- Apples
- Barley
- Beans (dried)
- Cheese (some but not all and mostly hard cheeses)
- Coffee Beans
- Cottonseed
- Dried fruits
- Herbs (dried)
- Lentils
- Peas (dried)
- Peanuts
- Rye
- Sorghum
- Sugar Beets
- Sugar Cane
- Tea (in bags)
- White potatoes
Please use caution when consuming the foods listed above especially if you are currently being exposed to mold or are detoxing from mold exposure.
Additional sources for this article include:
- https://www.drthrasher.org/mycotoxins
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC164220/
- https://www.who.int/news-room/fact-sheets/detail/mycotoxins
- https://www.frontiersin.org/articles/10.3389/fcimb.2018.00060/full
- http://www.micotoxinas.com.br/Boletim46.pdf
- Bullerman, L., Bianchini, A. (2007). “Stability of mycotoxins during food processing”. International Journal of Food Microbiology. 119(1–2): 140–146
- Wanda M. Haschek, Kenneth A. Voss, in Haschek and Rousseaux’s Handbook of Toxicologic Pathology (Third Edition), 2013
- John I. Pitt, in Foodborne Infections and Intoxications (Fourth Edition), 2013
- J.E. Smith, in Food Chemical Safety: Contaminants, 2001

cathleen says
hi, I am concerned I am living in a mold environment. I rent and have lived here for 4 years. my son has allergies and a slight cough and is always tired. I cannot smell that well and I feel foggy all the time and would like to move but cannot find a decent place right now. is my landlord responsible for a sick house and what can i do ?
Jennifer says
Hi Cathleen! I am so sorry that you are going through this! I have an article on my other website that addresses the whole landlord / tenant situation. In short, yes, your landlord is responsible. Have a look at the article and reach out to me with any questions at all! https://hybridrastamama.com/mold-in-a-home-you-are-renting/ (I am slowing updating and moving my mold content from my other website over to this one.)
Mary Anne says
How does one remove mycotoxins from the home on walls, floors and countertops after remediation? Products recommended are Benefect, vinegar, Everclear, theives, ammonia. Do you have a recommendation?
Jennifer says
Hi Mary Anne! Walls are tricky because mycotoxins could be IN and not just ON the walls. Currently the only products that have been proven to truly render mycotoxins inactive are the EC3 products and ammonia. Here are links to my posts on those:
https://moldhelpforyou.com/ec3-mold-solution/ and https://moldhelpforyou.com/does-ammonia-kill-mold/. Let me know if you have additional questions! Happy to help!
Juls says
Do you know if Benefect Decon 30 neutralizes/kills mycotoxins? Also, if mycotoxins can be in walls, would it be better to fog vs. wipe down with something to get rid of them?
Jennifer says
Hi Juls! Benefect Decon 30 has not been tested on mycotoxins. Based on the ingredients, is MAY have some ability to neutralize SOME mycotoxins but it would not be my first choice in products. Thermal fogging with the correct solution is the best way to deal with mycotoxins inside walls but remember, it will only penetrate so far. Wiping down the walls won’t be of much help if the mycotoxins are inside.