The Truth About Black Mold—And How You Can Stay Safe

You’ve probably heard about the dangers of black mold, an alleged silent killer that hides in water damage and ceiling tiles. But what is black mold? And is it dangerous?

Black mold, or Stachybotrys chartarum, surfaces as blackish-green spots or blemishes. It lives on moist, cellulose-rich surfaces like fiberboard, drywall, and gypsum board. Black mold is most attracted to moisture, which is why it lives in previously-flooded homes, leaky pipe areas, or anywhere with water damage.

Is black mold dangerous?

The short answer is—not really. But that doesn’t mean you should keep black mold as a pet.

Everyone has different levels of tolerance to allergens like mold spores, but that’s all black mold is—an allergen.1 Those with asthma, respiratory allergies, or immune suppression will feel the effects of black mold’s mycotoxins more than most folks.

As one source put it, “Previous reports of ‘toxic mold syndrome’ or ‘toxic black mold’ have been shown to be no more than media hype and mass hysteria.” 2

But whether you feel black mold symptoms or not, it’s best to get rid of black mold as soon as you find it.

What are the symptoms of black mold exposure?

If you find black mold on your property, there’s no need to panic. But black mold presents more health risks to sensitive groups like those with respiratory conditions or immune conditions.

Black mold exposure symptoms

According to the Centers for Disease Control (CDC), black mold spores can generate cold- or flu-like symptoms such as:

  • Stuffy nose
  • Wheezing
  • Skin and eye irritation

Longer exposure can cause more serious symptoms like:

  • Fever
  • Shortness of breath
  • Nausea

So while black mold probably won’t kill you, it can make you feel sick and should be removed as soon as possible.

How does black mold get inside a house?

Mold spores find their way inside by hitchhiking on clothes, pet fur, and air currents into your home. But spores can’t get comfortable without plenty of water. This is why you’ll usually find black mold around water-damaged areas impacted by plumbing issues like floods or leaky pipes.

Materials like drywall, carpet, or gypsum board can soak up water, creating a perfect home for a black mold colony. If you find water damage at home, it’s crucial to remove all the affected materials to prevent mold from growing.

Black mold removal and cleaning

Mold remediation in stores, offices, or schools is best left to the pros. This also applies to household mold exceeding 10 square feet.

The contractors you choose should have insurance and licenses from organizations like the Institute of Inspection Cleaning and Restoration Certification (IICRC).

Homeowners can handle cleaning about 10 square feet (roughly 3 feet by 3 feet) of black mold on their own.3 If the patch is small enough, a combination of bleach, water, scrubbing, and ventilation should do the trick.

Before treating mold on your own, prioritize ventilation and protective gear.

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Ask the pros

Removing black mold is a tough and dirty job. If you or anyone in your family is sensitive to mold allergies, has respiratory or immune issues, trust the professionals. 

Find a contractor in your area to get started.

Clear the air

Start the cleaning process by opening doors and windows to create a cross breeze. Dehumidifiers can also dry up the air and strip precious moisture away from mold growth.

Protect yourself 

Even if you aren’t sensitive to mold, it’s nasty stuff. Be sure to wear protective eyewear, non-porous gloves, and a breathing mask to protect yourself from getting sick.

Create a bleach mixture 

If the black mold growth in your home is small enough for you to treat alone, a simple mixture of bleach and water can help. Add one cup of bleach to one gallon of water and apply it to the moldy spots. You can also find commercial black mold removal products.

Apply the cleaner to the mold spot and scrub away the growth. Be sure to dry the area thoroughly when you’re done.


Do NOT mix bleach with ammonia. This combination can create toxic fumes that are far more dangerous than any mold you’re trying to clean.

Black mold prevention 

Nobody wants black mold in their home or building. Follow these rules to reduce the chances of mold on your property.

Watch for water

Flooding, leaky pipes, and malfunctioning appliances can all cause water damage. Once water seeps into a porous surface like drywall, black mold and its cousins are likely to appear. Water detectors can help you catch faulty appliances and leaks early.

If you do find water damage in your home, treat it and cut off the problem area’s water source as soon as possible. You’ll also need to remove flooring, ceiling tiles, or any other material that was affected by the water.

Keep it clean and dry 

It never hurts to clean regularly. Make sure humid areas and rooms with plumbing get regular spot checks. Add mold and mildew removal products to your cleaning routine, especially for the bathroom and kitchen.

Mold thrives on moisture, so use dehumidifiers in humid areas of your home like bathrooms, basements, or closets.

Final word on black mold: Best avoided—but not deadly 

As for black mold’s toxic reputation, those with immune suppression, asthma, or other respiratory problems are most at risk of feeling ill.

It’s not likely that you’ll die from black mold poisoning because it’s just not that toxic. That said, you should act quickly if you find it in your home. The good news is it’s treatable, removable, and preventable.

Black mold FAQ

Not big at all. Spores from black mold or the Stachybotrys chartarum can range anywhere between 2 and 100 microns.4 To give you a better idea, the average human hair is about 70 microns wide.

Mycotoxins are naturally occurring toxic compounds found in pantry food like cereals, dried fruit, nuts, and spices. Exposure can occur from eating infected food or through the animals who ate contaminated food.5

We found a handful of sources recommending treatments like tea tree oil, grapefruit, and vinegar (just not in the same mixture). And while we haven’t tested these remedies out ourselves, many of the natural items listed have antifungal properties that could dry out black mold.

However, we recommend looking to the pros if you need help with a larger mold colony.

Black mold thrives on water and porous material like drywall or wood which commonly mix in areas like ceilings, basements, and crawl spaces. You can tell if your home has black mold by simply looking and sniffing. If you still aren’t sure, you can find black mold test kits online for around $40.

Related pages on SafeWise


  1. Centers for Disease Control, “Facts About Stachybotrys chartarum and Other Molds” Last reviewed December 2019. Accessed October 13, 2021.
  2. Andrea T. Borchers, Christopher Chang, and M. Eric Gershwin, Clinical Reviews in Allergy & Immunology, “Mold and Human Health: A Reality Check” Published March 2017. Accessed October 13, 2021.
  3. Environmental Protection Agency, “Mold Cleanup in Your Home” Accessed October 13, 2021.
  4. Environmental Protection Agency, “Mold Course Chapter 1: Introduction to Molds” Accessed October 13, 2021.
  5. World Health Organization, “Mycotoxins,” Published May 2018. Accessed October 13, 2021.

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Katie McEntire
Written by
Katie McEntire
As a renter, pet-owner, and woman living alone, Katie McEntire takes safety seriously. She’s tested devices like pet cameras, home security systems, and GPS trackers in her own home and devices in the name of safety. In addition to testing, writing, and reviewing for SafeWise, she also makes videos for the site’s YouTube channel. She’s been featured on publications like TechGuySmartBuy, Forbes, Healthy Moms, and Digital Care. Katie has a Bachelor’s degree in Technical Writing from Austin Peay State University in Clarksville, Tennessee. She’s held previous writing positions at and Top Ten Reviews.

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  • Joel Hummel

    I came here after reading about the Black Fungus outbreak they are having in India right now. Apparently the two are NOT the same.

    On the one hand, there is Black MOLD, Stachybotrys chartarum, which we are likely to encounter from time to time in our household or work environments, and don’t need to fear, and then there is the Mucormycetes, that class of fungi referred to as Black FUNGUS, which can cause the disease Murcormycosis, which we are NOT likely to encounter but which can be very dangerous.

    That’s what they are having in India, and murcormycetes are found in soils, compost piles, rotting food/bread, or even in contaminated water. The reason they are having so many cases in conjunction with their covid-19 cases is because it affects most strongly anyone in a weakened state of health or immunocompromised state.

  • Theresa Knudson

    You have many important points about black mold, but it is dangerous. I had never had a mold problem before and never thought of mold as a threat. Then I got a new LG Direct Drive Inverter washing machine with a sticker saying “Certified Asthma & Allergy Friendly”. It has gray, rubbery material around the side opening door and two narrow circular spaces that hold water after the machine has been used. The gray material started getting black and I washed off some of the black but the stain remained even after using Clorox bleach and the black kept building. I kept washing it periodically, not knowing what caused it. I developed chronic sinusitis and headaches which kept getting worse along with chronic fatigue, but didn’t know this was causing my problem. I woke up at night with headaches and severe sinus problems on the side of my head next to the pillowcase. Then I looked up about the black recurring problem on Google and realized it was mold getting on clothes and bed linen when I washed it. They won’t replace the washing machine, but will replace the gray material. Now I will have to use paper towels (I prefer Bounty for strength and absorbency.) and dry not only the easy to reach gray lining, but dry its under-side and push paper towels into the spaces going around the door opening to get out all water every time I use the machine and use Clorox solution periodically to help discourage black growth.

    • David Hanks

      Since WD-40 is a water displacement agent, might this help minimize the problem maybe even help defend the ‘gray material’s or gaskets ? I do realize we are talking about application IN and around a washing machine, mixing with clothes. Some it may stain, some maybe not if they are treated with “Scotchgard”. I haven’t tried this myself but wondering if this could help mitigate a lot of this threat… Good luck !!