12 Mind-Boggling Mold Facts

David J. Allen

I spent the better part of 2 ½ years learning about mold and indoor air quality because my child's life depended on it. Now I help others avoid ever having to experience the same thing. The mold industry suffers from conflicting opinions and I do my best to distill loads of data into something practical and useful. I love hearing from and helping readers. • "A house desecrated by mildew, mold, or fungus would be a defiled place to live in, so drastic measures had to be taken." — Leviticus 14:45

Most people research mold where there’s a problem or they’re experiencing negative symptoms associated with mold.

However, mold is a fascinating life form about which there is much to learn.

Below we will investigate 12 interesting facts about mold that you might not have considered.

1. Mold is omnipresent (it’s everywhere)

Mold is so common that it grows literally everywhere.

It can be found both indoors and outdoors and in the most unlikely places.

Most of all, it craves warm, moist environments, which feed it to keep growing and expanding.

If mold grows in places where people live, it can cause breathing problems and other medical issues.

2. Mold can be multicolored

Mold is typically thought of as black or green, but in reality, it comes in many different colors, including orange, white, pink, and blue.

The color sometimes denotes a certain type of mold. For instance, red and orange mold is typically found outdoors. 

Pink mold likes to expand in the bathroom, thriving off of soap and shampoo molecules.

Green and black molds spell trouble and should be immediately addressed by a professional if found indoors.

3. Mold is omnivorous (it can live off of almost everything)

Mold is an equal opportunity eater and will munch on just about anything.

If there is something that mold will not eat, then it might not be suitable for human consumption either. 

For instance, mold will not eat certain heavily processed hamburger buns.

But it is able to live off something as small as a fingerprint, or a drop of dirty water left behind on a bathroom surface.

(Of course, mold only becomes truly problematic when there’s enough of it around. A fingerprint’s worth of mold on a shower curtain probably won’t harm you at all, and there’s no need to drive yourself crazy over it.)

4. Mold is a multispecies life form

While there are ultimately hundreds of thousands of mold species, only several thousand have been cataloged by humans.

Only a few of those thousands are harmful and toxic, so it is important to learn which molds to avoid.

5. Mold has been used as a biological weapon

Mold warfare has actually been around for hundreds of years and can be traced back as far as the 1300’s. 

Bio weapons have been created using T-2 trichothecene mycotoxins. Black mold (stachybotrys chartarum) also contains these same mycotoxins.

So if you have black mold in your home, you might be battling your own war against a biological weapon.

6. Some people are allergic to Christmas because of mold

If you or a loved one is sneezing or coughing in response to your Christmas tree, you might be experiencing a negative reaction to mold spores that cling to live trees.

The longer the tree remains in your home, the higher the mold count grows. Within two weeks, the mold count can climb up to 5 times its initial reading. 

7. Mold can cause sinusitis

While many people connect sinus problems with bacteria or viral components, the truth is that mold is a leading cause of sinus infections.

White blood cells in the body react to the presence of fungi.

The sinus lining seeks to trap mucus and ends up blocking drainage, leading to sinus issues. Mold loves the damp, dark environment in the nose, after all.

Additionally, it’s important to note that antibiotics are not formulated to address mold, only bacteria.

So this is the reason why sinus infections often linger.

8. Mold can grow in as little as 24-48 hours

Mold spores are the “invisible seeds that are everywhere.”

All they need in order to start sprouting is enough moisture content in the air or on some surface.

Visible water doesn’t even have to be present.

Even steam contains enough water to kick some mold spores into growth.

If only growing plants was that easy!

When the humidity in a room or vehicle remains above 50 percent for a long enough time, mold can start growing.

And, if a damp piece of clothing is left around the house (even in a dry room with low humidity), it, too, can get moldy within 1-2 days, or 24-48 hours.

9. Mold grows even in the desert

Since mold needs moisture or water to grow, it might surprise you that it can—and does!—even grow in the desert.

Picture that damp shirt we mentioned earlier: Even though it was in a dry room, it still had everything mold needed in order to grow. (Moisture, mold spores, time and decent temperatures.)

The same applies to the desert: Mold can’t grow in temperatures above 100 degrees, and the sun kills mold quickly and easily. But, where there’s water in the desert—or in houses in the desert and other hot areas of the country—mold can and does grow easily.

10. The ‘landlord special’ is as bad as it sounds: Painting over mold is dangerous and ineffective.

Sometimes tenants that report mold growth in their apartments are told it’s no big deal.

Maintenance shows up and paints over it. Bad idea, very bad idea.

Painting over mold will not kill it or handle the problem.

Not only will the mold just grow back over time, but even while you can’t see the ugly mold spots, you may still be affected by them.

Many mold off-gas harmful toxins called mycotoxins. They’re what gives mold most of its smell, so if you smell mold (dirty socks, or a musky odor), you’re breathing in something that can cause you serious harm.

Mold growth on walls or window sills should never just be painted over.

It has to be cleaned thoroughly first, and in some cases, parts of a wall or window frame will have to be removed and replaced. (It depends on what’s causing the problem: A forgotten spilled coffee that puddled on the window ledge? Or a poorly sealed window that’s allowed water to seep into the wall for months?)

The solution to mold is always to find and fix the cause of the water that’s reaching the area, and shut it off or make sure it doesn’t keep watering the wall, the window sill, the carpet, the drywall, etc.

Remember, since mold spores are literally everywhere, all it takes is a small amount of water or moisture for them to start growing.

And, so that you don’t drive yourself paranoid over every small spill, just know that the worst mold infestations are usually found inside of or behind walls, and happen because of plumbing leaks.

11. Bleach is actually one of the worst ways to kill mold, not the best.

Despite its popularity, bleach is actually one of the worst ways to kill mold.

Using bleach to kill mold is acceptable on non-porous surfaces only, and there are only a surprisingly small number of surfaces that actually qualify.

You can use bleach to deal with mold on a porcelain toilet, or a glass mirror, but should avoid its use on pretty much everything else.

Even tile grout is porous, and so are many bathtubs. And if the tub itself isn’t porous, the titles and ledges around it usually are.

Using bleach on mold is basically like watering it.

Bleach has an extremely high water content, and is usually 90-95% water.

Most household bleaches available at grocery stores are 5-6% sodium hypochlorite and 94-95% water.

Bleach is the Trojan horse of the mold world: People think it fights mold, but most of the time, it only feeds it!

When the chemicals that make up the other 5-10 percent of bleach evaporate—and they evaporate very quickly!—all that’s left behind is water.

That water penetrates the surface of whatever porous surface it’s being used on, and it basically waters the roots of mold.

Not only that, but the longer you keep and use an open bottle of bleach, the less and less of its active ingredients it retains. Bleach loses its cleaning power over time by simply evaporating into the air.

That means the older the bleach is that you’re using, the less effective it is going to be, and the more it is just water.

Eventually, all that’s left is water.

Of course, it goes without saying that you should never drink even the oldest bleach. It’s just not an effective way to kill old.

12. The International Space Station (ISS) has had mold problems

It may be comforting (or horrifying) to know that Earth isn’t the only place with a mold problem.

Mold growth is problematic even on the International Space Station.

Astronauts there apparently spend hours each week cleaning to get rid of mold and/or prevent its growth.

“Mold has been found growing on the walls of the International Space Station (ISS), revealing its natural presence in the spacecraft habitat,” says one study on mold in space, presented in June 2019 at the Astrobiology Science Conference.

Researchers were so concerned with the implications of their findings that they thought mold might contaminate other planets if not addressed before space travel.

“If these spores are able to withstand space radiation they might unintentionally contaminate other planets during exploration and colonization missions.”

Now that you know, you know

Now that you know probably more than you ever thought you would about mold, you can take better steps to deal with it in situations where it is causing you trouble.

Remember that mold is everywhere but that it especially loves dark, damp, warm places and will accumulate in areas of the house (and your body) that present these ideal conditions.

While some molds are harmless and exist only outdoors, others can be so powerful that they have been used as part of biological weapons.

This just gives insight into how serious an allergic reaction to mold can be.

If you are struggling with a mold allergy or mold infestation, you may want to consult a professional to get the best solution possible for your health and wellbeing.