Black Mold: The Ultimate Toxic Mold Removal Guide


When it comes to black mold, I have seen a lot!

As a certified Health and Safety professional, this gave me first-hand experience of how dangerous mold can be.

My encounter began when I was a teenager. I lived in a home that from time to time would have water leaks in the basement.

The leaks eventually caused large black furry like mold growth on the walls.

I remember continually spraying bleach and other cleaners to get rid of the problem, but days later it would just return.

I remember getting watery eyes, itchy throat and severe headaches when venturing in the basement.

At that time, I knew nothing about black mold or the toxins they release that can impact your health.

My experience with “Black Mold” goes back to those days as a teenager cleaning the black furry spots off the basement walls to a professional who has overseen and supervised countless successful mold remediation projects.

A Real Life Example Of How Black Mold Works

Mold is a resilient organism, and some species can be dangerous because of the toxins and spores they produce.

Several years ago, I was called in to assess a property where the occupant complained of musty odors and several health complaints.

First, I thought, this is a common problem but, let’s go look and see what we can find.

When I entered the home, the familiar smell took me back to my days as a teenager.

A foul, musty, earthy odor that was strong enough to make your throat itch and your eyes water. Just by walking into the home, I could tell from a professional standpoint that there was a mold problem.

I spoke with the occupant to get some information to pinpoint the problem.

During the discussion, the occupant mentioned the issue was in the kitchen. Each time they entered the kitchen the smell would get more noticeable.

Also, when they opened the cabinets, the scent would be very potent.

I knew then that this would be the first area to inspect. While inspecting the kitchen, I noticed that the baseboards had signs of water damage (they were discolored and warped).

I opened the cabinet under the kitchen sink, and there was the problem.

Upon close inspection, the mold was growing on the back panel of the cabinet, just around the drain line penetration. T

hen I gently removed a small section of the panel only to find that familiar black furry mold growth.


The first step was to communicate the findings to the occupant.

Next, we erected a containment around the kitchen area before removing the cabinets to see the cause and extent of the mold infestation.

When the lower cabinets were removed, it was apparent that the leak was caused by a small hole in the copper water supply line.

This leak was unknown to the occupant until the mold growth began to spread behind four of the cabinets.

I took a small sample and had it analyzed before the remediation began.

The lab results showed that one of the species growing behind the kitchen cabinet was indeed the Stachybotrys commonly called the “black mold”.

That mold remediation project was completed successfully, and the problem never resurfaced.

What is Black Mold?

Most safety professionals who perform indoor air quality assessment, will eventually get this question from people: What is Black or Toxic Mold?

So, let’s see if we can get the facts straight.

When you hear the term “Black Mold or Toxic Mold” is not a scientific name for a type of mold species.

The name black mold refers to Stachybotrys, a species of mold that is mainly found in buildings that have severe water damage over a long period.

Another thing to point out is that this mold species has a greenish black color.

There are thousands of molds that are black, many of which can be found indoors.

Therefore, not every mold that has a black or greenish color is Stachybotrys.

The only way to properly indentify the species of mold found growing on a surface is through sampling and analysis by a certified laboratory.

How To Get Rid Of Black Mold Safely

Black mold can be a nuisance for homeowners.

It can lead to costly mold remediation fees and pose a health issue for some individuals.

But if you take the right steps and learn how to remove mold safely and quickly, you can protect your home and your family without spending a fortune.

Getting Rid Of Black Mold Is A Step-By-Step Process

One of the most important things to keep in mind is using the right safety gear to protect your health.

But before you try to clean the mold on your own, make sure you consult with your doctor if you have any health conditions.

While mold may not affect everyone, some individuals can have adverse allergic reactions to even small amounts of mold exposure.

The first thing you want to address is the source of the moisture problem.

Finding and fixing the problem first will stop the mold from spreading and affecting more items.

Not to mention, if the issue is not repaired, the mold will come back after you remove the initial growth.

Next, you will need a couple of items.

You will need the items listed here: scrub brush, detergent, sanitizer (Lysol can be used), HEPA vacuum, portable fan, goggles, rubber gloves, and an N95 Particulate respirator at a minimum.

In some cases, you can use a Tyvek suit if you chose to.

If you notice, there is no bleach mentioned because you don’t need in most cases.

This cleaning method can be used to remove common molds from surfaces found in your home affected by surface growth only.

Not for items like drywall that is damaged by mold and moisture.

Depending on the amount of mold growth, you may want to seal off the vents, doors, and openings into other areas of your home with a sheet of plastic around vents.

This will help protect you and your family members.

Also, sealing off the area will stop the mold spores from spreading into other areas.

  1. If windows are located in the area, open them to allow ventilation.
  2. Use a vacuum with a HEPA filter to carefully remove any mold spores on the surface. HEPA vacuums contain filters that are capable of trapping tiny particles such as mold spores. This will stop mold spores from dispersing into the air.
  3. Once the wall has been thoroughly vacuumed; begin by applying the detergent to the brush or directly on the surface.
  4. Begin to scrub in a circular motion. Avoid oversaturating the wall.
  5. After the area has been scrubbed and molds have been removed, use a cloth or paper towel to dry the area.
  6. Clean the area by wiping it with a sanitizer like Lysol disinfectant wipes. This helps to kill any remaining spore on the surface of the wall.
  7. Dry the area again.
  8. Place a fan next to the wall and allow the area to dry for 24 hours. This ensures that there is no remaining moisture on the wall from the cleaning process.
  9. After 24 hours, assess the area and repeat the process if necessary.
  10. After the dry out process, some stains may still be visible. The molds will not regrow if the source of the initial moisture problem has been repaired.

How The Term “Black Mold” Became So Popular


One of the reasons the term black mold is common today started in the 1990’s.

Where Stachybotrys was blamed for a group of pulmonary hemorrhage cases involving infants in Cleveland.

The common link in all cases was the presence of Stachybotrys chartarum in the homes where the infants lived.

At the time investigators speculated that the infants inhaled the toxins produced by Stachybotrys which caused loss of life.

Later, the investigations failed to confirm that the deaths were caused by Stachybotrys chartarum.

However, the damage was already done, and widespread media coverage began.

Researchers and scientists were unable to confirm that the deaths were caused by Stachybotrys

Stachybotrys is not a common indoor mold.

It’s only present in about 2 to 5% of homes in the United States. For it to grow, it needs the right moisture conditions, temperature, the source of food and time.

Stachybotrys needs a high amount of moisture.

So it grows rapidly on building materials like drywall, particle board, wood, and other cellulose-based materials that remain wet for long periods.

And where water has accumulated from leaks or other moisture-prone areas.

Most mold species begin to grow within 24 – 48 hours after water intrusion or moisture problem.  However, Stachybotrys develops slowly and will start to germinate and grow in one to two weeks.

Even with its delayed growth, Stachybotrys becomes the dominant mold when conditions are just right and will eliminate the other molds that are present.

Once Stachybotrys finds the perfect conditions, it will continue to grow even if the there’s no moisture source.

In most cases, it’s often hidden in wall cavities, under subfloors, behind cabinets.

If Stachybotrys shows up in an air sample, wall sections and other hidden spaces, where it is likely to be growing should be inspected diligently.

Like how other molds, Stachybotrys spreads by generating spores and absorbing nutrients through the root-like structures.

The spores grow and form clusters that do not easily disperse with slight air movement or if the surface is wet.

This is because the spores are bonded together with a slimy covering.

The spores of will disperse through the air when the mold colony dries out or is disturbed.

Just one more thing to keep in mind, there are many other common household molds that look like Stachybotrys.

Some of these include Cladosporium, Aspergillus, and Alternaria. The only way to tell exactly if the mold growing on the surface in your home is Stachybotrys is by sampling and testing.

What Causes Black Mold

To explain what causes “Black Mold” or Stachybotrys, you should understand how and what causes mold growth in general.

All molds are microorganisms found in our natural environment. There are more than 300,000 different types of mold that occur naturally, and they come in a wide range of colors.

All molds act as nature’s recycling machine because they break down cellulose and organic matter.

They release small microscopic spores that migrate effortlessly through the air and create new colonies where the right conditions exist.

Whether its indoors or outdoors.

They digest cellulose or organic items like foods, fruits and vegetables.

And even building materials such as wood, paper, and insulation, to name just a few.

Molds can grow on any surface that provides them with a source of food and an ample supply of moisture.

In most cases, black mold in buildings is caused by flooding, leaks that have gone undetected for long periods, not drying out building materials quickly, and using the wrong methods remove the mold.

When the mold spore finds a source of moisture, food, humidity, and temperature it will begin to germinate and spread.

Unlike many other mold species, Stachybotrys tends to germinate at a slower rate.

Where common indoor molds begin to germinate and grow within 24 – 48 hours of the material becoming wet; Stachybotrys is slower and can take a week or more to develop.

They can grow on saturated wood, acoustical ceiling tiles, drywall, wall paper, wall paneling, plaster board surfaces, cotton items, cardboard boxes, and on any materials with cellulose content.

Here is a perfect example of what causes black mold (Stachybotrys) mold growth.

I was called out to look at a vacant home because of reports that water is running out the front door.

This was a vacant unit, so no one has a reason to enter the home for months.

We entered the home to assess the problem, and when we opened the door, we noticed the carpet was saturated throughout the entire home.

We also noticed small mold spotting on the walls and ceiling that got worse as we entered the master bedroom area.

In the master bathroom location there was the sound of running water, and upon closer observation, we noticed that there was a broken water line in the ceiling area of the building.

At the base of the bath vanity as well as on the base boards and the drywall, we observed the thick mold growth that. The building was vacant therefore we didn’t know long the pipe was leaking.

Just looking at the growth, we could tell that the leak had been present for some time.

A situation like this would promote the growth of Stachybotrys. All the elements to cause it’s to grow were present.

The building materials were saturated, the air in the home was humid, the food source was present, and excess moisture was present.  Not to mention the length of time the materials remained wet.

Is All Black Mold Toxic?

The color of a mold and the toxicity of mold are two completely different things.

Just because a mold is black does not make it toxic.

Many of them are not considered toxic. Molds can come in a wide range of colors from black, white, grey, and even yellow.

This color depends on the material on which it is growing and on the species itself.

Just looking at mold growing on the surface of a material won’t tell you if it’s toxic or not.

It’s virtually impossible to know anything about the mold growth on a surface without some form of lab testing.

Remember, the term Black Mold is not a scientific name.

Black Mold is a term commonly associated with Stachybotrys – a greenish black mold commonly found in severely water damaged buildings.  This mold can produce toxins that can have an impact on your health.

When you hear individuals referring to black mold they are referring to this species.

To clarify if all black molds are toxic, look at this situation.

Stachybotrys is greenish black and is considered to be toxic.  Cladosporium is another mold species that appears black but is not considered to be toxic to humans.

A few other molds that are blackish in color include Dresclera, Bipolaris, Exserohilum group, and Ulocladium[1]. These molds have no known toxin production.

Therefore, the answer to the question is a clear no!

Not all molds that are black are considered toxic.  The only to determine if the black spots growing on your walls are toxic, is to have the growth tested to determine the species.

When you identify the species, then you will know if it’s toxic or not.

How To Test For Black Mold

When it comes to testing for mold, there are no regulations on what level of mold is considered acceptable in any home.

This lack of regulation can make mold testing difficult and confusing.

There are many sampling methods used to detect mold species and their concentrations. However, keep in mind that sampling for mold is not necessary in all cases.

Say, for instance; you can see active mold growth, there is no need to perform a test. If you see it, the best thing to do is act fast and eliminate the source of moisture and remove the mold growth.

If you’re on the fence about mold testing you home, consider the benefits of mold testing.

Testing can be used to identify the various types of mold species found in the air, settled dust, on contaminated items, and to identify species by growing a fungi-mold culture in a petri dish.

Not to mention, sampling can be used to assess the effectiveness of mold remediation.  The methods frequently used in to test for mold are listed below:

DIY Mold Test Kits

Testing for molds in your home or office can be done with relative ease once you have the proper equipment, and step-by-step instructions. Mold tests that an individual or homeowner can perform include the following: damp wipe, air quality testing, tape lift samples on surfaces such as carpets, walls, upholstered furniture, etc. and swab samples.

  • Air Samples (special equipment needed)

Culture analysis (viable): This method of sampling is performed by pulling a measured volume of air through a sampling device that contains a petri dish (agar plate).

As the air is drawn into the device, the spores in the air are trapped on the growth media in the petri dish.

When this occurs, the spores present in the air are impacted on the sampling media and allowed to incubate and grow for a period.

The sample is then sent to a laboratory for analysis. This method is used to identify the species of molds present in the air

Non-Culturable air sampling: During this process, an Air-O-Cell cassette is attached to a sampling device that draws in a specified amount of air over a period.


The air-o-cell cassette contains a glass slide equipped with a sticky coating that traps spores as the air is drawn into the device.

This method of sampling captures mold spores, dust, and other airborne contaminants. The sampling media is then sent to an accredited laboratory for analysis.

This method of testing provides information on the airborne contaminants in the air at the time of the sampling event.

Non-Invasive Wall Cavity air sampling – Non-invasive wall cavity samples are collected by removing an electrical outlet plate and placing an Air-O-Cell cassette near the existing hole in the wall.

The wall is tapped intermittently during the 3-4-minute sampling time.

Invasive Wall Cavity air sampling – Invasive wall cavity sampling can be performed when a volume of air is collected over a period of time, in most instances 3-4 minutes.

The suspect area is first located.

These areas could show signs of damages such as staining or discoloration, rusting nails protruding from walls, signs of peeling paint, soft area, bubbling, and other indicators of water damage.

A drill or other method is gently used to create a small diameter hole about the size of a pen.

Then the collection tube with the collection Air-O-Cell cassette attached is inserted in the cavity.

A prescribed volume of air is collected over a 2-4-minute period of time. The sample is then sent to the lab for analysis.

  • Surface Testing (no special equipment needed)

These methods are used to find out if the suspected growth observed in a location is in fact mold.

And to identify the species of molds growing on the surface of the materials sampled.

The methods identified below generally do not require any instruments.

Tape lift samples are performed by using a piece of clear tape that is approximately two inches long to trap and lift suspected growth from the surface.

This method of sampling is performed by following the steps listed below:

  1. Hold the clear tape by the ends with the adhesive side positioned towards the area to be sampled.
  2. Place the tape on the suspect area and press firmly, avoid rubbing the back of the tape.
  3. Gently remove the tape from the surface and place it on a clean microscope slide. If no slides are available, tape the sample to the inside of a clear zip lock bag with the adhesive side down.
  4. Avoid folding the tape back on itself because doing so will make it impossible for the lab to accurately analyze the sample.
  5. Send the sample to a lab for analysis.

Swabs are used as a last resort to obtain samples for analysis. This process involves simply providing the lab with a swab of the growth.

Once an area is identified, the swab is removed from the casing and gently rolled on the suspected growth site.

The swab is then placed back in the tube, sealed, and sent to the lab for testing.

This method is used when the suspected area is too wet for tape lifts

Bulk sampling involves removing a section of the suspect area, placing it in a sealed bag, and sending it to a lab for analysis.

In most instances, a one or two square inch piece of the material is enough for the laboratory to conduct the analysis.

Dust Wipes – wipe surfaces where mold growth is suspected with a damp wipe which is then cultured for analysis.

The typical area wiped is one square foot. This practice is also used in testing the effectiveness of remediation and sanitization activities.

Sampling for mold indoors has some merits, it may or may not provide you with the answers when dealing with a mold-related issue.

No one sampling method or protocol can identify every spore present in a specific environment, measure mold toxicity, identify the molds potentially responsible health complaints, or identify safe mold spore levels.

How To Prevent Mold

The only way to find out if mold found in your home is toxic, is by laboratory analysis.

The key to preventing and getting rid of mold growth, is to control the source of the moisture.

Acting quickly when you have a leak or water intrusion is the best way to prevent a mold growth.

Most molds only need 24 – 48 hours to start germinating on wet or damp surfaces.

So if you want to avoid costly mold remediation fees you should’nt ignore the warning signs like musty odors, wet walls and flooring, furry growth on your walls, and things like that.

Don’t ignore them because it will end up costing you more in the long run.

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