Mold vs. Mildew: What’s the Difference?

Many people confuse mold and mildew, but there are a number of differences between the two. While they both are members of the fungi family, mildew is a more powdery, white to gray substance and tends to target plants whereas mold is green or black and attacks aging, stale, or rotting food. Both mold and mildew produce spores that travel through the air easily allowing them to spread quickly if not taken care of.

Mildew loves to attack plants and animals and tends to thrive in the more tropical, humid areas of the world. Mold on the other hand tends to attach itself to non-living materials such as plastic, wood, drywall, tile, or any other similar surface. They both love any type of moisture and will grow quickly and easily if left unchecked in favorable conditions.

Identifying a mold problem is only half the battle. Finding the root cause, such as water leaks, condensation, infiltration, or flooding, is necessary before you can completely eliminate mold. Many times it’s easy to spot. An obvious water or roof leak often leaves the tell tell signs of water stains before mold can take hold.

Other hiding spots for mold such as behind wallpaper for instance, can be more difficult to track down, especially if there are no visible signs like black or green spots showing through the wallpaper. Bathrooms without proper ventilation can get overly damp and have consistently high levels of humidity, a perfectly suited environment to promote mold growth.

Also keep in mind that not every instance of mold is of the toxic black mold variety. There are many different kinds of mold and while you don’t want any of them in your home, not all of them are as bad as black mold. Proper testing is recommended and there are a number of do-it-yourself mold testing kits that can be used.

If you suspect mold but can’t seem to find any it may be time to call in the big guns. Contacting a professional mold testing and inspection company may be necessary to help track down any hidden mold problems you may have. While this can be expensive, it may be necessary to completely eliminate your mold issues.

Five Frequently Asked Questions About Mold

If mold is present, what is the best way to eliminate it?

The answer lays the areas where the mold is present and its location. Mold found in furnishing items can be simply discarded at home or the building. However, mold on the surface that occupies not more than 10 square feet can be rid of by washing the area with soap and water. Molds of greater areas require professional assistance.

Is it possible to eliminate mold completely?

Generally, it is impossible though in cases a building can enjoy free of mold by the use of ait filtration but very limited situation like in the hospital operating rooms and manufacturing “clean rooms”.

Are there harmful and non-harmful molds?

There are about 100,000 types of mold and most people have the ability to tolerate exposure to moderate levels. The most serious health problem a person can get from the exposure is allergy and asthma. However, there are some molds that produce the chemical called ‘mytoxins’ that will likely produce illness to animals and people.

How much mold exposure is harmful?

It is impossible to give a definite answer and no one knows about it. It varies from degree of exposure and the ability of the person to tolerate.

Are there any reliable test to indicate the presence of mold?

Simple mold detectors need only the eyes and the nose. Noticeable discoloration like black or green indicates the presence of mold. A place with molds produces a smelly place which smell is either a little or very unlikely.

Causes of Black Mold

The most common causes of black molds formation or growth in homes are leaking pipes, a leaking roof, condensation, wet clothes, poor ventilation, a damp basement, flooding, water in house foundation and a humid weather. Molds start growing in your homes when the weather gets humid and continues for the next days.

Wet air and high humidity

Molds usually grow on walls, on bench surfaces and other surfaces due to the wet air when it rains for several days. Molds also grow in homes in areas where humidity in air naturally high. Indoor humidity is also increased when moisture inside the house evaporates. High humidity feeds molds. A humidity higher than 55 percent is enough for molds to start to grow in your homes.

water leakages in homes
Undetected leakages in homes can cause black molds.

Leakages from pipe system

Leakages in homes are also some of the causes of black molds. Leakages from pipes particularly those in areas which are unseen such as inside the wall can cause undetected growth of molds which could cause serious problems. Also, be sure to always check the attic, if your home has one, particularly the ceiling below the attic since leaking roofs may cause mold growth in this area. Cold surfaces can lead to the formation of condensation in your home which accumulates on metal pipes and on cold concrete floors that can be prime areas for mold growth.

Poor ventilation

Formation of pockets of stagnant moist air due to a poorly ventilated home is also one of the many causes of black molds. Poor ventilation also suggests that wet surfaces do not easily dry to eventually lead to mold formation.

Indoor moisture

Wet clothes left in the house for a long period of time can also cause house molds due to the moisture released by the clothes.


Flooding of your house can also cause growth of black molds since it only takes a surface to be wet for 24 hours for molds to start to grow. A damp basement can also be a growing area for molds since this area is usually not well ventilated. Basements are also usually colder which is a perfect condition for condensation that leads to creates dampness and leads to humidity.

Basement water leak

Water leaks also reach the basement to even increase likeliness of mold generation. The basement is the place where molds can be well set in since it is a place not usually visited by house occupants.

13 Facts About Mold

Are you worried about mold growing in your home? You should be — mold can cause serious health issues to you and your family.

Here are 13 facts that you should know about mold.

Mold can grow on any surface including glass.
  1. Mold is a type of fungus. Other types of fungi include yeast and mushrooms.
  2. Outside mold is found in soil, decaying vegetation, compost piles, rotting wood and fallen leaves. Outdoor mold can get inside through open windows and doors, ventilation systems and on pets, clothing and shoes.
  3. Mold can grow on any surface including glass.
  4. Mold does not discriminate and is often found in clean environments.
  5. Mold grows year round and in all types of climates although it favors a warm and humid environment.
  6. Some people are more sensitive to mold than others. People who are allergic to mold, have asthma or have a weakened immune system are most likely to be harmed through mold exposure.
  7. To grow, mold needs food such as high moisture levels, high temperatures and excess humidity. After a flood or water intrusion,dry out services can help eliminate the potential for mold growth.
  8. Mold is a decomposer of organic materials such as wood, plants and animals.
  9. Molds are strong allergens although most people are not allergic to them.
  10. Common indoor mold include: cladosporium, penicillium, alternaria and aspergillus
  11. Only some molds produce mycotoxins which can be harmful to a person’s health.
  12. Mold often grows in hidden places such as behind wall paper and paint or in attics and basements.
  13. There will always be mold spores in the air. It is impossible to completely rid a property of mold. The best one can do is stay on the look out for mold problems and take care of them as needed. If you find mold growth in your home, mold remediation specialists can take care of the problem.


Have you noticed immediately getting skin rashes after coming in contact with a mold colony? You must have touched stachybotrys.

Stachybotrys is the most common toxic black mold. It is scientifically named as Stachybotrys chartarum (or S. atra or S. alternans). They appear as greenish-black molds found in water-damaged cellulose rich materials. Examples of these are straw, hay, paper, and porous materials such as fiber board, and gypsum board that are exposed to much moist, humidity, water leaks and flood. Stachybotrys chartarum can also thrive on dust and lint.  These raise the probability of exposure to harmful household mold.

Hazards in Homes and Offices

Black mold stachybotrys is found to produce a high degree of mycotoxins that can be very hazardous to human when inhaled. Homes and offices may have stachybotrys thus family members or workers will sometimes complain of difficulty in breathing or skin irritation. In 1986, there was an outbreak of toxic mold among Chicago homes and residents  complained of headaches, sore throats, flu-like symptoms, persistent colds, diarrhea, fatigue, dermatitis and malaise. In late 1990s, articles on acute  idiopathic pulmonary hemorrhage in infants have linked the incident to  stachybotrys in bedrooms and attics of homes.

In a study by Johanning (1996) on the health status of office workers, he found out that workers exposed to more aerosols with Stachybotrys chartarum showed symptoms of lower respiratory irritation, dermatological and eye irritation, chronic fatigue, and recurrent allergic reactions. Those exposed for longer period of time during their employment developed more alarming symptoms of upper respiratory, skin and central nervous system disorders.

Mold Removal and Control

If you want to remove toxic black molds in the homes and offices, the first thing to do is to know what they look like, where to find them and how to clean them up.

How do you identify Stachybotrys chartarum? Stachy is visible in colony that initially appears white and turns to black, shiny, and slimy when in active state and in wet habitat. Spores of this type of mold can be sampled by direct swabbing, or using a plastic tape to lift some mold samples for laboratory analysis.

Stachybotrys best environment is a damp and humid area with nutrient source and time. A relative humidity of 90% usually from leaking pipes, roof, and sewage usually from continuous standing and moisture condensation is the best place for toxic molds to propagate. Stachybotrys can still survive even when the breeding area has lost its moisture.

You can always find stachybotrys in porous surfaces such as wallpaper, ceiling tiles, paper products, carpets with natural fibers, paper covering on insulation, and wood. They also grow in dust particles accumulating in your basement. The common places for black molds to propagate are the bathroom and sink.

When you have identified the areas with mold growth in your homes and offices, spray the areas first with detergents then scrub to eliminate the molds on the materials. Wetting the infested area will prevent the spores to spread by air on another surface. Materials such as carpet, drywall, papers and others must be thrown away if you see that black molds have grown in it. Sanding the surface of wooden material like furniture can save it. However, because Stachybotrys  is a highly toxic black mold, only mold removal specialist can tell you which can be salvaged or not. Mold biocides can be used to sanitize areas where black molds have been removed. This is to ensure that the remaining molds are killed.

In worst cases, when mold infestation is too much to bear, the entire house or building can be renovated or repaired. Mold growth is an indication of water leak problem that should be addressed immediately before the effects worsen. Before buying a house, it is advisable to check with your realtor if there is a clause in the contract on mold problems. In the past lawsuits have been filed against home insurance companies for failure to pay their clients for mold damages. Insurers have either removed or limited homeowner’s insurance claims nowadays on mold damages. So the best thing to do is to check the house before buying it.

Types of Mold

How can you tell what types of mold are lurking unchecked in your homes? Molds are so tiny, measuring less than 5 microns but they number around 1000 species and some species can really be dangerous to one’s health. There are countries where a system to categorize molds according to their health hazards has been adapted. The following are the hazard classifications for  different types of mold:

  • Hazard Class A: Molds belonging to this group are directly affecting one’s health through risk of infection or toxicity. These molds can be present in homes and offices. Controlling and exterminating molds in these areas is imperative.
  • Hazard Class B: These are molds that result to allergic reactions over longer period of time.
  • Hazard Class C: Molds in this category are not health risk but they can damage structures. Even this type of mold needs to be rid of.

The common types of mold can be divided into two: the black mold and the non-black molds. Some people have misconstrued the color of molds as an indicator of its toxicity. Mold colors do not really tell how toxic they are. Black molds aren’t always toxic, and toxic molds aren’t always black.

Generally, however, the black color carries an impression of being toxic. In fact, three types of mold that are really toxic —  stachybotrys, memnoniella, and acremonium — are really black molds. They contain mycotoxins or substances produced by molds that cause diseases or allergies.


Stachybotrys (or Stachy) is is a toxic mold belonging to Class A that thrives on highly moist environment or water damaged objects. They appear as black, shiny and slippery. Stachybotrys breeds in very damp or humid environment and can survive and grow after 24 hours of continuous wet condition like slow plumbing leaks, shower or bathing spill or water leaking on walls.

  • Where It Grows: They grow in colonies on high cellulose materials like hay, straw, wicker including materials like ceiling walls and tiles, wallpapers, insulation backing, paper files, cardboard, jute, dust and wood.
  • Health Hazard: Stachybotryotoxicosis is a disease caused by the mycotoxins in the fungus Stachybotrys. It was first reported in Russia in 1940 and people complained of common symptoms such as dermatitis, pain and inflammation of the mucous membranes of the mouth and throat, a burning sensation of the nasal passages, tightness of the chest, cough, bloody rhinitis, fever, headache and fatigue. In the 1990s, it was also reported to have caused respiratory discomfort and the deaths of infants in Cleveland, Ohio.


Acremonium (also known as Cephalosporium) is a type of fungus growing outdoor and indoor and can be classified as Hazard Class B or C.

  • Where It Grows: Acremonium grows in very wet environment like damp soil and decomposing plants. In buildings, they can grow in thermal and fiberglass insulations for heating and cooling systems. Often acremonium molds can be found in carpet and mattress dust, gypsum board, wallpaper and dry walls. They can also be found in a house with leaking water, and damp basement walls.
  • Health Hazard: Three varieties of the Acremonium species have been found to cause infections to man: Acremonium falciforme, Acremonium kiliense, and Acremonium recifei. Mycetoma, or Madura foot (maduromycosis) is a fungal infection focused in one area of the body and is caused by Acremonium. Other effects of Acremonium are pulmonary infections and infections of the cornea in individuals with low immune systems. Some findings link Acremonium to arthritis, pneumonia, peritonitis, endocarditis, keratitis, meningitis, and osteomyelitis.


Memnoniells echinata grows in soil and is very much alike with stachybotrys. Both are usually found growing together. The Memnoniella mold when found indoor can be dangerous because its tiny size makes it easier to enter the bronchial lining.

  • Where It Grows: This wind-borne mold develops in damp and warm areas and on cellulose materials like paper, sheetrock, plasterboard, ceiling tiles and wood. However, the mold is easily eliminated when the area or moisture source becomes dried up.
  • Health Hazard: Memnoniella does not pose great threat to humans but people with asthma can seriously be irritated and those with low tolerance to common allergies. Common symptoms are throat irritation, eye and nose itchiness and rashes.

If you think that your homes are mold-free, think again. If you are buying a new house or renting an apartment for your family, inspect every nook for any sign of mold infestation. Talk with the homeowner if you see molds developing and ask what can be done with the mold problem. The best way to get rid of molds is to regularly clean and scrub with bleach solution where molds are likely to develop such as in the bathroom, sink and basements.

Do You Have Mold in Your House?

Mold in house should be avoided. While it is impossible to get rid of all the mold and mold spores in your house, there are ways to reduce it and prevent its harmful effects. Mold in house should be regularly inspected and monitored.

Mold is a natural part of our environment as it helps to break down dead decaying matter such as the fallen leaves outside our house. But those molds inside the house can be very harmful. These molds can reproduce by releasing its spores in the air. As these spores float in the air, eventually they will find their way inside our houses. Invisible to our naked eye, these spores can attach themselves to almost everything. As mold can be found everywhere, both indoors and outdoors, we must keep our house mold free as much as possible.

Mold Can Be Helpful

Mold outside the house helps in decomposing dead leaves, woods and other plant debris. In this way, they are helpful. There are also some molds used in making antibacterial medicines like penicillin. There also some molds used in the food and beverage industry. These molds are produced and grown in a controlled setting. But mold in house is a big no – no.

The Risk of Indoor Mold

As long as there is moisture, mold in house can continue to grow. As moisture seeps through walls, floors, wood, and other materials, molds are able to survive in any surface. The damp environment will provide a good breeding ground for molds. Bathrooms, laundry rooms, kitchens and basements are best examples of damp places where molds would love to stay.

Mold in house can bring serious house problems. Having molds in places they should not be may give home owners a big headache. Mold in house can destroy the house itself. As molds attach themselves in your walls, it can leave stain marks and spots. Materials gets stained and discolored and overtime the materials would deteriorate.

As moisture seeps through walls, floors, wood, and other materials, molds are able to survive in any surface.

For houses made of wood, mold infestation can cause physical damage on the house and eventually ruining the house. This is frustrating especially those in flood-prone areas. Aside from the discolorations, mold in house can give a musty smell which you cannot ignore.

Aside from material damages, mold in house can cause serious health problems. Molds in house can release chemicals and spores. These spores when inhaled can be cause mold allergy symptoms. These symptoms include coughing, sneezing, watery eyes and the like. Aside from allergic symptoms, mold in house can trigger asthma attacks. An asthma attack requires immediate attention before it may lead to several complications. There are several molds that can release mycotoxins which can be harmful to our body.

How to Control House Mold

There are several ways in reducing and controlling the mold in house. You can make use of a dehumidifier to dry out your house. Using a dehumidifier, you will deny molds from having the moisture they need to grow and multiply. There are also some commercially available mold removers in the market today. You can also use bleach – water solutions or baking soda – vinegar mixtures.

Mold and Mildew

What are mold and mildew? Both mold and mildew are fungi that grow on moist and humid areas such as the bathroom, basements and kitchen. Both are reproduced by air-borne spores that quickly develop into a mold colony in 24 or 48 hours in areas that are continually wet.

Mold versus Mildew

Sometimes it’s hard to tell mold and mildew apart. Molds can appear black, red, green or blue but mildew is dull white or gray. Molds are usually found in food. Mildew develops in fabrics, showers and papers. Mildew are seen on damp clothes or fabrics as powdery or velvety that looks like sugar-crystal shapes with dull white or gray color. The two can be referred to interchangeably. However when discussing about the characteristics, health risks and control of mold and mildew, mold control experts refer to both as generally mold.

Spotting Mold or Mildew Growth

The three conditions for mold and mildew to grow are moisture, temperature and nutrient. When it’s hard to know where mold and mildew might be growing, be guided by the following:

  • Mold and mildew can be unsightly when they begin to infest homes and spread through the walls, ceiling, furniture, carpets, curtains and found in other areas in the house with water leaking such as the bathroom and kitchen sink . Mold spores can grow fast when they fall on damp and porous materials.
  • Because mold spores are microscopic they appear visible to the eyes when they have digested the nutrient source and have grown into a mold colony.
  • You can also tell the presence of molds by your sense of smell. Wet carpet eliminates a musty odor that tells you of mold growing under it.
  • Molds grow in humid environment that’s usually 50 to 90 degrees Fahrenheit. Areas with relative humidity of more than 60 or 70 % can be dehumidified to control mold growth. The kitchen is mostly hot for a long time; this is one area where molds usually breed fast.
  • Rotting food or even food in the fridge can be a nutrient source for mold spores to propagate. Fruits and vegetables left at room temperature must be checked if they are already rotten, and must be thrown immediately to the garbage bin. Left-over foods stored in the fridge for a long time can also be a breeding place for food molds even when the temperature is cool. Dispose garbage immediately to prevent mold growth problem.

Health Risks of Mold Infestation

Molds, like the toxic black mold variety of Stachybotrys, can affect health when people are constantly exposed to mold particles for a long time. People with allergies and pulmonary disorders are easily irritated by mycotoxins. They are toxic substances produced by fungi such as molds. These mycotoxins can spur allergic reactions, diseases and even death when the toxin level is intolerable. Some reported health problems associated with mold and mildew in homes and offices include:

  • Upper and lower respiratory problems such as cough, sneezing, runny nose, wheezing, difficulty in breathing, nose and throat irritation such as sinusitis and hay fever symptoms
  • Eye irritation characterized by watery, red and burning sensation in the eye area
  • Skin irritation such as contact dermatitis or rashes
  • Common skin diseases like athlete’s foot, and other infections such as yeast infections
  • Headache and fatigue

People with weak immune system or those classified as immune-compromised or immune-suppressed individuals are highly vulnerable to mold infection. A condition called aspergillosis of the lungs has affected immune-compromised individuals when they inhaled mold spores and these spores began growing in their lungs. Infants were reported to have died from pulmonary hemorrhage. It was found out that Stachybotrys mold spores were attached to their lungs.

Mold and mildew are part of the natural food cycle and they can never be eradicated. But because indoor molds are threats to one’s health and property, it is best to control mold when they start growing in your homes and offices.

Bathroom Mold

Have you noticed some black formation on your bathroom floors, walls, and ceilings? That’s bathroom mold.

Molds are common in the bathroom because it’s one place that’s always humid and damp. Molds can rapidly multiply in moist places. Steam from shower and running water causes humidity to increase inside the bathroom. Moreover, because water pipes can burst due to high water pressure when you open the shower or faucet, leaks inside the bathroom tile walls can also cause molds to grow unchecked. Water can penetrate from the walls and floors. When molds are not treated, the mold infestation can grow rapidly under the tiled walls and floors. Normally however, moist is ever present in the bathroom because it’s not one’s usual habit to wipe dry the bathroom tiles, walls and sinks after showering.

Sometimes bathrooms are not well ventilated and this is another reason why bathroom mold can develop easily. Poor circulation of air causes the bathroom area to become warm; that’s why some bathrooms should have fans not only to get rid of the stinky smell, but to allow cooler air to circulate.

Low lighting can also contribute to bathroom mold infestation. Rooms that are well-lit prevent molds from spreading in colonies. Dark rooms or areas where there is minimal sunlight or lighting are often left unclean and dust can accumulate. When spores of molds burst, they rapidly reproduce because the dust particles become their nourishment.

Molds nourish themselves from decaying or dead objects and even scum from soap and residues of body oil. Grimy bathroom is the last thing that you want if you are thinking of getting rid of the bathroom molds. These and other factors like moist and warm air are the best conditions for molds to multiply.

How to Control Bathroom Mold

What can be done to eliminate bathroom mold? Here are easy ways to control and eliminate bathroom mold.

  • Regularly clean your bathroom so that mold growth can be controlled. Scrub the bathroom tubs and sinks with a 50-50 solution of chlorine bleach and water. This will extinguish the mold spores.
  • Keep the areas clean and always dry. You can let it air dry by opening the windows or using fans to lessen the moisture and humidity.
  • Use undiluted vinegar to wipe on the surface of infested areas ; it is an inexpensive home remedy to mold control. Moms have been using vinegar to stop the growth of molds aside from preventing the musty odor.
  • Get rid of too many empty bottles of toiletries as these are also breeding spots for molds. Check for objects in your bathroom that sit on water. If possible, have a shelf to organize your shampoos, facial scrubs, soaps and other vanity products allowing them to air dry quickly.
  • Use quality mold control products with care and safety. Follow the instructions and never mix them with other products because it can result to toxic reactions and fumes.
  • Repair the area with molds especially if caulking has been observed. Mold control products will be useless if the mold has seeped into the leakages. The only remedy is to repair or remodel the bathroom.

Molds apparently do not really harm people. However people with asthma or allergies may manifest hypersensitivity to molds. Skin rashes, runny nose, eye irritation, cough, nasal congestion, aggravation of asthma or difficulty breathing are just a few indications of mold allergy. Some molds have high levels of mycotoxins which can cause fatigue, nausea, severe headaches, and irritation to the lungs and eyes to sensitive people.

Molds are so small that we often disregard them. But over time, they can be annoying, unsightly, and most specially, toxic. Maintaining a clean, dry and well-ventilated bathroom is one of the most effective ways on how to kill black mold and other types of mold.

Types of Mold

Mold is a fungus that reproduces from seed-like spores and can easily grow in many places of your property. Often, the mold will form in places that are humid and dark such as behind walls or in the attic. Once the mold has formed, mold remediation professionals can properly restore the affected areas.

There are around 1000 species of mold and some species can really be dangerous to one’s health. There are countries where a system to categorize molds according to their health hazards has been adapted. The following are the hazard classifications for different types of mold:

  • Hazard Class A

    Molds belonging to this group are directly affecting one’s health through risk of infection or toxicity. These molds can be present in homes and offices. Controlling and exterminating molds in these areas is imperative.

  • Hazard Class B

    These are molds that result to allergic reactions over longer period of time.

  • Hazard Class C

    Molds in this category are not health risk but they can damage structures. Even this type of mold needs to be rid of.

Common Types of Mold

Generally, however, the black color carries an impression of being toxic. In fact, three types of mold that are really toxic — stachybotrys, memnoniella, and acremonium — are really black molds. They contain mycotoxins or substances produced by molds that cause diseases or allergies.

Acremonium (also known as Cephalosporium)

This type of fungus grows outdoor and indoor and can be classified as Hazard Class B or C.


This common indoor mold can cause asthma problems, hay fever and allergic reactions. It forms in almost any color and is often found in food, plants and soil.


With more than 160 species, this mold produces mycotoxins. Aspergillus can cause infections and allergic reactions. It is found in soil and food.


This type of mold is most commonly found indoors on plants, soil and textiles. It can be harmful to human health, causing asthma problems, allergic reactions and weakening of the immune system. Cladosporium is dark green and black in color and has over 30 different species.


This type of mold can be found indoors in food and dust. It is harmful to those susceptible to it, such as people with weakened immune systems and allergies.

Stachybotrys (or Stachy)

This type of mold is a toxic mold belonging to Class A that thrives on highly moist environment or water damaged objects. They appear as black, shiny and slippery. Stachybotrys breeds in very damp or humid environment and can survive and grow after 24 hours of continuous wet condition like slow plumbing leaks, shower or bathing spill or water leaking on walls.