Mold FAQ

  1. What are molds?
  2. What is mildew and is it different than mold?
  3. Are there Federal regulations or standards regarding mold?
  4. What makes molds grow in a building?
  5. Why do molds give off musty odors?
  6. What are mycotoxins and are they dangerous to humans?
  7. Do molds affect my health?
  8. There is black mold in my building, What if it is the toxic kind you see on TV?
  9. How does mold develop in a structure?
  10. How do I know if I have a mold problem?
  11. When should I sample for mold?
  12. Can I control mold growth in a building?

What are molds?

Molds are tiny microscopic organisms that digest organic matter and reproduce by releasing spores. Molds are a type of fungi and there are over 100,000 species. In nature, mold helps decompose or break-down leaves, wood and other plant debris. Molds become a problem when they go where they are not wanted and digest organic building materials such as drywall, ceiling tiles, carpet, and wood.

What is mildew and is it different than mold?

“What is mildew?” The answer depends on whether you ask a scientist or a nonexpert. Mycologists, who study fungi, use the term “mildew” only for fungi that grow on plants. When mycologists say “Mildew,” they mean the white growth that causes diseases in plants.
People who are not scientists use the term “mildew” differently. For them, mildew is the discoloration caused by mold in buildings. The molds that grow around windows or in bathrooms are called “mildew.” Is mildew different than mold? The mycologist would say they are different. Mildew only grows on plants outdoors. The nonexpert, however, sees the effects of mold growing indoors and calls it “mildew.”

Are there Federal regulations or standards regarding mold?

Standards or Threshold Limit Values (TLVs) for airborne concentrations of mold, or mold spores, have not been set. Currently, there are no EPA regulations or standards for airborne mold contaminants.

What makes molds grow in a building?

Mold is in the atmosphere all around us as tiny spores. The spores need moisture to begin growing, digesting and destroying. Molds can grow on almost any surface, including; wood, ceiling tiles, wallpaper, paints, carpet, sheet rock, and insulation. The mold grows best when there is lots of moisture from a leaky roof, high humidity, or flood. There is no way to get rid of all mold spores from a building, because they are naturally occurring in the environment. Mold is controlled by keeping organic building materials dry.

Why do molds give off musty odors?

The musty odors produced by molds are known by scientists as Microbial Volatile Organic Compounds. (These compounds are abbreviated as mVOCs.) Some mVOCs produce musty and moldy odors, which result from the chemical changes taking place during the mold life process. They are waste products given off by actively growing molds. Health effects such as headaches, dizziness and nausea have been linked to exposure to mVOCs, but research is only beginning. Odors from mVOCs are a sign that mold is actively growing and so may indicate a level of mold contamination requiring remediation.

What are mycotoxins and are they dangerous to humans?

Mycotoxins are poisonous substances. “Myco” means fungus, so think of mycotoxins as “fungi toxins.” They are designed for chemical warfare against other organisms, even against other types of molds. Living molds may produce mycotoxins to discourage other molds or bacteria from growing in the same territory. Unfortunately, humans who inhale, ingest or touch mycotoxins may have a toxic reaction. Some mycotoxins have been shown to produce human health effects, while little is known about the possible harmful affects of some other mycotoxins.

We should not panic over mold toxins. Not all molds produce mycotoxins; furthermore, molds that can produce mycotoxins do not produce them in all situations. EPA cautions that finding molds in a building does not mean that mycotoxins are also in the building, and even when mycotoxins are present in a building, the quantities may not be large and thus health threatening.

Do molds affect my health?

Most molds do not harm healthy people. But people who have allergies or asthma may be more sensitive to molds. Sensitive people may experience skin rash, running nose, eye irritation, cough, nasal congestion, and aggravation of asthma or difficulty breathing. People with an immune suppression or underlying lung disease, may be at increased risk for infections from molds.

A small number of molds produce toxins called mycotoxins. When people are exposed to high levels of mold mycotoxins they may suffer toxic effects, including fatigue, nausea, headaches, and irritation to the lungs and eyes. If you or your family members have health problems that you suspect are caused by exposure to mold, you should consult with your physician.

There is black mold in my building, What if it is the toxic kind you see on TV?

There are thousands of different types of mold in the environment that come in a variety of colors. Just because a mold is black does not mean that it is any more or less toxic than mold that is green, blue, yellow or orange.

There has been a lot of media attention about a particular type of mold, Stachybotrys that has been reported to be very toxic. In the middle to late 1990’s there was an indication that this type of mold was linked to a respiratory disease called acute idiopathic hemorrhagic airway disease. In reality, all molds may cause the same type and severity of health reaction. No matter what color the mold is, it still needs to be cleaned up in the same way.

How does mold develop in a structure?

Mold is often found in areas where water has damaged building materials and furniture from flooding or plumbing leaks. Mold can also be found growing along walls where warm moist air condenses on cooler wall surfaces, such as inside cold exterior walls, behind furniture, and in closets where articles are stored against walls. Mold often grows in rooms with both high water usage and humidity, such as kitchens, bathrooms, laundry rooms, and basements. If you notice mold or know of water-damaged areas, it is time to take action to control its growth.

How do I know if I have a mold problem?

Mold problems are ALWAYS caused by a moisture or water problem. It does no good to clean up the mold, if you haven’t solved the water issue first. Environmental professionals “inspect” for mold through simple visual examination.

When should I sample for mold?

You don’t need to sample for mold because in most cases you can see or smell mold. Even a clean, dry house will have some mold spores, but not enough to cause health problems. If you smell mold it may be hidden behind wallpaper, in the walls or ceiling or under the carpet. If you suspect you have hidden mold be very careful when you investigate, protect yourself from exposure in the same manner as you would for a clean-up. Mold sampling should normally be reserved for determining if a mold clean-up or remediation activity has been successful.

Can I control mold growth in a building?

Yes you can.  Dry out the structure and fix any moisture problems. Stop water leaks, repair leaky roofs and plumbing. Keep water away from concrete slabs and basement walls.  Open windows and doors to increase air flow, especially along the inside of exterior walls. Use a fan if there are no windows available.

Clean and dry water damaged materials within 24 to 48 hours, or consider removing and replacing damaged material. Mold growth normally starts within 72 hours after an organic building material has become wet.