Frequently Asked Questions about Black
Questions and Answers on
Stachybotrys chartarum (Black Mold) and other molds
|1) I heard about toxic molds that grow in
homes and other buildings. Should I be concerned about a serious health risk to me and my
The hazards presented by molds that may contain mycotoxins should be considered
the same as other common molds which can grow in your house. There is always a little mold
everywhere - in the air and on many surfaces. There are very few case reports that toxic
molds (those containing certain mycotoxins) inside homes can cause unique or rare health
conditions such as pulmonary hemorrhage or memory loss. These case reports are rare, and a
causal link between the presence of the toxic mold and these conditions has not been
proven. A common-sense approach should be used for any mold contamination existing inside
buildings and homes. The common health concerns from molds include hay fever-like allergic
symptoms. Certain individuals with chronic respiratory disease (chronic obstructive
pulmonary disorder, asthma) may experience difficulty breathing. Individuals with immune
suppression may be at increased risk for infection from molds. If you or your family
members have these conditions, a qualified medical clinician should be consulted for
diagnosis and treatment. For the most part, one should take routine measures to prevent
mold growth in the home.
|2) How common is mold, including Stachybotrys
chartarum (also known by its synonym Stachybotrys atra) in buildings?
Molds are very
common in buildings and homes and will grow anywhere indoors where there is moisture. The
most common indoor molds are Cladosporium, Penicillium, Aspergillus, and Alternaria. We do
not have accurate information about how often Stachybotrys chartarum is found in buildings
and homes. While it is less common than other mold species, it is not rare.
|3) How do molds get in the indoor environment
and how do they grow?
Molds naturally grow in the indoor environment. Mold spores may
also enter your house through open doorways, windows, heating, ventilation, and air
conditioning systems. Spores in the air outside also attach themselves to people and
animals, making clothing, shoes, bags, and pets convenient vehicles for carrying mold
When mold spores drop on places where there is excessive moisture, such as where leakage
may have occurred in roofs, pipes, walls, plant pots, or where there has been flooding,
they will grow. Many building materials provide suitable nutrients that encourage mold to
grow. Wet cellulose materials, including paper and paper products, cardboard, ceiling
tiles, wood, and wood products, are particularly conducive for the growth of some molds.
Other materials such as dust, paints, wallpaper, insulation materials, drywall, carpet,
fabric, and upholstery, commonly support mold growth.
|4) What is Stachybotrys chartarum
Stachybotrys chartarum (also known by its synonym Stachybotrys
atra) is a greenish-black mold. It can grow on material with a high cellulose and low
nitrogen content, such as fiberboard, gypsum board, paper, dust, and lint. Growth occurs
when there is moisture from water damage, excessive humidity, water leaks, condensation,
water infiltration, or flooding. Constant moisture is required for its growth. It is not
necessary, however, to determine what type of mold you may have. All molds should be
treated the same with respect to potential health risks and removal.
|5) Are there any circumstances where people
should vacate a home or other building because of mold?
These decisions have to be made
individually. If you believe you are ill because of exposure to mold in a building, you
should consult your physician to determine the appropriate action to take.
|6) Who are the people who are most at risk for
health problems associated with exposure to mold?
People with allergies may be more
sensitive to molds. People with immune suppression or underlying lung disease are more
susceptible to fungal infections.
|7) How do you know if you have a mold problem?
mold infestations can usually be seen or smelled.
|8) Does Stachybotrys chartarum (Stachybotrys
atra) cause acute idiopathic pulmonary hemorrhage among infants?
To date, a possible
association between acute idiopathic pulmonary hemorrhage among infants and Stachybotrys
chartarum (Stachybotrys atra) has not been proved. Further studies are needed to determine
what causes acute idiopathic hemorrhage.
|9) What if my child has acute idiopathic
Parents should ensure that their children get proper medical
|10) What are the potential health effects of
mold in buildings and homes?
Mold exposure does not always present a health problem
indoors. However some people are sensitive to molds. These people may experience symptoms
such as nasal stuffiness, eye irritation, or wheezing when exposed to molds. Some people
may have more severe reactions to molds. Severe reactions may occur among workers exposed
to large amounts of molds in occupational settings, such as farmers working around moldy
hay. Severe reactions may include fever and shortness of breath. People with chronic
illnesses, such as obstructive lung disease, may develop mold infections in their lungs.
|11) How do you get the molds out of buildings,
including homes, schools, and places of employment?
In most cases mold can be removed by
a thorough cleaning with bleach and water. If you have an extensive amount of mold and you
do not think you can manage the cleanup on your own, you may want to contact a
professional who has experience in cleaning mold in buildings and homes.
|12) What should people to do if they determine
they have Stachybotrys chartarum (Stachybotrys atra) in their buildings or homes?
growing in homes and buildings, whether it is Stachybotrys chartarum (Stachybotrys atra)
or other molds, indicates that there is a problem with water or moisture. This is the
first problem that needs to be addressed. Mold can be cleaned off surfaces with a weak
bleach solution. Mold under carpets typically requires that the carpets be removed. Once
mold starts to grow in insulation or wallboard the only way to deal with the problem is by
removal and replacement. We do not believe that one needs to take any different
precautions with Stachybotrys chartarum (Stachybotrys atra), than with other molds. In
areas where flooding has occurred, prompt cleaning of walls and other flood-damaged items
with water mixed with chlorine bleach, diluted 10 parts water to 1 part bleach, is
necessary to prevent mold growth. Never mix bleach with ammonia. Moldy items should be
|13) How do you keep mold out of buildings and
As part of routine building maintenance, buildings should be inspected for
evidence of water damage and visible mold. The conditions causing mold (such as water
leaks, condensation, infiltration, or flooding) should be corrected to prevent mold from
- Keep humidity level in house below 50%.
- Use air conditioner or a dehumidifier during humid months.
- Be sure the home has adequate ventilation, including exhaust fans in kitchen and
- Use mold inhibitors which can be added to paints.
- Clean bathroom with mold-killing products.
- Do not carpet bathrooms.
- Remove and replace flooded carpets.
|14) I found mold growing in my home; how do I
test the mold?
Generally, it is not necessary to identify the species of mold growing in
a residence, and CDC does not recommend routine sampling for molds. Current evidence
indicates that allergies are the type of diseases most often associated with molds. Since
the susceptibility of individuals can vary greatly either because of the amount or type of
mold, sampling and culturing are not reliable in determining your health risk. If you are
susceptible to mold and mold is seen or smelled, there is a potential health risk;
therefore, no matter what type of mold is present, you should arrange for its removal.
Furthermore, reliable sampling for mold can be expensive, and standards for judging what
is and what is not an acceptable or tolerable quantity of mold have not been established.
|15) A qualified environmental lab took samples
of the mold in my home and gave me the results. Can CDC interpret these results?
for judging what is an acceptable, tolerable, or normal quantity of mold have not been
established. If you do decide to pay for environmental sampling for molds, before the work
starts, you should ask the consultants who will do the work to establish criteria for
interpreting the test results. They should tell you in advance what they will do or what
recommendations they will make based on the sampling results. The results of samples taken
in your unique situation cannot be interpreted without physical inspection of the
contaminated area or without considering the buildings characteristics and the
factors that led to the present condition.
|Summary: In summary,
Stachybotrys chartarum (Stachybotrys atra) and other molds may cause health symptoms that
are nonspecific. At present there is no test that proves an association between
Stachybotrys chartarum (Stachybotrys atra) and particular health symptoms. Individuals
with persistent symptoms should see their physician. However, if Stachybotrys chartarum
(Stachybotrys atra) or other molds are found in a building, prudent practice recommends
that they be removed. Use the simplest and most expedient method that properly and
safely removes mold.