Mold Questions, Answers, and Facts
- The key to mold control is moisture control.
- If mold is a problem in your home, you should clean up the mold promptly
and fix the water problem.
- It is important to dry water-damaged areas and items within 24-48 hours to
prevent mold growth.
Why is mold growing in my home?
Molds are part of the
natural environment. Outdoors, molds play a part in nature by breaking down dead
organic matter such as fallen leaves and dead trees, but indoors, mold growth
should be avoided. Molds reproduce by means of tiny spores; the spores are
invisible to the naked eye and float through outdoor and indoor air. Mold may
begin growing indoors when mold spores land on surfaces that are wet. There are
many types of mold, and none of them will grow without water or moisture.
(Mold growing outdoors on firewood. Molds come in many
colors; both white and black molds are shown here.)
Can mold cause health problems?
Molds are usually not a problem indoors,
unless mold spores land on a wet or damp spot and begin growing. Molds have the
potential to cause health problems. Molds produce allergens (substances that can
cause allergic reactions), irritants, and in some cases, potentially toxic
substances (mycotoxins). Inhaling or touching mold or mold spores may cause
allergic reactions in sensitive individuals. Allergic responses include hay
fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash
(dermatitis). Allergic reactions to mold are common. They can be immediate or
delayed. Molds can also cause asthma attacks in people with asthma who are
allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose,
throat, and lungs of both mold-allergic and non-allergic people. Symptoms other
than the allergic and irritant types are not commonly reported as a result of
inhaling mold. Research on mold and health effects is ongoing. This brochure
provides a brief overview; it does not describe all potential health effects
related to mold exposure. For more detailed information consult a health
professional. You may also wish to consult your state or local health
How do I get rid of mold?
It is impossible to get rid of all
mold and mold spores indoors; some mold spores will be found floating through
the air and in house dust. The mold spores will not grow if moisture is not present. Indoor
mold growth can and should be prevented or controlled by controlling moisture
indoors. If there is mold growth in your home, you must clean up the mold and
fix the water problem. If you clean up the mold, but don't fix the water
problem, then, most likely, the mold problem will come back.
Molds can gradually destroy the things they grow on. You can prevent damage
to your home and furnishings, save money, and avoid potential health problems by
controlling moisture and eliminating mold growth.
Who Should Do the Cleanup?
If you already
have a mold problem - ACT QUICKLY. Mold damages what it grows on. The
longer it grows, the more damage it can cause.
Who should do the cleanup depends on a number of factors.
One consideration is the size of the mold problem. If the moldy area is less
than about 10 square feet (less than roughly a 3 ft. by 3 ft. patch), in
most cases, you can handle the job yourself, following the guidelines below.
- If there has been a lot of water damage, and/or mold growth covers more
than 10 square feet, consult the U.S. Environmental Protection Agency (EPA)
guide: Mold Remediation in Schools and Commercial Buildings. Although focused on schools and
commercial buildings, this document is applicable to other building types. It
is available free by calling the EPA Indoor Air Quality Information
Clearinghouse at (800) 438-4318, or at epa.gov/mold/mold_remediation.html.
- If you choose to hire a contractor (or other professional service provider)
to do the cleanup, make sure the contractor has experience cleaning up mold.
Check references and ask the contractor to follow the recommendations in EPA's
Mold Remediation in Schools and Commercial Buildings, the guidelines of the American
Conference of Governmental Industrial Hygenists (ACGIH), or other guidelines
from professional or government organizations.
- If you suspect that the heating/ventilation/air
conditioning (HVAC) system
may be contaminated with mold (it is part of an identified moisture problem, for
instance, or there is mold near the intake to the system), consult EPA's guide
Should You Have the Air Ducts in Your Home Cleaned? before taking further action. Do not run
the HVAC system if you know or suspect that it is contaminated with mold - it
could spread mold throughout the building. Visit
epa.gov/iaq/pubs/airduct.html, or call (800) 438-4318 for a free copy.
- If the water and/or mold damage was caused by sewage
or other contaminated water, then call in a professional who has experience
cleaning and fixing buildings damaged by contaminated water.
- If you have health concerns, consult a health professional before starting