Mold, Moisture, and
Your Home

Mold
Basics
- 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.
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
department.
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.
Who Should Do the Cleanup
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.
-
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 of
the EPA, 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.
-
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
cleanup.
Tips
and techniques
The tips and
techniques presented in this
section will help you clean
up your mold problem.
Professional cleaners or
remediators may use methods
not covered in this
publication. Please note
that mold may cause staining
and cosmetic damage. It may
not be possible to clean an
item so that its original
appearance is restored.

-
Fix plumbing leaks
and other water
problems as soon as
possible. Dry all
items completely.
-
Scrub mold off hard
surfaces with
detergent and water,
and dry completely.
-
Absorbent or porous
materials, such as
ceiling tiles and
carpet, may have to
be thrown away if
they become moldy.
Mold can grow on or
fill in the empty
spaces and crevices
of porous materials,
so the mold may be
difficult or
impossible to remove
completely.
-
Avoid exposing
yourself or others
to mold.
-
Do not paint or
caulk moldy
surfaces.
-
Clean up the mold
and dry the surfaces
before painting.
Paint applied over
moldy surfaces is
likely to peel.
If
you are unsure about
how to clean an
item, or if the item
is expensive or of
sentimental value,
you may wish to
consult a
specialist.
Specialists in
furniture repair,
restoration,
painting, art
restoration and
conservation, carpet
and rug cleaning,
water damage, and
fire or water
restoration are
commonly listed in
phone books. Be sure
to ask for and check
references. Look for
specialists who are
affiliated with
professional
organizations.

What
to Wear When
Cleaning Moldy Areas
-
Avoid breathing
in mold or mold spores.
In order to limit your
exposure to airborne
mold, you may want to
wear an N-95 respirator,
available at many
hardware stores and from
companies that advertise
on the Internet. (They
cost about $12 to $25.)
Some N-95 respirators
resemble a paper dust
mask with a nozzle on
the front, others are
made primarily of
plastic or rubber and
have removable
cartridges that trap
most of the mold spores
from entering. In order
to be effective, the
respirator or mask must
fit properly, so
carefully follow the
instructions supplied
with the respirator.
Please note that the
Occupational Safety and
Health Administration
(OSHA) requires that
respirators fit properly
(fit testing) when used
in an occupational
setting; consult OSHA
for more information
(800-321-OSHA).
-
Wear gloves.
Long gloves that extend
to the middle of the
forearm are
recommended. When
working with water and a
mild detergent, ordinary
household rubber gloves
may be used. If you are
using a disinfectant, a
biocide such as chlorine
bleach, or a strong
cleaning solution, you
should select gloves
made from natural
rubber, neoprene,
nitrile, polyurethane,
or PVC. Avoid touching
mold or moldy items with
your bare hands.
-
Wear goggles.
Goggles that do not have
ventilation holes are
recommended. Avoid
getting mold or mold
spores in your eyes.
How
Do I Know When the
Remediation or Cleanup is
Finished?
You must have
completely fixed the water or
moisture problem before the
cleanup or remediation can be
considered finished.
- You
should have completed mold
removal. Visible mold and
moldy odors should not be
present. Please note that
mold may cause staining and
cosmetic damage.
- You
should have revisited the
site(s) shortly after
cleanup and it should show
no signs of water damage or
mold growth.
- People
should have been able to
occupy or re-occupy the area
without health complaints or
physical symptoms.
-
Ultimately, this is a
judgment call; there is no
easy answer. If you have
concerns or questions call
the EPA Indoor Air Quality
Information Clearinghouse
IAQ INFO at (800) 438-4318.
Moisture and Mold Prevention
and Control Tips
- Moisture
control is the key to mold
control, so when water leaks
or spills occur indoors -
ACT QUICKLY. If wet or damp
materials or areas are dried
24-48 hours after a leak or
spill happens, in most cases
mold will not grow.
- Clean and
repair roof gutters
regularly.
- Make sure
the ground slopes away from
the building foundation, so
that water does not enter or
collect around the
foundation.
- Keep air
conditioning drip pans clean
and the drain lines
unobstructed and flowing
properly.
- Keep
indoor humidity low. If
possible, keep indoor
humidity below 60 percent
(ideally between 30 and 50
percent) relative humidity.
Relative humidity can be
measured with a moisture or
humidity meter, a small,
inexpensive ($10-$50)
instrument available at many
hardware stores.
- If you
see condensation or moisture
collecting on windows, walls
or pipes ACT QUICKLY to dry
the wet surface and reduce
the moisture/water source.
Condensation can be a sign
of high humidity.
Actions
that will help to reduce
humidity:
- Vent
appliances that produce
moisture, such as clothes
dryers, stoves, and kerosene
heaters to the outside where
possible. (Combustion
appliances such as stoves
and kerosene heaters produce
water vapor and will
increase the humidity unless
vented to the outside.)
- Use air
conditioners and/or
de-humidifiers when needed.
- Run the
bathroom fan or open the
window when showering. Use
exhaust fans or open windows
whenever cooking, running
the dishwasher or
dishwashing, etc.
Actions that will help prevent
condensation:
- Reduce
the humidity (see above).
- Increase
ventilation or air movement
by opening doors and/or
windows, when practical.
Use fans as needed.
- Cover
cold surfaces, such as cold
water pipes, with
insulation.
- Increase
air temperature.
Testing or Sampling for
Mold
Is sampling
for mold needed? In most
cases, if visible mold
growth is present, sampling
is unnecessary. Since no
EPA or other federal limits
have been set for mold or
mold spores, sampling cannot
be used to check a
building's compliance with
federal mold standards.
Surface sampling may be
useful to determine if an
area has been adequately
cleaned or remediated.
Sampling for mold should be
conducted by professionals
who have specific experience
in designing mold sampling
protocols, sampling methods,
and interpreting results.
Sample analysis should
follow analytical methods
recommended by the American
Industrial Hygiene
Association (AIHA), the
American Conference of
Governmental Industrial
Hygienists (ACGIH), or other
professional organizations.
Suspicion of hidden mold
You may
suspect hidden mold if a
building smells moldy, but
you cannot see the source,
or if you know there has
been water damage and
residents are reporting
health problems. Mold may be
hidden in places such as the
back side of dry wall,
wallpaper, or paneling, the
top side of ceiling tiles,
the underside of carpets and
pads, etc. Other possible
locations of hidden mold
include areas inside walls
around pipes (with leaking
or condensing pipes), the
surface of walls behind
furniture (where
condensation forms), inside
ductwork, and in roof
materials above ceiling
tiles (due to roof leaks or
insufficient insulation).
Investigating hidden mold
problems
Investigating
hidden mold problems may be
difficult and will require
caution when the
investigation involves
disturbing potential sites
of mold growth. For example,
removal of wallpaper can
lead to a massive release of
spores if there is mold
growing on the underside of
the paper. If you believe
that you may have a hidden
mold problem, consider
hiring an experienced
professional.
Cleanup and Biocides
Biocides are
substances that can destroy
living organisms. The use of
a chemical or biocide that
kills organisms such as mold
(chlorine bleach, for
example) is not recommended
as a routine practice during
mold cleanup. There may be
instances, however, when
professional judgment may
indicate its use (for
example, when
immune-compromised
individuals are present). In
most cases, it is not
possible or desirable to
sterilize an area; a
background level of mold
spores will remain - these
spores will not grow if the
moisture problem has been
resolved. If you choose to
use disinfectants or
biocides, always ventilate
the area and exhaust the air
to the outdoors. Never mix
chlorine bleach solution
with other cleaning
solutions or detergents that
contain ammonia because
toxic fumes could be
produced.
Please note: Dead
mold may still cause
allergic reactions in some
people, so it is not enough
to simply kill the mold, it
must also be removed.
Ten Things You Should
Know About Mold
1. Potential health
effects and symptoms
associated with mold
exposures include
allergic reactions,
asthma, and other
respiratory complaints.
2. There is no
practical way to
eliminate all mold and
mold spores in the
indoor environment; the
way to control indoor
mold growth is to
control moisture.
3. If mold is a problem
in your home or school,
you must clean up the
mold and eliminate
sources of moisture.
4. Fix the source of
the water problem or
leak to prevent mold
growth.
5. Reduce indoor
humidity (to 30-60%) to
decrease mold growth
by:
a. venting
bathrooms,
dryers, and
other
moisture-generating
sources to
the outside;
b. using air
conditioners
and
de-humidifiers;
c.
increasing
ventilation;
d. and using
exhaust fans
whenever
cooking,
dishwashing,
and cleaning
6. Clean and dry any
damp or wet building
materials and
furnishings within 24-48
hours to prevent mold
growth.
7. Clean mold off hard
surfaces with water and
detergent, and dry
completely. Absorbent
materials such as
ceiling tiles, that are
moldy, may need to be
replaced.
8. Prevent
condensation: Reduce the
potential for
condensation on cold
surfaces (i.e., windows,
piping, exterior walls,
roof, or floors) by
adding insulation.
9.
In areas where
there is a perpetual
moisture problem, do not
install carpeting (i.e.,
by drinking fountains,
by classroom sinks, or
on concrete floors with
leaks or frequent
condensation).
10. Molds can be found
almost anywhere; they
can grow on virtually
any substance, providing
moisture is present.
There are molds that can
grow on wood, paper,
carpet, and foods.