Molds produce tiny spores to reproduce. Mold spores waft through the indoor and outdoor air continually. When mold spores land on a damp spot indoors, they may begin growing and digesting whatever they are growing on in order to survive. There are molds that can grow on wood, paper, carpet, and foods. When excessive moisture or water accumulates indoors, mold growth will often occur, particularly if the moisture problem remains undiscovered or un-addressed. 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.

Remember:

• 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.

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.

Keep in mind that:

1. The key to mold control is moisture control.
2. If mold is a problem in your home, you should clean up the mold promptly and fix the water problem.
3. It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth.

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 [guidance] 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.

Mold 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, follow the guidelines. However:

• If there has been a lot of water damage, and/or mold growth covers more than 10 square feet, consult EPA's Mold Remediation in Schools and Commercial Buildings. Although focused on schools and commercial buildings, this document is applicable to other building types.
• 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.
• 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.

Mold Cleanup Guidelines

Bathroom Tip:

Places that are often or always damp can be hard to maintain completely free of mold. If there's some mold in the shower or elsewhere in the bathroom that seems to reappear, increasing ventilation (running a fan or opening a window) and cleaning more frequently will usually prevent mold from recurring, or at least keep the mold to a minimum.

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 (see discussions: What to Wear When Cleaning Moldy Areas and Hidden 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.
• 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 consult our Frequently Asked Questions database and ask a question if you don't find what you need.

Moisture and Mold Prevention and Control Tips

Moisture Control is the Key to Mold Control

• 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 preceding page)
• 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.

Renters: Report all plumbing leaks and moisture problems immediately to your building owner, manager, or superintendent. In cases where persistent water problems are not addressed, you may want to contact local, state, or federal health or housing authorities. You can also contact your state health department.

Test 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.

Hidden Mold

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.

Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing.

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.

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, most likely, the mold problem will come back.

1. The key to mold control is moisture control.
2. Scrub mold off hard surfaces with detergent and water, and dry completely.
3. Fix plumbing leaks and other water problems as soon as possible.  Dry all items completely.
4. 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.
5. Avoid exposing yourself or others to mold (see discussions: What to Wear When Cleaning Moldy Areas and Hidden Mold).
6. 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.
7. 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.

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.

If properly designed, ultraviolet germicidal irradiation (UVGI) cleaners that use ultraviolet radiation from UV lamps may destroy indoor biological pollutants such as viruses, bacteria, and some molds that are growing on the moist interiors of HVAC surfaces (e.g., cooling coils, drain pans, or ductwork). But typical UVGI cleaners used in homes have limited effectiveness in killing bacteria and molds. Effective destruction of some viruses and most mold and bacterial spores usually requires much higher UV exposure than is provided in a typical home unit. Furthermore, dead mold spores can still produce allergic reactions, so UVGI cleaners may not be effective in reducing allergy and asthma symptoms.

Cleaning up after a flood can pose health risks. You and your family should wait to re-enter your home until professionals tell you it is safe, with no structural, electrical or other hazards.

Before you start cleanup activities, contact your insurance company and take pictures of the home and your belongings. Remember – drying your home and removing water-damaged items is your most important step for preventing mold damage.

Is There a Problem?

Was your home flooded? If so, and you were not able to dry your home (including furniture and other items) within 24-48 hours, you should assume you have mold growth. You need to completely dry everything, clean up the mold, and make sure you don’t still have a moisture problem.

You may see or smell mold on clothing, drywall, furniture, cardboard boxes, or books, but it may also be hidden under or behind items like carpet, cushions, or walls.

Mold Basics: How Molds Can Affect Your Health

Exposure to mold can lead to asthma attacks, eye and skin irritation, and allergic reactions. It can lead to severe infections in people with weakened immune systems.  Avoid contaminated buildings and contaminated water as much as you can.

Flood water may have carried sewage or chemicals into your home. This could expose you or your family to viruses, bacteria, disease carriers (such as mosquitos), and parasites, as well as mold.

You can protect yourself and your family from mold exposure by following these steps.

Before You Enter Any Moldy Site:

• Protect yourself and loved ones against hazards. People with breathing problems like asthma or who have weakened immune systems should stay away from moldy sites. Children should not take part in disaster cleanup work. Check for loose power lines or gas leaks. Make sure the electricity and gas are turned off. Look for sagging ceilings or floors or other structural problems. Watch out for wet, muddy, or slippery floors.
• Protect your mouth and nose against breathing in mold: wear at least an N-95 respirator. If you plan to spend a lot of time removing moldy belongings or doing work like ripping out moldy drywall, wear a half-face or full-face respirator.
• Protect your skin. Wear protective gloves (non-latex, vinyl, nitrile, or rubber). Do not touch mold or moldy items with bare hands.
• Protect your eyes. Wear goggles that provide complete eye protection. Choose goggles designed to keep out dust and small particles. Safety glasses or goggles that have open vent holes will not protect you against dust and small particles.

After You Leave a Mold Site:

• Protect yourself and loved ones. Shower and change your clothes.  This will help you avoid carrying mold and other hazards back to your current living quarters.

Should I Do This Myself?

This job may be too difficult or dangerous for you. It may be best to get help from experienced and qualified professionals if you can.  Hire a mold inspection or remediation professional affiliated  with or certified by the National Environmental Health Association (NEHA), the American Industrial Hygiene Association (AIHA), the Institute of Inspection, Cleaning and Restoration Certification (IICRC), or American Council for Accredited Certification (ACAC) to inspect, repair, and restore the damaged parts of your home. Your state also may regulate mold remediation.

Sampling for mold is not usually recommended. Understanding the results can be difficult, and no matter what kind of mold is in your home, you need to clean it up and fix the moisture problem.

If I Must Do This Myself, How Can I Do It Safely?

Follow these steps:

1. Put on the personal protective equipment described above to protect your eyes, nose, mouth, and skin.
2. Remove standing water and wet materials. Use a wet vacuum to remove water from floors, carpets, and hard surfaces. Dry your home and everything in it as quickly as you can – within 24 to 48 hours if you can.
3. Open all doors and windows when you are working and leave as many open as is safe when you leave.
   • Open inside doors, especially closets and interior rooms, to let air flow to all areas. Take doors off their hinges if you need to.
   • Open kitchen cabinets and bathroom vanity doors; remove drawers, wipe them clean, and stack them to dry.
   • Open the attic access to let air flow to the attic. Before you open the attic door, make sure nothing will fall on you.
4. When electricity is safe to use, use fans and dehumidifiers to remove moisture. Do not use fans if mold has already started to grow, because the fans may spread the mold.
5. Clean with water and a detergent. Remove all mold you can see. Dry right away.
6. If you use cleaning products, do not mix cleaning products together. DO NOT mix bleach and ammonia because it can create toxic vapors.
7. Painting or caulking over mold will not prevent mold from growing. Fix the water problem completely and clean up all the mold before you paint or caulk.
8. Throw away items that can’t be cleaned and dried. Throw away anything that was wet with flood water and can’t be cleaned and dried completely within 24 to 48 hours. If you have precious items that you want to preserve, follow these guidelines from the Smithsonian Institute: https://culturalrescue.si.edu/hentf/resources/resources-public-and-historic-property-owners/.

Safety Tips on Using Portable Generators

• If you use a portable generator for electricity use CAUTION to avoid carbon monoxide poisoning and fires.
• Use portable generators OUTSIDE and at least 20 feet away from buildings.
• Do not use portable generators inside your house or garage.
• Do not put portable generators on balconies or near doors, vents, or windows.
• Do not use portable generators near where you or your children are sleeping.
• Never refuel a generator while it is hot.

Am I Done?

• If you still see or smell mold, you have more work to do. After a remediation, there should be no signs of water damage or mold growth.
• You may need to ask a mold remediation professional to know whether your mold problem is completely fixed. As noted in the “Should I do this myself?” section, sampling for mold is not usually recommended; instead, a careful inspection of the work area for completion of the cleanup and absence of mold-related odors is usually appropriate.
• If you have health problems that get worse when you return home, like asthma or allergy attacks or skin or eye irritation, you may still have some mold.

Key Messages

Wear personal protective equipment. Wear an N-95 respirator at a minimum, goggles, and protective gloves.

Use portable generators carefully, outside and away from the home, to avoid carbon monoxide poisoning and fires.

Ensure the mold cleanup is complete before reoccupying your home.

After a hurricane, flood or other major storm, “green” products can be difficult to find. Bleach and dish detergent might be the only things available in your area. Bleach and dish detergent, common household items, can be used to clean mold in your home after a storm. The steps to take to clean up mold will depend on how much water damage your home suffered.

Clean-up actions after a flood

Important safety reminders:

• Wear personal protective equipment. Wear at least an N-95 respirator, goggles, and protective gloves.
• Open windows or doors when using any cleaning products.
• Never mix bleach with ammonia or any other cleanser.
• Children should not be involved in disaster clean-up.
• Have your home heating, ventilating, and air-conditioning system (HVAC) checked and cleaned by a service professional experienced in mold clean-up before you turn it on. If the system was flooded with water, turning it on will spread mold throughout the house.

What to Wear before entering a Home or Building with Mold Damage

• Goggles or eye protection
• N-95 respirator or one that provides even more protection
  (check packaging for “N-95”)
• Long-sleeved shirt
• Protective gloves
• Long pants
• Waterproof boots

CAUTION!

If you have a breathing problem like asthma, do not enter a building with mold damage. Mold can make asthma symptoms worse.

If you have a weakened immune system (such as from cancer treatment or medicines that suppress the immune system), do not enter a building with mold damage. People with a weakened immune system are more likely to get a serious illness from mold.

Children should also not enter buildings with mold damage.

Essential List of Items for Cleaning Mold:

• Bucket
• Stiff bristle brush
• N-95 respirators, or ones that provide more protection (check packaging for “N-95”)
• Goggles
• Protective rubber gloves
• Waterproof rubber boots
• Dish detergent
• Household bleach

Other Items That Can Be Helpful:

• Wet/dry vacuum
• Large plastic trash bags
• Towels (not fancy)
• Paper towels (for light cleanup and washing your own hands, etc.)
• Large plastic resealable bags for precious items
• First-aid kit
• Bottled drinking water

Be Safe When Cleaning Up Mold!

• Designate a safe, mold-free area outside of the mold cleanup area for first aid, personal hygiene, and storing/accessing food and water.
• When working in areas with mold, wear a N-95 respirator and wear protective gloves, boots, and clothing. Be sure to follow the instructions for wearing the respirator.
• Wash your hands thoroughly after mold cleanup, and change your clothes after working on mold cleanup activities.

The key to mold prevention is moisture control. Water entry into buildings or building crawl spaces should be controlled. If water enters a building through a leaking roof or because of a flood or accident, it should be removed immediately and affected areas should be dried out.

• Keep the building and furnishings dry.
• When things get wet, dry them quickly (24-48 hours).
• Perform routine maintenance, cleaning, and repairs.

Hidden Areas

Special attention should be given to areas that are hidden, but that might have gotten wet. Areas frequently overlooked and not dried carefully include:

• Behind walls
• Ceilings
• Crawl spaces
• Attics

In general, all wet areas should be completely dried within 48 hours to prevent mold from growing.

Routine Maintenance is Important

A number of items frequently involved in mold problems should be checked and maintained routinely.

Furnace Humidifiers

Furnace humidifiers must be cleaned regularly to prevent mold and bacterial growth. Ducts in which humidifiers are installed should also be checked to ensure water has not leaked into the furnace or filter areas. Stand-alone humidifiers should be cleaned very frequently to ensure that they are not moldy. Special attention should be paid to any filters in the humidifier because they can become moldy and the humidifier can spread spores throughout the area. Carpeted areas around the humidifiers should also be monitored for wetness. Humidifiers should be set to produce less than 60 percent relative humidity in the building. Relative humidity greater than 60 percent is likely to result in condensation in the building, which can lead to mold growth.

HVAC Systems

HVAC systems should be checked routinely because mold in a ventilation system may be spread throughout the building. Drain or condensate pans should also be checked routinely because they can become reservoirs for mold and bacteria if not installed and maintained properly. These pans are designed to remove water produced by cooling hot air from the ventilation system. If the pans do not drain, or are not cleaned frequently, they may allow water to enter the HVAC system and contaminate the ventilation ducts in the building. The pans themselves may also grow mold and allow mold spores to be spread throughout the building. Filters for the HVAC system also should be kept dry and changed frequently.

Toilet and Bathroom Areas

Toilet and bathroom areas should be carefully monitored for water and plumbing leaks. Signs of water damage should be investigated quickly, including:

• Rippling wall coverings
• Cracked drywall tape
• Peeling paint
• Other signs of water damage

These signs frequently indicate that water has leaked, and hidden mold growth and damage are likely. Water seepage into crawl spaces or basements should also be stopped quickly to ensure that mold will not grow, and measures such as the installation of sump pumps or a regrading of the area around the building should be considered to prevent future leaks. Any areas that smell moldy or musty should also be investigated to ensure that water has not entered and mold is not growing.

Buildings

Buildings should be located, landscaped, built and renovated with consideration for the climate. A building that is not suited to the climate can have moisture problems. Buildings inevitably will get wet, both inside and out, and they must be allowed to dry or mold will grow in them. Selection and location of building materials and furnishings can also be made with mold prevention in mind. In frequently damp or wet areas, more mold-resistant materials can be used; for example, some woods are more resistant to mold than particle board or pressed board.

Mold Prevention Tips

• MOISTURE CONTROL IS KEY
• Keep the building clean and dry. Dry wet or damp areas within 48 hours.
• Fix leaky plumbing and leaks in the building envelope as soon as possible.
• Watch for condensation and wet spots. Fix the sources of moisture problems as soon as possible.
• Prevent moisture due to condensation by increasing surface temperature or reducing the moisture level in air (humidity). To increase surface temperature, insulate or increase air circulation. To reduce the moisture level in air, repair leaks and increase ventilation (if outside air is cold and dry), or dehumidify (if outdoor air is warm and humid).
• Keep heating, ventilation and air conditioning (HVAC) drip pans clean, flowing properly and unobstructed.
• Vent moisture generating appliances, such as dryers, to the outside where possible.
• Maintain low indoor humidity, below 60 percent relative humidity (RH), ideally 30 percent to 50 percent, if possible.
• Perform regular building and HVAC inspections and maintenance as scheduled.
• Don't let foundations stay wet. Provide drainage and slope the ground away from the foundation.
• If you are not experienced with home/building repairs you may want to consult a professional when making repairs, or for assistance with mold-prevention-related changes to your home/building.