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 materials such as our homes.
What makes molds grow in my home?
Mold enters your home as tiny spores. The spores need moisture to begin growing, digesting and destroying. Molds can grow on almost any surface, such as 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 molds and mold spores from your home. But you can control mold growth by keeping your home dry.
Can I be exposed to mold?
When molds are disturbed, they release spores into the air. You can be exposed by breathing air containing these mold spores. You can also be exposed through touching moldy items, eating moldy food or accidental hand to mouth contact.
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, 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.
When is mold a problem?
You know you have mold when you smell the "musty" odor or see small black or white specks along your damp bathroom or basement walls. Some mold is hidden growing behind wall coverings or ceiling tiles. Even dry, dead mold can cause health problems, so always take precautions when you suspect mold.
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 dressers, headboards, 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 in your home, it is time to take action to control its growth.
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.
Can I control mold growth in my home?
Yes you can. Dry out the house and fix any moisture problems in your home:
- 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 in your home, especially along the inside of exterior walls. Use a fan if there are no windows available.
- Make sure that warm air flows into all areas of the home. Move large objects a few inches away from the inside of exterior walls to increase air circulation.
- Install and use exhaust fans in bathrooms, kitchens, and laundry rooms.
- Ventilate and insulate attic and crawl spaces. Use heavy plastic to cover earth floors in crawl spaces.
- Clean and dry water damaged carpets, clothing, bedding, and upholstered furniture within 24 to 48 hours, or consider removing and replacing damaged furnishings.
- Vacuum and clean your home regularly to remove mold spores.
- Check around your windows for signs of condensation and water droplets. Wipe them up right away so mold can't start to grow.
What can I use to clean up mold?
Clean up mold and take care of the problem by following the advice above to keep your home dry and keep mold out. Act fast! Mold damages your home as it grows. Clean it up as soon as possible.
Size the Moldy Area
Decide if you have a large or small area of mold. A small area is less than about ten square feet, or a patch three feet by three feet square. To clean a small area, follow the advice below. You may use a cotton face mask for protection.
If you have a lot of mold damage (more than ten square feet) consider hiring a cleaning professional. If the moldy area has been contaminated by sewage or is in hidden places, hire a professional. To find a professional, check under "Fire and Water Damage Restoration" in your Yellow Pages. If you decide to clean up on your own, follow the guidance below.
Use Protection
Wear goggles, gloves, and breathing protection while working in the area. For large consolidated areas of mold growth, you should wear an Occupational Safety and Health Administration (OSHA) approved particle mask.
Seal the Area
Seal off area from the rest of your home. Cover heat registers or ventilation ducts/grills. Open a window before you start to clean up.
Remove Items
Remove all your furnishings to a mold-free area. Clean the surrounding moldy area then follow cleaning directions below for the items you removed and the new space.
Bag Moldy Trash
Bag all moldy materials and tie off the top of the bag. Bring them outdoors and place in your garbage container right away.
Scrub Surfaces
- First wash with a mild detergent solution, such as laundry detergent and warm water. Allow to dry.
- (Optional step) Then wipe with a solution of 1/4 cup bleach to one gallon of water. Wait 20 minutes and repeat. Wait another 20 minutes.
- Last apply a borate-based detergent solution and don't rinse. This will help prevent mold from growing again. A borate-based laundry or dish washer detergent has "borate" listed on the ingredients label.
Clean and Wash
Give the entire area a good cleaning, vacuum floors, and wash any exposed bedding or clothing.
Monitor
Check regularly to make sure mold has not returned to the clean-up area.
What cleans moldy furniture and other items?
- For wood, metal, plastic, glass, ceramics, and other objects that don't absorb water but are washable – wipe them with a solution of lukewarm water and laundry detergent.
- For clothes, bedding, and other materials that absorb water and are washable – wash them in the laundry.
- For beds, sofas, and other furniture that absorb water but are not washable – these items may need to be discarded. Or, try to save them by vacuuming well and allowing to air out. If there is no odor it may be okay. Mold can come back, so watch for any mold growth or mold related health problems. Discard the item if you suspect mold is growing inside or outside the item.
Should I paint over mold?
No. Don't paint or caulk over mold. The mold will grow under the paint and the paint will peel.
I'm a renter or landlord, what help can you provide for a mold problem?
Mold problems in buildings are a result of water and moisture problems. Excess moisture comes from leaks or condensation. Tenants and landlords both have responsibilities for addressing water and moisture problems that can cause mold. Generally, fixing leaks is the landlord's responsibility and reducing condensation is the renter's responsibility. See our mold resources for renters and landlords.
Who are my local contacts for more information about mold?
In Washington, you can contact your local county health department for more information about mold. If you live outside of Washington State, try contacting your county or state health department.
More Resources
- Print Version of this Webpage (PDF)
- Information Line: 360-236-3090 - Answers the most frequently asked mold and indoor air quality questions.
- Mold, CDC - Frequently asked questions, identifying mold problems and cleanup, and workplace resources.
- Mold, EPA - Resources for homeowners, schools, and building managers.
Content Source: Indoor Air Quality Program