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Pest SolutionsPESTS + WEEDSUSING PESTICIDES OR HERBICIDES?
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Mold
Stachybotrys chartarum + other species
Updated Jun 30, 2022
Make a Positive Identification
Species: Black Mold
Fevziie Ryman, iStock
Black mold (Stachybotrys chartarum) is often dark colored. It forms webs of filaments (hyphae) that grow on surfaces. They form blotchy patterns. When black mold grows indoors, it can harm your health and damage structures.
Species: Black Mold
Tony Webster from Minneapolis, Minnesota, United States, CC BY-SA 2.0, via Wikimedia Commons (cropped)
Black mold grows in high-humidity, poorly ventilated spaces such as bathrooms, kitchens, and laundry rooms. The photo shows a poorly ventilated bathroom with mold on shower tiles.
Species: Black Mold
MartinFredy, iStock
Black mold grows where there is water damage such as shown in the photo. It grows on a range of materials, including drywall, wood, paper, carpet, painted walls, and cardboard.
Species: Black Mold from Water Damage
"Black Mold" by satemkemet is marked with CC BY-SA 2.0 (cropped).
Severe water damage due to flooding or fire suppression often supports extensive black-mold growth. It requires repair before the home is safe for habitation. Seek professional help for severe water and mold damage.
Species: Other Molds
Vincent van Zeijst, CC BY-SA 4.0, via Wikimedia Commons (cropped)
Other types of mold contribute to food spoilage. Examples include Cladosporium, Penicillium, and Aspergillus. These food-spoiling molds also grow on moist surfaces in structures.
Species: Fuzzy Mold
Ftwitty, iStock
The food-spoiling molds often grow as a powdery or fuzzy coating on surfaces. The photo shows a fuzzy mold growing on a window sill. These molds harm your health when they grow on indoor surfaces.
LOOK-ALIKES: ALGAE, MOSS & LICHENS
Species: Algae
Ftwitty, iStock
Algae grows outdoors on moist surfaces such as vinyl siding and wooden decks. It grows in shady locations such as the north side of buildings.
Different risks or methods
Use a scrub brush and soapy water to get rid of algae as needed. Pressure wash as needed.
Species: Moss
"Free Insulation" by Luke-Milliron is marked with CC BY-NC-ND 2.0 (cropped)
Moss grows outdoors. It doesn’t cause negative health impacts. Moss becomes a problem when it grows on roofs, patios, and walkways.
Different risks or methods
Remove moss by scraping and scrubbing.
Species: Lichens
"Lichen close-up" by Linda, Fortuna future is marked with CC BY-NC 2.0 (cropped)
Lichen grows outdoors. Its growth doesn’t cause negative health impacts. Lichen generally doesn’t require management.
Helpful
Lichens are usually not a problem and can be left alone.
Mold Benefits
- Molds are important in the natural world. They are fungi that break down organic materials such as wood.
- When molds grow outdoors, they are not a problem.
Mold Risks
- Molds growing indoors are a problem and require action.
- Indoor mold growth has a negative impact on indoor air quality and human health.
- Mold exposure can cause a stuffy nose, sore throat, coughing, or skin rash. People who have asthma or are immune-compromised may have severe reactions to mold.
- Unchecked mold growth damages structures and stains surfaces. Mold damage requires repair.
Don’t let mold grow in your home or structures you care about. Mold is a human health hazard. It damages structures.
Risk Card
Does it cause harm?
Adults & Children
High
Skin & lung iritation, severe reactions for people with asthma
Property
High
Damages structures
Pets
High
Same as people
Annoyance
High
Difficult to get rid of
Environment
None
Harmful indoors, beneficial outdoors
Action Highly Recommended
Mold indoors is a health hazard. Take action right away.
TAKE ACTION
If mold is growing in your home, you need to remove the mold and fix the moisture problem.
Do I need to take action?
Yes. If you find mold in your home, clean it up right away. Take action to reduce moisture and increase ventilation where you found mold growth.
What if I do nothing?
- Mold affects human health. Reactions to mold are common in people and pets. Mold exposure irritates eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people. Molds can trigger asthma symptoms in sensitive individuals.
- Mold can damage your property. Unchecked mold growth damages and stains surfaces in structures. Mold damage requires repair.
Do you need professional help?
If controlling mold in your home seems overwhelming, consider hiring a professional. See How to Hire a Mold Removal Specialist.
Prevent Mold
Yanggiri, iStock
Improve Ventilation & Air Circulation / Filtration
- Ventilate shower, laundry, and cooking areas.
- Install a ventilation fan to vent humid areas of your home.
- Clean the fan blades periodically to keep mold from growing in the fan itself.
Flowingking, CC BY-SA 4.0
Clean Air Duct Surfaces
- As part of your home maintenance plan, include professional air duct cleaning services.
- They remove dust, debris, and mold from air ducts.
- Mold spores enter your home’s air duct system. Mold can grow in the ducts when there is enough moisture.
zeleno, iStock
Monitoring and Ongoing Efforts
- Look for mold where you have previously removed it. Clean it as needed.
- Fix moisture problems. Seek professional help if needed.
- Improve ventilation and air circulation / filtration.
- Unless the moisture problem has been fixed, mold will probably grow again.
Solutions for Mold (Indoors)
How mold spores get into structures:
- Mold spores enter your home on our bodies, pets, and through open doorways, windows, and vents.
- The spores are circulated by heating and air-conditioning systems.
- There is no way to prevent spores from entering your home.
Determine the extent of mold damage to various materials in your home:
- Remove and dispose of moldy carpet, furniture, and cloth. Once they develop mold, porous materials can’t be salvaged. Dispose of them in a landfill.
- For semi-porous materials such as drywall and wood flooring, determine the extent of the mold damage. If the mold can’t be scrubbed off, the materials should be removed. Or scrub and scrape mold off the material, if it’s cleanable.
- Mold can be removed from hard (non-porous) hard surfaces such as glass and sealed countertops.
Removing mold:
- Scrape and scrub mold off cleanable materials.
- After scraping and scrubbing mold, use disinfectant.
- Then use fans and dehumidifiers to circulate air. Moving the air will help to dry out an area.
- See mold-cleaning methods.
Preventing mold:
- You must fix the moisture problem that supports mold growth.
- Use preventive measures to keep mold from regrowing.
To control mold growth, you must lower indoor humidity levels. Humidity must be less than 50% all day and throughout the year to prevent mold growth. If you can’t get the humidity below 50%, mold will likely regrow. Improve ventilation by installing a bathroom fan, for example, which helps to lower humidity.
NEED HELP?
Consider a licensed pest control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon and other states can suggest other methods.
Jump to
| Method | Does it work? | Is it safe? | Recommendation |
|---|---|---|---|
A Determine Extent of Mold Damage |
Effective |
Moderate risk |
Recommended |
B Scrape, Scrub & Disinfect, Then Dry |
Effective |
High risk |
Use if Necessary |
|
C If Using Disinfectant, Protect Yourself & Minimize Risks
|
A
Determine Extent of Mold Damage
Non-Chemical Method
yavdat,iStock
Determine Extent of Mold Damage
Recommended
- Examine the mold damage in your home.
- Determine damage to porous materials such as carpet, furniture, and clothing.
- For semi-porous materials such as drywall and wood flooring, determine the extent of the mold damage.
- Hard (non-porous) surfaces such as glass and metal can be cleaned. See mold-cleaning methods below.
| Does it work? | Effective
|
| How much effort? | High effort Mold is a human health hazard. All effort to control it is required. |
| What's the risk? | Moderate risk Wear an N95 respirator mask (or better) to protect your lungs when cleaning mold. |
| Possible risk of exposure or harm from chemicals | NONE |
Examine materials. Dispose of moldy porous materials and mold-damaged semi-porous materials. Remove drywall as needed. Fix leaks.
Laymul, iStock
yavdat,iStock
"Stripped Wall" by Pattie is marked with CC BY-NC-ND 2.0 (cropped).
MartinFredy, iStock
B
Scrape, Scrub & Disinfect, Then Dry
Chemical Method: Use with caution
Mitt, iStock
Scrape, Scrub & Disinfect, Then Dry
Use if Necessary
- Scrape and scrub off of cleanable surfaces.
- Use disinfectant.
- Dry the area with a fan.
| Does it work? | Effective You must Use preventive measures to keep mold from regrowing. |
| How much effort? | High effort Scraping and scrubbing mold requires significant effort. It is required to control mold. |
| What's the risk? | High risk
|
| Possible risk of exposure or harm from chemicals | El uso de pesticidas conlleva cierto grado de riesgo. El riesgo más bajo se produce sin el uso de pesticidas. You may be exposed to a pesticide if you:
Follow directions closely to reduce risk. |
Remove mold from hard surfaces. Then disinfect it and dry it.
Weston Miller, Oregon State University
VisualCommunications, iStock
If Using Disinfectant, Protect Yourself & Minimize Risks
Chemical Method: Use with Caution
amixstudio, iStock
Wear a Respirator, Eye Protection & Gloves
- Wear an N95 respirator mask (or better) to protect your lungs when cleaning mold.
- Wear goggles to protect your eyes, and gloves to protect your skin from mold and cleaning products.
Why is it Important to Read Disinfectant Labels?
- They have detailed information on how to use the product correctly and legally.
- They contain information on potential hazards of the product.
- They offer instructions you should follow for poisonings and spills.
READ THE LABEL & Follow Instructions
It has instructions to protect you and the environment.
- Household disinfectants are registered pesticides.
- Labels describe the areas that can be treated. For example hard, non-porous surfaces include glass, metal, and most countertops. Wood and linoleum may absorb the product.
- Sometimes the surface needs to remain wet with disinfectant for a period of time in order to work. Check the label for “contact time” or “dwell time.”
- Use a magnifying glass for small print.
- Pay attention to CAUTION, WARNING, and DANGER statements.
- Pay attention to the PRECAUTIONARY STATEMENTS.
- The law states you must read and follow disinfectant instructions.
Protect Yourself
Eye, skin & lung irritants
- Wear an N95 respirator (or better), gloves, safety glasses, a long-sleeve shirt, pants, socks, and shoes.
- Avoid contact with eyes, skin, or clothing.
- Never mix bleach with ammonia. When combined, these two common household cleaners release a toxic gas. Exposure can cause eye and throat irritation. High concentrations can lead to coma or death.
Storage & Disposal
- Store in a secure storage area away from children.
- Don’t put unused disinfectant products in the trash. Take them to a hazardous waste facility.
- Never pour product down any drain or waterway.
Call 1-800-CLEANUP (1-800-253-2687) to find out where to dispose of disinfectants.
For the Portland metro region in Oregon, contact Metro’s Recycling Information. Call 503-234-3000, email or visit Metro’s website
More about:
About Using Pesticides on School Grounds in Oregon
If using pesticides on school grounds, there are special rules in Oregon. See School Integrated Pest Management (Oregon Department of Agriculture).
NEED HELP?
The National Pesticide Information Center (NPIC) can answer questions about pest control chemicals.
1-800-858-7378 or npic@ace.orst.edu
Consider using a licensed pest or weed control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon and other states can suggest other methods.
HEALTH & SAFETY TIP
Never mix bleach with ammonia. When combined, these two common household cleaners release a toxic gas. Exposure can cause eye and throat irritation. High concentrations can lead to coma or death.
yudhistirama, iStock
Content provided by editor Weston Miller and writers J. Jeremiah Mann and Kaci Buhl.
Peer reviewed by OSU Department of Horticulture.
MOLD REFERENCES
Mold
US Environmental Protection Agency
Facts about Stachybotrys chartarum
Centers for Disease Control and Prevention
Mold
Centers for Disease Control and Prevention
Moisture Control and Mold
National Pesticide Information Center