Facts, Information and Resources

Molds are fungi that can be found in virtually every environment, indoors and outdoors, year round. No one knows how many species of fungi exist but estimates range from tens of thousands to perhaps three hundred thousand or more. Mold spores can survive harsh environmental conditions, such as dry conditions, that do not support normal mold growth.

Research has found that damp building conditions can lead to respiratory illnesses in occupants. Dampness in buildings can occur for a variety of reasons such as high indoor humidity, condensation, and roof leaks.

People who are sensitive to mold may experience stuffy nose, irritated eyes, wheezing, or skin irritation. People allergic to mold may have difficulty in breathing and shortness of breath. People with weakened immune systems and with chronic lung diseases, such as obstructive lung disease, may develop mold infections in their lungs. If you or your family members have health problems after exposure to mold, contact your doctor or other health care provider.

Mold is everywhere. 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.

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.

The resources below and links within those sites provide most of the information available regarding mold as it impacts humans.

Routine air sampling for mold is not recommended because air concentrations cannot be interpreted with regard to a health risk.

There are no established health-based standards for acceptable levels of biological agents in indoor air.

Mold issues are the homeowners’ responsibility. There are many good resources for identifying and addressing mold issues many of which can be found below. Remediation can sometimes involve extensive work but may also be addressed with less effort if water issues are discovered and responded to early.

If you believe that mold is a problem in your place of residence:

  • Identify the source - Molds grow best in warm, damp, and humid conditions, and spread and reproduce by making spores.
  • Remove the mold – This may involve removing entire sections of drywall, carpeting, furniture, and/or ceiling tiles. See below in resources how to do this.
  • Clean and dry the area – see below in resources for remediation recommendations.

Mold issues in your rental property are an issue that should be addressed by you and your landlord. It is the responsibility of the landlord to make repairs and do whatever is necessary to put and keep the premises in a fit and habitable condition. It is the duty of the tenant to keep that part of the premises that the tenant occupies and uses as reasonably clean and safe as the condition of the premises permits. You should always try to work with your landlord first to resolve problems involving mold.

In the case of landlord/tenant disputes, please refer to the Montana Landlord Tenants’ Rights & Responsibilities information available at the Montana Department of Justice website in the resources section below. The Montana Legal Services Association can often provide assistance to renters and has resources for obtaining repairs from landlords and other information on leases, rental agreements and security deposits.

Sensitive individuals should avoid areas that are likely to have mold, such as compost piles, cut grass, and wooded areas. Inside homes, mold growth can be slowed by controlling humidity levels and ventilating showers and cooking areas. If there is mold growth in your home, you should clean up the mold and fix the water problem. Mold growth can be removed from hard surfaces with commercial products, soap and water, or a bleach solution of no more than 1 cup of bleach in 1 gallon of water. (See resources below for more information)

Workplace mold issues are addressed by the Montana Department of Labor. The website for addressing this kind of 'air quality' based workplace issue can be located on their website.

If you choose to use bleach to clean up mold:

  • Never mix bleach with ammonia or other household cleaners. Mixing bleach with ammonia or other cleaning products will produce dangerous, toxic and dangerous fumes.
  • Open windows and doors to provide fresh air.
  • Wear non-porous gloves and protective eye wear.
  • If the area to be cleaned is more than 10 square feet, consult the U.S. Environmental Protection Agency (EPA) guide titled Mold Remediation in Schools and Commercial Buildings. Although focused on schools and commercial buildings, this document also applies to other building types. You can get it by going to the EPA mold remediation web site found in the resources section below.
  • Always follow the manufacturer’s instructions when using bleach or any other cleaning product.

Specific Recommendations:

  • Keep humidity levels as low as you can—no higher than 50%--all day long. An air conditioner or dehumidifier will help you keep the level low. Bear in mind that humidity levels change over the course of a day with changes in the moisture in the air and the air temperature, so you will need to check the humidity levels more than once a day.
  • Use an air conditioner or a dehumidifier during humid months.
  • Be sure the home has adequate ventilation, including exhaust fans.
  • Add mold inhibitors to paints before application.
  • Clean bathrooms with mold killing products.
  • Do not carpet bathrooms and basements.
  • Remove or replace previously soaked carpets and upholstery.

Additional Resources: