South Dakota Safety Council Banner

Fact Sheets: At Home Fact Sheets: At Play Fact Sheets: At Work Fact Sheets: On the Road Fact Sheets: Whats New Fact Sheets: Search

Fact Sheet

Molds are the most common forms of fungi found on earth. They can grow on almost any material, as long as moisture and oxygen are available. Most molds reproduce through the formation of spores, tiny microscopic cells that are resistant to drying and are released into the air. Airborne spores are found both indoors and outdoors. When spores land on a suitable moist surface, they begin to grow and release chemicals that digest and can eventually destroy the surface and underlying materials. Molds can also cause adverse health effects.

Health Effects of Mold Exposure
Molds can cause mild to severe health problems in sensitive individuals when a sufficient number of airborne spores are inhaled. Some individuals are far more sensitive than others. The most common health effects associated with mold exposure are allergic reactions.
Symptoms may include:
  • Sneezing
  • Runny nose
  • Eye irritation
  • Cough
  • Congestion
  • Aggravation of asthma
  • Dermatitis (skin rash)
People at Greatest Risk
Infants, children, and the elderly are more susceptible to health problems attributable to molds. In addition, people with the following underlying health conditions may be more sensitive to molds:
  • Individuals with allergies or existing respiratory conditions including asthma, sinusitis, or other lung diseases.
  • Individuals with a weakened immune system (e.g., HIV patients).
  • Recent organ or bone marrow transplant patients.
  • Patients recovering from recent surgery and receiving chemotherapy or long-term steroid treatment.
How to Recognize Mold
Mold may be recognized by:
  • Sight - They usually appear as distinctly colored woolly mats (e.g., mildew is black and is one of the most common molds in a household).
  • Smell - They often produce a foul odor, such as a musty, earthy smell.
Preventing Mold Growth
The key to mold prevention is moisture control. Mold will not grow if moisture is absent.
  • Remove excess moisture with a wet-dry vacuum and dry out the building as quickly as possible (preferably within 24 to 48 hours).
  • Use fans to assist in the drying process.
  • Clean wet materials and surfaces with detergent and water.
  • Discard all water damaged materials.
  • Discard all materials visibly contaminated with mold.
  • Remove and discard all porous materials that have been wet for more than 48 hours. Porous materials cannot be cleaned and may remain a source of mold growth. These materials include the following:
    • Carpeting and carpet padding;
    • Upholstery, wallpaper, drywall;
    • Floor and ceiling tiles, insulation materials;
    • Clothing;
    • Leather;
    • Paper, wood;
    • Food.
General Cleanup Tips
  • Make sure the working area is well ventilated.
  • Place mold damaged materials in a plastic bag and discard.
  • Clean mold off hard surfaces and other nonporous materials with detergent and water, and dry completely.
  • Disinfect these cleaned surfaces with one of the following household bleach solutions:
    • 1/4 cup household bleach per 1 gallon of clean water for light contamination.
    • 11/2 cups household bleach per 1 gallon of clean water for heavy contamination.
CAUTION: Do not mix bleach with other cleaning products that contain ammonia.
Highly toxic chlorine gas can be produced.
  • Avoid breathing mold spores. A N-95 respirator is recommended.
  • Avoid touching mold with your bare hands. Long gloves that extend to the middle of the forearm are recommended. Use ordinary household rubber gloves when cleaning surfaces with water, bleach, and a mild detergent. Gloves made from natural rubber, neoprene, nitrile, polyurethane, or PVC are recommended if using a disinfectant, biocide, or strong cleaning solution.
  • Avoid getting mold spores in your eyes. Goggles without ventilation holes are recommended.

U.S. Dept. of Labor, OSHA

Contact the South Dakota Safety Council at
or phone 605-361-7785 or 1-800-952-5539.