IAQ.net Resources

MOLD: WORKER AND EMPLOYER GUIDE TO HAZARDS AND RECOMMENDED CONTROLS MOLD REMEDIATION Moisture control is a key strategy for preventing and reducing mold growth. If possible, prevent water from coming into a home before flooding and water infiltration occurs. If water does enter a home, damp or wet building materials and furnishings should be removed, cleaned and/or dried within 24 to 48 hours to prevent the growth of mold. iii If mold growth is present, visually survey the types of materials and the size of the area affected. A moisture meter may be used to determine moisture levels in building materials (e.g., carpet, wallboard, wood, brick, and concrete) and moisture content following water damage. Meters also can be used to monitor progress in drying wet materials. In addition, an infrared survey can be performed for understanding the extent of water damage. Although sampling for mold is not usually necessary, it may help in guidance of mold remediation activities. Materials that cannot be dried and fully cleaned should be removed using methods that minimize occupant and worker exposure to spores. Drying can involve the use of fans, blowers and/or dehumidifiers. However, the more humid the air, the less effective the blowers will be. It is often more cost-effective to remove and replace the building materials, e.g., fiberglass batting, than to dry and clean mold-contaminated materials. Mold may also grow on hidden surfaces, such as the back side of drywall, wallpaper, or paneling, the top of ceiling tiles, the underside of carpets and pads, etc. Other possible locations of hidden mold can include pipe chases and utility tunnels (with leaking or condensing pipes), walls behind furniture (where condensation forms), condensate drain pans inside air handling units, porous thermal or acoustic liners inside ductwork, or roof materials above ceiling tiles (due to roof leaks or insufficient insulation). Mold may present an odor and require removal of building materials, such as wall paper and drywall. TYPES OF MATERIALS: NON-POROUS, SEMI-POROUS, OR POROUS (WATER PENETRATES READILY) Non-porous materials (e.g., metal, glass, hard plastics, etc.) can be dried out, fully cleaned and reused. Clean hard and non-porous materials using a detergent (e.g., dishwashing liquid or laundry detergent). After cleaning with a detergent, surfaces can be rinsed, if necessary, with a disinfectant made of 1/2 cup liquid household bleach mixed into one gallon of water (Caution: DO NOT mix bleach with cleaning products that contain ammonia, DO NOT use a higher concentration of bleach to water than recommended, and DO NOT use bleach on metal materials). Semi-porous materials (e.g., wood and concrete), if structurally sound, can be cleaned with detergent and if necessary, disinfected with bleach Porous materials (e.g., drywall, carpets, insulation, ceiling tile, etc.) are very difficult to fully clean because water and mold penetrate into them. As a general rule, if a porous material has been wet for over 48 hours, it is best to remove and replace it. 3

• Cover
• Blank Page