The key to mold control is moisture control. Solve moisture problems before they become mold problems! With this concept in mind, the Occupational Health and Safety Division assigns responsibility to the Department that oversees the affect facilities. The following mold prevention tips should be practiced:
- Fix leaky plumbing and leaks in the building envelope as soon as possible
- Watch for condensation and wet spots. Fix source(s) of moisture problem(s) as soon as possible.
- Maintain indoor humidity below 60% relative humidity (RH). *(ASHRAE standard recommends indoor RH be maintained between 30%-60%)
- Keep HVAC drip pans clean, flowing properly, and unobstructed.
- Perform regularly scheduled building/HVAC inspections and maintenance.
- Clean and dry wet or damp spots within 48 hours.
- Provide drainage and slope the ground away from the foundation. Don’t let foundations stay wet. In cases of emergency water intrusion (i.e. flooding) it is imperative that the designated maintenance department responds to such damage using the strategies presented in Table 1 (Taken from the EPA Guidelines to Mold Remediation in Schools and Commercial Buildings) within 24-48 hours. These guidelines are designed to help avoid the need for mold remediation by taking quick action before growth starts. Depending on the size of the area involved and resources available the responsible maintenance department may need to seek the professional assistance to dry the area as quickly as possible.
Table 1: Water Damage – Cleanup and Mold Prevention Guidelines for Response to Clean Water Damage within 24-48 Hours to Prevent Mold Growth* Water-Damaged Material† Actions Books and papers -For non-valuable items, discard books and papers. -Photocopy valuable/important items, disscard originals. -Freeze (in frost-free freezer or meat llocker) or freeze-dry. Carpet and backing – dry Within 24-48 hours§ -Remove water with water extraction vacuuum. -Reduce ambient humidity levels with dehhumidifier. -Accelerate drying process with fans. Ceiling tiles -Discard and replace. Cellulose insulation -Discard and replace. Concrete or cinder block Surfaces -Remove water with water extraction vacuuum. -Accelerate drying process with dehumidiifiers, fans, and/or heaters. heaters. Fiberglass insulation -Discard and replace. Hard surface, porous flooring§ (Linoleum, ceramic tile, vinyl) -Vacuum or damp wipe with water and mildd detergent and allow to dry; scrub if necessary. -Check to make sure under flooring is dry; dry under flooring if necessary. Non-porous, hard surfaces (Plastics, metals) -Vacuum or damp wipe with water and mildd detergent and allow to dry; scrub if necessary. Upholstered furniture -Remove water with water extraction vacuum. -Accelerate drying process with dehumidiifiers, fans, and/or heaters.
-May be difficult to completely dry within 48 hours. If the piece is valuable, you may wish to consult a restoration/water damage professional who specializes in furniture. Wallboard (Drywall and gypsum board) -May be dried in place if there is no obbvious swelling and the seams are intact. If not, remove, discard, and replace. -Ventilate the wall cavity, if possible.. Window drapes -Follow laundering or cleaning instructions recommended by the manufacture. Wood surfaces -Remove moisture immediately and use dehumidifiers, gentle heat, and fans for drying. (Use caution when applying heat to hardwood floors.) -Treated or finished wood surfaces may bbe cleaned with mild detergent and clean water and allowed to dry. -Wet paneling should be pried away from wall for drying. * If mold growth has occurred or materials have been wet for more than 48 hours, consult Table 2 guidelines. Even if materials are dried within 48 hours, mold growth may have occurred. Items may be tested by professionals if there is doubt. Note that mold growth will not always occur after 48 hours; this is only a guideline. These guidelines are for damage caused by clean water. If you know or suspect that the water source is contaminated with sewage, or chemical or biological pollutants, then Personal Protective Equipment and containment are required by OSHA. An experienced professional should be consulted if you and/or your remediators do not have expertise remediating in contaminated water situations. Do not use fans before determining that the water is clean or sanitary. † If a particular item(s) has high monetary or sentimental value, you may wish to consult a restoration/water damage specialist. § The sub floor under the carpet or other flooring material must also be cleaned and dried. See the appropriate section of this table for recommended actions depending on the composition of the sub floor.
Table 2: Guidelines for Remediating Building Materials with Mold Growth Caused by Clean Water* Material or Furnishing Affected Cleanup Methods† Personal Protective Equipment Containment SMALL – Total Surface Area Affected Less Than 10 square feet (ft2) Books and papers 3 Minimum N-95 respirator, gloves, and goggles None required Carpet and backing 1, 3 Concrete or cinder block 1, 3 Hard surface, porous flooring (linoleum, ceramic tile, vinyl) 1, 2, 3 Non-porous, hard surfaces (plastics, metals) 1, 2, 3
Upholstered furniture & drapes 1, 3 Wallboard (drywall and gypsum board) 3 Wood surfaces 1, 2, 3 MEDIUM – Total Surface Area Affected Between 10 and 100 (ft2) Books and papers 3 Limited or Full Use professional judgment, consider potential for remediator exposure and size of contaminated area Limited Use professional judgment, consider potential for remediator/occupant exposure and size of contaminated area Carpet and backing 1,3,4 Concrete or cinder block 1,3 Hard surface, porous flooring (linoleum, ceramic tile, vinyl) 1,2,3 Non-porous, hard surfaces (plastics, metals) 1,2,3 Upholstered furniture & drapes 1,3,4 Wallboard (drywall and gypsum board) 3,4 Wood surfaces 1,2,3 LARGE – Total Surface Area Affected Greater Than 100 (ft2) or Potential for Increased Occupant or Remediator Exposure During Remediation Estimated to be Significant Books and papers 3 Full Use professional judgment, consider potential for remediator/occupant exposure and size of contaminated area Full Use professional judgment, consider potential for remediator exposure and size of contaminated area Carpet and backing 1,3,4 Concrete or cinder block 1,3 Hard surface, porous flooring (linoleum, ceramic tile, vinyl) 1,2,3,4 Non-porous, hard surfaces (plastics, metals) 1,2,3 Upholstered furniture & drapes 1,2,4 Wallboard (drywall and gypsum board) 3,4 Wood surfaces 1,2,3,4 Table 2 continued
*Use professional judgment to determine prudent levels of Personal Protective Equipment and containment for each situation, particularly as the remediation site size increases and the potential for exposure and health effects rises. Assess the need for increased Personal Protective Equipment, if, during the remediation, more extensive contamination is encountered than was expected. Consult Table 1 if materials have been wet for less than 48 hours, and mold growth is not apparent. These guidelines are for damage caused by clean water. If you know or suspect that the water source is contaminated with sewage, or chemical or biological pollutants, then the Occupational Safety and Health Administration (OSHA) requires PPE and containment. An experienced professional should be consulted if you and/or your remediators do not have expertise in remediating contaminated water situations.
†Select method most appropriate to situation. Since molds gradually destroy the things they grow on, if mold growth is not addressed promptly, some items may be damaged such that cleaning will not restore their original appearance. If mold growth is heavy and items are valuable or important, you may wish to consult a restoration/water damage/remediation expert. Please note that these are guidelines; other cleaning methods may be preferred by some professionals. Cleanup Methods
Method 1: Wet vacuum (in the case of porous materials, some mold spores/fragments will remain in the material but will not grow if the material is completely dried). Steam cleaning may be an alternative for carpets and some upholstered furniture.
Method 2: Damp-wipe surfaces with plain water or with water and detergent solution (except wood – use wood floor cleaner); scrub as needed.
Method 3: High-efficiency particulate air (HEPA) vacuum after the material has been thoroughly dried. Dispose of the contents of the HEPA vacuum in well-sealed plastic bags.
Method 4: Discard _ remove water-damaged materials and seal in plastic bags while inside of containment, if present. Dispose of as normal waste. HEPA vacuum area after it is dried.