Cleaning Up Mold
There are thousands of types of mold.
All are potentially allergenic and some are alleged to be toxic.
Regardless of the type of mold, it is essential that mold contamination and water damage be corrected, not ignored.
They are strong indicators of building problems that can lead to occupant health problems and building material deterioration.
Left unchecked, these become serious liabilities.
Successful removal of mold growth requires an understanding of the cause, the problem and the extent of contamination.
Basic steps in any mold cleanup include:
- Physical removal of colonized materials
- Removal of associated dusts and debris
- Prevention of dusts and spores generated during cleanup from entering occupied or clean areas
- Use of appropriate protective equipment by knowledgeable cleanup workers.
Before starting the basic steps of mold remediation, it is essential to perform a building inspection.
During an inspection, the location and extent of visible fungal colonization is determined, along with an inventory of visibly moldy interior surfaces.
The observations must continue during remediation to identify additional areas of possible mold growth that may have been hidden during the initial inspection.
The next step is physically removing contaminated materials.
Porous materials with obvious mold contamination should be discarded.
Common porous materials affected by mold include paper-based gypsum board, fibrous ceiling tiles, insulation, textile floor and wall covering, upholstered furniture and pressed wood products.
Tap water with detergents or surfactants is effective for cleaning most non-porous materials like sheet metal, ceramic tiles, glass, etc.
Techniques that reduce dust emission from the moldy surfaces should be considered during the third step of mold cleanup.
For example, applying a gentle water mist to colonized surfaces may be effective in suppressing dust during removal, but water mists and sprays must not wet surrounding infrastructure or disperse mold into the air by the impact of droplets.
Without appropriate care, spores from colonized surfaces in one area of a building can be dispersed by air currents into previously unaffected areas of the building.
A combination of damp wiping and vacuum cleaning with a machine equipped with a high-efficiency particulate air (HEPA) filter should be adequate to remove dusts from non-porous surfaces.
Personnel involved in the cleanup process need to use personal protective equipment (PPE) as elevated levels of airborne mold spores can be potentially harmful to one’s health.
Respirators, goggles and gloves are adequate for minimal cleanup, while full-body disposable protective clothing and respiratory protection is required for more extensive projects.
In addition, personnel should have appropriate training for mold remediation.
While it is important to know how to remediate mold, it is more important to prevent mold and moisture problems.
Buildings should be built and operated with processes in place to prevent moisture and mold from occurring.
The first and second steps are proper building design and construction, respectively, complete with a moisture management plan.
The third is an ongoing operation and maintenance plan that insures effective moisture management on a daily basis.
The recent proposed American National Standard, GREENGUARD Mold and Moisture Management, addresses all of these elements.
In additional, the U.S. Environmental Protection Agency (EPA) has some excellent guidance tools including:
IAQ Tools for Schools Action Kit – IAQ Reference Guide – Appendix H: Mold and Moisture
Indoor Air Quality Building Education and Assessment Model (I-BEAM) Text Modules: Fundamentals of IAQ in Buildings
Building Air Quality: A Guide for Building Owners and Facility Managers – Appendix C: Moisture, Mold and Mildew.
Certain building materials are available in the market that have been tested and verified to be mold resistant according to ASTM D 6329-98.
Use of these materials, examples of which can be found at www.greenguard.org/Default.aspx?tabid=155, provides one important step in controlling mold.
Subjected to enough dirt and moisture, any material can support superficial mold growth.
However, applying proper moisture management processes including the use of mold resistant products can reduce the hazards of mold contamination.
For more information regarding mold, please read the white paper, A Practical Guide to Avoiding Moisture and Mold.