Developing a Mold Operations and Maintenance Control Program The purpose of a mold operations and maintenance (O&M) control program is to provide guidelines for the prevention and control of mold growth in buildings. The objective of the program is to develop a proactive approach to controlling mold growth so that building systems and building environments are not impacted and to implement appropriate corrective actions. Molds are found in all environments, indoors and outdoors. Molds live in soil, on plants, and on dead and decaying organic matter. Molds spread by releasing spores which then settle on surfaces of all types. Since molds generally only have the potential to cause problems when present in large numbers, the best way to prevent problems is to keep molds from amplifying (i.e. spreading in large numbers) in the home and workplace. Molds need two things to survive and grow – food and moisture. Because mold “feeds” on most organic materials, including dust and many building materials, it is virtually impossible to prevent mold amplification by eliminating its food source. Experts agree that the best way to prevent mold from spreading is to correct moisture problems before they create an environment that encourages mold growth by means such as:
A visual inspection is the most important initial step in identifying a possible amplification problem. The extent of any water damage and mold growth should be visually assessed. Building conditions supporting mold growth must be corrected as rapidly as possible in order to prevent amplification. Repair of the defects that led to water accumulation or elevated humidity should be conducted in conjunction with, or prior to, implementing corrective actions. Specific methods of assessing and addressing mold growth should be based on the extent of visible growth and underlying damage to building materials. As a general rule for all response actions, the use of respiratory protection, gloves, and eye protection is recommended. Extensive growth, particularly in heating, ventilating, and air conditioning (HVAC) systems should be assessed by an experienced health and safety professional and remediated by personnel with training and experience in handling materials damaged by microbial growth. Lesser areas of impact can usually be assessed and corrected by building maintenance personnel with proper mold O&M training. In order to prevent growth from recurring, underlying defects causing moisture buildup and water damage must be addressed. Effective communication with building occupants is an essential component of all remedial efforts. The key to prevention and control of mold growth is proper maintenance of building materials and systems. The Environmental Protection Agency (EPA) has issued general guidance for how to deal with mold in schools and commercial buildings. Also, the New York City Department of Health has developed Guidelines on Assessment and Remediation of Fungi in Indoor Environments. The Occupational Safety and Health Administration (OSHA) has issued a Safety and Health Information Bulletin, a very good reference guide to mold in the workplace. It is important to remember that mold growth occurs when moisture problems are not addressed promptly and properly. In all situations, the underlying cause of water accumulation must be rectified or mold growth will recur. Any initial water infiltration should be stopped, and the affected areas cleaned immediately. An immediate response, (within 24 to 48 hours), and thorough clean up, drying, and/or removal of water damaged materials will prevent or limit mold growth. If the source of moisture is elevated humidity, relative humidity should be maintained at levels below 60% to inhibit mold growth. Emphasis should be on ensuring proper repairs of the building infrastructure so that water damage and moisture buildup does not recur. To reiterate, the key to prevention of growth of molds is proper general building maintenance. Proper maintenance will lead to fewer moisture problems and thus, fewer mold growth problems within a building. General building maintenance needs to include quick response to moisture problems, proper air filter changes, proper cleaning of air handling units, and proper treatment of building water systems, such as cooling towers and recirculated systems. As noted earlier, the extent of any water damage and mold growth should be visually assessed. This assessment is important in determining remedial strategies. Heating ventilation and air conditioning (HVAC) systems should also be visually checked, particularly for damp filters, damp conditions elsewhere in the system, and overall cleanliness. Ceiling tiles, gypsum wallboard (sheetrock), cardboard, paper, and other cellulose-containing materials should be given careful attention during a visual inspection. The use of equipment such as a borescope to view spaces in ductwork or behind walls, or a moisture meter to detect moisture in building materials, may be helpful in identifying hidden areas of microbial growth and the extent of water damage. The goal of corrective action is to remove or clean damaged materials in a way that prevents the emission of mold and dust from leaving a work area while protecting the health of workers performing the abatement. Thus, there are two basic components of the corrective action program:
For further information on preventative measures and appropriate corrective actions, refer to the EPA guidance document Mold Remediation in Schools and Commercial Buildings, available at www.epa.gov/mold/mold_remediation.html. The New York City Department of Health and Mental Hygiene Bureau of Environmental and Occupational Disease Epidemiology Guidelines on Assessments and Remediation of Fungi in Indoor Environments available at the following web site: www.health.state.ny.us/nysdoh/indoor/mold.html. The OSHA Guide to Mold in the Workplace is available at www.osha.gov/dts/shib/shib101003.html. This article is provided by Peter Cappel with Gobbell Hays Partners, Inc. (GHP). Mr. Cappel is a Vice President with GHP and provides consultation to clients on industrial hygiene, IAQ, microbial assessments and infection control. Mr. Cappel can be contacted at pcappel@ghp1.com.
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