MIIA’s Loss Control staff have responded to a number of indoor air quality issues at members' facilities in the past. The issues relate to odors, excessive dust, moisture, mold growth, and a variety of symptoms that building occupants attribute to air quality. Symptoms include headaches fatigue, sinus congestion, and eye, nose and throat irritation.
Indoor air contaminants can be drawn in from the outside or can originate from within the building, causing air quality problems. Many of these problems are easily corrected and can be solved in-house.
After surveying these buildings, we have identified a number of common sources. This bulletin highlights some indoor air quality problems and the recommendations for their resolution.
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Common Problems
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Recommendations
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- Air exhaust from the building gets drawn back into the building through nearby fresh air intakes.
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- Make rooftop exhaust outlets taller than fresh air intakes. Consider separating exhaust fan outlets from operable windows, doors, and fresh air intakes by at least 25 feet
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- Exhaust from vehicles on nearby roadways, parking lots, garages, or loading docks gets drawn back into the building through nearby fresh air intakes.
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- Require vehicles at loading docks, other entrances, or near fresh air intakes to turn off idling engines while loading or unloading. Posting signs would remind drivers to turn off their engines. Consider relocating fresh air intakes away from vehicle exhaust areas.
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- The heating, ventilation and air conditioning system may be recirculating contaminants into the air.
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- Change filters according to the manufacturer's specification or more frequently, as needed, and use a medium efficiency filter. Ensure filters are the correct size. Install improved filtration equipment to remove contaminants. Check filter tracks and filter placement for any gaps
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- Specialized activities such as laboratories, art rooms, chemical storage areas, print shops, and kitchens contribute to air contaminants.
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- Install local exhaust. Adjust the heating, ventilation and air conditioning system to provide make-up air and test to verify performance. Place the specialized activity area under negative pressure.
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- Remodeling or building repairs impact indoor air quality.
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- Isolate work areas. Install temporary local exhaust. Seal off returns in work area. Close outdoor air damper during reroofing. Schedule remodeling and building repair work during unoccupied periods. Keep ventilation system in operation to remove contaminants and odors.
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- Housekeeping or maintenance activities and procedures impact indoor air quality.
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- Select non-toxic cleaning products. Use high-efficiency particulate arrestance (HEPA) vacuums vs. low-efficiency paper-bag collectors. Minimize use of deodorizers and fragrances. Remove trash daily. Improve storage practices, purchasing only what is needed. Remove bird droppings near or on rooftop fresh air intakes. Shift time of painting, cleaning, pest control, and other contaminant-producing activities to avoid occupied periods. Use wet and non-wet methods to capture and remove all dust. Schedule cleaning to keep dust and dirt from accumulating.
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- Shrubbery planted in front of fresh air intakes allows contaminants to be drawn in and circulated through the building.
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- Remove shrubbery and other vegetation planted in front of or near fresh-air intakes to prevent drawing in pollen, dust and fungal spores.
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- Liquid spills, leaks, or moisture contribute to conditions that promote microbial growth such as mold and mildew.
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- Stop moisture incursions. Seasonally inspect and repair leaking roofs to prevent water from entering the building. Check crawlspaces for standing water. Drain, clean and decontaminate drip pans, cooling towers, room air conditioners, humidifiers, and dehumidifiers on a regular basis according to manufacturers' specifications. Replace water-damaged carpets, furnishings or building materials. Install drip pans that drain properly.
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- Contaminants and odors emanate from newly installed carpets, furniture, wall and window coverings, newly dry-cleaned drapes and other textiles.
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- Ask supplier to store new furnishings in a clean, dry, well-ventilated area until volatile organic compound out-gassing has diminished. Schedule installation of carpet, furniture and wall coverings to occur during periods when the building is unoccupied. Accept only fully dried, odorless dry-cleaned products. Steam clean carpeting and upholstery, then dry quickly, ventilating to accelerate the drying process.
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Pollutant and Source Inventory
For information about the minimum ventilation rates and acceptable indoor air quality for building occupants, the American Society of Heating, Refrigerating and Air-Condition Engineers (ASHRAE) issued Standard 62-989 entitled Ventilation for Acceptable Indoor Air Quality, which can be obtained by calling 1-800-527-4723.
To assist MIIA members, a checklist for air pollutant sources is attached to this bulletin. This checklist may be adapted and used for your buildings. For more information, contact Jeffrey Siena, MIIA Loss Control Manager, at (800) 882-1498.
Source: Building Air Quality: A Guide for Building Owners and Facility Managers, US Environmental Protection Agency, Indoor Air Division, Office of Air and Radiation, December 1991.
