By: Linda Barlow, freelance writer |
Odors and other gaseous contaminants in commercial buildings can cause a variety of health effects and less-than-ideal working conditions . Source control and ventilation are crucial components of a multi-pronged strategy for removing harmful gases from the air building occupants breathe.
When something stinks, you know it. But not all gaseous contaminants – including volatile organic compounds – can be identified by smell alone. In fact, the issue of controlling VOCs and other gaseous contaminants may be even more important when there are no odors associated with them to trigger complaints.
Health effects of VOCs may include:
- Eye, nose and throat irritation
- Loss of coordination
- Liver, kidney and nervous system damage
- Allergic skin reaction
Source Reduction and Removal
Pollutant source removal or reduction are effective approaches to resolving IAQ problems related to gaseous contaminants when sources are known and control is feasible.
When source removal is not possible or practical, there are a number of steps that can be taken to reduce the amount of odors, VOCs and gaseous contaminants indoors:
- Safely discard partially full containers of old or unneeded chemicals. Gases can leak even from closed containers.
- Buy limited quantities of VOC-emitting products that are used only occasionally or seasonally.
- Use sealants on all exposed surfaces of paneling and other furnishings.
- Allow time for building materials in new or remodeled areas to off-gas pollutants before occupancy.
- Adopt integrated pest management techniques to reduce the need for pesticides.
- Store food properly, and dispose of garbage promptly.
- Select or specify low-emitting products when building or remodeling.
Odors and gaseous contaminants can be controlled by diluting them with outdoor air, as long as there is a consistent and appropriate flow of supply air that mixes effectively with room air . Minimum ventilation rates per the ASHRAE 62.1 standard are 5 cfm/person in office areas, 10 cfm/person in classrooms, and 20 cfm/person in health clubs.
Another technique is to use dedicated exhaust ventilation systems to isolate and remove contaminants by maintaining negative pressure in the area around the contaminant source. Local exhaust can be linked to the operation of a particular piece of equipment (such as a kitchen range) or used to treat an entire room (such as a smoking lounge, restroom or custodial closet).
Avoid re-circulating air from areas that are strong sources of contaminants. Confine activities that produce odors and gaseous contaminants to locations that are maintained under negative pressure relative to adjacent areas. Finally, make sure that external vents are located well away from the fresh air intake of the HVAC system to avoid recontamination.
Editor’s Note: In our next Healthier Indoor Air blog, we’ll discuss how to use filtration to remove VOCs and other harmful gases from the breathing air.