By understanding the complexities surrounding indoor air quality, and by following certain principles, design professionals can play a crucial role in improving IAQ for building occupants
By understanding the complexities surrounding indoor air quality, and by following certain principles, design professionals can play a crucial role in improving IAQ for building occupants.
Take a deep breath. Exhale. Do you know what was in the air that you just inhaled?
The Food and Drug Administration requires Nutrition Fact labels on food products to help us decide whether to eat or not eat a particular food. We are not, however, provided with similar help in understanding what's in the air we're breathing-or what impact those chemicals in the air might have on our health.
The air in buildings comes from the outside, yet it is not necessarily always "fresh" and may in fact be contaminated with numerous chemicals, formaldehyde and ozone. That not-so-fresh "outside" air is then brought into our buildings where more chemicals (emitted from building materials and furniture) are added to the mix. Pollutants from building occupants (clothing, personal care products, breathing and other activities) increases the chemical concentrations, as do the chemicals and ozone emitted from our office equipment (computers, printers, and copy machines) and the products we use to clean our indoor environments.
The result is indoor air that is a complex chemical soup whose ingredients include:
- Volatile organic compounds (VOCs) emitted from building materials, contents and cleaning agents
- Semi-volatile organic compounds (SVOCs) from fire retardants, pesticides and plasticizers
- Microbial organisms and microbial volatile organic compounds (MVOCs) from mold
- Inorganic chemicals such as carbon monoxide, nitrogen dioxide and ozone
- Particulate matter from generated fuel combustion, occupant activities and equipment
Human bodies were not designed to accommodate many of the chemicals to which we are exposed, and the subsequent health impacts of this exposure are becoming more widely understood. The U.S. Environmental Protection Agency defines these impacts as:
- Sick Building Syndrome Symptoms (SBS):
"Term that refers to a set of symptoms that affect some number of building occupants during the time they spend in the building and diminish or go away during periods when they leave the building; cannot be traced to specific pollutants or sources within the building."
- Building Related Illnesses (BRI):
"Diagnosable illness whose symptoms can be identified and whose cause can be directly attributed to airborne building pollutants (e.g., Legionnaire's disease, hypersensitivity pneumonitis). Also: A discrete, identifiable disease or illness that can be traced to a specific pollutant or source within a building."
- Multiple Chemical Sensitivity (MCS):
"A condition in which a person reports sensitivity or intolerance (as distinct from ‘allergic') to a number of chemicals and other irritants at very low concentrations. There are different views among medical professionals about the existence, causes, diagnosis, and treatment of this condition."
While the design for good indoor air quality (IAQ) is a complicated endeavor, implementing four basic design principles can go a long way toward providing healthier indoor environments:
- Source Control: By reducing the indoor air chemical concentrations, we can reduce the pollutant burden added to the outdoor air brought inside. This reduces occupants' exposure to potentially harmful chemicals. The selection of low-VOC content materials is a first step; much more important is the selection of low-emitting materials. Research has shown that some low-VOC content building materials, and particularly some paints, may still emit VOCs and formaldehyde.
- Ventilation Design: If natural ventilation is used, pay particular attention to the quality of the outside air. Local air quality data will determine if the air is suitable for human use and good health. If a mechanical system is used to supplement or replace operable windows, then adequate filtration, ventilation rates and humidification should be considered.
- Building and IAQ Commissioning: Originally intended to ensure energy efficiency, commissioning also ensures improved air quality and occupant comfort. Regular building re-commissioning is advisable to continually fine-tune the building and catch air quality and efficiency deficiencies before they become pronounced. Air quality testing before occupancy, before and after the flush-out, and after occupancy can convincingly assure building owners and occupants that the building is ready for occupancy.
- Building Maintenance: Maintaining mechanical systems (filter changes) and cleaning with environmentally friendly cleaning agents is critical to protecting the building asset and can significantly improve the air quality and occupant health over the long term.
CONNECTING AIR AND HEALTH
Imagine that we could test the indoor air surrounding your workspace or home to identify the individual chemicals within. We could then begin to connect those chemicals to potential short- and long-term health effects based on
exposure to "Chemicals of Concern" (i.e., carcinogens, reproductive toxicants and chemicals with chronic or long-term human health effects).
Such testing may happen sooner than we think.
In the early 2000s, a specification was developed for a large California state office building that sought to reduce the occupants' exposure to these chemicals. Special Environmental Requirements Section 01350 requires manufacturers to test products in a test chamber; to identify the rate of individual chemical and formaldehyde emissions; and to model the predicted chemical concentrations (based on the material quantity, the volume of air in the space, and the air exchange rate) that could be expected in a typical office and classroom building. The modeled VOC concentrations are then matched against various chemical lists provided by the state of California EPA Office of Environmental Health Hazard Assessment (OEHHA), including a list of 80 chemicals for which it has developed Chronic Reference Exposure Levels (CRELs) to indicate safe levels for long-term exposure with conservative safety factors for uncertainty built in.
Section 01350 requires building material manufacturers to identify VOCs that are listed as carcinogens and reproductive toxicants, and those that have modeled chemical concentrations that exceed safe CRELs. If the material's VOC concentrations exceed the safe CRELs, they should not be used in a building. Many building product manufacturers are now submitting their materials for section 01350 testing and are using third-party certifiers to substantiate compliance.
Ideally then—if we did our job correctly—we would not expect to find any of the eliminated chemicals in the building air during the IAQ commissioning and IAQ testing conducted at the end of a construction project. However, building construction is not an exact science, so some chemicals might still be found. In that case, we would go back to the individual material test data and search for the problem chemicals and identify the material the might be causing the high-VOC concentrations.
LABELS AND CERTIFICATIONS: NO EASY ANSWER
Most design professionals would like quick and easy answers for creating good indoor air quality and selecting green building materials. Industry and third-party certifiers would like to provide those answers. However, it is important to really understand what is-and is not-included in some of the following commonly-provided certifications:
- California Special Environmental Requirements Section 01350: This specification is not a label or certification and is not owned by any company. This is a good tool to identify potential IAQ health hazards, but does not provide information on other material sustainability attributes (e.g., SVOCs, recycled content, recyclability, etc.).
- Carpet and Rug Institute (CRI) Green Label Plus program: The CRI has its members' carpets and adhesives tested for VOC emissions and the results are used to model the predicted chemical concentrations in a typical office and classroom building in accordance with California Section 01350. While this label does provide information on the predicted IAQ, it does not provide information on other material sustainability attributes.
- Scientific Certification Systems (SCS) Indoor AdvantageTM and Indoor AdvantageTM Gold certifications: SCS is a third-party certifier of building products for manufacturers. Its Indoor Advantage certification provides information on compliance with IAQ and VOC emission criteria established by the Business and Institutional Furniture Manufacturers Association (BIFMA) Standard for low-emitting Office Furniture Systems and Seating. Indoor Advantage Gold certification is based on Section 01350 IAQ performance for offices and classrooms. While this certification does provide information on the modeled VOC indoor air concentrations, it does not provide information on other material sustainability attributes.
- FloorScore: This certification, developed by the Resilient Floor Covering Institute and SCS, indicates a compliance with VOC concentration requirements of Section 01350 and also requires manufacturers to implement a supply chain management program to identify and reduce target chemical VOCs from the final product. This certification does not provide information on other material sustainability attributes.
- Green SealTM: Green Seal provides certification on the VOC content for wet building products such as paints, coatings, sealants and cleaning agents. It does not provide information on VOC emissions and concentrations, nor does it provide information on other material sustainability attributes.
- GREENGUARD Environmental Institute, GREENGUARD for Children & SchoolsSM: The GREENGUARD Children & Schools Product Certification Program certifies that building products commonly used in schools are in compliance with Section 01350 requirements. It also includes limits on emissions of total phthalates (SVOCs). While this certification does provide information on the modeled VOC indoor air concentrations and begins to address SVOC emissions, it does not provide information on other material sustainability attributes (e.g., recycled content, recyclability, etc.).
Additional certification programs can be used to gather other bits and pieces of sustainable product information; unfortunately, at this time, we only have single attribute labels and certifications that do not give the complete sustainable material story. Consequently, it is incumbent on designers to ask questions about building materials and to request information from manufacturers about product performance. There are no easy answers-yet. The more questions we ask, and the more frequently we ask them, though, will result in the information we need to ensure good indoor air quality and healthier building occupants.
Anthony Bernheim, FAIA, LEED AP, is principal, Sustainable Design Services, for HDR Architecture Inc. He has nearly 25 years of experience as an architect, with a unique expertise in integrating sustainable and high-performance building techniques and methodologies. Bernheim is especially recognized for his expertise in indoor air quality; his leadership and participation was key in the development of an innovative green building Special Environmental Requirements specification (now known as section 01350) that established nationally-recognized standards for improved indoor air quality and material resource efficiency.