How Do We Measure Indoor Air Quality?
SCS product testing procedures
The Scientific Certification Systems (SCS) Indoor Advantage™ certification program employs product selection, collection, handling, and testing protocols that were developed by the California Department of Health Services indoor air quality research staff in accordance with the Business and Institutional Furniture Manufacturer’s Association (BIFMA) Furniture Emissions Standards. These protocols are the result of a consensus process that captured the input of a range of stakeholders, including architects, scientists, designers, manufacturers and government agencies.
Scientific Certification Systems evaluates manufacturers’ internal processes and quality control systems to determine the number of product samples that must be collected and tested in the laboratory. Samples are wrapped and packaged as prescribed by the California Department of Health Services and the BIFMA standards so as to preserve their chemical integrity. Collection, handling, and shipping are documented using internationally recognized chain-of-custody procedures.
The Indoor Advantage laboratory testing protocols adhere to American Society for Testing and Materials (ASTM) Practice D5116 for small-scale chamber product testing and ASTM Practice D6670 for full-scale chamber testing. These protocols define the procedure by which product samples are tested in controlled chambers to determine the emission rate of each chemical on the California Office of Environmental Health Hazard Assessment (OEHHA) Chronic Reference Exposure Levels (CRELs) list as well as for any chemical listed as a probable or known carcinogen or as a reproductive toxicant. All SCS-certified products must be tested annually or when product formulations change, as such changes can impact the product’s emissions profile.
Product testing in environmental chambers
There are three scales of product testing chambers: small-, mid- and large-scale. Mid-scale chambers are designed to accommodate an entire piece of furniture, while large-scale chambers may accommodate an entire office furniture system. The Business and Institutional Furniture Manufacturer’s Association (BIFMA) M7.1 standard authorizes the use of all three scales of testing chamber and requires that every certified product passes at least one mid or large-scale test. California Special Environmental Requirements Specification 01350—the basis for the Indoor Advantage Gold™ certification—specifies the use of only small-scale testing chambers, which are used to test components and raw materials of larger products. The data about particular product components that are generated by small chamber testing enable manufacturers to identify specific links in their supply chain that are hindering the air quality emissions performance of their final product. Manufacturers thus have the opportunity to work with their suppliers to ensure that all of the component materials that go into their products uphold their standards for environmental sustainability.
The BIFMA M7.1 standard specifies that all newly manufactured products that have been selected for testing in any of the three scales of testing chamber should be subjected to a three-day conditioning period before being placed in the testing chamber for a period of for four days. California Standard 01350 for small-scale testing specifies a ten-day conditioning period for new products before the same four-day test period. The conditioning period specified by both standards is intended to allow for initial off-gassing by products fresh off the assembly line in order to ensure that chamber tests yield accurate information about product emissions that are likely to continue over the long-term and thus might induce chronic health problems.
Measuring and modeling product emissions
After a product has completed the four-day testing period inside the testing chamber, technicians follow Environmental Protection Agency (EPA) and American Standards Testing Methods (ASTM) methods to measure the chamber concentrations of various individual volatile organic compounds (VOCs) that are know to pose health risks. In accordance with the BIFMA Standard for Formaldehyde and TVOC Emissions of Low-emitting Office Furniture Systems and Seating (BIFMA X7.1), technicians also record chamber concentrations of formaldehyde, total aldehydes, total volatile organic compounds (TVOC), and 4-phenylcyclohexene, as well as any other highly abundant compounds.
The emissions rate calculated for each of the chemicals of concern is used to model the concentration of that chemical that would be found if the product were used in a standard office, classroom, residential or hospital application. Three variables factor into this analytical modeling process:
- The amount of product being installed into the indoor space
- The dimensions of the indoor space under consideration
- The weekly average air exchange rate for the indoor space under consideration
