(4) Last, PCO-based IPPT may not just produce active agents to attack indoor pollutants, but they may also produce harmful ozone and formaldehyde as by-products.
Within the Government of Canada's Clean Air Regulatory Agenda (CARA), researchers from the National Research Council of Canada (NRC) have recognized a critical standardization gap, as sound evaluation protocols and test methods were limited to comprehensively and fairly validate IPPT manufacturers' claims.
While available standards address important aspects of indoor pollutant removal performance, (5-8) none deal with other specific performance issues for indoor applications such as: harmful by-product formation to protect human health; re-emission of captured VOC; and IPPT testing in chambers that can simulate air velocity and turbulence levels typically found in indoor environments, (9) as well as simulate visible light illumination using a conventional indoor lighting source (instead of a UV source).
NRC researchers focused on three priority areas to develop a protocol to assess IPPT performance, specifically:
Test Methods to Evaluate Toluene and Formaldehyde Removal and Re-Emission, and By-Product Formation." (2) This protocol provides a method to determine the performance of IPPT in terms of their capacity to remove two important indoor air pollutants in Canadian indoor environments, formaldehyde and toluene.
The protocol was used to differentiate the formaldehyde removal performance of a conventional gypsum board with that of a sorptivebased IPPT gypsum board.
In contrast, the sorptive-based IPPT gypsum board has an Re value of only 0.9%, indicating minimal re-emissions.
In summary, NRC researchers have developed a protocol to evaluate the performance of IPPT in their ability to remove formaldehyde and toluene and to determine re-emissions of captured pollutants and by-product formation.