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Quantifying Byproduct Formation from Portable Air Cleaners Using a Proposed Standard Test Method



Michael F. Link, Rileigh Robertson, Dustin Poppendieck


In response to the COVID-19 pandemic, air cleaning technologies were promoted as useful tools for disinfecting public spaces and combating airborne pathogen transmission. However, no standard method exists to assess potentially harmful byproduct formation from air cleaners. Through a consensus standard development process, a draft standard test method to assess portable air cleaner performance was developed and a suite of air cleaners employing seven different technologies was tested. The test method quantifies not only the removal efficiency of a challenge chemical suite and ultrafine particulate matter, but also byproduct formation. Clean air delivery rates (CADRs) are used to quantify the chemical and particle removal efficiencies and an emission rate framework is used to quantify the formation of formaldehyde, ozone, and other volatile organic compounds. We find that the tested photocatalytic oxidation and germicidal ultraviolet light (GUV) technologies produced the highest levels of aldehyde byproducts having emission rates of 202 µg h-1 and 243 µg h-1, respectively. Additionally, GUV using two different wavelengths, 222 nm and 254 nm, both produced ultrafine particulate matter.
Environmental Science and Technology


air cleaner, volatile organic compounds, indoor air quality


Link, M. , Robertson, R. and Poppendieck, D. (2024), Quantifying Byproduct Formation from Portable Air Cleaners Using a Proposed Standard Test Method, Environmental Science and Technology, [online],, (Accessed May 19, 2024)


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Created April 30, 2024, Updated May 7, 2024