Photocatalytic oxidation of VOCs: Assessing health risks and mitigation strategies for safer indoor air environment
Smaiyl M. Satybaldiyev B. Haghighat F. Haghighat Mamaghani A. Uralbekov B.
February 2026Elsevier B.V.
Journal of Hazardous Materials Advances
2026#21
Photocatalytic oxidation (PCO) is increasingly employed for the removal of volatile organic compounds (VOCs) from indoor air. A growing body of evidence indicates that PCO can generate toxic by-products, including formaldehyde, acetaldehyde, benzene, and other hazardous compounds. These by-products are recognized environmental contaminants with established carcinogenic and other adverse health effects. This review examines the key determinants of by-product formation—indoor VOC concentrations, relative humidity, light irradiance, and catalyst surface properties—with emphasis on indoor-relevant concentration ranges. The health risks associated with these by-products are assessed using metrics such as the hazard quotient (HQ), hazard index (HI), and cancer risk (CR). Calculations based on literature-derived datasets indicate that these indicators often exceed acceptable thresholds, suggesting potential health concerns associated with the PCO technology. Furthermore, evaluations of commercially available PCO-based air cleaners show that some devices may emit more by-products than they remove, resulting in a net degradation of indoor air quality. To support safer deployment, mitigation routes are outlined—operational optimization, catalyst engineering, and integrated adsorptive stages—complemented by predictive modeling to identify safe, energy-efficient operating windows. Based on current evidence, widespread residential deployment of PCO-based air cleaners warrants further evaluation; priorities include long-term exposure assessment under realistic loads, refinement and validation of predictive models, and field confirmation that engineered operating windows reliably control by-products without compromising indoor air quality.
Air cleaners , By-product , Formaldehyde , Health risks , Indoor air environment , Photocatalytic oxidation
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Center of Physical-Chemical Methods of Research and Analysis, al-Farabi Kazakh National University, Almaty, Kazakhstan
Department of Building, Civil and Environment Engineering, Concordia University, Montreal, QC, Canada
Center of Physical-Chemical Methods of Research and Analysis
Department of Building
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026