Most people breathe more polluted air indoors than outdoors, impairing human health, comfort and productivity. The best approach for providing a healthy indoor air is source identification and elimination with ventilation using clean outdoor air. However, it is not possible to eliminate all indoor air pollution sources in all indoor environments, and ventilation per se cannot be used if the outdoor air is polluted, and can have a negative impact on the energy performance of the building. Thus, air cleaning technologies are seen as promising effective methods to provide clean indoor air and many have been emerging in the market. However, given the sparse public and market information, the technologies’ limitations, the lack of standardisation and citizens’ understanding, there is a need to consolidate accessible information on existing technologies for indoor air cleaning and to progress beyond the state-of-the-art involving the various stakeholders.