VTT Technical Research Centre of Finland tests concluded that Naava filtrated up to 65% of VOCs from the air with a single pass. In this research, two different VOCs (toluene and methyl ethyl ketone) were used. When the VOC concentrations were close to realistic indoor concentration levels, Naava’s VOC removal efficacy was significant with a single pass through Naava. Even in extreme VOC concentrations Naava was able to remove VOCs with a single pass without the biofilter getting “clogged” as normal air purifiers often do.