We further challenged the effectiveness of the catalytic approach by comparing the rate of formaldehyde build-up in the room while recirculating the OR air through the air cleaning device with and without the catalyst. While a corner stationed air filtering device is not expected to completely prevent formaldehyde build-up from a source in the center of the room, we found that the rate of formaldehyde accumulation is significantly inhibited when both catalyst and activated carbon are present compared to when only activated carbon is present. After approximately 8 minutes, the concentration increases in a linear manner. The slope of the fit for the linear portion of the data is 0.023 when catalyst and activated carbon are present and 0.073 when activated carbon is present without catalyst. Comparing the slopes of the two conditions shows that the formaldehyde concentration in the OR increases 3.2 times more rapidly when catalyst is not present. As formaldehyde evaporates into the air from the formalin solution, the air recirculating device equipped with catalyst constantly removes a portion of the supplied formaldehyde as it pulls in polluted air at a rate that is high enough to slow the speed of contamination.