Purification capability of potted plants for removing atmospheric formaldehyde

The purification capabilities of four kinds of foliage plants for formaldehyde, which is a main indoor air pollutant, are examined. The purification capability (P_a) is introduced using a tin oxide gas sensor-output. P_a is derived by dividing the peak value of the sensor-output by the full-width at half maximum. Formaldehyde is one of the typical chemical substances which cause sick-building syndrome. The abilities of the following plants are examined: rubber plant, Boston fern, golden pothos and snake plant. The purification capabilities of these plants for formaldehyde in the amount. of 10 ppm are about 19, 15, 23 and 12 respectively. The number becomes greater as the capability is higher. There are several features in P_a characteristics as a function of formaldehyde concentration. Namely, the P_a characteristics for rubber plant and Boston fern can be shown by a linear increasing function. The characteristics are measured until the concentration of 40 ppm. The characteristic of golden pothos is almost constant and the characteristic of snake plant has a maximum value at the concentration of 20 ppm.