Abstract
Little is know about indoor air pollution by plasticizer phthalic acid esters (PAEs). We developed a simple method the Internfacial Passive Adsorption (IPA) to determine the migratory rate of PAEs through the interface from building materials to the adsorbent attached to the surface. Authentic PAEs on the glass plate surface moved quantitatively to the adsorption disc (EmporeTM C18), which was fitted for Fick's law of diffusion. After the adsorption disc had been placed in contact with a vinyl sheet for 1 - 14 days, adsorbed PAEs were measured. The adsorbed amount of di(2-ethylhexyl)phthalate (DEHP) increased in proportion to the contact time, whereas the increase of diethyl phthalate (DEP) or di-n-butyl phthalate (DnBP) each day was larger during the first five days rather than afterwards. We speculated that the movement of DEP or DnBP from the material to the adsorbent was more rapid than that of diffusion in the material. The rate of movement increased together with temperature. A plot of log moving rate vs. the reciprocal of the temperature (1/T) gives a straight line with negative correlation. It was suggested that the moving rate of the PAE obtained by this method relates to the emission rate of the corresponding PAE into air. The IPA method can be used to “Evaluate the PAE emission potential of materials” and “Specify the PAE emission source in on-sites”.
