STUDIES ON PERMEATION OF VOLATILE ORGANIC-COMPOUNDS THROUGH COMMERCIAL POLYETHYLENE FILMS TO PASSIVE SAMPLERS

Studies were carried out on permeability of polyethylene membranes of two thicknesses (15.5 and 38 mu m) with respect to vapours of those vo latile organic compounds (VOCs) which are pollutants most frequently f ound in indoor air, especially in dwelling air. On the basis of model experiments done in flow-through exposure chambers, the calibration co nstans k for 12 passive dosimeters (with respect to each compound pres ent in a gaseous standard mixture) were determined. Six of these dosim eters were recalibrated in a humidified gaseous standard mixture to de termine the influence of air humidity on analyte trapping. It was foun d that the thin polyethylene film has high permeability to the selecte d compounds and can be used for membrane preparation in passive dosime ters of permeation type. The foil was found to be quite homogeneous. T his can simplify the dosimeter calibration procedure, since not each m embrane but only a membrane material must be calibrated. Air humidity was found to influence the permeation through a polyethylene membrane in spite of its hydrophobic character. The humidity effect should be f urther studied in detail.