Effect of phase of toluene on filtration performance of electret filter media against di-octyl-phthalate aerosols.
Jasper-W; Hinestroza-J; Mohan-A; Thompson-D; Barker-R
J Int Soc Respir Prot 2005 Oct; 22(Fall/Winter):97-105
Performance degradation of electret filter media when exposed to toluene in a laboratory setting was investigated using a custom-made exposure apparatus. Three types of electret filter media were exposed to toluene in liquid and gas phases. Experimental data indicated that the penetration percentage of di-octyl-phtalate (COP) aerosols through electret filter media was not influenced by exposure to toluene vapors for periods up to eight hours. The filtration performance for all three types of electret filter media decreased more than 30% when the samples were exposed to controlled amounts of liquid toluene. Pressure drop changes of the filter media prior and after exposure to liquid toluene were statistically negligible. Neither morphological changes nor degradation of the polymer fibers were observed after exposure of the filter media samples to liquid toluene. Thermodynamic simulations were performed to determine the molar flux of liquid and gas through the filter media specimens. Experimental results obtained via capillary gas chromatography were within 6% of the predicted toluene concentration values. The decrease in performance was attributed to changes in the density and spatial distribution of the electret charges on the surface of the polymer fibers.
Air-filters; Air-flow; Filters; Respirators; Respiratory-protective-equipment
College of Textiles, North Carolina State University, Raleigh, NC 27695
Issue of Publication
Journal of the International Society for Respiratory Protection