Particles having aerodynamic diameters smaller then about five microns are the greatest health hazard contained in airborne dust. Most air filter textile fibers are about twenty microns in diameter, and they are not very effective in the capture of fine respisable particles. To be effective, a filter must be either very fine in fiber diameter or "electrostatically charged". While fine fiber filters have a high mechanical efficiency they may, under certain circumstances, be shed and breathed in, creating a HEALTH HAZARD. Filters made from coarser electrically charged fiber eliminate this problem.

This uses a mixture of two different types of polymers to enhance a highly stable charge on every individual fiber of the electrostatic air filter surface. This active charge works very effectively in capturing and retaining sub-micron particles.