Answered by on Friday, October 16, 2009
According to allergist William Davis, M.D., a professor at Columbia University, "HEPA [or High Efficiency Particulate Air] filters work because they retain particles down to 0.3 microns, and many allergens are larger than that." Clean your home regularly with a HEPA filter vacuum and you will significantly reduce any sneeze-provoking dander from cats or dogs. HEPA vacuums can also take care of allergens from down and other feather pillows and comforters as well as from mold. "The HEPA filters don't work quite as well on dust mites," notes Dr. Davis notes, because those allergens are sometimes smaller than 0.3 microns.