On Sat, 17 Oct 2009 11:58:29 -0400, "EXT"
wrote:

Dysons sometimes mention they use a Hepa final
filter to clean the air. Hepa is not a standard and can mean many things,

When you wrote Hepa, if you meant HEPA, there is a HEPA standard:
they are able to trap at least 99.97 percent of particles of .3
microns.