In fact, a genuine HEPA filter has been rated to remove 99.7% of all particle contamination from the air, as long as those particles are 0.3 microns or larger. Now, when you stop to consider that a traditional hair from your head is 100 microns wide, you will see that this filter should remove even the smallest contaminates from the air. When used in combination with other forms of technology, like activated carbon odor control or UV light technology, you will have a purifier which works at a very high level of success.
Some brand manufacturers believe, however, that the best will take this technology and improve in it even more. Using the original filter, they will give adjustments to the composition and in some cases, can produce a HEPA filter which works at an even higher rate of success than the original. Since these brand manufacturers are making these adjustments to the actual filter themselves, they will be the only types of air purifier which can market these particular adjusted filters.