We utilize Absolute Filtration, a filtration method that the bottled water industry recognizes as an indicator of water purity. An Absolute-rated filter removes 100% of all particles of a given size. Filters are usually rated in microns, according to the size of particles that a filter will remove. A micron is one one thousandth of a millimeter. A 1 micron Absolute filter will remove 100% of all particles that are 1 micron (or larger) in size. Many spring waters are produced using 1 micron absolute filters. At CRYSTAL GEYSER ® ALPINE SPRING WATER ™, we exceed this standard by using 0.1 micron absolute filters. This unique, advanced absolute filtration technology effectively removes 100% of all particles 10 times smaller than the 1 micron industry standard for filtration. So, in answer to this question, we use a filter ten times smaller than an absolute 1 micron filter, and to our knowledge, no other bottler in the United States filters to this level of purity.