These Big Blue whole house Carbon filters employ a high grade carbon with industry-leading surface area allowing for the greatest efficiency of the carbon absorption.
GAC (Granular Activated Carbon) is simply carbon in the form of granules. This increases the surface area available for absorption of the unwanted chemicals within your water supply. It also extends the life of the cartridge, maximizing time between cartridge changes.
This filter cartridge is Tested and Certified by NSF International against NSF/ANSI Standard 42 for material requirements only.