The Black Berkey filters are made from a patented blend of various components, including, for example, high-quality carbonized coconut shell. Berkey Water Systems confirms that there is no graphene oxide in the composition of the filter elements.
Furthermore, Berkey Water Systems does not have any test reports available that verify the reduction of graphene oxide by the Black Berkey filters. Without test results, they cannot claim that the filter elements are capable of reducing or removing this contaminant.