SHUK Rubber & Gaskets now has the world's first Blue Coloured EPDM Potable Gasket. The blue EPDM gaskets meets the AS/NZ 4020 standard certified by the AWQC. The blue gasket allows inspectors, water authorities and contractors to have the confidence visually that AS/NZ 4020 certified potable gaskets have definitely been installed and not just a piece of rubber.