ENVIRONMENTALLY FRIENDLY. CFIA APPROVED. SANITIZER. Protocol K-651 is a tub, tile, and grout cleaner made from an organic salt/surfactant blend designed to quickly penetrate dirt, oil, grease, calcium carbonate, lime, rust, and other everyday soils. K-651 is safe to use on any surface (must be thoroughly rinsed from all surfaces after use). The blend of surfactants and organic salts enables K-651 to outperform traditional acid-based cleaners. For specific use in food plants, see directions.