ENVIRONMENTALLY FRIENDLY. PHOSPHATE FREE. Protocol K-671 is a toilet bowl cleaner made from an organic salt surfactant blend that acts as an acid with a pH of less than 1.5. It is designed to quickly penetrate urine, calcium, lime, rust, and other bowl soils. This unique and carefully chosen blend of organic surfactants and organic salts enables this product to address most of today’s safety, transportation, and environmental concerns while keeping the product effective. Protocol K-671 is ideal for industries where personnel safety may be at risk, and environmental impact is a concern.