Porcelain cleaning solution is a mild acid cleaner that removes soap, scum and scale from bathroom surfaces including plastic, porcelain, ceramic, fiberglass, floors and fixtures. Authorized by USDA for use in federally inspected meat and poultry processing plants. USDA rating: C-2; for use in toilets and/or dressing rooms. Green Seal Certified. 27 RTU gallons per bottle. 6 2-liter bottles per box.