Destroys: Lime, Calcium, Rust caused by hard water build-up. Think formula coats and effectively covers bowl for that all around clean; remains in contact with tough mineral stains longer for a deeper clean; dissolves stubborn rust, calcium and lime stains - even below the waterline; leaves your toilet bowl completely clean, shiny and fresh smelling. Safe for plumbing and septic systems. Contains no phosphorus. Health. Hygiene. Home. www.rbnainfo.com. Questions? 1-800-228-4722. For more ingredient information visit www.rbnainfo.com. This bottle is made 25% post-consumer recycled plastic. Encourage your local authorities to establish a program to recycle this bottle.