Chemical dispensing systems with integral backflow protection provide a means of mixing potable water with chemicals to provide the user with a chemical solution that is ready for use. In industrial and institutional cleaning operations, it is desirable and convenient to dispense cleaning solutions derived from potable water and concentrated products; however, a dispensing device connected to potable supply constitutes a cross-connection, which could be a source of contamination to the potable water. ASSE 1055 identifies accepted methods of backflow protection, as well as test methods for evaluating backflow systems incorporated into a chemical dispensing system.