Chemical dispensers are typically connected to potable water systems and therefore need backflow protection to prevent the concentrated cleaning chemicals from contaminating the water distribution system.

Chemical dispensers, and specifically the backflow protection provided therein, are controlled by a National Standard - American Society of Sanitary Engineering (ASSE) 1055: Performance Requirements for Chemical Dispensers.

Two National Plumbing Codes are in force throughout the USA: the International Plumbing Code (IPC)written by the International Codes Council (ICC), and the Uniform Plumbing Code (UPC), written by International Association of Plumbing and Mechanical Officials (IAPMO). States or cities typically adopt one or the other to control plumbing installations in their regions. Both plumbing codes require adherence to ASSE 1055 requirements for chemical dispensing equipment.

Hydro chemical dispensers with built-in Air Gap or E-Gap eductors meet ASSE 1055 Performance Requirements and are listed with the ASSE.

The map below shows the states and localities that have adopted the two plumbing codes.