Yes. IPC 608.17.7 requires backflow protection wherever a chemical dispenser connects to the potable water system, such as an ASSE 1055 device, an air gap fitting, a vacuum breaker or an RPZ. Maricopa County requires food businesses to run a separate water line to the dispenser and use ASSE 1055 air gap compliant units.
What the plumbing code allows
The 2024 International Plumbing Code addresses dispensers by name. Section 608.17.7 says: "Where chemical dispensers connect to the potable water distribution system, the water supply system shall be protected against backflow in accordance with Section 608.14.1, 608.14.2, 608.14.5, 608.14.6, or 608.14.8."
Those cross-references translate to five choices:
| Section | Protection | Notes from the code |
|---|---|---|
| 608.14.1 | Air gap | Measured from the outlet to the flood rim of the receptor |
| 608.14.2 | Reduced pressure principle assembly (RPZ) | "The relief opening shall discharge by air gap" |
| 608.14.5 | Pressure or spill-resistant vacuum breaker assembly | Critical level "not less than 12 inches (305 mm) above all downstream piping and outlets" |
| 608.14.6 | Atmospheric-type vacuum breaker | Works only "when the critical level is installed at the required height" |
| 608.14.8 | Chemical dispenser backflow device | "shall comply with ASSE 1055 or shall be equipped with an air gap fitting" |
Notice what's missing: a plain double check or a dual check isn't on the list. Those are low-hazard devices, and concentrated chemicals aren't low hazard.
We checked Phoenix's 2024 IPC amendments under Ordinance G-7397. Phoenix amends several backflow sections, including secondary protection, pits and clearances, but not 608.14 or 608.17.7, so the model text applies.
Maricopa County's rule for food businesses
Restaurants, bars, cafeterias and other permitted food establishments go through county plan review, and the county's construction guide is stricter on the details. Under its janitorial station section:
- "It is required to provide an additional water line at the mop sink/utility area to supply the chemical dispensers."
- "Valves of any type are not permitted downstream of a mop sink faucet with an atmospheric vacuum breaker."
- "Installed chemical dispenser backflow preventers must be ASSE 1055 air gap compliant."
- "Appropriate backflow protection must be installed for those chemical dispensers that do not comply with the standards."
That second rule is easy to break without noticing. An atmospheric vacuum breaker is a backsiphonage-only device in the code's Table 608.1, and the code's irrigation section says it flatly: "Valves shall not be installed downstream from an atmospheric vacuum breaker." Tee a dispenser hose or a shutoff valve off the faucet outlet and the vacuum breaker stays under pressure, so it can't open to air when it's needed. The county's fix is a dedicated supply line for the dispenser.
The guide also asks you to "Place approved chemical dispensing systems in a manner that does not interfere with the storage or use of maintenance equipment."
What Mesa lists
Mesa's point-of-use table names the device for each piece of equipment. For "Chemical and Soap Dispensers," the acceptable protection is an air gap, a PVB or an SVB (City Code 8-1-9). Mesa's chapter also requires that point-of-use assemblies be "installed no more than five (5) feet above finished floor level" and be reachable for testing, and that the customer have point-of-use assemblies "tested annually."
So in Mesa a dispenser protected by a testable PVB or SVB goes on the yearly test list along with the assembly at the meter.
What to check in your janitor closet
- 1Is the dispenser on its own water line, or teed off the mop faucet? A tee off the faucet outlet is the most common problem.
- 2What's the dispenser's backflow device? Look for an ASSE 1055 marking or a visible air gap fitting on the unit.
- 3Is the mop faucet's vacuum breaker clear? No valve, sprayer or hose shutoff should sit after an atmospheric vacuum breaker.
- 4Is anything mounted too low? A vacuum breaker needs its critical level above the outlets it protects.
- 5Who installed the dispenser? If a chemical vendor installs or swaps the unit, ask them to confirm the device standard in writing, and have a licensed plumber handle the water connection.
None of this is about the chemical brand. It's about the connection. HQ tests, repairs and replaces domestic backflow assemblies for restaurants and commercial buildings, and can look at the janitor closet on the same visit.
For the rest of a kitchen's equipment, see backflow for soda, ice and coffee machines and air gaps and indirect waste for commercial sinks. Opening a new place? Our page on what Maricopa County checks in restaurant plan review covers the full plumbing list.