Not by name in Phoenix. The 2024 IPC the city uses has no hair interceptor section, but its general interceptor rule and Phoenix City Code let the city require one when solids could harm the sewer. Arizona's cosmetology rules also require shampoo bowl drains that run freely, so a hair trap under each bowl is the practical fix.
What the plumbing code says in Phoenix and the Valley
The IPC handles interceptors in Section 1003. The trigger is Section 1003.1, and it's written broadly: "Interceptors and separators shall be provided to prevent the discharge of oil, grease, sand and other substances harmful or hazardous to the public sewer, the private sewage system or the sewage treatment plant or processes." Hair isn't named, but a steady load of it can block a line, so it can fall under "other substances" when the reviewer thinks it does.
The specific sections that follow name grease, oil, sand, laundries, bottling plants and slaughterhouses. None of them names salons or barbershops. That's the gap people run into when they search for a salon interceptor code section. It isn't there in the model IPC.
Section 1003.2 is where Phoenix changed the model text. The Phoenix version says each interceptor is "designed and installed in accordance with the manufacturer's instructions and the requirements of the Authority Having Jurisdiction." The city's amendment notes give the reason: City Code Section 28-13 gives the Director of Water Services approval authority for all interceptors. In other words, the plumbing code points you to the city, and the city decides.
Other Valley cities that use the IPC start from the same Section 1003.1 idea. Local amendments can differ, which is why the plan reviewer's comments on your tenant improvement set are the final word for your address.
### What Phoenix City Code adds
Phoenix's sewer use rules (City Code Chapter 28) are where the real teeth are. The code bars discharging "Solid or viscous pollutants, FOG, petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin that can cause interference or pass-through or that can cause obstruction to the flow in sewers or other damage to the POTW." POTW means the city's sewer and treatment system.
Chapter 28 also lists who must install interceptors. It names laundries, food service, service stations, auto repair shops, carwashes and commissaries, and Phoenix City Code then adds "and other facilities when the Director determines they are necessary for the proper handling of liquid wastes containing grease or oil in excessive amounts, or any flammable wastes, solids, or other harmful ingredients." A salon isn't on the named list, but it fits the "other facilities" door if the Director decides hair is a problem at that site.
If one is required, Phoenix City Code says "Interceptors must be of a type and capacity approved by the Director." So don't buy one online and hope. Use a model the city will accept.
What Arizona's salon rules require at the shampoo bowl
The Arizona Barbering and Cosmetology Board doesn't regulate plumbing parts, but its rules shape the drain question anyway.
First, a salon has to have a shampoo bowl. Under A.A.C. R4-10-403, an establishment where licensees do barbering, cosmetology or hairstyling must have "at least one shampoo bowl and one hair dryer, which may be a blow dryer."
Second, that bowl has to drain. R4-10-112 tells the establishment licensee to "Clean and disinfect shampoo bowls using a disinfectant listed under subsection (A)(5) and ensure drains are free running." R4-10-112 also says to "Discard hair and nail clippings immediately after each client." A bowl that won't drain falls short of that rule, even though the board never says the word interceptor.
That's the practical link. A hair trap is the simplest way to keep a shampoo bowl drain free running day after day.
Where other codes do name hair interceptors
Some places write the rule out in full, which shows where the idea comes from. New Jersey's plumbing subcode, Section 6.7.4, says: "Shampoo sinks in barbershops, beauty parlors, and other grooming facilities shall have hair interceptors installed in lieu of regular traps."
Those rules don't apply in Arizona. They're useful for one reason: a designer, franchise spec or landlord from out of state may show them to you, and it helps to know they aren't Valley law. In Phoenix, the question runs through Section 1003.1, the Director's approval power and the plan reviewer.
### What a hair interceptor looks like
Manufacturers build hair interceptors for this job. Jay R. Smith describes its Figure 8750 like this: "This solids interceptor is typically installed on the lavatory or sink in dormitories, motels and beauty salons." It goes on: "It intercepts hair and sediment which is commonly encountered in these areas."
Cleaning is the whole point of the design. Per Jay R. Smith, the "Unit is easily cleaned by removing cleanout plug on bottom of body and dropping perforated basket." The maker adds that it "also serves as a safeguard against losing rings and other valuable jewelry due to accidental dropping into lavatory drain."
Salon furniture makers also sell hair catchers that fit under a backwash unit. If you go that route, make sure the part is approved for plumbing use and that the drain still holds a water seal against sewer gas, either in the interceptor body or in a trap below it. See what a P-trap does for why that seal matters.
Salon scenarios: when a hair interceptor makes sense
Here's how it plays out for common Valley jobs.
| Situation | Code requirement for a hair interceptor | What we'd suggest |
|---|---|---|
| New salon build-out in Phoenix, plan reviewer asks for one | Yes, the Director can require it and approve the type | Install the approved model at each shampoo bowl |
| New salon build-out, no reviewer comment | Not named in the 2024 IPC | A hair trap per bowl is still smart, since R4-10-112 wants drains free running |
| Retail space converting to a salon | Tenant improvement permit; reviewer decides | Plan hair traps and backflow devices at the same time |
| Existing salon, bowls clog every few weeks | No new code trigger | Add hair traps and have the branch line cleaned |
| Barbershop with only lavatory sinks for shaves | Not named | Optional; a basket strainer may be enough |
| Salon suite with one bowl per suite | Board rules still require a bowl that drains | One compact hair trap per bowl |
Two things flip the answer. A plan reviewer's comment makes it mandatory. A clog history makes it worth doing even without one.
The tenant improvement is the easiest time to add them. The walls are open, the bowls are going in and the inspector is coming anyway. Our page on plumbing for a commercial tenant improvement walks through that process.
### Don't forget the water side of the shampoo bowl
The drain gets the attention, but the supply matters too. A shampoo bowl's hand sprayer can sit in dirty water in the bowl, which creates a backflow risk. Mesa's backflow code lists "Shampoo Basins" with acceptable protection of "AVB, PVB, SVB," all types of vacuum breakers, and it lists "Pedicure Station" for salons that also do nails. For how Phoenix and other Valley cities review backflow when a salon moves in, see whether a new tenant or change of use needs a new backflow assembly.
What to do before you open
Before opening day, confirm what the city asked for, then fit a hair trap at every bowl and give staff a cleaning routine.
- 1Check your plans. Look for a plan review comment on interceptors or "solids." If there is one, use the model the city approves.
- 2Count your bowls. Plan one hair trap per shampoo bowl, placed where staff can reach the cleanout.
- 3Set a cleaning routine. Empty baskets on a schedule, and log it with your board cleaning tasks so drains stay free running.
- 4Keep hair out of the bowl. Rinse cut hair off before the shampoo, and brush loose hair into the trash.
- 5Watch for slow drains. If a bowl slows down even with a clean basket, the problem is past the trap. Our page on why salon shampoo sinks drain slowly covers the next steps.
Emptying the basket is a quick staff task, not a service call. That's the fix.
HQ Plumbing & Air installs and repairs commercial fixtures, piping and interceptors, with upfront pricing and free estimates.