Plain answers to the questions operators ask about handwashing sinks, mop and service sinks, and food-prep sinks, covering code requirements, temperatures, placement and cost. For which sinks your kitchen must have, see the required-equipment guide.
A hand sink, or handwashing sink, is a dedicated basin used only for washing hands, kept separate from warewashing, food-prep and utility sinks. It must be stocked with soap, paper towels or a dryer, and warm running water, and be conveniently located so staff wash hands often. Using it for anything but handwashing, or blocking it with dishes, is a common violation. It is required in every commercial kitchen.
Yes. The FDA Food Code and virtually every local health department require a dedicated handwashing sink that is used only for handwashing, separate from your warewashing, prep and utility sinks. It must be accessible, unobstructed, and stocked with soap and hand-drying means. Combining handwashing with any other sink is a violation. The number and placement depend on your layout, so check the required-equipment guide and confirm at plan review.
A compliant hand sink needs hot and cold running water delivered through a mixing valve, soap in a dispenser, and a way to dry hands (paper towels or an air dryer), plus a waste receptacle nearby. It must be accessible and used only for handwashing. Signage reminding staff to wash hands is often required. Keep it unobstructed and stocked at all times; an empty or blocked hand sink is a frequent inspection finding.
The FDA Food Code requires a handwashing sink to deliver water at a minimum of 100°F (38°C), warm enough for effective, comfortable handwashing. It should reach that temperature quickly. Too-cold water discourages proper washing. This hand-sink demand is part of sizing your water heater, along with your dish machine and three-compartment sink. Confirm your local minimum, as some jurisdictions specify their own figure.
There is no single number; it depends on the size and layout of your kitchen and how far staff would have to travel to wash. Codes generally require hand sinks to be conveniently located in or adjacent to food-prep, warewashing and, sometimes, service areas, plus restrooms. Large or spread-out kitchens need several. Your plan reviewer sets the count for your specific layout, so confirm during plan review.
Hand sinks must be conveniently located so staff can wash frequently without leaving their work area, typically in or immediately adjacent to food-preparation and warewashing areas, plus restrooms. They cannot be blocked by carts, trash cans or equipment, and cannot double as prep or dish sinks. The goal is that a handwashing sink is always within easy reach. Exact placement is confirmed by your health department at plan review.
Yes, like other fixtures the hand sink drain generally must discharge with proper backflow protection, and the faucet must maintain an air gap above the flood rim so the potable supply cannot be contaminated. Requirements come from your local plumbing code. A hand sink usually does not need to route through a grease trap since it is not a source of grease. Confirm drainage and backflow specifics with your plumbing inspector.
Hand sinks are typically mounted with the rim around 30 to 34 inches from the floor for comfortable use, though ADA-accessible fixtures follow specific mounting-height and clearance rules. Wall-mounted units are common in kitchens. Confirm both the general mounting height and any accessibility requirements that apply to your facility, since public-facing and employee fixtures can be governed by different rules. Verify with local building and accessibility codes.
A hand sink is usually wall-mounted with hot and cold supply through a mixing faucet delivering at least 100°F, a drain with proper backflow protection, and soap and towel dispensers mounted alongside. It must be placed for easy access and not blocked. Because supply, drainage and backflow details are governed by plumbing code, have a licensed plumber install it, and confirm placement with your health department before finalizing.
No. Handwashing must occur at a dedicated handwashing sink, never in a food-prep sink or warewashing sink, to prevent contaminating food and food-contact surfaces. This is a code violation in most jurisdictions. The prep sink is for washing produce and thawing or preparing food; the hand sink is only for hands. Provide a properly located, stocked hand sink so staff never need to improvise.
Most jurisdictions require a mop sink, service sink or curb sink (or an approved equivalent like a floor drain with a can-wash) so mop water and other liquid waste are disposed of properly rather than in food-prep, warewashing or hand sinks. It supports proper cleaning of the facility. Exact requirements vary, so confirm whether your operation needs a dedicated mop/service sink in the requirements for your area.
Generally yes. Health codes typically require a dedicated utility, mop or service sink for filling mop buckets and disposing of mop water and cleaning wastewater, so it never goes into food or handwashing sinks. Some very small operations may use an approved alternative like a floor sink with a curb. Because rules and acceptable alternatives vary, confirm your requirement with your local health department during plan review.
A mop sink, also called a service or curb sink, is a low floor-mounted or curbed basin used to fill mop buckets and dump mop water and other cleaning wastewater. Its low, splash-guarded design lets staff empty heavy buckets safely. It keeps dirty water out of food-prep, warewashing and handwashing sinks. Most have a threaded faucet high enough to fit a bucket and a floor-level drain.
Mop water should be dumped only in a designated mop, service or curb sink (or an approved floor drain), never in a food-prep, warewashing or handwashing sink, since it is contaminated wastewater. Emptying mop buckets into food-contact sinks is a health violation and a contamination risk. If you lack a mop sink, that is a gap to fix. Confirm the approved disposal point for your facility with your health department.
A service sink (or utility/mop/curb sink) is a basin dedicated to janitorial tasks: filling and emptying mop buckets, rinsing cleaning tools and disposing of cleaning wastewater. Keeping these tasks out of food-prep, warewashing and handwashing sinks prevents cross-contamination. It is usually a durable, low-set floor or wall basin with a high faucet. Many health codes require one or an approved equivalent in a commercial kitchen.
Like other plumbing fixtures, a mop or service sink's drain generally must be properly trapped and vented to work correctly and to keep sewer gases out, per your local plumbing code. Backflow protection on the supply is also typical. The exact venting and trap requirements depend on the installation and code, so have a licensed plumber design it and confirm the specifics with your plumbing inspector.
Basic molded floor-mount mop sinks often run about $150 to $500, with stainless or larger service sinks higher, and faucet, mop hanger and hose bringing up the total. Installation, including drain, trap, vent and backflow protection, can cost as much as or more than the fixture. Prices vary by material and size. Budget for the plumbing, not just the basin itself, when planning a mop sink.
A floor sink is a small, recessed drain basin set into the floor that receives indirect waste from equipment such as dish machines, ice machines and three-compartment sinks through an air gap. It is not the same as a mop sink, though both live near the floor. Floor sinks capture drainage while preventing back-siphonage. Requirements and placement are set by your plumbing code and equipment layout.
A utility sink is a general-purpose deep basin for cleaning tasks that do not belong in food or handwashing sinks, such as filling buckets, rinsing tools and, in some setups, doubling as a mop/service sink. In a commercial kitchen a dedicated mop or service sink usually handles janitorial wastewater. Whether a utility sink satisfies your mop-sink requirement depends on the requirements for your area.
A prep sink is a dedicated sink for food preparation, washing produce, thawing under running water, and portioning, kept separate from warewashing, handwashing and utility sinks to avoid cross-contamination. It often has one or two bowls and may include a drainboard. Whether you are required to have one depends on your menu and local code, especially if you handle fresh produce or raw proteins. Confirm your requirement locally.
It depends on your menu and jurisdiction. Operations that wash produce, thaw foods under running water, or do significant raw prep are often required to have a dedicated food-prep sink separate from warewashing and handwashing sinks. Beverage-only or very limited-menu concepts may not. Because it hinges on what you actually prepare and local rules, confirm your requirement with the requirements for your area or your health department.
No. A food-prep sink is for food-related tasks only and cannot be used for handwashing, which requires a dedicated hand sink. Washing hands in a prep sink risks contaminating food and food-contact surfaces and is a code violation. Likewise, do not use the prep sink for warewashing or mop water. Each sink type has a single approved purpose; provide a separate, accessible hand sink for staff.
Most kitchens need at least three sink types serving different purposes: a three-compartment (warewashing) sink, one or more dedicated handwashing sinks, and a mop/service sink, plus a food-prep sink depending on the menu. That is why counting bowls is misleading; it is about function. The exact count and placement depend on your layout and local code. See the required-equipment guide and confirm with your health department.
A bar sink (often a compact three- or four-compartment underbar unit) is built for washing glassware and mixing drinks behind the bar, sized small to fit tight spaces. A prep sink is a food-preparation basin for washing produce and prepping food in the kitchen. They serve different functions and locations and are not interchangeable, and neither replaces a dedicated handwashing sink. Our commercial sink guide compares the types.
Clean and sanitize the basin, faucet handles and surrounding surfaces regularly, since a hand sink is touched constantly, and keep the drain clear. Refill soap and paper towels before they run out, and make sure hot water still reaches at least 100°F. Never let it become a dumping spot for food, dishes or mop water. A clean, fully stocked, unobstructed hand sink is what inspectors expect to see.
A basic wall-mounted commercial hand sink often runs about $150 to $500, with hands-free (knee, foot or sensor) models and stainless units costing more. Faucet, soap and towel dispensers and installation add to the total, and plumbing for supply and drainage can exceed the fixture cost. Prices vary by material and features. Our commercial sink guide covers specifying hand and other kitchen sinks.
The FDA Food Code sets a minimum of 100°F (38°C) at the handwashing sink, and it should reach that temperature promptly. This warm-water demand, along with your warewashing sink and dish machine, drives water heater sizing; undersized heating leaves hand sinks running cold. Some jurisdictions specify a slightly different minimum or maximum for scald safety, so confirm the exact figure with your local health department.
Most codes require the hand sink to deliver tempered water through a combination or mixing faucet so a single stream comes out warm (at least 100°F), rather than separate scalding-hot and cold taps. Hands-free activation (wrist, knee, foot or sensor) is required in some jurisdictions to reduce recontamination. Confirm the specific faucet and activation requirements with your local plumbing and health codes before purchasing.
Clear the strainer and check the trap first, since soap scum and debris are common causes. A plunger or small hand auger usually clears a soft clog. Avoid harsh chemical drain cleaners in commercial lines. Because a hand sink must stay available for handwashing at all times, a persistent clog is worth a prompt plumber call rather than leaving the only nearby hand sink out of service.
Mop and service sink drains are commonly 3 inches, though sizes vary by fixture and code, and the trap and vent must be sized to match. Correct drain sizing keeps heavy, debris-laden mop water flowing without clogging. Because drain, trap and vent requirements are set by your local plumbing code and the specific fixture, confirm the correct size with a licensed plumber and your plumbing inspector.
Some prep sinks include a disposal for food scraps, but whether it is allowed, and whether the discharge must route through a grease interceptor, depends on your local plumbing and sewer rules. Many municipalities restrict or prohibit commercial disposals or require solids interceptors. Because rules vary and affect your drainage design, see our commercial sink guide and confirm with your local plumbing authority before specifying a disposal.
Almost always more than two. A typical kitchen needs a three-compartment warewashing sink, at least one dedicated handwashing sink, and a mop/service sink, plus a prep sink depending on the menu, each serving a distinct, non-interchangeable purpose. Two sinks rarely satisfies code because handwashing, warewashing and janitorial functions cannot share a basin. The exact set is confirmed at plan review; see the required-equipment guide.
Molded floor-mount mop sinks are commonly around 24 by 24 inches with a 10- to 12-inch-deep basin, sized to hold a mop bucket, while wall-mounted service sinks and larger stainless utility sinks vary. The key is fitting your mop bucket for easy filling and dumping without splashing. Choose a size and curb height that let staff empty heavy buckets safely, and confirm any code minimums locally.
A hand sink is used only for washing hands and must be stocked with soap, towels and warm water and kept accessible. A prep sink is for food tasks like washing produce and thawing. They are never interchangeable, since handwashing in a food sink, or prepping food in a hand sink, causes cross-contamination and violates code. Both are separate again from warewashing and mop sinks, each with its own required purpose.