Without hot water, a commercial kitchen cannot operate. From both a sanitation and legal standpoint, hot water is necessary to help fight germs, keep food safe for consumption and ensure that sanitary codes are being met.

Basically, hot-water temperatures in a commercial establishment must be hot enough to kill bacteria and other germs on glasses, dishes and silverware, as well as to stop the spread of germs. This is why most departments of health require employees to wash their hands after using the bathroom or preparing food.

At the same time, hand-washing-sink water temperatures cannot be too hot, because that can scald the skin of those it comes into contact with. Also, water any hotter than necessary to kill germs isn’t more effective.

The idea is to make sure water temperature strikes a happy balance.

Temperature Requirements

First, some discussion about the legal requirements of restaurant hot-water temperatures. While the Occupational Health and Safety Administration (OSHA) doesn’t specify restaurant hot-water requirements, many states have different regulations. You’ll have to check with your state for specific requirements.

The U.S. Food and Drug Administration (FDA) specifies a restaurant hot-water requirement for hand-washing to be at least 110 degrees Fahrenheit; this is a mandatory requirement throughout the establishment, including restrooms.

The restaurant hot-water requirements for dish-washing vary by state, but most health departments require a water temperature of anywhere from 140 to 165 degrees Fahrenheit. For sanitizing dishes, health department water temperature requirements can range from 165 to 180 degrees Fahrenheit.

Commercial kitchens must have a source of potable water drawn from a public water supply or county-approved water source, such as a well that is regularly tested for purity.

Water Pressure Requirements

Water temperature is another requirement necessary for providing proper sanitation in commercial kitchens. If the proper flow is not maintained problems can be encountered. While a 110-degree temperature is required for hand-washing, the length of time that the water must contact hands is also critical.

Most experts recommend that employees in commercial kitchens wash their hands for a minimum of 30 seconds to properly rid their hands of germs. If that minimum cannot be maintained due to low water pressure, or if low pressure leads to frustration that causes employees to not maintain that length of time while washing their hands it could lead to the spread of germs.

Water Capacity and Availability

Another factor related to restaurant hot-water temperatures that is crucial in commercial kitchens is that of capacity. While it may be possible to heat water to the 110-degree temperature needed for proper hand-washing, maintaining it over a long period of time – notably, the amount of time the establishment is open – is a must.

A water tank without enough capacity will run out before long, and then it will take a period of time to heat an additional supply of water to the proper temperature. That will take time, and is not acceptable as it may leave your employees or patrons with water temperatures below the minimum temperature for a time.

Therefore, it is critical that you have a water tank that has enough capacity to hold enough heated water, not only for hand-washing but also at temperatures suitable for dishwashing and sanitation.

You do not want to risk the health of your patrons – and the health and reputation of your business – so check with a plumber or your maintenance professional to make sure your water tank is sufficiently large and has a sufficient heating element to maintain proper hand-washing-sink water temperature.

Three-Sink Requirements

Maintaining proper water temperatures means nothing if proper techniques to keep the spread of germs in check are not followed.

Your dish-washing sink may be kept at the proper temperature of 150 degrees Fahrenheit, for instance, but if your employees are constantly dipping dishes into water that has been exposed to germs all day, someone is going to get sick, as bacteria thrive in hot water.

For that reason, many health departments require commercial kitchens, if they don’t have a mechanical dishwasher, to employ a three-compartment sink system to ensure that dishes, glassware and silverware are not only properly cleaned but disinfected and not exposed to germs.

  • Sink #1: This sink is reserved for washing, which is usually done with water temperatures of at least 140 degrees Fahrenheit. It is not enough to only use one sink for cleaning and sanitizing as washing soil and food off dishes only makes them appear clean but will not remove germs. This sink should be filled with a cleaning solution of water and soap or a degreasing agent. Dish cloths or scrub brushes may be used, but remember that they will become dirty and need to be cleaned and sanitized at regular intervals. 
  • Sink #2: This sink is used for rinsing only, and the water temperature should be at a minimum of 120 degrees Fahrenheit. The middle sink will be used for removing cleaning agents and will get dirty over time, so it will need to be replaced on a regular basis.
  • Sink #3: The third sink in the system may be the most important, as it ensures that all bacteria is removed and killed. You may use an EPA-approved water sanitizer, which usually comes in tablets or powder form. Local health codes differ as to how long the dishes need to soak and at what temperature, so be sure to inquire.

You could also use the hot water sanitization method, which as the name suggests means that you expose dishes to the proper temperature – usually over 165 degrees Fahrenheit – for a certain period of time.

It’s difficult to do this on your own, and there are sink heaters on the market designed to circulate water at a preset temperature.

Dish Drying and Handwashing Requirements

The way that dishes are dried after washing is critical, because it doesn’t matter what the handwashing sink water temperature is if you spread germs after sanitizing by using an improper drying method.

The FDA requires that all dishes be air-dried after sanitizing.

Towels should never be used for drying dishes after washing, because it’s impossible to know whether the towel is free of germs and towels can spread pathogens. Use a drying rack and drip dry your dishes.

There are also commercial drainage shelves available on the market for establishments with a large volume of dishes to dry.

For this reason it’s also not recommended to use towels to wash tables and other preparation surfaces. This practice can spread germs around.

Most experts recommend using a commercial sanitizer spray and letting it sit for a period of time before wiping it up with paper towels.

The same thing goes for hand-washing. Your employees may wash their hands for 30 seconds with water at the proper temperature of 110 degrees Fahrenheit, but if they then go to dry them with a germ-ridden towel they will only re-contaminate their hands. It’s better to air-dry or use disposable hand towels – or use hand sanitizer with at least 60% alcohol if water and soap is not available.