Finding it tough to keep your commercial kitchen up-to-date with FOG rules? You're in good company! This post will tell you what equipment could lead to FOG and give you recommended grease management solutions. It is critical that restaurant owners, professional chefs, and catering business managers all stay compliant, observing regulations and avoiding potential fines or prosecution. Keep reading to find out more!

What is FOG?

FOG, which stands for Fats, Oils and Grease, is a by product found in commercial kitchen operations. It's created from cooking that uses or produces fats, oils and greasy substances. When FOG cools down or is not disposed of properly, it becomes solid and can clog pipes and sewers when it is disposed of down sinks and drains.

FOG is produced by a surprising number of kitchen equipment. Deep fryers, grills, ranges, combi ovens and rotisserie ovens are some examples. FOG can block drainage systems which can cause back-ups of waste water that are damaging not only to structural pipework but can also have significant environmental repercussions.

Fats, oils and grease as a result of cooking and food production can also be released into mains sewer systems through equipment channels that aren't as apparently obvious. Other sources of FOG can be dishwashers used for cleaning greasy utensils, sinks used to rinse and wash cookware, food processors for processing oily ingredients or even floor drains.

Commercial equipment that may produce FOG

  1. Commercial Fryers:
    • Used for frying food items, commercial fryers immerse food in hot oil, causing fats and oils from the food to mix with the frying oil.
    • FOG Production Level: High.
  2. Griddles and Grills:
    • Used to cook various food items directly on their surfaces, griddles and grills extract fats and oils from the food during the cooking process.
    • FOG Production Level: Medium to High, depending on the type and quantity of food being cooked.
  3. Combi Ovens:
    • Capable of multiple cooking methods, combi ovens can produce FOG when used for roasting or baking fatty foods.
    • FOG Production Level: High, but can vary based on usage.
  4. Rotisseries:
    • Used for cooking large cuts of meat, rotisseries rotate the meat allowing fats to drip and accumulate.
    • FOG Production Level: High, particularly when cooking fatty meats.
  5. Braising/ Boiling/ Bratt Pans and Tilting Skillets:
    • Used to fry, sauté, braise, and simmer food, these pans and skillets heat food and cause the fats and oils within to liquefy and accumulate.
    • FOG Production Level: Medium - High.
  6. Wok Ranges and Stir Fry Stations:
    • Used for stir-frying, these stations heat large quantities of oil and food, causing fats to melt and mix with the oil.
    • FOG Production Level: High.
  7. Pasta Cookers/Potato Peelers:
    • Used for boiling pasta/peeling large quantities of potatoes which release starch. While not exactly FOG, it can potentially cause issues within the drainage system.
    • FOG Production Level: FOG production is 0; however, starch could potentially be a problem.
  8. Dishwashers and Pot/Utensil Washers:
    • While not a direct source of FOG, dishwashers can contribute to FOG accumulation in drains and grease traps due to washing dishes and cookware that have fats, oils, and grease on them.
    • FOG Production Level: FOG production is 0; however, the output of FOG into wastewater systems is Medium - High.
  9. Pot Wash Sinks:
    • Used to rinse and wash used dinnerware, cutlery and cookware before entering dishwashers/pot and utensil washers for in-depth cleaning.
    • FOG Production Level: FOG production is 0; however, FOG output into wastewater systems is High.
  10. Food Prep Sinks:
    • Used to rinse/wash ingredients before preparation.
    • FOG Production Level: FOG production is 0; FOG output into wastewater systems is Low.
  11. Floor Drains:
    • Spaced around kitchen floors to ensure any spillages or floor cleaning can be easily dealt with without any safety hazards.
    • FOG Production Level: FOG production is 0; FOG output into wastewater systems depends on the size of the kitchen and level of operations.  

By understanding the potential FOG production levels or contributing levels of these pieces of commercial kitchen equipment, operators can implement appropriate measures to manage and mitigate the risks associated with FOG accumulation, ensuring a safer and more efficient kitchen operation.

Not all FOG producing or FOG distributing equipment can be protected by strict grease management practices. Some, that are plumbed into the main drainage system, will need additional measures to prevent FOG from entering the sewers and causing blockages.

Recommended grease management solutions for kitchen equipment type

Stringent grease management practices are critical in any commercial kitchen, especially when it comes to equipment. Practices and procedures, no matter how rigorous, are not sufficient on their own and so it's vital to have alternative effective solutions where possible to avoid FOG (Fats, Oils, and Grease) accumulation. Read more about Why Great Grease Management Practices Don't Eliminate the Need for a Grease Trap.

FOG producing equipment such as griddles and fryers need regular cleaning and maintenance. This equipment, on its own, is not connected to a mains outlet and so wouldn't require a dedicated grease trap. However, strict grease management practices and correct disposal of grease are imperative as well as a suitable grease management solution for sinks where equipment is rinsed.

For combi ovens, wok ranges, self-cleaning rotisserie ovens and bratt pans that have a mains water connection, a grease trap is essential to prevent FOG from entering sewer systems. Correctly sized passive manual grease traps or automatic grease traps or GRU's are recommended.

In the case of pasta cookers and potato peelers that produce starch and that have a connection to the main water supply, bio-dosing systems should be sufficient. However, always check with your local water authority for verification.

When it comes to dishwashers, pot and utensil washers and any sinks, a grease trap should always be correctly installed. A manual passive grease trap or automatic grease trap that is correctly sized for the total flow rate is recommended.


These scenarios give examples of the type of grease management solution on a unit by unit basis. However, it isn't a workable or viable solution for the majority of businesses to have individual solutions per equipment. There are a couple of solutions to address this issue.

Firstly, you could calculate the total flow rate of water through equipment for the entire kitchen and then install one , two or more grease traps depending on the size and flow rate of the kitchen, either passive manual stainless steel grease traps or automatic grease traps (GRU's), at strategic points around the kitchen, at the last point before waste water enters the main sewer system. Where equipment has a very high output of FOG, water authorities may require a dedicated grease trap specifically for that unit. Find out more about How Do I Know If I Should Get a Manual or Automatic Grease Trap?

Secondly, you could opt for a large external or underground grease interceptor, or outdoor epoxy grease traps, through which all the drainage and kitchen waste water is connected and flows through. What is the Best Material for a Grease Trap?

Bio-dosing systems such as GreasePak, can be used in conjunction with other grease management solutions or as stated above, in relation to equipment that produces potentially harmful substances such as starch. Bio-dosers release measured quantities of solutions containing bacteria into grease traps or directly into pipes or drains to break down FOG. These solutions can reduce the frequency of cleaning required for grease traps.


Regardless of the grease trap option that is best for your business, staff education plays a huge role in ensuring the effectiveness of grease management solutions for all equipment types. Training employees on proper maintenance and emphasising the importance of grease management will result in better overall kitchen hygiene and help to prevent blockages and, potentially, costly fines.

Don't let clogged drains or costly repairs worry you. By understanding appropriate grease management solutions, you can have a clean environment and minimise potential risks. Act now to enjoy hassle-free cooking processes in your commercial kitchen!