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FOG - Fats, Oil & Grease

What is FOG?
FOG is a pollution prevention term for fats, oils, and grease.  Restaurants and other food service establishments (FSEs) use FOG in their kitchens and improper management of FOG can lead to costly and unpleasant sewer blockages.

Types of FOG
Tallow or oil used in deep fryers is known as Yellow grease. It can be recycled and reused for a variety of purposes.  “Grease recyclers” (also known as “grease renderers") will come to your location and collect this byproduct for later use in products such as soaps, cosmetics, and biodiesel fuels.

On the other hand, any FOG that is in your plumbing system is known as Brown grease.  It needs to be removed so that it doesn’t clog the system.  “Brown grease haulers” come collect the brown grease from traps and interceptors and dispose of it properly.

Controlling FOG
Grease traps and grease interceptors help keep FOG out of your pipes, the city sewers, and the environment beyond, but they don’t clean themselves.  Grease traps are kept indoors and usually maintained by restaurant employees.  Grease interceptors are found outdoors and are typically cleaned by professional services.  Even when using an outside company to service the traps, it’s important to make sure the job is done correctly.

The biggest contributor to sewer back-ups is improper maintenance.  All the sinks, dishwashers, and floor drains are connected by the same piping, so neglecting just one element can still affect the whole system.  Traps and interceptors need to be cleaned regularly.  Floor drains should be cleaned at least once a year.  If you forget, the foul odors seeping through your floors and vents will surely remind you.

What you can do

  • Scrape and wipe down pots, pans, and work areas prior to washing.
  • Dispose of food waste directly into the compost bin or trash.
  • Do not pour waste oil directly into the drain, parking lot, or street.
  • Do not use emulsifiers or solvents other than dishwashing detergents.

For more information, including plumbing diagrams, grease interceptor details, and helpful posters for kitchen staff, please click on one of the links below:

English Brochure

Spanish Brochure

Fact Sheets:

Best Management Practices Posters: