Grease traps are designed to reduce the amount of oils, fats and greases (FOGs) that get into the main sewers. Grease can build up in the central sewer system and cause blockages, foul odours, and pest infestations. Grease traps were first used in Victorian times. They are simply boxes placed within the wastewater drain from kitchen sinks to the foul sewer system. Grease traps are only designed to collect kitchen wastewater and should not be used for wastewater from other sources like the toilet.
Grease traps can be made from various materials, including stainless steel, and mild steel. The most effective commercial models must be sized in accordance with IS EN 1825 (part 1 and 2). Regular food vendors and food shops usually require up to 200 litres, but this depends on the size of their kitchen and their FOG output.