Commonly labeled “Brown Grease” in the industry, FOG is the collective term for the byproduct of animal fats (lard), vegetable oils and cooking grease from food preparation and dishwashing.


Butter, shortening, margarine, peanut butter, meat trimmings, uncooked poultry skin, cheeses, cream, milk, sour cream, ice cream

FOG fats


Vegetable oil, canola oil, olive oil, corn oil and other cooking oils



Gravy, mayonnaise, melted meat fat, bacon and sausage grease, boiled poultry skin

FOG grease

Why is FOG a problem?

In commercial food service establishments and industrial food processing facilities, FOG is generated in large quantities. Interceptors and wash down processes designed to capture FOG need to be constantly monitored and maintained to prevent FOG from passing into the sewer system.

Three-quarters of the sewage collection infrastructure in the United States is so clogged and damaged by brown grease that sewers are estimated to be functioning at only half their capacity. According to the Wall Street Journal (June 2001), local governments spend $25 billion a year to remediate grease-related issues — such as blockages, backups and overflows — to keep the sewers flowing.

cleaning a clogged grease trap

Even if FOG is properly collected, disposal is still a problem. Grease Trap Waste (GTW) is typically transported to and dumped/tipped at receiving stations located at a relatively few municipal sewage (POTW) or commercial wastewater treatment plants where haulers pay fees of $.05-$.30/gallon (US Data). Traditional methods of treatment and disposal include dewatering, drying, composting, land application, incineration, and landfilling.

All these methods are cost additive and do nothing to capture the rich energy resources that are available in the waste, nor do they reduce CO2 or methane emissions as FOG decomposes. Only Greasezilla® “Gets the Grease Out” and produces a marketable biofuel and headworks-ready effluent water easily handled by treatment plants.