Criminal conspiracy to steal used cooking oil shows how trash can become treasure

Federal prosecutors recently described an interstate criminal enterprise with all the trappings of organized crime: clandestine warehouses, money laundering and stolen goods transported across state lines. The mid-September 2026 announcement stated that 19 defendants faced charges; two had just pleaded guilty, while the remainder are slated for trial in April 2027.

The stolen material was not drugs, guns or jewels. It was leftover cooking oil.

According to prosecutors, members of the group drove trucks to restaurants in 10 states, siphoned used cooking oil from collection tanks and transported it to depots for resale. The alleged motive was simple: Used cooking oil has value. It can be refined into biodiesel. A viscous fluid that the food industry formerly considered garbage has become valuable enough to spur a large-scale criminal operation.

This oil-theft scheme points to a larger lesson. People tend to think of waste as trash, sewage, slag, manure and other seemingly useless or disgusting substances. But historians, anthropologists and geographers increasingly recognize that “waste” is a category defined by humans. Technologies, markets, laws and cultural assumptions all determine what is discarded, what is kept and why. Waste describes a material’s status, not necessarily its substance.

As an environmental historian who studies how societies transform nature into commodities, I am also interested in the other side of the process: how materials classified as waste can be converted back into things of value.

Nothing in nature is wasted. A fallen tree becomes food for fungi and insects, while its nutrients eventually return to the soil or the atmosphere; animal feces feed creatures ranging from bacteria to dung beetles. In ecosystems, one organism’s leftovers routinely provide for another’s needs.

Human societies, by contrast, frequently remove unwanted materials from circulation. The question of where those materials go – and whether they remain useless – is part of the history of waste.

Scholars in a growing field called “discard studies” examine this process. Sociologist Zsuzsa Gille describes different “waste regimes,” the ideologies and concepts that people use to determine what’s valuable and what’s disposable.

Calling something “waste” does not mean that its physical properties are irrelevant. A toxic chemical can poison a river. But whether people dump, recycle, store or reprocess that substance – and whether they classify it as waste at all – depends on human decisions.

Industrialization did not invent waste, but it dramatically changed its scale and geography. During the 19th century, factories and processing plants brought raw materials together in unprecedented quantities and consolidated their unwanted residues in the same sites. That concentration created disposal problems. It also generated new incentives to find profitable uses for what industry left behind.

Consider whey. Cheesemaking produces extraordinary quantities of the watery liquid left behind after milk coagulates. For much of the 19th and 20th centuries, cheese manufacturers disposed of the whey as an unwanted residue. Dumped into waterways, whey encourages bacterial and algal growth that depletes oxygen and can damage aquatic ecosystems.

Beginning in the 1970s, ultrafiltration allowed producers to separate and concentrate whey proteins. A troublesome liquid became whey powder, lactose and protein concentrates, all of which can be used in baked goods, infant formula, animal feed and protein supplements.

Coal-fired power plants provide another example. Coal combustion leaves behind fly ash, a fine mineral residue that companies dumped in landfills or stored in enormous ash ponds. In the 1930s, engineers discovered that fly ash could replace a portion of the Portland cement normally used to make concrete. This new application diverted waste from disposal while reducing demand for energy-intensive cement production.

There is much to admire in these transformations. Repurposing leftover materials can reduce pollution, conserve resources and lower the amount of material dumped into landfills or waterways. The ecological ideal of “cradle-to-cradle” design rests on precisely this insight. Just as in nature, the output of one process can become the input of another.

Yet finding a market for waste does not necessarily solve the problems that the waste created in the first place.

Cottonseed provides a striking example. During the 19th century, American cotton growers regarded seeds as an enormous nuisance. Cotton ginning generated mountains of seeds, and many operators simply dumped these unwanted byproducts into nearby waterways, where they accumulated in foul-smelling, decaying masses. The problem became serious enough that Southern states began restricting cottonseed dumping in the mid-1800s.

Then manufacturers learned to crush cottonseed for oil to be used in soap, cooking and as a substitute for animal fats. They turned the remaining material into fertilizer and animal feed. By the late 19th century, something previously seen as garbage had become the foundation of a major new industry.

Cottonseed boosters proclaimed a transformation of waste into wealth. In 1911, entrepreneur Luther A. Ransom celebrated cottonseed’s ability to produce “edible oil without olives; medicinal oil without codfish; butter without cows; ice cream without cream; lard without hogs.”

But manufacturers also sometimes diluted more expensive olive oil and lard with cheap cottonseed oil. Beginning in the early 20th century, the chemical process of hydrogenation allowed producers to turn liquid vegetable oils into semisolid fats suitable for shortening and margarine. Partial hydrogenation also produced artificial trans fats, which were eventually linked to increased cardiovascular risk.

In 1911, Procter & Gamble introduced Crisco, a vegetable shortening made from hydrogenated cottonseed oil. Consumers could use Crisco in place of lard or butter for frying and baking. Decades before the heart disease risks of partially hydrogenated oils were understood, the company marketed Crisco as an expression of purity and modern food technology.

The problem was not that cottonseed oil was secretly “waste.” It was that industrial processing widened the gap between what manufacturers knew about a product’s origins and composition and what consumers understood about those attributes. Turning a discarded material into a valuable commodity solved one problem while creating another. Consumers increasingly had to trust manufacturers to tell them what they were buying.

Sewage sludge presents an even sharper dilemma. Wastewater treatment produces nutrient-rich dregs that can be processed into biosolids and spread on farmland, returning nitrogen and phosphorus to soils. But wastewater also carries contaminants. Researchers have found a group of chemicals known as PFAS – persistent and potentially harmful “forever chemicals” more formally known as perfluoroalkyl and polyfluoroalkyl substances – in some sewage sludge. Their presence raises concerns that a system designed to salvage nutrients can also recycle pollutants.

Used cooking oil seems like an almost perfect example of recycling. Refiners turn oil discarded by restaurants and other waste fats into transportation fuel, extracting additional value from crops already grown and oils that have already served their original purpose.

But government policies regarding clean fuel have made some products that carry the label “waste” economically valuable. Because fuels made from used cooking oil can qualify for financial incentives unavailable to some virgin oils, demand has occasionally pushed prices for used oils above those of newly produced vegetable oils.

That creates an unusual temptation: mix cheaper virgin oil into used cooking oil – or simply pass virgin oil off as waste. Researchers and regulators have raised concerns about fraud in the rapidly growing international markets for used cooking oil.

Generating new uses for discarded matter does not eliminate the politics of waste. It can intensify them. Who decides whether something counts as waste? Who profits when something once considered disposable becomes a valuable commodity? And who can verify what a supposedly recycled material actually contains?

Stolen restaurant cooking oil offers an unexpectedly useful way to think about this problem. The fats and oils inside the tank did not physically change when thieves began siphoning them out. What changed was their status and their value.

That transformation captures one of the paradoxes at the heart of the history of waste. Matter is never worthless, but assigning it a price does not necessarily make its environmental and social costs disappear.

Sometimes finding a use for waste solves a disposal problem. Sometimes it merely gives the problem a new price.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Edward D. Melillo, Amherst College

Edward D. Melillo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.