Neste's Green Fuel Empire Has a Dirty Supply Chain Problem

Neste has built its reputation on being the world's largest producer of sustainable aviation fuel, a company that turns yesterday's cooking grease into tomorrow's jet fuel. It has attracted billions in investment, secured long-term contracts with major airlines, and positioned itself at the center of the aviation industry's decarbonization story. But an investigation has exposed a significant crack in that foundation: Neste's top Malaysian supplier was accepting fresh palm oil and recording it as used cooking oil, with no apparent scrutiny from the Finnish company.

The distinction matters enormously. Used cooking oil, or UCO, is classified as a waste product. When it is processed into fuel, it qualifies for generous renewable energy subsidies and carbon credits under both European Union and U.S. regulatory frameworks. Fresh palm oil, by contrast, is a virgin agricultural commodity whose production is directly linked to deforestation, peatland destruction, and significant greenhouse gas emissions. Substituting one for the other is not a paperwork error. It is fraud that corrupts the entire carbon accounting system that sustainable aviation fuel is supposed to rely on.

The deeper problem here is structural. The sustainable fuel supply chain stretches across continents, from restaurant fryers in Southeast Asia to refineries in Rotterdam, and the verification mechanisms at each handoff are remarkably thin. Neste, like other biofuel producers, relies heavily on certification schemes and supplier declarations rather than direct physical auditing of feedstock origins. When a supplier in Malaysia can accept fresh palm oil and classify it as waste with no questions asked, it suggests that the incentive to cheat is strong and the cost of getting caught is low.

This is not the first time the used cooking oil supply chain has come under scrutiny. The EU's own anti-fraud office, OLAF, has previously flagged large-scale UCO fraud involving Chinese suppliers, and investigative outlets including Transport and Environment have documented how the market for certified waste oils has become a magnet for adulteration precisely because the financial rewards are so high. The EU's Renewable Energy Directive offers multiplied credits for waste-based fuels, which means a liter of fraudulently classified palm oil can generate two or three times the subsidy value of conventional biofuel. That premium creates a powerful pull toward manipulation at every node in the supply chain.

Neste's exposure is particularly significant because of its scale and its public positioning. The company processes millions of tonnes of feedstock annually and has repeatedly emphasized the rigor of its supply chain due diligence. If its top Malaysian supplier was operating this way, the question is not just whether Neste knew, but whether the audit systems it relies on are capable of detecting this kind of substitution at all.

The second-order consequences of this story reach well beyond one company's reputational damage. Sustainable aviation fuel is currently the centerpiece of the aviation industry's climate commitments. The International Air Transport Association has endorsed SAF as the primary mechanism for reaching net-zero by 2050, and regulators in both the EU and the U.S. have structured significant tax incentives around it. The Inflation Reduction Act's blender's tax credit, for instance, is directly tied to lifecycle carbon intensity calculations that assume feedstock integrity.

If the feedstock data feeding those calculations is fraudulent, then the carbon reductions being claimed, and the policy architecture built around them, are partially fictional. Airlines buying SAF certificates to offset their emissions may be purchasing credits that represent no real-world carbon benefit. Investors financing SAF infrastructure are doing so on the basis of a regulatory premium that could collapse if fraud becomes systemic and regulators are forced to tighten verification requirements sharply.

There is also a feedback loop worth watching. As demand for UCO rises, driven by policy mandates and subsidy structures, the price of genuine waste cooking oil increases, which in turn raises the financial incentive to substitute cheaper virgin oils. The policy designed to clean up aviation fuel may be inadvertently accelerating the fraud it depends on preventing.

Neste has not yet been found to have knowingly participated in fraud, and the company may well argue it was itself a victim of supplier deception. But the more uncomfortable question is whether the entire certified biofuel model, as currently designed, is robust enough to carry the weight that climate policy is placing on it. The answer, based on what this investigation suggests, is probably not yet.

Regulators who have been content to let certification bodies do the heavy lifting may soon find themselves having to choose between tightening the system in ways that dramatically reduce the available feedstock pool, or accepting that a meaningful share of green aviation fuel is not as green as advertised.