(NAFB.com) – The Environmental Protection Agency is investigating the supply chain of at least two renewable fuel producers amid industry concerns that some may be using fraudulent feedstocks for biodiesel to secure government subsidies. Farm Policy News says the EPA declined to elaborate further or identify the companies being targeted because the investigations are ongoing. A flood of used cooking oil from China and elsewhere is causing several senators to question whether some of the shipments meant to supply the biofuel market may be fraudulent. Producing biodiesel from sustainable ingredients like cooking oil can earn refiners a number of state, federal, and environmental climate subsidies, including tradeable credits under the Renewable Fuel Standard. Investigators are trying to determine whether some supplies labeled as used cooking oil are cheaper and less sustainable virgin palm oil that’s been associated with deforestation and other environmental damage. Cooking oil imports reached three billion pounds in 2023.