A representative from a company selling a genetically engineered meat alternative faced tough questions at the Sustainable Foods Summit held in San Francisco at the end of January.

Nick Halla, chief strategy officer of Impossible Foods, gave a presentation about his company’s Impossible Burger as a sustainable solution to the problems of industrial meat production. He claimed their lab-created burger uses about 74 percent less water, generates about 87 percent fewer greenhouse gases and requires around 95 percent less land than conventional ground beef from cows. Halla said the Impossible Burger is seeing rapid acceptance in the marketplace, sold in many restaurants and “better burger” chains.

Doubts about Impossible Burger’s safety

But Halla’s PowerPoint slides didn’t mention that the Impossible Burger’s key ingredient is a genetically engineered protein called soy leghemoglobin or “heme.” The presentation also didn’t mention that the U.S. Food and Drug Administration told Impossible Foods that the company hadn’t demonstrated the safety of heme after it applied to the FDA seeking GRAS (generally recognized as safe) status. Despite FDA’s concerns, Impossible Foods sold its GMO-derived burger for public consumption anyway.