The U.S. Food and Drug Administration (FDA) has finalized its determination that partially hydrogenated oils (PHOs) are not "generally recognized as safe" (GRAS) for human consumption.

PHOs are the primary sourced of trans fat in processed foods, and now manufacturers will have three years to remove them from their products.

"The FDA's action on this major source of artificial trans fat demonstrates the agency's commitment to the heart health of all Americans," said FDA's Acting Commissioner Stephen Ostroff, M.D. "This action is expected to reduce coronary heart disease and prevent thousands of fatal heart attacks every year."

In 2013, the FDA made a tentative determination that PHOs could no longer be considered GRAS, and has now finalized that determination in an effort to improve Americans' health.

"Studies show that diet and nutrition play a key role in preventing chronic health problems, such as cardiovascular disease and today's action goes hand in hand with other FDA initiatives to improve the health of Americans, including updating the nutrition facts label," said Susan Mayne, director of the FDA's Center for Food Safety and Applied Nutrition. "This determination is based on extensive research into the effects of PHOs, as well as input from all stakeholders received during the public comment period."

Until the three-year compliance period is over, the FDA recommends consumers look for trans fat on nutrition labels. Foods are currently allowed to be labeled as having "0" grams  of trans fat if they contain less than 0.5 grams per serving; this includes PHOs.  Many companies are already working to remove PHOs from their products, and may complete their elimination before the three-year compliance date.