FDA determines that PHOs (trans fat) is no longer 'generally recognized as safe' - Ban coming soon 11/08/2013 - 00:00 More than decade ago, a sea change began in the American diet, with consumers starting to avoid foods with trans fat and companies responding byreducing the amount of trans fat in their products.This evolution began when FDA first proposed in 1999 that manufacturers be required to declare the amount of trans fat on Nutrition Facts labels because of public health concerns. That requirement became effective in 2006.However, there are still many processed foods made with partially hydrogenated oils (PHOs), the major dietary source of trans fat in processed food. Trans fat has been linked to an increased risk of coronary heart disease, in which plaque builds up inside the arteries and may cause a heart attack.