Ensuring food safety in this "New Era of Smarter Food Safety" amid the increasing use of whole genome sequencing (WGS) provides many new challenges for food safety professionals, including how to apply new tools and interpret findings obtained with them in the context of laws and regulations that have been around for decades. While these challenges are many and multi-faceted, it is helpful to look back to the "old" era of food safety, to some of the foundational concepts and definitions established in the initial 1938 Food, Drug, and Cosmetic Act (21 U.S.C. §331); hereafter referred to as the "FD&C Act") that are still in full force today.