I had thought any stevia-derived product would have to go through a formal FDA review process to be allowed in processed food products as a sweetener. This article is the first I've heard of this "self-determination of GRAS status" mechanism. GRAS means "Generally Recognized as Safe." If anyone knows more about this mechanism, please leave a comment.
Sweet Success for Stevia…finally :: News :: Natural and Nutritional Products Industry Center: "both companies used the same sling shot – a route called “self-determination of GRAS status.” This allows for the safety of the product to be decided by the views of experts, as long as there are significant published, peer-reviewed studies, available in the public domain. Wisdom Natural Brands and Cargill both hired teams of stevia experts (with FDA experience) to garner enough scientific support for each of their respective ingredients."