Generally recognized as safe

Generally Recognized as Safe (GRAS) is a United States of America Food and Drug Administration (FDA) designation that a chemical or substance added to food is considered safe by experts, and so is exempted from the usual Federal Food, Drug, and Cosmetic Act (FFDCA) food additive tolerance requirements.

GRAS exemptions are granted for substances that are generally recognized, among experts qualified by scientific training and experience to evaluate their safety, as having been adequately shown through scientific procedures (or, in the case of a substance used in food prior to January 1, 1958, through either scientific procedures or through experience based on common use in food) to be safe under the conditions of their intended use.

The substance must be shown to be "generally recognized" as safe under the conditions of its intended use. The proponent of the exemption has the burden of proving that the use of the substance is "generally recognized" as safe. To establish such recognition, the proponent must show that there is a consensus of expert opinion regarding the safety of the use of the substance. However, the existence of a severe conflict among experts regarding the safety of a substance precludes a finding of general recognition.

When a use of a substance does not qualify for the GRAS exemption that use of the substance is subject to the premarket approval mandated by the FFDCA. In such circumstances, the FDA can take enforcement action to stop distribution of the food substance and foods containing it on the grounds that such foods are or contain an unlawful food additive. 

A GRAS designation typically exists in one of three forms:
 * 1) Self-affirmed. The manufacturer of this chemical or substance had performed all necessary research, including the formation of an expert panel to review safety concerns, and is prepared to use these findings to defend its product's GRAS status.
 * 2) FDA-pending. The manufacturer has performed all the aforementioned due diligence, and submitted to the Food & Drug Administration for GRAS approval.
 * 3) No comment. The FDA has reviewed a product's GRAS claim and responded with "no comment"; i.e., no further challenges on the product's GRAS status.