更多关于食品添加剂的法规，请详见美国FDA 21 CFR 第570部分关于食品添加剂的法规汇总。
§ 570.6 Opinion letters on food additive status.
（a） Over the years the Food and Drug Administration has given informal written opinions to inquirers as to the safety of articles intended for use as components of, or in contact with, food. Prior to the enactment of the Food Additives Amendment of 1958 （Pub. L. 85–929, Sept. 6, 1958）, these opinions were given pursuant to section 402（a）（1） of the Federal Food, Drug, and Cosmetic Act, which reads in part: “A food shall be deemed to be adulterated if it bears or contains any poisonous or deleterious substance which may render it injurious to health”。
（b） Since enactment of the Food Additives Amendment, the Food and Drug Administration has advised such inquirers that an article:
（1） Is a food additive within the meaning of section 201（s） of the act; or
（2） Is generally recognized as safe （GRAS）; or
（3） Has prior sanction or approval under that amendment; or
（4） Is not a food additive under the conditions of intended use.
（c） In the interest of the public health, such articles which have been considered in the past by the Food and Drug Administration to be safe under the provisions of section 402（a）（1）, or to be generally recognized as safe for their intended use, or to have prior sanction or approval, or not to be food additives under the conditions of intended use, must be reexamined in the light of current scientific information and current principles for evaluating the safety of food additives if their use is to be continued.
（d） Because of the time span involved, copies of many of the letters in which the Food and Drug Administration has expressed an informal opinion concerning the status of such articles may no longer be in the file of the Food and Drug Administration. In the absence of information concerning the names and uses made of all the articles referred to in such letters, their safety of use cannot be reexamined. For this reason all food additive status opinions of the kind described in paragraph （c） of this section given by the Food and Drug Administration are hereby revoked.
（e） The prior opinions of the kind described in paragraph （c） of this section will be replaced by qualified and current opinions if the recipient of each such letter forwards a copy of each to the Department of Health and Human Services, Food and Drug Administration, Center for Veterinary Medicine, Office of Surveillance and Compliance （HFV–200）, 7500 Standish Pl., Rockville, MD 20855, along with a copy of his letter of inquiry, on or before July 23, 1970.
（f） This section does not apply to food additive status opinion letters pertaining to articles that were considered by the Food and Drug Administration to be food additives nor to articles included in regulations in this Subchapter E if the articles are used in accordance with the requirements of such regulations.
[41 FR 38644, Sept. 10, 1976, as amended at 54 FR 18281, Apr. 28, 1989; 57 FR 6476, Feb. 25, 1992]