The Food and Drug Administration has begun the process of updating its current guidance on food ingredient safety assessment, commonly referred to as the Redbook, and is requesting comments from stakeholders regarding what changes or additions should be considered. The comment period initially was scheduled to conclude on Feb. 9, 2015, but at the request of several groups, including the Grocery Manufacturers Association, the American Beverage Association, the Snack Food Association and the American Frozen Food Institute, the F.D.A. extended the comment period until May 11.

The Redbook was first published in 1982 with the aim of providing guidance for industry and other stakeholders regarding information used by the F.D.A.’s Center for Food Science and Applied Nutrition (CSFAN) to evaluate the safety of food and color additives. The F.D.A. issued a revised draft of the document in 1993, and a subsequent revision, Redbook 2000, was issued in 2000 and updated in 2007.

In announcing its intent to revise the Redbook, the F.D.A. noted the Federal Food, Drug, and Cosmetic Act (the F.D.&.C. Act) requires the agency’s premarket approval of the use of a new food or color additive, including the new use of an approved additive. With regard to premarket approval, the safety of food additives and color additives used in foods must be established by evaluating the probable exposure to the substance and appropriate toxicological and other safety information. Approval of any new food additive or color additive used in foods depends, in part, upon the outcome of toxicity tests that are performed and evaluated before marketing.

The F.D.A. said the law also allows a manufacturer to market a substance for a use without premarket approval, if the substance is generally recognized as safe (GRAS). However, general recognition of safety based upon scientific procedures requires the same quantity and quality of evidence as is required to obtain food additive approval.

The Redbook establishes a system of tiered recommendations for additives in foods providing guidance on how much toxicity testing should be done depending on the level of estimated exposure to a substance in foods. It helps interested parties understand the F.D.A.’s expectations regarding determining the human exposure that will occur from the use of the ingredient in foods; determining which toxicity studies are appropriate; designing, conducting, and reporting the results of toxicity studies; and submitting the information to the F.D.A. as part of a safety assessment.

In its current undertaking, the agency specifically asked stakeholders to address the following issues in their comments:

1. Which parts of the Redbook should be updated, and how should the F.D.A. prioritize updates?

2. What should be the scope of the revised guidance, and what other guidance documents should be addressed or incorporated by reference?

3. What new assays, test methods, and endpoints would be useful for safety assessment? The F.D.A. asked stakeholders to give justifications for why and how their proposed new methods should be considered.

4. Key studies and considerations for study interpretation for each of the regulatory categories of food and cosmetic ingredients and chemical contaminants overseen by CSFAN.

5. Ways to make the guidance more useful to stakeholders.

6. Ways to make F.D.A. processes and criteria for safety assessment clearer to stakeholders.

The F.D.A. said specific examples, precise wording, or other clear and direct suggestions that address those issues would be particularly welcome.

Earlier this year, food industry groups requested the comment period be extended because of the scope of the issues the F.D.A. asked them to address.

“The Grocery Manufacturers Association and our members believe that the Redbook provides sound guidance for assessing food ingredients and look forward to working with the agency to enhance the Redbook, which has always been based on sound scientific principles,” said Emilia Lonardo, vice-president, consumer product safety and science policy for the G.M.A., in submitting the organization’s request for extending the comment period. “We applaud the agency for holding an open, transparent process in soliciting feedback. Because of the strength of the scientific approach and principles currently included in the Redbook, the opportunity to enhance the Redbook guidance through this transparent process will only benefit the public and private sector users of the Redbook.”

To submit comments electronically, visit and enter FDA-2014-N-1497 in the search box.

F.D.A. officials at a Dec. 9, 2014, advisory meeting with stakeholders said the Redbook revision would be a multi-year process and that a draft guidance was not expected to be issued until 2017.