“This determination requires food manufacturers to submit a food additive petition for safe uses of phos and to phase out the uses of phos that are not included in a food additive petition by June 2018,” explained Roger Lowe, executive vice-president, strategic communications, G.M.A.

Phos have been helpful in creating layers expected in laminated pastries.

Petitions can be filed with the F.D.A. for the use of phos in small quantities as a food additive: any substance that’s intended use results in or may reasonably be expected to result, directly or indirectly, in its becoming a component or otherwise affecting the characteristics of food. This legal definition requires those who wish to use food additives to gain premarket approval from the F.D.A., and it excludes food additives that do retain GRAS status.

“When F.D.A. made its tentative determination on GRAS status for phos in late 2013, it encouraged the food industry to submit a food additive petition for specific pho uses and use levels so that the agency could confirm that there is a ‘reasonable certainty of no harm’ associated with these specific uses,” Mr. Lowe said.

The G.M.A. submitted such a petition, arguing that some uses of phos are important for the production of safe food products, including use as color and flavor carriers, pan release agents and other processing aids. If the F.D.A. finds that the G.M.A.’s petition proves these low levels of usage detailed in the petition pose no threat to consumers’ health, then phos will be approved for use in those specific capacities. And it will apply to any manufacturer wanting to use phos in that way.

“Once a petition is reviewed and a regulation is issued, then as long as the company uses phos in accordance with the regulation, any company can use it,” Dr. Naum said. “These petitions and regulations aren’t unique per company.”

The review process, however, takes as long as is necessary to vet the research. An initial review confirms the F.D.A. has everything required before the petition is formally filed. Then the filing is announced in the Federal Register, and the F.D.A. can begin reviewing.

“What happens sometimes, depending on the information, is there may be a lot of back and forth where we recognize that there might be some additional information we need to be able to make a determination or complete our evaluation,” Dr. Naum said. “Depending on how long it takes for the company or organization to submit that information to us will determine how long the review takes.”

Neither the F.D.A. nor the G.M.A. would comment on the current petition submitted by the G.M.A. as it is currently under review.

“I would be surprised if people availed themselves of that option because it’s something that the industry has decided is not a positive thing to have on their labels,” Ms. Culhane said of the processing aid petitions.