WASHINGTON — The Department of Health and Human Services on Monday announced a new effort to catalog the many additives in the U.S. food supply, most of which entered with little oversight.

Companies looking to add a new substance to human or animal foods will need to notify the Food and Drug Administration, and provide details on how they deemed the additive “generally recognized as safe,” or GRAS. Manufacturers with GRAS substances already on the market would need to let the FDA know for the first time how the additive is used — information that would be made public in a database, HHS officials said.

While companies would not need to prove existing additives are safe, something advocates have long pushed for, their notices would give the FDA a clearer log of the many chemicals Americans ingest through their food every day. Agency staff and outside researchers could then begin to understand which ones are harmful to human health.

“This is a major step forward,” said Vani Hari, who is popularly known as the FoodBabe, and has been an adviser and ally in the administration’s food policy efforts. Hari, who has been a leading voice on social media about food additives, said the biggest benefit of the new policy would be “transparency, so we can know what we are eating.”