The Food and Drug Administration has issued a final rule defining gluten-free for voluntary food and beverage labeling. In order to use the term on its label, a food must meet all of the requirements of the definition, including that the food must contain less than 20 parts per million of gluten, according to the agency. The rule also requires foods with the claims “no gluten,” “free of gluten,” and “without gluten” to meet the definition for “gluten-free.”

Food manufacturers will have a year after the rule is published to bring their labels into compliance with the new requirements, the F.D.A. said.

“We encourage the food industry to come into compliance with the new definition as soon as possible and help us make it as easy as possible for people with celiac disease to identify foods that meet the federal definition of ‘gluten-free’,” said Michael R. Taylor, the F.D.A.’s deputy commissioner for foods and veterinary medicine.

The F.D.A. was directed to issue the new regulation by the Food Allergen Labeling and Consumer Protection Act, which directed the F.D.A. to set guidelines for the use of the term gluten-free to help people with celiac disease maintain a gluten-free diet.

The final rule may be reviewed by following this link: Gluten-free definition.