Products labeled as gluten-free must now meet federal standards.

WASHINGTON — Gluten-free product makers take note: Your products must now meet Food and Drug Administration rules.

In August 2013 the F.D.A. issued a final rule in the Federal Register defining what characteristics a food must have to be labeled “gluten-free. A year later, that rule is in effect, and any food product bearing a gluten-free claim labeled on or after Aug. 4, 2014, must meet the rule’s requirements.

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 F.D.A. The rule also requires foods with the claims “no gluten,” “free of gluten,” and “without gluten” to meet the definition for “gluten-free.”

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

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.

 “This standard ‘gluten-free’ definition will eliminate uncertainty about how food producers label their products,” said Felicia Billingslea, director of the F.D.A.’s division of food labeling and standards. “People with celiac disease can rest assured that foods labeled ‘gluten-free’ meet a clear standard established and enforced by F.D.A.”

Andrea Levario, executive director of the American Celiac Disease Alliance, was among those who applauded the new rule.

“We are extremely pleased that the U.S. gluten-free standard is officially in place,” Ms. Levario said. “Millions of Americans can now shop with confidence knowing that products with a ‘gluten-free’ label meet F.D.A.’s requirements. A uniform standard across food agencies will help consumers even more and we hope U.S.D.A. will move swiftly to implement the same standard.”