The FDA implemented new guidelines for labeling packaged foods as gluten-free. The gluten-free claim can only be made on foods containing less than 20-parts-per million of gluten.

Those products are crucial to those who have celiac disease. The disease affects 1% of the American population, but is one of the world’s most prevalent genetic auto-immune conditions. It’s a condition that damages the lining of the small intestine and prevents it from absorbing parts of food that are important for staying healthy. Gluten, a type of protein often found in wheat, barley, rye, and possibly oats, can trigger that symptom.
The new regulation makes sure companies can’t label products "gluten-free" if they are cross-contaminated from other products in the same facility. Food packaging that fails to meet the requirements "will be subject to regulatory action."
The new regulations don’t apply to restaurants, but the Food and Drug Administration is encouraging them to comply
Source-Medindia