Guidance for Industry: Gluten-Free Labelling of Foods; Small Entity Compliance Guide
The U.S. Food and Drug Administration has issued a guide for small food businesses to help them comply with new federal requirements for the voluntary use of the term "gluten free" on food products.
From August 5, 2014 all FDA-regulated food products labeled on or after that date, and bearing the gluten free claim, must comply with the rule's requirements.
For more info checkout the guide:
Guidance for Industry: Gluten-Free Labeling of Foods; Small Entity Compliance Guide