FDA: Gluten free is now official

Starting [August 5, 2014], gluten-free has a legal definition.

…A gluten-free claim means the food contains less than 20 parts per million of gluten, the protein found in grains such as wheat, barley and rye, an FDA spokeswoman said, adding that this is consistent with the threshold followed by other countries and international bodies that set food safety standards.

Source: FDA Regulates Meaning of ‘Gluten-Free’

Similarly, “fat free” means there is less than 0.5 g of fat per labeled serving.  There can and will be trace amounts.