Have you ever seen "food grade" and wondered what made those materials different?
While USDA, 3A, NSF, etc have different certifications and requirements to be met, in general there are things that help differentiate these materials for food contact.
In recent years, there has been a stronger and stronger push for "food grade" materials to be blue in color specifically. Why is this? Simplest reason is that blue material tends to contrast to foods quite well visually as very, very few foods are blue in color.
The benefit of this, is that blue materials are visually easier to see due to this contrast. As a result, foreign matter can be seem much easier by the naked eye and recalls can be issued for smaller overall distributions as the material can be found so much more rapidly. Compare this to natural (typically white) materials or other materials such as glass, and its fairly easy to imagine how these materials can slip detection that much more often, especially if they blend into the same color as the food they're blending in with.
Materials such as Tecaform UD Blue can provide excellent visual identification, optical sensors, metal detection or even x-ray detection. These materials make the chance of contamination getting out of a production area that much lower, resulting in a decline in recalls and a more favorable public perception.