USDA meat stamp a Contaminant ?

Does anyone know have a good explanation of the meat stamp that can appear as a piece of foreign material in a grinding process? Please also differentiate between the stamp and another foreign material such as colored plastic, etc.

Info provided at the USDA website state that it is food grade and not harmful. 

Please assist, thanks.

It's very commonly seen in grinding operations, the stamp IS food grade and not considered foreign material. 

if it an issue to have the bit of colour in your grind, just trim the stamp out before grinding..voila problem solved. 

I'm thinking from your question, that you have a foreign material problem that your trying to solve, so it may be best to trim it out at your facility under you get everything else under control. If you are tempering frozen meat prior to grinding, and that's where the plastic is coming from, your tempering process may need reviewed and you might want to add an actual check for carton liner integrity when dumping the contents out. If the product isn't tempered enough, it will take a piece of bag with it because it's frozen between pieces of meat