For what its worth Food grade comes in several different types of plastic. The best is HDPE High Density PolyEthelene. The best example for reference is the white plasice used for water barrels. It is somewhat translucent but can be colored with a wide variety of non reactive additives.
You will find HDPE used Widely in the food industry from food handling to processing....
the next are PETE, LDPE, PP, and PS... Ployethelene Terephthalate, Low Density PolyEthelene, Polypropelene, and Plystyrene, respecively.
the nmbers on the container stand for the plastic...
1 = PETE or PET
2 = HDPE
3 = PVC
4 = LDPE
5 = PP
6 = PS
7 = While food grade is a composite you will find that on Temporary one time use. its hard to recycle.
I know more than you all will ever want to know...
My injection mold work was with Polystyrenes and plastics used in Lead Acid Battery manufacture.
deb