Flexi Says: Plastics can be food-grade but are not edible technically. Food-grade does not mean that it is edible. It also is different from environmentally friendly, sustainable, or biodegradable. Food-grade means the material (like plastics) does not react or change chemically when it comes in direct contact with the food we consume as part of the harvesting, processing, or packaging of the food. There are several things that go into qualifying plastics as food-grade material.