The containers l deal in are "Food-Grade" inasmuch as they were once used to carry food. Chemical-grade containers are similar and l'm sure there's some overlap in their tolerance for haz-chems, they are often made of exactly the same material.
The containers l use are HDPE, meaning High Density Polyethylene, the name of a group of plastic resins defined by a density of greater or equal to 0.941 g/cm^3 amongst other parameters. HDPE is a thermoplastic.
All this is only relevant because it's irrelevant if you know what l mean - it all comes down to their previous contents, not the containers, when looking at re-use for foodstuffs. These containers as they are in my possession aren't meant for the storage of food as they have not been laundered. You will need to disinfect them, and even then l would only use them for raw / intermediate materials and not for storing finished product. People often use them to store grain, rice, etc.
As for containers that once held strong acids and bleaches - some say they will never be fit for re-use and can at best only be granulated and recycled, at worst consigned to landfill. I only deal with food-grade containers.