storing dog food

Anyone use a plastic barrel or container to keep dog food in? I'm now buying food 3 bags at a time / 40 lbs a bag and was looking for a better way to keep them then just sitting around in bags. I heard somewhere that regular plastic and or metal containers (like garbage cans) can leak toxins into the food and that special containers are needed. Not sure it that's true but was looking for something plastic that can keep 100 to 120 lbs of food secure and fresh. A quick google search had plenty of containers but nothing big enough to suit my needs.

Thanks, Danny