Preventing them from licking the can

Honestly, I have never known of a cat or dog cut while licking the can, but how could that not be a danger???? So when I do not plan to take the garbage out immediately, and may not have an empty nut can to store the cat food tins, then what I do is fill the emptied container with water and leave it in the sink til it can be safely removed from the realm of cat control.