Diane, I think lard from the supermarket will keep at least a year. Iam not sure about home-rendered lard. When I was a child, my mom kept it in a root cellar in a big can for a long time and that wasn't as cool as refrigeration.

If you are asking because you have some that you are wondering about, smell it, and if it still smells fresh and has no mold, it is probably fine. A rancid smell is pretty easy to detect. And if by PC, you mean health concerns, my opinion is that it is probably more healthy than vegetable shortening.