Let's open things up and find out!
First, the beans in tomato sauce:
But what about the wieners (is that a great name for a film or what)?
It looked like Van Camp's Pork and Beans with Little Smokies cut up in them. But really, really salty. And you wouldn't have wanted to sleep in the same room with me. Draw your own conclusions there. But no stomach cramps, vomiting, or death. Again, much like when the pack was brand-new. So rest assured, if you have a decade-old Beef Frankfurter MRE in your basement, you can eat with a reasonable expectation that you may not become poisoned.
As long as you're not in an enclosed space without circulation.