Is it safe to eat defrosted bacon that has was put back in the freezer opened?

It is generally not safe to refreeze bacon that has been defrosted, especially if it was left opened. Bacteria can grow on food that has been thawed and left at room temperature, increasing the risk of foodborne illness. If the bacon was defrosted in the refrigerator and has not been left out for more than two hours, it can be cooked and consumed safely. However, once cooked, it can be safely frozen again.