Self-rising flour question

I have a bag of self rising flour that has probably passed the time when the leavening will work. My question is, can you use it in place of regular flour, or will anything you make become too bitter if it requires the addition of baking soda or baking powder?

Also, is there any way to test it to see if it still is active enough to use?

You can tell I'm a northerner as we don't generally use a self rising flour for baking...