Recently when a rare urge to bake came over me, I reached in the pantry for cooking spray and scratched my head.  First I wondered, "Why do I have 3 cans of cooking spray? and then I asked myself, "Why have they all expired?  I thought they had a shelf life of...forever!"  I was wrong.  So I did a little research and found that products like cooking sprays can be used after the date, but they won't be as effective, or their taste, texture or appearance might change.

As for foods, there are items that have expiration dates and items that have sell by or best by dates.

The Food and Drug Administration website says, "Joint recommendations from FDA and the U.S. Department of Agriculture on storing foods in the refrigerator are based on refrigerator temperatures of 40 degrees F or lower, and vary by type of food. For a listing of these recommendations for various food types, see the Refrigerator and Freezer Storage Chart.

Shelf-stable foods that do not need refrigeration in order to be safe can be kept at room temperature until their “use-by” date. For best quality, store them in clean, dry, cool (below 85 degrees F) cabinets away from the stove or appliance (such as refrigerator) exhaust."

I keep a carton in the fridge for 5 days and I will discard it then, even if it smells fine.  I once got sick on sour milk so that's probably why I err on the side of caution.  What guidelines do you follow in your house when it comes to expiration or best by dates?  Have you ever been surprised by something you thought would never expire?  Here's a video about the shelf life of some common items.   https://www.youtube.com/watch?v=bcLHl3OIuhg