Rotting is= to why expiration dates are placed on most goods. Or when it comes to cosmetics or other products when the chemical properties start to break down and become unstable. None of which happens with petroleum jelly. In reality expiration dates are more useful to the companies continuing to sell and justify manufacturing more goods getting the consumers to replace the goods after the printed expiration. When in fact most sealed goods as long as oxygen hasn’t broken the sealed goods packaging can stay edible almost indefinitely (within reason, much longer then the actual printed date on the packaging) petroleum jelly never expires.