Well, at work I often gather the little condiment packages in the cafeteria, and save them in my desk drawer. Was cleaning it out yesterday, and came upon some that had gotten pushed back and forgotten in the far back! Not sure how old they were, but the mayonnaise was no longer flat - it was ballooned out round and tight! I had NO intention of opening one! Treating them like potential little fat-bombs, I carefully placed them all into a styrofoam food tray and then into the trash. The older ketchup showed some ballooning too - into the trash with them! Potential catastrophe averted!! Hate to have had them blow in my top desk drawer....!