Good reminder for all.
A few weeks ago, I needed something from my main first aid kit which is packed in a medium sized, soft sided bag. Upon trying to zip the bag open, I noticed that the nylon based zipper had been gummed up with an unknown substance. After struggling for a few minutes to finally get the kit opened which included the use of multi-tool pliers on the zipper pull, I found the source of the problem. There was a small bottle of liquid disinfecting soap (laying on it's side) which had leaked the soap into the bag. The leaked soap ruined some supplies such as bandages of various sizes, ABD pads, telfa pads etc and also leaked onto the length of the zipper. Judging by the semi-solid (dried out) remnants of the previously liquid soap, it had leaked quite some time ago. This resulted in some new first aid supply purchases and luckily I was able to get the zipper cleaned up enough so that it still works.
Had this been a real emergency and time was of the very essence, I would to of had to cut the bag open with a knife in order to gain quick access to the first aid supplies.
I also have a bulk pack of AA Alkaline batteries that have been carefully stored, meaning no extreme high/low temps/humidity etc. These batteries have a "best before" date out to Dec. 2013. However as you can see, the batteries are leaking. I sent a nice email to the manufacturer and they are sending me a couple of replacement packs in return...no questions asked. Had I not checked these on a regular basis and waited until I really needed the batteries...it would of been too late.