Matt Springer has been giving presentations around San Francisco about home earthquake preparedness since 2008 (for more information about the presentation, go to his earthquake preparedness website). This blog is devoted to posts ranging from technical "how-to" articles to more philosophical "should-you" topics. New articles will be posted at most about once a month, so people who subscribe won't be subjected to lots of e-mail.

Tuesday, March 22, 2016

Further adventures with expiration dates for food and water: Emergency water envelopes and S.O.S. Food Packets

Long-time readers of this blog (there are some, aren’t there...?) will know that I’ve developed a minor obsession with seeing how long I can use emergency food and water past their expiration dates.  That’s not as wacky as it sounds, since most “expiration dates” on food are normally "use-by dates," and are actually “best-by dates," arrived at by a variety of approaches that have nothing to do with them becoming harmful to health.  Tossing and replacing good food and water is wasteful of money and effort.  Still, some supplies really do go bad, so it’s worthwhile to figure out where to draw the line.

I’ve already told readers about the FDA’s statement that you can ignore the expiration date on sealed, commercially bottled gallon water jugs, and I’ve determined and reported that MREs (Meals Ready to Eat, a popular kind of military and emergency relief ration) are as good as a can of Hormel chili even after a decade and a half, 7 years after their theoretical best-by date.  However, in addition to gallon water jugs and MREs, I have additional emergency supplies in the form of US Coast Guard-approved emergency water envelopes (125 ml; 4.3 FL. oz.) and “Survival food packets” (also listed as "Emergency Food Rations") from S.O.S. Food Labs, Inc. that are single-serving meals in the form of good tasting fat, sugar, and protein.  Both of these are good for storage in portable go-bags, in the car, and at work due to their light weight and compact size.  I purchased both kinds of rations some time around 2006-2007, I think, and they each had manufactured dates of 2005 and expiration dates of 2010.  I put them in my portable emergency kit at home, in my office at work and in my UCSF lab, and in my car, and forgot about them for a while.

The fact that two completely different kinds of emergency supplies from the same company both have the exact same stated shelf life should already suggest to us that these dates are somewhat arbitrary, and I have interpreted them loosely.  Since the car is sometimes out in the hot sun, I have been good about periodically replacing the food and water in the car (more on this below), but the supplies at home and work just sat there, and in early 2016, I realized that I should probably check them.  It seems that my earlier successes with eating expired supplies have apparently made me a bit overly confident!

Water envelopes

Let’s start with the water envelopes.  These are silver colored packets that, according to S.O.S. Food Labs, are plastic-lined aluminum packets (tri-laminate foil film structure; see figure on the right).  The S.O.S. rep also told me that the plastic lining is BPA-free, which puts this water in a similar situation to water that has been commercially bottled, unopened, in the BPA-free gallon jugs as in my earlier article about being able to ignore that expiration date.

These envelopes are truly indestructible.  I haven’t pushed it to the max, but you can put a good bit of pressure on the envelopes and they don’t burst or leak.  S.O.S. tells me that they have an average burst in foot lbs of 862.  As a testament to the twisted sense of humor of those who created them (or perhaps a testament to those people having fingernails and teeth like razor blades), there is a little notch at one corner of the envelope that says “tear here.”  But you can’t tear there.  You can’t tear anywhere.  If you cut a real notch with scissors or a knife, you still can’t tear there.  Only by slicing or cutting the envelope completely open can you get at the water inside, so if you get stranded somewhere with these water envelopes and no knife or scissors or vampire, I’m afraid you’ll probably perish.

But the water won’t perish.  I opened it using the extreme method above, and found the water to be just fine.  Perfectly clear, no odor, and only the slightest stale flavor that is expected in water that has sat for a long time and can be removed by aerating the water; just expose it to air and shake it.  There was only the slightest hint of that taste, even 6 years after the "expiration date."  Therefore, since the water rations cost a lot and are heavy to ship, I opted to keep those water envelopes for emergencies for the foreseeable future.  Even if there was the slightest bit of some unknown chemical leaching in the water in small amounts, I feel ok about using such water for a few days or weeks in an emergency, even if I wouldn’t necessarily want to live on the stuff on a daily basis.

S.O.S. Food packets

On the other hand, I had mixed results with the food bars.  These are high-fat intentionally and have a lot of sugar; there are many ways in which they could go bad by having something grow in them or having the fat go rancid.  MRE rations are good for much longer than their best-by dates suggest (see my articles about the expiration date actually being based on subjective opinions by taste testers and my subsequent article describing my enjoyable experience eating a 14-year-old MRE), but these S.O.S. food rations are not MREs and might not be as stable.

Many of my packages are dated 2010-2015, but I had four 2005-2010 packages in the lab, each containing 9 bars.  I noticed that three of the four packages were still tightly vacuum packed, but the fourth one had ballooned out a bit.  The one that ballooned out a bit had an "old cooking oil" smell that you also find in old nuts, and had probably oxidized, so I discarded it.  New bars taste kind of like peanut butter and sesame and are very sweet (if you click on the first photo to enlarge it, you can see the actual ingredients).  However, I opened one of the expired but still-vacuum-packed packages and sampled a bar, and found that while it smelled fine and it still tasted ok, it had the slightest old flavor as an after-taste.  I'm sure they are still good in an emergency but I decided to order replacements for the 2005-2010 food bars just in case.  Still, these are 11 years old and 6 years past their printed use-by date, so I’m guessing it’s reasonable to keep them around for about 10 years before replacing them.

I was pleasantly surprised, however, when I replaced the 2010-2015 bars that were in my car and opened the old one.  These were fine under controlled temperature conditions, but I had assumed that with frequent baking in the hot sun, the bars stored in the car would go bad very quickly.  Not at all; the package was still tightly vacuum-packed, and the bars inside were just as good as the 2010-2015 bars that had been stored indoors.  There was one little section of the bar that was more solid than the rest and hard to bite through, but it all tasted so good that I admit I finished off the rest of it as a late night snack!  Then I thought about the presence of vegetable shortening in the ingredients, which for something manufactured in 2010, certainly means partially-hydrogenated oils, and decided not to snack on the remaining eight bars in that opened package for casual use.  I can live with a bit of trans fats for a few days after a regional emergency.


As long as the packaging is intact and there is no extra air, a food product in which nothing has grown in 5 years should not spawn life during the subsequent 5 years.  It's always possible that some spore could be in there that takes over 5 years to activate, but I think that is unlikely.  I also presume that if chemicals haven’t leached out of the packaging over 5 years and the product is not stored in the heat or light, it’s doubtful that chemicals will leach out into the food in the subsequent 5 years to an unhealthy extent for temporary emergency use.  I’m presuming that if it doesn’t taste or smell bad, then the worst risk of eating it is that the culinary experience won’t be ideal.  However, I don’t have the authority to officially pronounce food to be safe, although I’m pretty confident of the logic and you can draw your own conclusions.  Similarly, it is my OWN opinion that the envelope water will be fine for much longer than the use-by date.  My information about ignoring the use-by date on unopened bottled water comes straight from the FDA, so I can confidently repeat it to my readers.  In contrast, the use of “expired” water ration envelopes is my own conclusion from the evidence and you can draw your own conclusions from what I’ve reported here.  In both cases, I take no responsibility if you sample vintage rations and grow a second nose.

>>back to blog


  1. Hi. I have an entire lot of food bars and water packets that expired in 2014. Expensive stuff and really not wanting to toss it all. It is that coast guard approved mayday stuff. Thoughts? Thanks!

  2. Well, if the water packets are the same ones mentioned in this article, I would think they are fine. Remember that I found the ones dated with a best by date of 2010 to be good, so those dated with best by of 2014 should be good as well. For the food bars, if the same ones as referenced in the article, the ones I had with a best by date of 2015 were good, even if having been in the hot sun; and the ones with best by date of 2010 were basically good but with a slight annoying aftertaste. It follows then that those with best by date of 2014 should be good. Remember that in both cases, my caveat in the article still applies; I don't have the authority to officially pronounce food to be safe after a best by date, but my personal experience suggests that it is.

  3. As a bit of advice I had a pack of water and food that was approaching it's "end of life" they had about a year to they expiry date. And like you described I had 1 food pack that was ballooning. I contacted the manufacturer who not only sent a new food pack they sent me new food and water packs. I did send the 1 bad pack back to them but well worth it.


COMMENT POLICY: Comments on blog posts can be very useful, raising issues and adding helpful information. However, some people attempt to post generic comments with embedded links to irrelevant websites. Due to this comment spam, all submitted comments will be verified by me first so there will probably be a delay before legitimate comments get posted. If your comment is taking a while to show up, it probably just means that I have not checked my e-mail yet. NOTE THAT COMMENTS THAT ARE ACTUALLY ADVERTISEMENTS WILL NOT BE POSTED.