Letter Re: Can Contaminants Pass Through Mylar Bucket Liners?

Hello Mr. Rawles,
I communicated with you from time to time over the past two years while stationed overseas. As I said before, your site was a true morale booster after a hard day’s work. Thank you sooooo very much! I discovered your web site a few months prior to transferring overseas and began serious preparation at that time and have continued. I returned to the U.S. two weeks ago for my twilight tour (final tour before retirement). I continue to be a dedicated reader and have purchased some of your materials. I do have three questions regarding plastic pails. Last summer while home on leave I tried to put away as much as possible but unfortunately ran out of [confirmed] food grade pails. Since I had no other option given my situation, I purchased some new plastic pails from Home Depot. With both the food grade and Home Depot pails I put my grains in heavy duty mylar bags with oxygen absorbers, sealed them and then placed them in the pails. I have three questions: Can chemicals from the plastic pails penetrate the mylar bags? Should I discard all of the items stored in the manner I described above in the Home Depot pails? If these items are still safe, do you suggest I take the mylar bags of food from these pails and transfer them to food grade pails at this point? Thank you very much for your assistance. – Marilyn B.

JWR Replies: I get this question frequently. While mylar bucket liners are often described as “gas-impermeable”, there are several factors that can contribute to a loss of their integrity. These include:
1.) An inadequate seal of the top of the bag. Unless you use a heat sealer and you get an absolutely perfect seal, then you can’t be sure about permeability.

2.) Pinholes or tears. Just one pinhole in the mylar liner will allow vapors to enter.

3.) Time. Mylar isn’t 100% gas impermeable (although they are much less permeable that the HDPE buckets themselves). So over time, it is conceivable that contaminants inside a bucket could end up inside the liner.

So to be absolutely safe, you’d have to discard any food stored in non-food grade buckets.

As I’ve mentioned before in SurvivalBlog, your non-food grade buckets should be marked and specifically relegated to non-food storage purposes, such as storing tools, clothing, web gear, and ammunition.

The “Rawles Gets You Ready” family preparedness course has details on determining whether or not particular buckets are truly food grade.