Dear Mr. Rawles –
Regarding the recent post on “Forever Preps”….
“Forever Prep #3: “Dry” Bleach This has often been covered by various sources on SurvivalBlog, but so-called “dry” bleach (pure Calcium Hypochlorite) lasts forever. If you go a little crazy and buy two 25 pound boxes of it from a big box store, you can make a solution that can purify about 4 million gallons of water! And, by the way, this Forever Prep is also very cheap (about $45-$50 for 25 pounds) and takes almost no storage space.
You must store dry bleach extremely securely if you have even a remote risk of an unauthorized person gaining access to it. A child or pet could be fatally poisoned by only a small amount of calcium hypochlorite. You could also get sick if you don’t use it appropriately to purify water with the correct chemistry. I store my containers in their original packaging in a metal locker, with high visibility instructions and warnings all over the inside of the locker and secured to the buckets themselves in waterproof plastic sleeves. JWR has posted the correct mixing ratios for use. (See the SurvivalBlog archives.)”
I have to add something to these comments: It is important to know that calcium hypochlorite emits corrosive vapors over time, just sitting there on the shelf. These vapors have amazing penetrative properties. The vapors will rust steel with a vengeance. I noticed some nearby canned food, which usually will sit in like new condition on a shelf not far from the “dry bleach” completely coated in rust after just a four months. The vapors went right through a new, still sealed package of disposable lighters. They are completely rusted, still “new” inside their unopened package. There were saltine crackers and other boxed dry foods kept in the same cabinet – all tasted funny and “off” although they too were stored sealed, new in the original packaging.
Keep all dry bleach completely sealed in an airtight container that is non-porous. Glass and metal come to my mind… if one could find a metal that would not corrode. I can tell you for a fact that ordinary ziploc bags do not qualify as non-porous. All of my issues cited above occurred while the dry shock was sealed inside not one but two ziploc bags. Poly 5-gallon buckets are no good either, I understand, as there are pores in the plastic that vapors will penetrate over time. I would think Mylar could be okay but I will defer to other’s expertise on that matter. Hopefully this info can keep someone else from learning my lesson the hard way – and save themselves the loss of a cupboard full of stored food and tools. – Rusty in California