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 [1] 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