Letter Re: Chlorine Bleach and Its Uses

Chlorine bleach is a great multi-use item to store.  It can be used to treat water, disinfect/clean, deodorize latrines, and probably lots of other things. Here are some quick numbers:
Water purification:
16 drops (1/8tsp) per gallon/4 liters.  Let stand for 15 minutes, retreat if water does not smell of Chlorine.  

CDC recommends a fresh 1:10 to 1:100 solution for cleaning up blood spills

FEMA recommends 8oz of  bleach to 5 gallons of water for killing mold and 4 oz to 5 gallons for disinfecting flood-contaminated articles:
(That’s 125ml / 20liters and 250ml / 20 liters for metric folks)

Bleach does have some problems – it has a limited shelf life (6 months to 2 year depending on who you ask).  It’s also messy and nasty to clean up if spilled.
Taking a trip to Costco today, I discovered that they have Calcium Hypochlorite pool shock in stock.   This chemical may be used to make your own bleach solution. (See the EPA Web site.)
Add and dissolve one heaping teaspoon of high-test granular calcium hypochlorite (approximately 1/4 ounce) for each two gallons of water. The mixture will produce a stock chlorine solution of approximately 500 mg/L, since the calcium hypochlorite has an available chlorine equal to 70 percent of its weight. To disinfect water, add the chlorine solution in the ratio of one part of chlorine solution to each 100 parts of water to be treated. This is roughly equal to adding 1 pint (16 oz.) of stock chlorine to each 12.5 gallons of water to be disinfected. 
To remove any objectionable chlorine odor, aerate the water as described above.
In metric, you need to mix in approximately 7.5ml of powder (by volume) for every 8 liters to get a 5% bleach solution.
In short, 1 kilogram of pool shock can be mixed to make almost 1,400 liters of standard bleach solution.  [Which is enough to treat many thousands of gallons of water!] A one-pound box makes just under 165 gallons.
You must be ABSOLUTELY CERTAIN to get the pool shock that only contains Calcium Chlorite.  The other types of Chlorine, Tri-Chlor and Di-Chlor are not suitable for this. Be advised that this stuff is a powerful oxidizer, and should be stored in dry container, sealed away from moisture.  It can also catch fire violently if put in contact with brake fluid and similar substances, so be careful.  But the increased shelf life and mess-free storage, in my opinion, outweigh any negatives. – JN

JWR Replies: I concur wholeheartedly that bleach is important to store for family preparedness. One important proviso: You want to buy only plain bleach–not bleach with scent or any other additives that could be poisonous. Be sure to check the label before buying liquid bleach. It must have ONE, AND ONLY ONE ingredient: Calcium Hypochlorite!