Just remember that if you are storing bleach as a means of water purification that it only lasts about 6 months, after that it turns into salt water. You may want to look into some powdered chlorine. I have read of pool chemicals being used for this. Do some research on it, but the powdered stuff will last indefinitely.
Info found directly from Clorax from "The Hydrated Horse" blog:
Thank you for asking about the shelf life of Ultra regular CLOROX liquid bleach.
When bleach and water are mixed together to create a cleaning or disinfecting solution, the solution is only good for 24 hours. The temperature of the water does not affect the cleaning or disinfecting abilities of the solution. After the 24 hours, the solution begins to lose needed disinfecting properties. Therefore, it is recommended that for disinfecting purposes, the solution is made fresh daily.
Our bottles do not have an expiration date, however, they do have a production date. Once you understand how to read the production date, you can decipher the shelf life of the bottle. Please look below for a chart explaining our production codes.
CODE PLANT YEAR DATE
MD21002 MD2 1= 2001 002nd day of year
A90288 A9 0= 2000 288th day of year
We recommend storing our bleach at room temperatures. It can be stored for about 6 months at temperatures between 50 and 70 degrees Fahrenheit. After this time, bleach will be begin to degrade at a rate of 20% each year until totally degraded to salt and water. Storing at temperatures much higher than 70 degrees Fahrenheit could cause the bleach to lose its effectiveness and degrade more rapidly. However, if you require 6% sodium hypochlorite, you should change your supply every 3 months.