FEMA, the American Red Cross and others all recommend Chlorox, Purex or chlorine as a method for water purification in emergency. These bleaches normally contain 5.25 – 6% chlorine. Avoid using bleaches that contain perfumes, dyes and other additives. Chlorox has recently come out with a new product “Clorox Ultra”. They have changed the concentration of Sodium Hypochlorite (chlorine) from 5.25% concentration to 6%, and they have added Sodium Hydroxide. They are doing this to reduce the size of the containers. Chlorox has stated that this is safe to use for water purification.
Common household Clorox Ultra, Chlorox, Purex or chlorine bleach may be used to disinfect water in the following amounts. Four drops per quart gives 10 ppm in clear water. This amount should be increased to eight drops in turbid (cloudy) water. Sixteen drops will provide 10 ppm per gallon of clear water. You should be able to get a slight odor of chlorine after the waters sits for the 15 minutes.
If not, add more Clorox. What most organizations that recommend chlorine don’t tell you is that chlorinated bleach loses it strength with time. After one year on the shelf, it will have lost 50% of its strength, so double the dose on old chlorine.
Detailed Guide: How to Purify Water with Bleach
Warning – Chlorine will not reliably kill Giardia and Cryptosporidium. SODIS, boiling, chlorine dioxide tablets and good water filters are more reliable.
While chlorine will not kill Giardia and Cryptosporidium reliably, it is effective against most other bacteria’s.
Don’t pour purified water into contaminated containers. Sanitize your water jugs first.
Clorox Bleach Sanitizing Solution
To sanitize containers, mix 1-tablespoon chlorine bleach into one gallon of water. Always wash and rinse items first, and then let each item soak in chlorine bleach sanitizing Solution for 2 minutes then drain and air dry.