How to use bleach to purify drinking water

After former President Trump mused about consuming disinfectants, public health officials were quick to state the dangers of doing just that. Believe it or not, there are circumstances when diluting a substance like bleach in water you plan on drinking is actually a good idea. In some cases, it could save your life so it is a skill worth learning. Let’s talk about how to use bleach to purify drinking water.

Why use bleach?

Boiling water is usually a person’s first line of defense when it comes to water purification. Unfortunately, if utilities get knocked out as a result of a natural disaster, you may not have the option of boiling water.

Practical reasons to have bleach on hand:

  • It is a household product with a variety of uses including cleaning and disinfecting.
  • Bleach is very affordable and can be purchased by the gallon.
  • It is accessible almost everywhere you shop: grocery stores, hardware stores, and big box stores.
  • Bleach can make water potable and also combat mold and mildew (white vinegar works well for mold too)

Does the type of bleach you use, matter?

The type of bleach that you use matters. You may find different fragrances and extras, but there are only two classifications of bleach: chlorine and non-chlorine.

To disinfect water with bleach, you need to buy regular, unscented chlorine bleach with an active ingredient of sodium hypochlorite. The concentration (of sodium hypochlorite) should be between 6 and 8.25 percent. This doesn’t mean that you have to stop buying color safe, scented, and hybrid bleaches. You can buy both and use them for different purposes. One for prepper uses and the other for laundry.

Clorox Regular Unscented Bleach

This is regular, unscented bleach with a 7.5% concentration of sodium hypochlorite. Be sure to also get some liquid droppers to disperse the correct amount of bleach into the water you are treating.

Bleach Concentrate

A very common question is whether or not you can use the bleach that is labeled as “concentrated bleach” to purify water. The answer is found on the bottle. As long as the sodium hypochlorite concentration is between 6 and 8.25 percent, then the answer is yes! The most “concentrated” bleach is usually around 8.25% chlorine (or sodium hypochlorite) bleach.

How to use bleach to purify drinking water:

Now that you’ve established a fresh supply of chlorine bleach, it is time to put all that you have learned to use. You don’t want to wait until you’re in the midst of a crisis to try this technique. Let’s mix up a batch of treated water so that you can get your technique down.

It’s time to collect the water you want to treat. This can be water from a tap, rainfall you collected from your gutters, river, lake, snowpack, or another source. Of course, the higher quality your source, the better your water will be. This is a good time to remove particulates from the water by filtering it through a strainer or cloth.

  1. Add bleach to your water. Add either 8 drops of 6% bleach or 6 drops of 8.25% bleach to one gallon of water.
  2. Inspect your water and make necessary adjustments. If the water is cold, cloudy, or colored, experts recommend doubling the bleach to 12 – 16 drops respectively.
  3. Patiently wait. Allow your mixture to stand for about 30 minutes.
  4. Smell and adjust if necessary. When you smell your solution, it should smell slightly like chlorine. If you don’t detect a slight chlorine odor, add another 12 – 16 drops and allow the water to stand for 15 more minutes.
  5. Reduce the levels of bleach in the water. If the chlorine taste is off-putting, you can aerate your water by transferring it into another clean container. Allow the water to stand (uncapped) for several hours in the new container before drinking it. You can also pour the water back and forth between two containers. This will speed the evaporation of the chlorine in the water.

How to use household bleach for water disinfection:

This video is very informative and helpful. His instructions are based on a quart whereas mine are based on a gallon.

how to use bleach to purify drinking water

How to mix larger batches of purified water

Here are some ratios for larger quantities.

If you’re using 6% chlorine bleach:
  • 2 drops of bleach per liter or quart of water
  • 8 drops per gallon of water
  • 16 drops per 2 gallons of water
  • 1/3 teaspoon per 4 gallons of water
  • 2/3 teaspoon per 8 gallons of water
If you’re using 8.25% chlorine bleach:
  • 2 drops of bleach per liter or quart of water
  • 6 drops per gallon of water
  • 12 drops per 2 gallons of water
  • 1/4 teaspoon per 4 gallons of water
  • 1/2 teaspoon per 8 gallons of water
How to use bleach to purify drinking water
How to use bleach to purify drinking water

Let’s talk about the shelf life of bleach

Did you know that bleach has a shelf life? If you’re surprised and hearing this for the first time, then it’s a goo thing that you’re reading this.

According to the iconic Clorox Company, you need to track the age of your bleach. A company representative told Ron Fontaine -the owner of, “We recommend storing our bleach at room temperatures. It can be stored for about six months at temperatures between 50 and 70 degrees Fahrenheit.

After that time-frame the bleach will degrade 20 percent annually until it’s nothing more than water and salt. Also, store your bleach in a cool place because if it is stored above 70 degrees then it’s going to degrade faster.

Tips for storing purified water

Long-term water storage is a wise move that can pay off when disaster strikes. Here are some purified water storage tips that I learned from the Centers for Disease Control and Prevention (CDC):

  1. Only use clean, food-grade storage containers to store your purified water.
  2. If you must use non-food-grade containers, get durable containers with caps that can be tightly screwed on.
  3. Never ever recycle old containers for water -especially if they ever contained toxic materials.
  4. If you are uncertain of the origin, find out if the container you’re considering is FDA approved.
  5. Always sanitize every container that you plan to use. Mix one teaspoon of fragrance-free chlorine bleach with 1 gallon of water and pour it into the container. Shake vigorously. Let stand 30 seconds before you empty it and allow it to air dry.
  6. Label every container with a “Drinking Water” label and include the date.
  7. Replace all water at 6-month intervals to maintain freshness.
  8. Never keep your water near containers that carry gas, pesticides, or other toxic solutions.

10 Bleach facts to know before you buy too much:

  1. Bleach can purify water, but it’s a carcinogen.
  2. Bleach is sodium hypochlorite (a poison.)
  3. Avoid scented and enhanced bleach for water purification.
  4. Bleach can help you clean your dishes with minimal water.
  5. Bleach expires after 3-6 months so if you choose to use it, label it with the date, and rotate accordingly.
  6. You will need bleach alternatives for water purification.
  7. Your tap water already contains some bleach.
  8. Swimming pools contain DANGEROUS levels of bleach.
  9. Bleach is a pesticide.
  10. Bleach can irritate asthma.

I know that I would want to know those things if I were considering bleach for water purification.

Other uses for bleach

Preserve flowers with bleach

Dr. Joan Rose of the Water Quality and Health Council recommends picking flowers while you wait for your power to be restored. Simply mix 1/4 teaspoon of unscented chlorine bleach per quart or pint of water into the vase, and you will destroy the bacteria that causes your flowers to wilt.

Sanitize with bleach

You can sanitize the surfaces and dishes in your home using bleach. Sanitizing is essential in any influenza or viral outbreak (which we have learned from recent events.)

To sanitize with bleach, mix 1 teaspoon of bleach with a cup of water. Dip a cleaning towel into the mixture and wipe the surfaces thoroughly to disinfect. Rinse off the surfaces before drying.

How to use bleach to kill mold and mildew

Killing mold and mildew is especially essential if your home is powerless for weeks or months. This is because the air won’t circulate the way that it did with home heating and air conditioning units. It will be much easier for your home to grow mold and mildew and quickly become a health hazard. Thankfully, household bleach (and white vinegar) can kill these things.

To kill mold and mildew with bleach, mix one cup of bleach with one gallon of water. Saturate the mold with this solution using a spray bottle of rag. Allow the solution to sit for 10 minutes before scrubbing the surface clean. Ventilate the area, wear eye protection, and use a face mask to avoid breathing in spores that are in the air while cleaning.

Environmental Protection Agency (EPA) warning

The EPA guidelines state that when a disaster strikes, we should only use water that has been “properly disinfected” for drinking, cooking, cleaning, and brushing our teeth. This is important to avoid the disease causing microorganisms that dwell in water supplies.

The EPA recommends boiling water and using a bleach additive to kill the organisms that could make you sick. However, this is not a perfect solutions to your dilemma. The water could still be laced with salts, heavy metals, and toxic chemicals. Some of them are added by your water company and others naturally find their way into your water supply.


How to use bleach to purify drinking water
How to use bleach to purify drinking water

Bleach has so many uses for preppers and survival, Unfortunately you can’t just store and forget about it because it has a shelf life. Make sure that you label and rotate your bleach. You should always have a fresh supply of bleach because when the next “viral outbreak” occurs (which is has), there will be no good replacement for old fashioned household bleach!

If you are looking for other methods of water purification, please check out the article below!

Would you consider purifying your water with bleach? Do you have a fresh supply of bleach? What other uses have you found? Comment below to share!

See you soon!