How to Purify Water with Bleach: Easy-to-Follow Guide

Clean, purified water is essential for our survival. And with most water that we encounter out in the wild (and sometimes even tap water) being impotable, it’s important to know how to purify it. One common method is to purify water with bleach.

It’s really important to know all the details before you try to purify water with bleach, as using too much (or too little) can pose a serious health threat.

But worry not, I am here to tell you exactly what to do!

Getting the Ratios Right

It’s essential to get the ratios right when purifying your water. If you use too little bleach, some bacteria and viruses can survive. If you use too much, you can get sick and get stomach pain, cramps, vomiting and more.

Generally, the rule of thumb in order to purify water with bleach is to add 8 drops of bleach to 1 GALLON of water. Or 2 drops of bleach per 1 LITER of water. The proportions are the same – just the measurement unit differs.

Use an eyedropper (pipette) in order to add the bleach. Always use regular bleach like Clorox, not scented variants as those contain chemicals that will do us harm.

Finally, make sure that you use bleach that contains no more than 8.25% sodium hypochlorite. If the amount is lower (but not under 5%), you can still use it as instructed above.

bleach for purifying water

See also: Urine Filter: Don’t Waste Your Waste

Now when you all know the formula, you may start with the purifying process. The purifying must be done with properly disinfected water, weather it’s for drinking, cooking or washing.

This process contains some steps you must follow, which are explained in this article below.

Purifying water with bleach – How to do it

The best choice is to disinfect the water by using your favorite household bleach. The best ones are the regular ones or those what are unscented and use no dyes or other additives.

As it is indicated on their labels, unscented chlorine bleach products are suitable for purifying and disinfection.

The best options are bleaches that contain between 5.5% to 8.25% of sodium hypochlorite. Scented, color safe and those with added cleaners are not recommended for use.

The may cause some infections or other medical problems. It’s also recommended that you use your bleach in a well-ventilated area, as the fumes can be a bit toxic if inhaled for too long.

drinking water in the wilderness

Now that we’ve got these covered, here are the steps you need to follow to purify water with bleach:

1. Filter the water if it is cloudy or if you’re not 100% sure it’s free of impurities.

Depending on what you have on hand, you can use layers of clean cloth to filter it, a coffee filter or napkins / paper towels. This is just basic filtering, but something that needs to be done.

If the water is still cloudy after filtering, repeat the process with a clean filter.

Alternately, you can read my tips on how to make your own water filter from scratch. This might come in handy!

2. Next, add the bleach respecting the rule of 2 drops per 1 quart (1 liter). Only use unscented bleach with a chlorine concentration between 5.25% and 8.25%.

Only add bleach to cold / room temperature water. Adding it to boiling hot water will render the bleach ineffective.

3. Mix well the bleach into the water and let it stand for 30 minutes while you are in a ventilated area.

Smell the water afterwards – it should have a slight chlorine odor at this point.

If it doesn’t, repeat the process and let the water sit for 15 more minutes.

Only after that you can use the purified water.

IMPORTANT! This method should only be used in emergency situations, not as a long term way of purifying water. While the bleach will kill viruses and bacteria, the fact that you can’t filter the water properly comes with other potential health problems.

How much bleach is needed to purify water

purifying water with bleach

If you are in a hurry and can’t do the math, or you just want to double check to see that you have the proportions right, here is a table that will help you determine the correct amount of bleach to use with water for disinfecting it:

Volume of water

Amount of Bleach to Add*

1 quart/liter2 drops
1 gallon (4 liters)8 drops
2 gallons (8 liters)16 drops
4 gallons (16 liters)32 drops
8 gallons (32 liters)64 drops
*Use bleach that contains 5.25% to 8.25% sodium hypochlorite.

There may also be a situation where the chlorine taste is too strong. If this happens, pour the water several times from one clean container into another. After that, let the water stand for a couple of hours, and then you are free to use it.

Do not mix the bleach with ammonia or other cleaners into your water. This could result in a health hazard.

Bleach tablets are a great alternative to carrying liquid bleach with you, as they are much safer to carry and reduce the risk of spillage.

If this is your choice method of purifying your water, then simply follow the directions on the package.

Advantages and Disadvantages of purifying water with bleach

Although purifying water with bleach is very easy and quick, there are some disadvantages, as stated below. It is up to you to decide what you will do to make your water safe to drink and use.


  • Bleach is usually cheap. This means that you may find a gallon of bleach for just 2 dollars. Using bleach for purifying the water is a much less expensive approach than any other chemical treatment.
  • Besides the fact that the bleach is very inexpensive, it is also very widely available. If you want to purify the water, you will just need to visit the closest grocery store, gas station or supermarket. Most likely, you already have some at home.
  • If you want to purify 1 liter of water, you would only use a couple of drops. So you don’t need large quantities available for emergency water purification.
  • Even the most contaminated water will be almost 100% safe for drinking as bleach kills almost all viruses and bacteria.
  • Comparing to some other chemicals, bleach won’t discolor the water, after it has been treated. For example, if you use iodine, it may leave the water with an off-color and also very unpleasant taste.
  • Finally, bleach evaporates quickly. This means that once the disinfection is done, if you keep the water in a clean container for at least a few hours, the chlorine will evaporate (so no more chlorine odor or smell).


  • It has a short shelf life. It can’t be stored for a long period of time, usually no longer than six months. While you can still use it after this time, it will be weakened so risky for purifying water (you can use too little, for example).
  • Bleach is effective against a lot of things, but it does not kill all the harmful contaminant in the water. Some of the organisms that bleach is not able to eliminate are protozoa and Cryptosporidia. Water that has been contaminated with feces is at risk of developing Cryptosporidia, for example.
  • Another disadvantage of bleach is that in some situations, it may be poisonous. The body can tolerate bleach when it’s watered down, but only at the right amount. Too much of it can cause side effects and, in severe cases, even be fatal.
  • Inhaling the fumes from bleach is also a danger, so be sure to use it in a well-ventilated area. If you feel your eyes burning or you find it difficult to breathe, please seek medical attention immediately.
  • Humans who have problems with asthma should be even more careful. Just a little inhalation of bleach can cause a serious attack.
  • Bleach is not very environmentally-friendly, so you have to take extra special care when using it around your campsite. It can leech into the ground if spilled, contaminating food and water supplies for the animals that live in the area. Not to mention it will also kill any plants it happens to spill on.
drinking water in the wild

Is it safe to put bleach in drinking water?

If you closely follow the guidelines (2 drops per quart/liter), bleach is safe in drinking water. It purifies it, making the water safe to drink. But don’t add too much, as it can have serious side effects, from tummy ache to diarrhea and even death.

Why Drinking Purified Water is Important

Water is one of the fundamental needs of human survival. Adults should generally drink 2 liters of water (or similar liquids) each day. The human body can’t even survive for more than three days without water. That’s how essential it is.

Generally, the modern human uses between 15 to 30 liters (4-8 gallon) of water each day for drinking, washing and keeping things clean.

Unfortunately, with the natural disasters that occur, water may not always be safe to drink. Drinking contaminated water can cause many types of symptoms and diseases such as:

  • Sick stomach
  • Vomiting or diarrhea
  • Skin rashes
  • Worm disease
  • Reproductive and development problems

This is only a small percentage of the problems you could experience, and compounded with the fact that you’ll be hiking in the wilderness, far from civilization, you don’t want to be stuck sick and alone without any means of calling for help.

This is why it’s important to know how to purify your water – and today’s article helps you exactly with that.


As the human body is more than 60% water, it’s very important to know that consuming purified water is essential to your well being.

Now whether you drink clean water from the tap, from store-brought bottles, boiled water or water purified with bleach doesn’t matter that much. What matters is that the water you drink is clean and healthy.

Before using any bleach for purifying, please be sure that the bleach you are using does not contain perfumes or any other additives. It should only contain sodium hypochlorite. Perfumes and additives can be toxic and may cause really serious health problems.

You should also be careful about the expiry date of the bleach. The best choice is always to use a fresh gallon of bleach for every purifying process.

Although you don’t need to trash the old one, it’s not best that you take it with you on your camping trip. It might be best to keep it at home and use for cleaning around your home instead as for purifying water for drinking.

And now, if you want to be even more prepared for an unexpected situation, you can continue to read my tips on how to survive in the wilderness with nothing for more insight.

If you have some extra tips or personal experiences with purifying water, no matter if they are good or bad, feel free to share with us in the comments below.


7 thoughts on “How to Purify Water with Bleach: Easy-to-Follow Guide”

  1. This is amazing. Kudos to you for sharing this important article. I will surely take note of the tips you mentioned since you’ll never know what might happen in case of emergencies. We really need to be more knowledgeable about these kinds of survival tips. Will definitely share this around.

  2. I cannot see myself using this technique in the near future, but it is of course nice to know just in case. Since you said it can be dangerous, so I think I will just choose boiling water if needed. Also, there are some organisms that bleach cannot eliminate like protozoa and Cryptosporidia.

  3. Most people would prefer water filtration/purifying devices. But a bleaching agent can come in handy during an emergency situation. You should be careful with the quantity you use, though.

  4. You should consider adding twice the amount of bleach recommended if the water you are purifying is cloudy and you cannot decant/filter it.

  5. I want to store good clean tap water for long periods of time. It would seem proper to also add some bleach to this water but in much less amounts. How many drops per gal.?

    • If the water is clean and the recipient is also clean and everything’s stored appropriately, there is no need to add extra bleach. If unsure, before using, boil it or add bleach then… but there is really no real reason to do it with already clean water stored properly in a clean container.


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