Bleach for Survival?

The possession of a bottle of household bleach can mean the difference between life and death. How you may ask?  Well let’s start at the beginning with the ingredients of bleach.

What is bleach made of?

Bleach is a chemical compound made from Chlorine and Sodium Hydroxide (Caustic soda or lye) a white solid metallic base and alkali of sodium. This is diluted with water to create a caustic soda solution and has chlorine, with a chemical formula of Cl2 added. Two chlorine atoms form this diatomic molecule. The bonding between these two atoms is weak, making the chlorine molecule highly reactive when chlorine is circulated through the weak caustic soda (NaOH) solution in either gas or liquid form to create Sodium Hypochlorite, otherwise known as bleach. The chemical compound formula for sodium hypochlorite is NaOCl. This is an alkaline salt, which will break down over time and is not in fact an acid.

Which bleach should I use for survival?

There are two types of bleach – chlorine bleach, the one most commonly used, and peroxide bleach – advertised in bleaches that you can safely use on colored clothing. Peroxide bleach does not kill germs. What we are concerned with for survival purposes is chlorine bleach, as it kills most germs. You also do not want to use bleach that has additives – like lavender or pine scented additives – to it because these will interfere in survival uses. The part we are interested in is the chlorine because this has the kill power.

How long does it last?

Don’t think that stockpiling bleach for long periods is going to save you money. It is good to have some on hand for emergency situations but do use and replace when you need to so that should a SHTF situation arise your bleach is not out of date.

Bleach should last for around six months before it starts separating – that is why its best to store at around 50 to 70 degrees F and out of direct sunlight.  Preventing ultraviolet light from reaching the bleach, improves its chemical stability and effectiveness.  Bleach comes in thick white plastic containers to eliminate light – if you are concerned about plastic and want to decant into glass jars then opaque glass jars need to be used or paint the glass jars. It can be used past its use-by date for normal household use like washing, cleaning floors, and so forth if you just up the amount – instead of using a teaspoon use a bit more for the same effect with out of date stuff – this is OK to do for around 6 months after use-by date.  DO NOT USE OUT OF DATE BLEACH FOR TREATING WATER –YOU ARE PLAYING WITH YOUR LIFE!

Why does bleach go out of date – well we mentioned that the bond between chlorine atoms was weak making them highly reactive. Now when the mixture is formed of caustic with chlorine it eventually starts separating out into the salts from which it was formed, making it ineffective in killing pathogens.

What’s better than bleach?

You can use calcium hypochlorite [Ca(OCl)₂.] As you will see from its chemical formula it has lime (calcium oxide) and chlorine – that’s the stuff used to keep swimming pools clear. One buys calcium hypochlorite for use with swimming pools as dry granular “Chlorine” or as a powder for treating pools, and sometimes as those “pills” you put into a container that distribute small doses to keep the pool clear.

Benefits of Calcium hypochlorite

You can add a very small amount to make your water drinkable – this will depend on the amount of other matter in the water. If you need more facts on chlorination of drinking water then this is a useful page. The bonus is that as it isn’t in a liquid form it is lighter to carry around and will store for much longer periods of time than bleach. It also kills more pathogens than bleach can kill.

So why aren’t we all using calcium hypochlorite instead of bleach?

This chemical must be stored in a well-ventilated, dry and cool spot – not always possible in a bug out situation. As people who own swimming pools know your chemicals must be kept away from heat and moisture. Exposure to these can lead to explosions, whether by accident or on purpose – watch this YouTube video but don’t show the kids – otherwise they might want to experiment!

In a survival situation you may be exposed to fire hazards and water or other liquids. A fire where calcium hypochlorite is involved burns fiercely and is hard to put out, plus there is the possibility of the release of chlorine gas – highly toxic and used in warfare. The chances are though that you will be keeping a relatively small amount of calcium hypochlorite stored for an emergency – so it is your call. Instead of having to replace supplies of bleach every 3 to 6 months the calcium hypochlorite will last a long time.

What can bleach/ calcium hypochlorite be used for in survival situations?

We all know about the day-to-day uses – whitening clothes and keeping surfaces clean and clear of germs, removing coffee stains from mugs but bleach can do so much more – especially in a survival situation. So always keep bleach or calcium hypochlorite on hand – you never know when your life may depend on it. When bleach is mentioned in this article remember that calcium hypochlorite can also be used but for the sake of easy reading we will just use the word bleach EXCEPT where we give instructions under drinking water below on preparing the two solutions.

Treating water with bleach

The best way to make sure water is safe to drink is to bring it to the boil, allow boiling vigorously for around 1 minute or so, then cooling it before using. Make sure any sediment remains at the bottom when you pour if you have not used a filter system.

You can use bleach instead of boiling although it is not advisable to do this for long periods of time. In emergency situations when systems have broken down and your water is not pure than add 1/4 teaspoon of bleach to 1 gallon of water, shake a little to circulate through, leave to stand for around 20 minutes and then drink – it should have a slight smell of bleach to indicate the solution was strong enough to kill the germs. If the water is very dirty and cloudy you need to add a little more bleach and wait for a longer period of time. Watch this video to see how to use bleach to purify water:

Treating water with calcium hypochlorite

Now if you are using calcium hypochlorite – that’s the dry granules you will need to add 1/2 of a teaspoon (around 3 milliliters) to one 1 gallon (4 liters) of water. THIS IS NOT FOR DRINKING – THIS IS YOUR SOLUTION TO ADD TO THE WATER YOU NEED TO PURIFY. KEEP IT AWAY FROM CHILDREN AND LABEL IT CLEARLY.  One gallon of this solution will treat 100 gallons of water. This solution is just like bleach – it will not remain stable and will have to be discarded after a few days. If you are into chemistry then this article will answer any further questions you may have about calcium hypochlorite.

Using bleach is advised by health authorities in emergency situations to avoid people getting typhoid, cholera or dysentery – the single biggest risk factors after the initial fatalities and injuries caused by major natural disasters – when piped water systems are disrupted. If the water is really dirty, in addition to the bleach you could use this method used by soldiers to filter the water – if you have a piece of cloth, some charcoal and gravel to hand.

Fruit and vegetables

After major disasters you don’t know if fruit and vegetables have been contaminated with ecoli or various other contaminants when sewers overflow and piping is disrupted – be safe by washing vegetables and fruit in a weak bleach solution – the same strength as used for disinfecting water. In these situations preferably peel fruit – but only after sanitizing – otherwise bacteria may be transferred from the skin by the knife used to peel. If possible rather than eating raw –cook all fruit and vegetables  – the high heat should destroy the germs.

Cut flowers

There is nothing worse than flowers standing in a glass vase of green murky water – and it can smell too!  Bleach acts as a biocide – killing off the bacteria that cause the water to go green. It is a bit of a tightrope act – adding enough to kill the bacteria but not enough to affect the flowers. Usually ¼ teaspoon to a fairly large 16-ounce vase will do the trick.

Cutting Boards, Meat cleavers and Knives

When processing meat make sure all boards used to cut meat are given a thorough scrub with bleach as well as the knives used – including the handles and those ridges where the blade joins the haft to disinfect them.

Medical instruments

If you have to administer first aid in a SHTF situation disinfect needles, tweezers and anything used to clean out wounds first with a bleach solution to reduce the risk of infection. You may not be able to boil instruments, so this is a good second best.


Again to reduce the risk of flies settling and insect contamination wipe over all food preparation surfaces with a fairly strong bleach solution. It won’t last for more than few hours but will strong the nasties landing for a while.

Staving off Giardia

Campers and travellers are frequently afflicted by bloating, abdominal cramps, nausea and bouts of watery diarrhea all due to a microscopic parasite called Giardia found worldwide but more especially in areas where sanitation is poor and water is untreated. Bleach does the job of killing these off too rather than the iodine tablets backpackers often carry – the iodine gives the water a rather nasty taste and doesn’t break down in the environment like bleach does.


To eliminate armpit odor use a few drops of bleach to roughly one ounce of water and wash the area. It does not burn and will kill the bacteria that cause odor – a boon in a survival situation where you may not have access to lots of fresh water to bathe in or an arsenal of deodorants, soaps and the like.

Controlling mosquitoes to avoid malaria, dengue, Zika and other diseases

Disinfecting puddles

When there has been a flood or storm the water standing around in puddles functions as a major breeding ground for insects – think of the recent Zika outbreak – puddles of rainwater in urban environments provided place for the mosquitoes to breed. If you can’t drain the water you can add a little bleach to make sure the larvae die.

Rainwater barrels

Rainwater harvesting tanks can also become a breeding ground –put ½ a cup of bleach into a 2,500-liter tank (660 gallons) once a month. Even though there are gauzes and grids somehow the mosquitoes do find a way in and one female mosquito can produce hundreds of eggs that turn into those nasty wriggling larvae. Watch this video to see some tips on storing water for an emergency:

If it is raining don’t think you are safe –mosquitoes can fly between the raindrops! Often they hide in cupboards and under furniture during the day to come out at night and bite – so make sure those cupboards are mosquito free. Only if there is a strong wind are you safe outside from the incoming little bloodsuckers, which can apparently fly between 20 to 40 miles in search of their diet of blood according to the American Mosquito Association.

Just a word of warning – don’t add to ponds – you will kill off the fish and tadpoles – and they are what we want to preserve to take care of the mosquito larvae.

Whichever you choose – you now know the pros and cons – bleach or calcium hypochlorite are your go-to substances in a survival situation. Both kill bacteria and viruses effectively, stop smells and then conveniently break down, so they are not chemically active for long periods of time.

About Jeanie Beales

Jeanie Beales
Traveler, photographer, writer. I'm eternally curious, in love with the natural world. How people can survive in harmony with nature has fueled my food safety and survival gardening practices. At the age of 12, I found a newspaper advertisement for a 155-acre farm at a really good price and showed my parents one Sunday morning. They bought it and I happily started planting vegetables, peanuts, maize and keeping bees with the help of the local labor. Once I married wherever we moved it was all about planting food, keeping chickens and ducks, permaculture and creating micro-climates. I learned how to build wooden cabins and outdoor furniture from pallets, and baked and cooked home-grown produce, developing recipes as I went along. Over the years on numerous trips to wild places and cities I've learned all sorts of survival hacks, but there is always someone out there who can teach you a new trick so I remain an eternal student and forever humble.


  1. Avatar

    I recently purchased dry bleach is this the same as liquid bleach? how would you use this to treat water for drinking and can you? I was thinking this could be a good product to have for emergency situations and easier to carry in a bug out bag than liquid bleach.

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    If using shock to purify water how much to each gallon would you use.

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