Does Bleach Expire? Here’s What We Found Out

One of the biggest ironies of human existence is the fact that things like food and other amenities that we wished didn’t expire do while things like plastic that we wished did not last forever actually don’t expire. Then there are some things that are a bit ambiguous when it comes to their operational life and one of them happens to be bleach. A common doubt among those who use bleach in their cleaning regime is does bleach expire? Let us find out.

 

Why it is hard to detect when bleach has gone bad?

Unlike other cleaning agents, bleach’s primary function as a disinfectant works at a microscopic level. This means that unless you examine the spot you just cleaned under a microscope, there is no way of knowing if it worked other than waiting to see if you get sick or not. That is why it is absolutely necessary to know the shelf life of bleach so that you can be confident that it had the desired effect on the germs rather than making your cleaning efforts a farce.

What is bleach made up of?

Before looking into the haste with which bleach goes bad, it is important to understand its composition. Most bleach that you can buy is a dilute solution of some form of hypochlorite. This solution releases chlorine which is what kills the germs. Ideally, the chlorine should only be released under specific conditions. However, a small amount of chlorine is constantly released by bleach which means that eventually, it will run out of chlorine.

 

Does bleach expire?

Yes, So it should be pretty clear to see that bleach indeed does expire. Once it can no longer produce chlorine on demand, it ceases to have any effect on the germs. At this point, using it as a disinfectant is as effective as using plain old water.

 

How long does bleach take to expire?

Now that we know of bleach’s propensity to eventually run out of juice, it is important to understand its viable lifetime so that you can be sure that the bleach you are using can still work effectively as a disinfectant.

There are multiple scenarios that can affect the expiry date of bleach. It has a shelf life of 6 months. What this means is that it won’t lose any of its strength for the first six months provided you do not open the bottle. The belief that bleach can last forever if kept in its original packaging is a myth. Post-six months, it will start degrading and lose 20% of its efficacy with each passing year. This means that an unopened bottle of bleach will be worse than useless in 5 years.

Say you open the bottle. Now its longevity depends on how you store it. If you keep it in the original bottle and screw the cap securely after every use while ensuring that no water or pretty much anything else gets into the bottle then you can expect a viable period close to an unopened bottle of bleach. It is also important to keep it in a cold and dry place away from direct sunlight. However, if you are careless with its storage then a bottle of bleach can be rendered totally useless in as little as two weeks.

Finally, we have to talk about dilution. For most practical cleaning purposes, you need to dilute bleach and some might feel that it is clever to dilute the entire bottle of bleach and storing it instead of diluting a part of it every time you need some. This is a big no-no. A diluted bleach solution of 10% (1 part bleach and 9 parts water) will degrade completely in a single day. Yes! You read that right. The more diluted the bleach is, the faster it will degrade. Therefore, always store it at its default concentration and dilute it only when needed.