I like using a dilution of bleach to clean counters and sinks, especially after handling raw meat. But I’ve found a few sources that say you have be re-mix bleach solution every day to make sure it’s really killing germs. Somewhere in the murk of my memory, I think Alton Brown has said the same.
And yet when I try to look up a citation, I get a lot that seem to come from the same garbling of a WHO recommendation, that talk about contact with organic matter, light, heat, and evaporation degrading bleach solution.
So if I make some solution and keep it in a closed, opaque bottle away from contaminants and heat, it seems like it would keep working just fine. When I have done this in the past, it always still smelled like the municipal pool for weeks after I made it.
What’s the straight dope on this? Because bleach is cheap and effective, but re-mixing every day would be a total pain in the ass.
I think your idea of a closed, opaque bottle is a good one.
Companies sell cleaning products that contain bleach. You would think that they have a rather long shelf life. For example there’s Clorox Clean-up With Bleach in a spray bottle that we use at home.
Sprayer bottles don’t have much contact with outside air, aside from the small amount that enters to take the place of what you’ve sprayed out. Bottles where you pour out the cleaner need to be used or replaced fairly often (especially hydrogen peroxide–that stuff only lasts about a month after you open it up and pour some out, if you use some every day or so; after that, it’s mostly just sterile water).
foodservice professional here, i’d change it every 4 hours. most of the bleach has evaporated by hour 4.
this is if you’re just using a bleach solution in a bucket.
You should be good here, although if the container is not sealed, then andrewbub is correct. 4 hours is more than enough time for a 400 ppm solution of chlorine to drop below the effective level 200 ppm due to evaporation. Also, be sure that you are not contaminating the solution.
If you want to test this, go get some chlorine test strips from the health department or any foodservice equipment supplier.
I think I’d personally just skip the bleach altogether and go find myself a good quat disinfectant. Just as good on germs, and a whole lot less harsh on clothing and other things. Plus they typically smell decent as well.
I saved this from a thread on another forum a long time ago.
"How long does diluted and undiluted bleach last?
For the answer to this question, see the clorox@casupport.com email to the Director of WCMC EHS dated February 6, 2003:
Thank you for asking about the shelf life of Ultra regular CLOROX liquid bleach.
When bleach and water are mixed together to create a cleaning or disinfecting solution, the solution is only good for 24 hours. The temperature of the water does not affect the cleaning or disinfecting abilities of the solution. After the 24 hours, the solution begins to lose needed disinfecting properties. Therefore, it is recommended that for disinfecting purposes, the solution is made fresh daily.
Our bottles do not have an expiration date, however, they do have a production date. Once you understand how to read the production date, you can decipher the shelf life of the bottle. Please look below for a chart explaining our production codes.
CODE PLANT YEAR DATE
MD21002 MD2 1= 2001 002nd day of year
A90288 A9 0= 2000 288th day of year
We recommend storing our bleach at room temperatures. It can be stored for about 6 months at temperatures between 50 and 70 degrees Fahrenheit. After this time, bleach will be begin to degrade at a rate of 20% each year until totally degraded to salt and water. Storing at temperatures much higher than 70 degrees Fahrenheit could cause the bleach to lose its effectiveness and degrade more rapidly. However, if you require 6% sodium hypochlorite, you should change your supply every 3 months.
I hope this information is helpful. Again, thank you for giving me this opportunity to discuss our product.
Sincerely,
Mary Brylinski Product Specialist
MEB/cl
3463673A "