Bleach EXPIREs quickly-- wonder what else does....

Did an experiment in college to find out how long bleach remains potent once exposed to air. I don't remember the exact results, but it degrades pretty quickly. I guess the same applies when mixed the water.

 

i bought a bottle of clorox to dump into a storm drain now and again to keep mosquito eggs from hatching. after a few years, the clorox ate its way through the plastic bottle

 

What did the mosquitoes eat their way through?

 

Without going too far into chemistry , the bleachy molecule in bleach is a strong and non-selective oxidizing agent. Each molecule has an effective bullet, but only one.

When you mix bleach with water, unless latter is very pure (like distilled), that water contains other molecules that undergo bleaching. So, efficacy is lost.

Top-posted sniff test is probably a good way to know if it's still bleachy. Or put a drop on some colorful fabric that has no other critical uses. Get real scientific and compare bleached areas between a fresh dilution and one that has been stored.

Whether your dilution lasts only a day, or longer, mostly depends on everything else in there besides H2O.

"chlorox ate" @3. Yes even polyethylene will eventually get bleached, though it resists better than most (may I say it presents very few handles?). Despite its fragility and lack of modernness, glass is a superior storage vessel. No handles at all. Keep it in the dark though, with photons around bleach will bleach itself.

 

The Material Data Safety Sheet for one Chlorox (TM) product does not disclose %sodium hypochlorite because it is considered a trade secret. I admit to being amused.

==
If you want the hot stuff, consider calcium hypochorite in solid form. Sold for swimming pools. Hand and eye protection.

 

For more profit, perhaps.
5% was once the norm, and then extra strength 6% came out. That might be the norm now. Less than 5%, and you are probably paying too much. I currently have a bottle of pool shock, which is 12%, that I got from a discount store for less than two bottles of household bleach.

Don't know how available it is to consumers, but if you want a chlorine with a longer shelf life when in solution, look for a chloramine. Many municipal water supplies use it.

 

FYI - The former MSDS (Material Safety Data Sheet) is now known as the Safety Data Sheet (SDS). And yes, the exact % is a trade secret

 

Haven't read up on it all that much, but some of the byproducts don't sound that great : Chloramine Facts - Citizens Concerned About Chloramine (CCAC)

The city uses it here, which affects us when taking a shower, but all our drinking and cooking water passes through a RO/DI filter.

 

Trihalomethanes are the big one, but using straight chlorine produces more. Bleach will make some potential carcinogens while doing its job, but the immediate danger is when mixing it with other cleaners. Must likely know that ammonia and it will release chlorine gas. Acids will do the same. Peroxide will release oxygen; bad in an enclosed space. Other chemicals will result in other toxic chemicals, like carbon tetrachloride.

Chloramine isa problem for the aquarium hobby, as you are left with ammonia after neutralizing the chlorine, which is another chemical unfriendly to most life here.

PS: Our neutralphils make hypochloride for killing microbes.

 

It seems that this particular "trade secret" would be more legal formality than actual useful fact.

 

But we know it's between 3-7% by weight!

 

Salt tablets have expiration dates on them. What does salt become when it expires?

 

Brine?

 

I'm thinking the trade secret bit is just so they would only need to make changes to the first page of of the 10 page SDS for their various bleach products, and to allow for formulation changes without doing the SDS.
Safety Data Sheets (SDS) | The Clorox Company

Purified, bottle water only requires an expiration date in New Jersey. It's just easier to print it on all the bottles than just ones for NJ.

 

Hypertension?

Bob Wilson

 

Salt (assuming NaCl) may be informative for some expiration dates. It will absorb water so its 'chemistry' factually changes. However if one is taking those to replace losses from sweating or intestinal hyperactivity, they remain 100% effective.

CaCl2 sold as a dehumidifier also absorbs water (obviously, yes?). If it has done so to its capacity, it no longer absorbs water. A date of expiration would be sensible for that.

==
Word of the day: deliquescent means absorbing so much water that a puddle results. So to speak. Has some value as in insult for people with sesquipedalian leanings.