Q. I have a small bottle of chlorine bleach which hasn’t been used for a while – don’t know how long. I opened it today and it no longer has that nice, clean, bleach-y smell. It really has no smell at all. Will it still be functional as bleach? If not, how long does it take for this to happen? What happened to the smell? How do I dispose of it, if it is now useless?

A. Thanks for the question; here’s a little background on the shelf-life of Clorox® Regular-Bleach:

The active ingredient, sodium hypochlorite, naturally breaks down into salt and water. The hotter the temperature the bottle is stored at, the faster the decomposition. Generally, bleach stored at room temperature (~70°F) maintains its label strength active level (6% sodium hypochlorite) for approximately six months before starting to degrade into salt and water. After a year, it will still have enough active ingredients to perform well, since it is always diluted before use; just use a little more bleach or a little less water to dilute it. Note that for EPA registered disinfectant uses, always use bleach at label strength, which usually means no more than 5 months past the purchase date, and the bottle must have been properly stored.

Since you don’t remember when you bought your bleach, and it has no bleach smell, it is definitely quite old. The missing bleach smell indicates that most of the active ingredients have converted to salt and water. You are right, it won’t function much as bleach anymore. To dispose of it, I would add it to your toilet bowl and then flush—any small amount of sodium hypochlorite active that may remain will finish breaking down as it travels through your home’s pipes and out to the sewer. You can find many different ways to use it at http://www.clorox.com/cleaner_home/ so your next bottle is used up more quickly.