What Happens If You Clean With Expired Bleach?

Though there is no expiration date printed on the bottles, bleach does expire. After six months, bleach begins to lose its potency and is generally considered expired after one year.

While fresh bleach has a potent smell and can cause skin irritation, older bleach is less harmful. As time goes on, bleach slowly breaks down into salt water. Expired bleach won't become more toxic and hurt you, but it will do a worse job of helping you clean and isn't an effective disinfectant.

If you notice that the scent of your bleach is less powerful, it has likely started to degrade. You can still use this for cleaning, but you will need to use a larger volume than normal and there's no way to know if it's still strong enough to kill germs. If there's no scent at all, cleaning with bleach will not be effective. 

While it can typically last for a year, bleach will break down more quickly if stored improperly. Bleach that has been mixed with water will only retain its cleaning power for a few days, so it's a good idea to always use a fresh batch.

How to figure out if your bleach is expired

Though bleach will not have an official expiration date, it does have a manufactured date that will help you determine the shelf life of your bleach. Since bleach will go bad faster if exposed to light or stored in temperatures either much hotter or colder than 70 degrees Fahrenheit, a best-by date wouldn't be reliable in determining if the bleach is still good. This is why the manufacturing date is on the bottle rather than a firm expiration date.

When you look at the bottle, there should be a line with a letter and numbers printed in black ink. The starting letter and number show the location where the bleach was made, the following five numbers express the date, and the last two are manufacturing information. For example, a code reading A82223419 would mean that the bleach was made on the 234th day of 2022, or August 2nd. Once you know the date the bleach was manufactured, you can determine when it will begin to break down.

What to do with expired bleach

Even though bleach loses its strength over time, it's still important to dispose of it safely in case the active ingredients are still present. If you are connected to the city's sewer system, flushing the bleach down the toilet or pouring it down the drain are good options, as long as you make sure to run water. Diluting the bleach with water makes it safer as it goes down the drain, and if you're pouring a lot of bleach, you may need to do it in several batches to ensure enough water is washing it away. It's crucial not to pour bleach down a drain with any other cleaners and to dispose of it in a well-ventilated room. 

Septic systems don't always respond well to this method of disposal, since it can build up in the tank. If you have large quantities of expired bleach or if you're unsure about dumping it down the drain, consider contacting a local hazardous waste facility. They may be able to accept drop-offs or pick it up from you.