The Brown Bottle: Storing Hydrogen Peroxide at Home

Hydrogen Peroxide: The Best Antiseptic. Across the world, hydrogen peroxide is a ubiquitous item in every medicine cabinet. Its primary use is for cleaning and sterilizing wounds during first aid emergencies, and it's a must-have household item available at your local drugstore. However, unlike other common chemicals like rubbing alcohol and nail polish remover, hydrogen peroxide comes in its signature brown, opaque bottle. This distinctive packaging is not just for show; it has a fascinating purpose.

The reason why hydrogen peroxide is so widely used as an antiseptic is because it is a really good oxidizing agent. Essentially, hydrogen peroxide can oxidize and kill bacteria that can cause infections, particularly in open wounds. However, as a chemical, hydrogen peroxide is not very stable. In the presence of light, it spontaneously decomposes into oxygen gas and water—two compounds that will not fare as well in killing bacteria.

If hydrogen peroxide were packaged in the clear, translucent bottles that other chemicals like rubbing alcohol come in, most of it would have already decomposed before you could even open the bottle. The purpose of hydrogen peroxide's signature brown, opaque packaging is to specifically combat this—to prevent as much light as possible from making it through the bottle.

However, even so, once the bottle is opened, light will inevitably make it into the bottle and catalyze the decomposition of the hydrogen peroxide. Though the brown packaging drastically improves its shelf-life, it is important to note that if left in an already opened bottle, it will eventually completely decompose, leaving behind a bottle of water and nothing more. Thus, it is important to remember that after opening the bottle, it will only be good to use for a few more months before you need to replace it.