Yes, bleach is an incredibly effective disinfectant, thanks to its active ingredient sodium hypochlorite. But you may be surprised to know that it does so at a far more efficient rate when diluted with water. Nine parts water to one part bleach is the recommended ratio for killing germs. It’s important to note that bleach has a shelf life. After six months, it starts to degrade and will become around 20% less effective with each passing year.