Campden tablets can be used to sanitise wine musts and juices. Can also be used during racking as both a measure to prevent bacteria from spoiling the wine. They can also be used as an antioxidant to keep air from staling the wine.
Along with this, Campden Tablets can be used in removing chlorine which is particularly useful to beer makers. Chlorine in water reacts with compounds in malted barley and can create unpleasant off flavours.