Sodium Metabisulphite

It is used in photography.[13] Concentrated sodium metabisulfite can be used to remove tree stumps. Some brands contain 98% sodium metabisulfite, and cause degradation of lignin in the stumps, facilitating removal.[14] It is also used as an excipient in some tablets, such as paracetamol. A very important health related aspect of this substance is that it can be added to a blood smear in a test for sickle cell anaemia (and other similar forms of haemoglobin mutation). The substances causes defunct cells to sickle (through a complex polymerisation) hence confirming disease.

Sodium metabisulphite is added as an excipient to medications which contain adrenaline (epinephrine), in order to prevent the oxidation of adrenaline.[10] For example, it is added to combination drug formulations which contain a local anaesthetic and adrenaline,[10] and to the formulation in epinephrine autoinjectors, such as the EpiPen.[11] This lengthens the shelf life of the formulation,[10] although the sodium metabisulphite reacts with adrenaline, causing it to degrade and form epinephrine sulphonate.[12]