Sodium Metabisulfite

Description

Food additiveIt is used as a food additive, mainly as a preservative and is sometimes identified as E223. It may cause allergic reactions in those who are sensitive to sulfites, including respiratory reactions in asthmatics as well as in those who do not identify with the condition.[1].It is present in many dilutable squashes (i.e. fruit juice concentrates) and in candy bars such as Mounds.[2]. Sodium metabisulfite and potassium metabisulfite are the primary ingredients in Campden tablets, used for wine and beer making. The acceptable daily intake is up to 0.7 mg per kg of body weight. Sodium metabisulfite has no side effects; it is oxidised in the liver to harmless sulfate and excreted in the urine.[3]Sanitization / Cleaning agentIt is commonly used in homebrewing and winemaking to sanitize equipment. It is used as a cleaning agent for potable water reverse osmosis membranes in desalination systems. It is also used to remove chloramine from drinking water after treatment.Other usesConcentrated 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.[4]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.