Molecular formula Na2S2O5 or Na2O5S2
Molecular weight 190.11
Physical state: – Sodium meta bi sulphite appears as a white crystalline or powder solid with a slight sulphur odour. Toxic by inhalation. Strongly irritates skin and tissue. Non-combustible, but may decompose to emit toxic oxide fumes of sulphur and sodium when heated to high temperature. A corrosive acid when mixed with water. Used as a food preservative and as a laboratory reagent.
Melting point greater than 302 °F (Decomposes) (NIOSH, 2016)
Uses
Sodium and potassium meta bi sulphite have many major and niche uses. It is widely used for preserving food and beverages.
• Sodium metabisulfite is added as an excipient to medications which contain adrenaline (epinephrine), in order to prevent the oxidation of adrenaline.[6] For example, it is added to combination drug formulations which contain a local anaesthetic and adrenaline,[6] and to the formulation in epinephrine autoinjectors, such as the EpiPen.[7] This lengthens the shelf life of the formulation,[6] although the sodium metabisulphite reacts with adrenaline, causing it to degrade and form epinephrine sulphonate.[8]
• In combination with sodium hydrosulfite it is used as a rust-stain remover[9]
• It is used in photography.[10]
• 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.[11]
• 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 substance causes defunct cells to sickle (through a complex polymerisation) hence confirming disease.
• It is used as a bleaching agent in the production of coconut cream
• It is used as a reducing agent to break sulfide bonds in shrunken items of clothing made of natural fibres, thus allowing the garment to go back to its original shape after washing
• It is used as a SO2 source (mixed with air or oxygen) for the destruction of cyanide in commercial gold cyanidation processes.
• It is used as a SO2 source (mixed with air or oxygen) for the precipitation of elemental gold in chloroauric solutions.
• It is used in the water treatment industry to quench residual chlorine.
• It is used in tint etching iron-based metal samples for microstructural analysis.
• It is used as a fungicide for anti-microbe and mould prevention during shipping of consumer goods such as shoes and clothing. Plastic stickers and packaging (such as Micro-Pak™) containing the anhydrous, sodium meta bi sulphite solid active ingredient are added prior to shipping. The devices absorb moisture from the atmosphere during shipping and release low levels of sulphur dioxide.
• It is used for preserving fruit during shipping.
• It is used as a solvent in the extraction of starch from tubers, fruit, and cereal crops.
• It is used as a pickling agent to treat high pressure reverse osmosis water desalination membranes for extended storage periods between uses.
Molecular weight 190.11
Physical state: – Sodium meta bi sulphite appears as a white crystalline or powder solid with a slight sulphur odour. Toxic by inhalation. Strongly irritates skin and tissue. Non-combustible, but may decompose to emit toxic oxide fumes of sulphur and sodium when heated to high temperature. A corrosive acid when mixed with water. Used as a food preservative and as a laboratory reagent.
Melting point greater than 302 °F (Decomposes) (NIOSH, 2016)
Uses
Sodium and potassium meta bi sulphite have many major and niche uses. It is widely used for preserving food and beverages.
• Sodium metabisulfite is added as an excipient to medications which contain adrenaline (epinephrine), in order to prevent the oxidation of adrenaline.[6] For example, it is added to combination drug formulations which contain a local anaesthetic and adrenaline,[6] and to the formulation in epinephrine autoinjectors, such as the EpiPen.[7] This lengthens the shelf life of the formulation,[6] although the sodium metabisulphite reacts with adrenaline, causing it to degrade and form epinephrine sulphonate.[8]
• In combination with sodium hydrosulfite it is used as a rust-stain remover[9]
• It is used in photography.[10]
• 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.[11]
• 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 substance causes defunct cells to sickle (through a complex polymerisation) hence confirming disease.
• It is used as a bleaching agent in the production of coconut cream
• It is used as a reducing agent to break sulfide bonds in shrunken items of clothing made of natural fibres, thus allowing the garment to go back to its original shape after washing
• It is used as a SO2 source (mixed with air or oxygen) for the destruction of cyanide in commercial gold cyanidation processes.
• It is used as a SO2 source (mixed with air or oxygen) for the precipitation of elemental gold in chloroauric solutions.
• It is used in the water treatment industry to quench residual chlorine.
• It is used in tint etching iron-based metal samples for microstructural analysis.
• It is used as a fungicide for anti-microbe and mould prevention during shipping of consumer goods such as shoes and clothing. Plastic stickers and packaging (such as Micro-Pak™) containing the anhydrous, sodium meta bi sulphite solid active ingredient are added prior to shipping. The devices absorb moisture from the atmosphere during shipping and release low levels of sulphur dioxide.
• It is used for preserving fruit during shipping.
• It is used as a solvent in the extraction of starch from tubers, fruit, and cereal crops.
• It is used as a pickling agent to treat high pressure reverse osmosis water desalination membranes for extended storage periods between uses.