Sodium metabisulfite

Sodium metabisulfite is an inorganic and white to yellow powder with a low sulfur odor that has lots of applications in conservator, antioxidant, and disinfectant agent. It’s also known as sodium pyrosulfite

Properties

Chemical formula	Na2S2O5
Molar mass	190.107 g/mol
Density	1.48 g/cm3
Melting point	170  ͦC
Solubility	soluble in water and glycerol
chemical structure

 

Production

Sodium metabisulfite can be prepared with the reaction between sodium hydroxide and sulfur dioxide.

SO2 + 2 NaOH → Na2SO3 + H2O

For increasing yield, Na2SO3 reacts with SO2:

SO2 + Na2SO3 → Na2S2O5

Applications

Sodium pyrosulfite has many applications in the food and beverage industry, it is an antioxidant and preservative agent in these contexts.

Food

Sulfating agents are mostly used as anti-spoilage in the food industry.

For keeping fruits or other things like clothing during shipping, this matter is used as an anti-microbe and can prevent mold. Also, it has a disinfectant effect on foods by playing an acidic role.

This matter has a loosening effect on foods like a loaf and in bakery SMBS will increase the looseness of dough and simplify kneading.

Na₂S₂O₅ is a preservative agent in dried foods like apple, potato, chips and It has an anti-browning effect on apple and potato because SMBS is a reduction agent and will reduce the enzyme activity. Furthermore oxidation resistance effect helps to consume oxygen in vegetable texture and stop the activity of oxidizing enzymes, this matter also can prevent breaking of vitamin C.

In addition for production commercial wine, it plays an important role.

Medical and pharmacology

It can prevent adrenaline from oxidation and because of this is usable in medicines which contain adrenaline, and also in the medical field, it can detect sickle cell anemia.

Water treatment:

In the water treatment industry, SMBS helps to the neutralization of residual chlorine and reduction of chromium.

Cosmetic

Sodium pyrosulfite is used in cosmetics as a reduction agent.SMBS has a disinfectant and preservative effect in personal care and exists in hair care material such as hair dyes, hair bleaches and, so on.

This substance is completely safe in cosmetics because it has big particles and they can’t be absorbed by the skin easily.

Laboratory

Sodium pyrosulfite is a laboratory reagent that is usable in the production of benzene, formaldehyde, chloroform, and vanillin hydroxyl.

Na₂S₂O₅ has other applications too, for example, that is a bleaching agent in the paper industry and textile and is a dechlorination agent in the leather industry and cotton scouring.

Danger

Na₂S₂O₅ is a toxic substance for Ingestion, inhalation, and eye or skin contact, it will be an acid when composing with water.

Inhaling SMBS can cause coughing and other breathing symptoms that can make asthma for a long time.

Ingestion of this substance can cause abdominal pain, vomiting, diarrhea, etc. Also, it will distribute circulatory and make a depression.

In skin contact, it creates etching and redness.

It’s really dangerous when contact with eyes, it will create stinging, tearing, corneal damage, and blindness that could be irreversible.

SMBS is also allergic to those who are sulfite-sensitive and can make gastrointestinal disturbances and shortness of breath.

 

References

https://pubchem.ncbi.nlm.nih.gov/

https://en.wikipedia.org/

https://nutrition.basf.com/

http://www.sodiummetabisulfite.cn/

https://waqaschemicals.com/

https://www.fengchengroup.com/