Sodium Metabisulfite Wiki

Brief Introduction

Sodium metabisulfite is a white, crystalline powder, it is used as a preservative, bleaching agent, antioxidant, leavening agent, color fixative, coagulant, mold inhibitor, dechlorinate agent, cotton fabric cooking agent, reductant, concrete water reducing agent, mineral processing agent, etc.. Sodium metabisulfite is also used to make other sulfite compounds. Sodium metabisulfite is very soluble in water and is very acidic.

Basic information

Chemical Properties

Specifications

Production Process

1. After melting, clarification, and efficient filtration, sulfur is added to the sulfur incinerator by a sulfur pump.

2. After compression, drying, and purification, the air is passed through a sulfur incinerator and burned with sulfur to produce SO2 gas (furnace gas).

3. The furnace gas is cooled by the waste boiler to recover steam, and then enters the desulfurization reactor to remove the sublimated sulfur in the gas, obtaining a pure gas with a SO2 content of 20.5% (volume). Enter the sodium hydroxide synthesis reactor.

4. Soda ash enters the alkali mixing tank from the soda ash tank and is mixed with the mother liquor to prepare a suspension of a certain concentration.

5. The alkaline solution is pumped into the third stage sodium hydroxide reaction kettle and reacts with the sulfur dioxide gas from the second stage.

6. Sulfur dioxide gas enters from the first stage reaction kettle and passes through the first, second, third stage reaction kettles in sequence. The tail gas enters the tail gas scrubbing tower.

7. After the materials of the first stage reaction kettle are qualified, the qualified materials are placed in a centrifuge to achieve solid-liquid separation. The solid (wet caustic soda) enters the airflow dryer and is dried with hot air to obtain the finished caustic soda product. The mother liquor is reused in the alkali mixing station.

8. After the first level materials are discharged, the second level materials are discharged to the first level, and the third level materials are discharged to the second level. The alkali solution is then injected from the alkali mixing tank into the third level kettle.

Solubility

Soluble in water and its water solubility increases with temperature, 54g/100ml at 20°C and 81.7g/100ml at 100°C. It produces sodium bisulfite (HSO3−) when dissolved in water and the aqueous solution is acidic with the PH 4.0-5.5 (10 % aqueous solution).

Na2S2O5 + H2O = 2 NaHSO3

Soluble in glycerin, slightly soluble in ethanol, insoluble in benzene.

Regulatory Information

FDA

Sodium metabisulfite is generally recognized as safe (GRAS) when used as a preservative except in meats, foods recognized as a source of vitamin B1 and fresh fruits or vegetables.

EFSA

Sodium metabisulfite (E223) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and categorized in “ additives other than colours and sweeteners”.

EFSA

Sodium metabisulfite (E223) is listed in Commission Regulation (EU) No 231/2012 as an authorised food additive and categorized in “ additives other than colours and sweeteners”.

Hazard

Sodium metabisulfite is currently listed in Annex III Part B of Directive 95/2/EC as an authorised food additive. As such food labelling is required where sulphite residues exceed 10 mg/kg (ppm). This is labelled E223 with maximum permitted residues in crustacean products set at 150 mg/kg. However it is now accepted that sulphites, when present in foodstuffs, can cause allergic reactions in vulnerable persons and can constitute a danger to health (Collins-Williams, 1983). Metabisulfite is regarded as one causative agent of asthma attacks (Gunnison & Jacobsen, 1987). In accordance with this, EU Directive 2003/89/EC will make allergen labelling a requirement for all food stuffs produced in the European Community, which have been treated with sodium metabisulfite.

Sodium metabisulfite typically found in consumer products should pose little a risk of symptoms due to skin or inhalation exposure since sodium metabisulfite is used in very low concentrations. Sodium metabisulfite can produce the following adverse health affects:

Contact – Skin exposures can cause symptoms ranging from minor skin irritation or itching to redness and swelling. Eye exposure to sodium metabisulfite may result in redness, tearing or moderate eye irritation.

Inhalation – The inhalation of sodium metabisulfite dusts can cause nose and throat irritation or coughing. Repeated or prolonged exposures may cause sore throat or nosebleeds. Inhalation may also cause severe respiratory reactions and aggravate asthma or other breathing diseases.

Ingestion – The ingestion of sodium metabisulfite may cause irritation of the mouth and throat, nausea, vomiting and diarrhea.

Other Effects – The International Agency for Research on Cancer (IARC) has not classified sodium metabisulfite as a carcinogen (cancer causing).

FAQs

Is sodium metabisulfite toxic in food?

Sodium metabisulfite is generally recognized as safe (GRAS) for use in food by regulatory agencies like the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) when used within approved limits.

What food has sodium metabisulfite in it?

Sodium metabisulfite is commonly used in a variety of foods as a preservative and antioxidant. The following types of foods may contain sodium metabisulfite:

Dried fruits, wine and beer, processed vegetables, baked goods, fruit juices and concentrates, seafood, condiments and sauces, processed potatoes, jams and jellies, beverages, and etc..

What’s the other names (synonyms) of sodium metabisulfite?

Sodium metabisulfite is also called as sodium metabisulphite, SMBS, Sodium pyrosulphite, Disodium pyrosulphite.

What is the difference between sodium metabisulfite and sodium metabisulphite?

They are totally the same product. Only word origins are different, f is from French, and ph is from Greek. 

What is the PH of sodium metabisulfite? 

4.0-4.8.

Who is the manufacturer of sodium metabisulfite in China? 

Qingdao Tianya Chemical Co., Ltd is the leading manufacturer of sodium metabisulfite in China. We are China’s leading sodium metabisulfite factory and exporter. 

Where is the raw materials origin of Tianya’s sodium metabisulfite? 

The raw materials origin is China.