焦亚硫酸钠

Description

Sodium Metabisulphite Food Grade · CAS 7681-57-4 · Na2S2O5. UNII 4VON5FNS3C. Solubility: 54 % (NIOSH, 2024); Solubility: 66.7 g/100 g water at 25 °C; Solubility: 54%.

Identification

CAS Registry Number	7681-57-4
PubChem CID	656671
Molecular formula	Na2S2O5
UNII (FDA)	4VON5FNS3C

Computed Descriptors

Molecular Weight	190.11
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	0
Exact Mass	189.89825401
Monoisotopic Mass	189.89825401
Topological Polar Surface Area	125
Heavy Atom Count	9
Formal Charge	0
Complexity	136

Physical & Chemical Properties

Solubility	54 % (NIOSH, 2024)
Solubility	66.7 g/100 g water at 25 °C
Solubility	54%
Density	2.36 g/cm³
Density	1.4
Density	1.4 @25 °C
LogP	-3.7
Decomposition	150 °C
pH	4,0-5,5 (10 % aqueous solution)

Physical description & handling notes

• Sodium metabisulfite appears as a white crystalline or powder solid with a slight sulfur odor. Toxic by inhalation. Strongly irritates skin and tissue. Noncombustible, but may decompose to emit toxic oxide fumes of sulfur and sodium when heated to high temperature. A corrosive acid when mixed with water. Used as a food preservative and as a laboratory reagent.
• Dry Powder; Other Solid; Wet Solid; Large Crystals; CBI; Liquid
• White crystals or crystalline powder
• White to yellowish crystals or powder with an odor of sulfur dioxide; [NIOSH]
• WHITE POWDER WITH CHARACTERISTIC ODOUR.
• White to yellowish crystals or powder with a slight odor of sulfur.

Regulatory Status

Regulatory & Food Contact	FDA Substance added to food: ANTIMICROBIAL AGENT, ANTIOXIDANT, COLOR OR COLORING ADJUNCT, DOUGH STRENGTHENER, ANTIOXIDANT; FLOUR_TREATMENT_AGENT; PRESERVATIVE: Food Additives ANTIMICROBIAL AGENT, ANTIOXIDANT, COLOR OR COLORING ADJUNCT, DOUGH STRENGTHENER, FLOUR TREATING AGENT, FREEZIN JECFA ADI: 0-0.7 mg/kg bw TRS 891-JECFA 51/30 FAS 42-JECFA 51/95
GHS notification summary	0.4% (11 / 3060)

GHS Hazard Classification

GHS notification summary	0.4% (11 / 3060)
Reported hazard statements	H302, H318, H317, H334, H335, H402, H412, H320

Documented Uses

• CIR ingredient: Sodium Metabisulfite
• Sodium and potassium metabisulfite are used as antioxidants in photographic film development. [Kanerva, p. 1637] Used as an antioxidant (food preservative, pharmaceutical aid, silage preservative; [HSDB] Used in the pickling stage of leather production; [PMID 21938525]
• Leather Tanning and Processing [Category: Industry]
• Photographic Processing [Category: Other]
• Sodium Metabisulfite functions as reducing agents in cosmetic formulations. ... Sodium Bisulfite, and Sodium Metabisulfite /also/ function as antioxidants.
• In foods, as preservative; lab reagent

Synonyms

Sodium metabisulfite; 7681-57-4; Sodium pyrosulfite; Sodium disulfite; Disodium pyrosulfite; Natrii disulfis; Campden Tablets; Disodium metabisulfite; Natrium pyrosulfit; Natriummetabisulfit; sodium pyrosulphite; Sodium bisulfite anhydrous; Natrium metabisulfurosum; Sodium pyrosulfite (Na2S2O5); Disodium pentaoxodisulfate; 4VON5FNS3C

Frequently Asked Questions

What are the CAS number and molecular formula of Sodium Metabisulphite Food Grade?

CAS 7681-57-4; molecular formula Na2S2O5; molecular weight — g/mol.

What other names is Sodium Metabisulphite Food Grade known by?

Sodium metabisulfite, 7681-57-4, Sodium pyrosulfite, Sodium disulfite, Disodium pyrosulfite, Natrii disulfis.

What is the regulatory status of Sodium Metabisulphite Food Grade?

Documented regulatory listings: FDA Substance added to food: ANTIMICROBIAL AGENT, ANTIOXIDANT, COLOR OR COLORING ADJUNCT, DOUGH STRENGTHENER,; ANTIOXIDANT; FLOUR_TREATMENT_AGENT; PRESERVATIVE: Food Additives; ANTIMICROBIAL AGENT, ANTIOXIDANT, COLOR OR COLORING ADJUNCT, DOUGH STRENGTHENER, FLOUR TREATING AGENT, FREEZIN.

Is Sodium Metabisulphite Food Grade classified as hazardous?

0.4% of GHS notifications report no hazard classification (11 of 3060).

What are the key physical properties of Sodium Metabisulphite Food Grade?

Solubility: 54 % (NIOSH, 2024); Solubility: 66.7 g/100 g water at 25 °C; Solubility: 54%; Density: 2.36 g/cm³.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.