Sodium Thiosulfate
na2s2o3 · SODIUM THIOSULPHATE · Thiosulfate · SODIUM HYPOSULFITE · HYPO · Na2O3S2 · Sodium Thiosulfite · Sodium Thiosulfat
Identifiers & Physical Properties
| CAS No. | 7772-98-7 |
|---|---|
| Molecular formula | Na2O3S2 |
| Average molar mass | 158.11 g/mol |
| Monoisotopic mass | 157.90842442 g/mol |
| SMILES | O=S([O-])([O-])=S.[Na+].[Na+] |
| InChIKey | AKHNMLFCWUSKQB-UHFFFAOYSA-L |
| PubChem CID | 24477 |
| ChEMBL | CHEMBL2096650 |
| ChEBI | CHEBI:132112 |
| EC No. | 231-867-5 |
| DTXSID | DTXSID9042417 |
Chemical & Physical Properties
| Topological polar surface area | 104 |
|---|---|
| Hydrogen bond donors | 0 |
| Hydrogen bond acceptors | 4 |
| Rotatable bonds | 0 |
| Heavy atoms | 7 |
| Formal charge | 0 |
| Complexity | 82.6 |
| Chemical classes | Other Classes -> Sulfur Compounds |
| Cosmetics | Reducing |
| LogP (partition coefficient) | -4.35 (calculated) |
| Density | 1.6671.7 g/cm³1.01 g/mL at 25 °C |
| Color/Form | POWDERCOLORLESS MONOCLINIC CRYSTALS |
| Solubility | PRACTICALLY INSOL IN ALCOHOL50 G SOL IN 100 CC WATER231 G @ 100 °CSolubility in water, g/100ml at 20 °C: 20.9Immiscible with alcohol.Soluble in water. Insoluble in alcohol. |
| Human Drugs | FDA approved drugs -> Active ingredientEMA approved medicines: Human medicineAntidotes and other substances used in poisonings > Specific |
| Animal Drugs | Pharmaceuticals -> UK Veterinary Medicines Directorate List |
| Decomposition | DANGEROUSWHEN HEATED TO DECOMP, THEY EMIT HIGHLY TOXIC FUMES OF /DISODIUM OXIDE AND SULFUR OXIDES/.300 °C |
| Melting point | 48.5 °C48°C |
| Vapor pressure | Vapor pressure at 20 °C: negligible |
| Refractive index | INDEX OF REFRACTION: 1.489 ALPHA, 1.508 BETA, 1.536 GAMMAOPTIC SIGN + |
| Boiling point | 100°C |
| Bulk density | 1350kg/m3 |
| Storage conditions | Store at +5°C to +30°C. |
| Physical state | Solid |
| Specific gravity | 1.667 |
| Color | White |
| pH | 6.0-8.5 (25℃, 50mg/mL in H2O) |
| Sensitivity | Hygroscopic |
| Merck | 14,8694 |
| Stability | Stable. Incompatible with strong acids, strong oxidizing agents, iodine, mercury. |
| Cosmetics Ingredients Functions | REDUCING |
| InChI | 1S/2Na.H2O3S2/c1-5(2,3)4/h(H2,1,2,3,4)/q2*+1/p-2 |
| InChIKey | AKHNMLFCWUSKQB-UHFFFAOYSA-L |
| SMILES | [Na+].[Na+].[O-]S([O-])(=O)=S |
| LogP (partition coefficient) | -0.428 (est) |
| FDA 21 CFR | 184.1807310.545582.6807 |
| CAS DataBase Reference | 7772-98-7(CAS DataBase Reference) |
| EWG's Food Scores | 1 |
| NCI Dictionary of Cancer Terms | sodium thiosulfate |
| FDA UNII | L0IYT1O31N |
| NCI Drug Dictionary | sodium thiosulfate |
| ATC code | V03AB06 |
| EPA Substance Registry System | Sodium thiosulfate (7772-98-7) |
| UNSPSC Code | 12352305 |
| NACRES | NA.23 |
| GHS pictogram | GHS07 |
| Signal word | Warning |
| GHS hazard statements | H335-H315-H319 |
| GHS precautionary statements | P264-P280-P305+P351+P338-P337+P313P-P264-P280-P302+P352-P321-P332+P313-P362 |
| Hazard symbols | Xi |
| Risk statements (R) | 36/37/38 |
| Safety statements (S) | 24/25-23-36-26 |
| Water hazard class (WGK) | 1 |
| RTECS number | XN6476000 |
| F | 3 |
| TSCA inventory status | TSCA listed |
| Customs code | 28323000 |
| Storage class | 11 - Combustible Solids |
| Hazardous substances data | 7772-98-7(Hazardous Substances Data) |
| Toxicity | LD50 orally in Rabbit: > 5000 mg/kg |
| REACH registrations | Active |
Safety & Regulations
| GHS classification | Not ClassifiedAggregated GHS information provided per 2963 reports by companies from 8 notifications to the ECHA C&L Inventory. |
|---|---|
| Regulatory information | Chemical: Thiosulfuric acid (H2S2O3), disodium saltThiosulfuric acid (H2S2O3), sodium salt (1:2) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Thiosulfuric acid (H2S2O3), sodium salt (1:2) are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)Status: Active Update: 24-04-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/14321Sodium thiosulphate: Does not have an individual approval but may be used under an appropriate group standard |
| Other safety information | IMAP assessments - Thiosulfuric acid (H2S2O3), disodium salt: Environment tier I assessment |
| Fire hazards | Not combustible. Gives off irritating or toxic fumes (or gases) in a fire. Risk of explosion on contact with oxidizing agents. |
| Hazards summary | Potential combustible dust hazardDecomposes slowly in water with potential generation of toxic and flammable hydrogen sulfide and corrosive hydrogen sulfite and sulfuric acidVery soluble in waterExtremely low vapor pressureMay violently decomposes at 223 deg C[CHEMINFO] ADI = 0-0.7 mg/kg[JECFA] May be used in food up to 0.1%[Hawley] See Potassium thiosulfate. |
| FDA requirements | 121.101LIMITATIONS: GRAS, SEQUESTRANT IN SALT UP TO 0.1% |
| EPA Safer Chemical | Chemical: Sodium thiosulfate |
| Chemical Dangers | Decomposes on heating. This produces toxic fumes including sulfur oxides. Reacts violently with strong oxidants. |
| Hazard Classes and Categories | Not Classified |
| Explosive Limits and Potential | DRY TRITURATION WITH OXIDIZING AGENTS SUCH AS POTASSIUM CHLORATE, POTASSIUM PERMANGANATE, OR NITRATE MAY CAUSE EXPLOSION.WHEN SODIUM NITRITE & THIOSULFATE MIXT WAS HEATED TO EVAPORATE TO DRYNESS, VIOLENT EXPLOSION OCCURRED. |
| Fire fighting | In case of fire in the surroundings, use appropriate extinguishing media. |
| First aid measures | Fresh air, rest.Rinse and then wash skin with water and soap.Rinse with plenty of water for several minutes (remove contact lenses if easily possible).Rinse mouth. |
| Safe storage | Separated from strong oxidants. |
| Spillage disposal | Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. |
| Eye Prevention | Wear safety goggles. |
| Fire Prevention | NO contact with oxidizing agents. |
| Inhalation Risk | A nuisance-causing concentration of airborne particles can be reached quickly when dispersed. |
| Ingestion Prevention | Do not eat, drink, or smoke during work. |
| Inhalation Prevention | Avoid inhalation of dust. |
| Protective Action Criteria (PAC) | 5.8 [mg/m3]64 [mg/m3]380 [mg/m3] |
| Signs and Symptoms | Redness. |
| Human Toxicity Excerpts | REMARKABLY INERT IN VIVO, EXCEPT FOR OSMOTIC DISTURBANCES. ... ACTS AS OSMOTIC CATHARTIC. |
| Drug Induced Liver Injury | Drug Induced Liver Injury Rank (DILIrank 2.0)Sodium thiosulfatevNo-DILI-concernNo matchDOI:10.1016/j.drudis.2016.02.015 |
| F | 3 |
| Water hazard class (WGK) | 1 |
| TSCA inventory status | TSCA listed |
| RTECS number | XN6476000 |
| Customs code | 28323000 |
| Toxicity | LD50 orally in Rabbit: > 5000 mg/kg |
| Risk statements (R) | 36/37/38 |
| Signal word | Warning |
| GHS pictogram | GHS07 |
| Hazard symbols | Xi |
| Safety statements (S) | 24/25-23-36-26 |
| Storage class | 11 - Combustible Solids |
| GHS hazard statements | H335-H315-H319 |
| REACH registrations | Active |
| GHS precautionary statements | P264-P280-P305+P351+P338-P337+P313P-P264-P280-P302+P352-P321-P332+P313-P362 |
| Hazardous substances data | 7772-98-7(Hazardous Substances Data) |
Applications & Uses
Description
Sodium thiosulfate is a commonly used chemical material, as the fixing agent in photography, film and printing plate-making industry, as a reducing agent used in tanning. It is used as a bleaching agent for removing residual and a mordant in the paper and textile industries, as antidotes of cyanide poisoning in medicine, as dechlorination agent and fungicides of drinking water and wastewater in water treatment, as a copper corrosion inhibitor of circulating cooling water and a deoxidizer of boiler water systems. It is also used for Cyanide wastewater treatment. Soda ash and sulfur are generally used as raw materials in industry, soda ash reacts with sulfur dioxide produced by the combustion of sulfur to produce sodium sulfite, then add sulfur for boiling reactions, and then filter, bleach, concentrate and crystallize, etc, can obtain sodium thiosulfate pentahydrate. Other production waste containing sodium sulfide, sodium sulfite, sulfur and sodium hydroxide can also be used, after appropriate treatment to get the product. The above information is edited by Yan Yanyong of Chemicalbook.
Uses
1. Sodium thiosulfate is Used in manufacture of the fixing powder and preparation of the photographic industry fixer, desiccant. Used as a reducing agent of dichromate in leather tanning industry. 2. Sodium thiosulfate is an important inorganic chemical raw material. It can be used in the synthesis of pesticides Bisultap, Thiosultap disodium, CARTAP and so on. 3. Used as analytical reagents, mordant and fixer. 4. Used as new insecticides, with stomach poisoning, uptake and contact action effects, it can prevent and treat rice yellow stem borer, stem borer, leaf roller, rice thrips and vegetables, fruit pests. 5. With uptake and strong contact, stomach poisoning effects, it can prevent and treat various rice pests and vegetables, fruit pests. 6. Used as the chlorine removal agent for Pulp and cotton fabric bleached, as chelating agents, anti-oxidants in the food industry, as detergents, disinfectants in the pharmaceutical industry. 7. Used as chelating agents, antioxidants, anti-browning agent, as the dechlorination agent of chlortetracycline hydrochloride (or chlortetracycline) chilled with ice, dechlorination reaction is as follows: More chlorine content will cause side reactions of free sulfur, so only used for very dilute concentrations of chlorine. Used as salt chelating agent, limited content is 0.1% or less.
Uses
Sodium thiosulfate is a common analytical reagent used in iodometric titration to analyze chlorine, bromine, and sulfide. Other uses are in bleaching paper pulp, bleaching straw, ivory, and bones, for removing chlorine from solutions, silver extraction from its ores, a mordant in dyeing and printing textiles, and as an antidote to cyanide poisoning. Another major application is in photography, where it is used as a fixer to dissolve unchanged silver salts from exposed negatives. Sodium Thiosulfate is used primarily as a medicament against cyanide poisoning, able to convert cyanide into thiocyanate, a reaction which is catalyzed by the enzyme Rhodanese. Antioxidant.
Uses
Sodium Thiosulfate is a sequestrant, antioxidant, and formulation aid that is a powder soluble in water. it can be used in alcoholic bev- erages at 5 ppm and in table salt at 0.1%. it is also termed sodium hyposulfite.
Uses
Sodium thiosulfate (thiosulfate) Known simply as “hypo,” an abbreviated form of the incorrect form hyposulfite, this white crystal was made by boiling calcium thiosulfate with sodium sulfate. It is soluble in water and oil of turpentine but not in alcohol. The property of sodium thiosulfate to dissolve silver halides was discovered in 1819 by Sir John Herschel and was probably first used to fix photographic images by L. J. M. Daguerre. After Daguerre published its use in his 1839 manual W. H. F. Talbot finally used it to fix calotype negatives and silver chloride prints, although he continued to stabilize them with potassium iodide and sodium chloride presumably for the variety of colors possible. Sodium thiosulfate was the primary fixing agent throughout the 19th century and is still used today.
General Description
Sodium thiosulfate (Na2S2O3) can be obtained from Na2S2O3.10H2O by heating above 100 °C. It can be synthesized from sodium sulfate.
Preparation & Synthesis
Preparation
Sodium thiosulphate is an important chemical commodity that is known to photographers as "hypo". It can be prepared by the reaction of sodium sulphite and the bisulphite with H2S: 2Na2S03 + 2NaHS03 + 2H2S -> 3Na2S203 + 3H20 It can also be prepared by the reaction of sulphur with sodium sulphite above 60 °C Na2SO3 + S -> Na2S2O3 and by the reaction of H2S and permanganate. Sodium thiosulphate decomposes at 310°C to form sulphur and Na2S03 , and at 400°C to form Na2S4 and Na2S. It absorbs S02 to form free sulphur and Na2S04 . Sodium thiosulphate forms many hydrates and their solubility relationships are quite complex.
Preparation
Sodium thiosulfate is a common reducing agent. It reduces iodine to iodide anion forming sodium tetrathionate. This reaction is utilized in the so-called iodometric titration: 2S2O32ˉ + I2 → S4O62ˉ + 2IˉSodium thiosulfate reacts with chlorine to form sodium bisulfate and hydrochloric acid. This reaction removes chlorine from aqueous solutions:Na2S2O3 + 4Cl2 + 5H2O → 2NaHSO4 + 8HClSodium thiosulfate reacts with hydrochloric acid, decomposing to sulfur and sulfur dioxide: Na2S2O3 + 2HCl → 2NaCl + S + SO2 + H2O.