PH: ABOUT 12.5HAS RELATIVELY HIGH BUFFER CAPACITY /0.5% SOLUTION/AQ SOLN ARE STRONGLY ALKALINE13.5 (20°C in H2O)
Lebensmittelzusatzstoffe
Use unspecified -> FDA Substance added to foodANTICAKING AGENT OR FREE-FLOW AGENT, DRYING AGENT, HUMECTANT, PROCESSING AID -> FDA Substance added to food
Dichte
1.1 to 1.7 at 68 °F (USCG, 1999)2.614Relative density (water = 1): 1.41.1 to 1.7 @ 15°C2.33 g/mL at 25 °C(lit.)
Color/Form
COLORLESS MONOCLINIC CRYSTALSUSUALLY OBTAINED AS A GLASSALSO ORTHORHOMBIC CRYSTALSDUSTLESS WHITE GRANULESCOLORLESS TO WHITE OR GRAYISH-WHITE, CRYSTAL-LIKE PIECES OR LUMPSLUMPS OF GREENISH GLASSWHITE POWDERSLIQUIDS CLOUDY OR CLEAR
Löslichkeit
VERY SOL IN COLD & HOT WATERSOLUBLE IN DILUTE SODIUM HYDROXIDEINSOLUBLE IN ALCOHOL, ACIDS /NONAHYDRATE/SOL IN WATERINSOL IN ALCOHOLINSOL IN ACIDS, SALT SOLNIn commerce mole ratios of SiO2 to Na2O vary from 1.5 to 3.3. ... The higher the ratio (e.g., the less sodium) the lower the solubility and alkalinity.VERY SLIGHTLY SOL OR ALMOST INSOL IN COLD WATERLESS READILY SOL IN LARGE AMT OF WATER THAN IN SMALL AMTANHYD DISSOLVE WITH MORE DIFFICULTY THAN HYDRATE IN WATERGLASS FORM SOL IN STEAM UNDER PRESSUREPARTIALLY MISCIBLE WITH PRIMARY ALC & KETONESMISCIBLE WITH SOME POLYHYDRIC ALCH2O: solublevery slightly soluble cold H2O [MER06]
Corrosivity
Sodium metasilicate is considered to be too corrosive to be widely used in consumer product laundering formulations.
Siedepunkt
BOILING POINT: 100 °C -6H20 /NONAHYDRATE/102 °C @760 [mm Hg]2355 °C(lit.)
Decomposition
Solutions of sodium metasilicate, when heated or acidified, are hydrolyzed to free sodium ions and silicic acid.
Schmelzpunkt
1089 °CMELTING POINT: 48 °C IN WATER OF CRYSTALLIZATIONHEAT OF HYDRATION: -24.15 KCAL/MOLEEFFLORESCENTORTHORHOMBIC BIPYRAMIDAL PLATELETS /NONAHYDRATE/1410 °C(lit.)
Brechungsindex
1.520
Lagerbedingungen
-20°C
Aggregatzustand
powder
Farbe
Colorless
Geruch
Odorless
Biologische Quelle
mouse
Merck
13,8751
Dielektrizitätskonstante
16.0(Ambient)
Stabilität
Stable. Incompatible with acids, most metals, many organic materials.
Kosmetik-Inhaltsstoffe Funktionen
BUFFERINGANTICORROSIVE
InChIKey
NTHWMYGWWRZVTN-UHFFFAOYSA-N
CAS Datenbank
1344-09-8(CAS DataBase Reference)
EPA chemische Informationen
Sodium silicate (1344-09-8)
Sicherheit & Vorschriften
GHS-Einstufung
DangerH314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]P260, P261, P264, P271, P280, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P319, P321, P363, P403+P233, P405, and P501 (click each P-code to see the statement)This chemical does not meet GHS hazard criteria for 7.2% (290 of 4043) of reports.H290 (13.9%): May be corrosive to metals [Warning Corrosive to Metals]
Regulatorische Informationen
Chemical: Silicic acid (H2SiO3), disodium saltChemical: Silicic acid, sodium saltRegulation (EC) No 178/2002 (amended)Silicic acid, sodium salt is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Silicic acid, sodium salt 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)Silicic acid (H2SiO3), sodium salt (1:2) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Silicic acid (H2SiO3), 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: 31-03-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/16162
Weitere Sicherheitsinformationen
IMAP assessments - Silicic acid (H2SiO3), disodium salt: Environment tier I assessmentIMAP assessments - Soluble silicates: Human health tier II assessment
If large doses are ingested, some irritation of mucous membranes may occur, similar to that caused by caustic soda solution. (USCG, 1999)
Gefahrenübersicht
General term for a group of compounds with varying quantities of sodium oxide (Na2-O) and silica (Si2-O)
Anwendungen & Verwendung
Beschreibung
Sodium silicate, 2Na2OSiO2, is the simplest form of glass. It is found as lumps of greenish glass soluble in steam under pressure, white powders of varying degrees of solubility, or liquids cloudy or clear. It is noncombustible; however, when the powdered form is suspended in air, it could cause a dust explosion if an ignition source is present. Breathing the dust may also cause health problems. The glass form could also create a hazard to responders in an accident. It is not listed as a hazardous material in the DOT Hazardous Materials Tables. The primary uses are as catalysts, soaps, adhesives, water treatment, bleaching, waterproofing, and flame retardant.
Verwenden
Sodium Silicate is a product used as a preservative for eggs.
Aqueous solutions are characterized by the weight ratio of silica to sodium oxide, usually 1.6 to 3.8
Solutions are strongly alkaline and corrosive
[Merck Index] A strong skin and eye irritant
Toxic by ingestion at high doses
[CAMEO] A medium strong base in solution
25-50% Aqueous solution: Aerosol is a skin, eye, and respiratory tract irritant
[ICSC] Corrosive to rabbit skin (when tested at 53.5% molar ratio of 1.6 and 82% molar ratio of 2.4)
Sodium metasilicate was not sensitizing in a local lymph node assay study of mice
Similar uses and adverse effects are expected from the hydrous and anhydrous forms (Sodium metasilicate pentahydrate, Sodium metasilicate nonahydrate, Sodium metasilicate, Sodium silicate, and Potassium silicate). The main hazard of soluble silicates is their alkalinity and potentially corrosive effects on metal and tissue. [Ullmann]
A corrosive substance that can cause injury to the skin, eyes, and respiratory tract
[ICSC] A strong skin, eye, and mucous membrane irritant
[CAMEO] Causes burns
A respiratory tract irritant
[IUCLID] In high-dose, 4-week feeding studies of dogs and rats, polydipsia and polyuria were observed
Dogs but not rats had renal lesions
Oral LD50 (rat) = 1280 mg/kg (10% solution)
[HSDB] pH of 1% solution = 13
[IPCS-PIMs] No reports on reproductive effects
[REPROTOX] Corrosive to moistened rabbit skin
Not sensitizing in a local lymph node assay study of mice
Similar uses and adverse effects are expected from the hydrous and anhydrous forms (Sodium metasilicate pentahydrate, Sodium metasilicate nonahydrate, Sodium metasilicate, Sodium silicate, and Potassium silicate). One case of occupational contact urticaria reported from sodium silicate
[OECD SIDS: Soluble Silicates - 2004] A severe skin irritant
Human ingestion of 1 mL/kg causes changes in tubules (including acute renal failure and necrosis), hematuria, and nausea or vomiting
[RTECS] Causes burns
Inhalation may cause corrosive injuries to upper respiratory tract and lungs
[Alfa Aesar MSDS]
FDA-Anforderungen
Substance added directly to human food affirmed as generally recognized as safe (GRAS).
As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Sodium metasilicate is found on List D. Case No: 4081Pesticide type: insecticide, fungicide, antimicrobialCase Status: RED Approved 09/91OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.Active ingredient (AI): Sodium metasilicateAI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.As a general rule, pesticide chemicals other than ..., sodium metasilicate (not to exceed 4% by weight in aqueous solution)... are not for the purposes of section 408(a) of the Act generally recognized as safe.Residues of sodium metasilicate are exempted from the requirement of a tolerance when used as a surfacant, emulsifier, wetting agent, suspending agent, dispersing agent, or buffer in accordance with good agricultural practices as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest.Residues of sodium silicate are exempted from the requirement of a tolerance when used as a surfactant, emulsifier, wetting agent, stabilizer, or inhibitor in accordance with good agricultural practices as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest.
Reactivity Profile
SODIUM SILICATE contains a variable amount of water of hydration. Rate of dissolution depends on the degree of hydration, the amount of water that is used as solvent (less soluble in large amounts of water) and the temperature (higher temperature means quicker solution). Aqueous solutions react as bases. Reacts violently with fluorine [Lewis.]
Brandbekämpfung
Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:In case of fire in the surroundings, use appropriate extinguishing media.
Erste-Hilfe-Maßnahmen
Fresh air, rest.First rinse with plenty of water for at least 15 minutes, then remove contaminated clothes and rinse again. Refer for medical attention .First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.Rinse mouth. Give one or two glasses of water to drink. Do NOT induce vomiting. Refer for medical attention .
Erste Hilfe
INGESTION (large doses): give water or milkdo NOT induce vomiting. (USCG, 1999)
SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.
Verschüttetes entsorgen
Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Personal protection: self-contained breathing apparatus.
Preventive Measures
SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.
Evaporation at 20 °C is negligiblea harmful concentration of airborne particles can, however, be reached quickly on spraying.
Skin Prevention
Protective gloves.
Unerwünschte Wirkungen
Dermatotoxin - Skin burns.Nephrotoxin - The chemical is potentially toxic to the kidneys in the occupational setting.
Expositionspfade
The substance can be absorbed into the body by inhalation and by ingestion.
Toxizitätsübersicht
The Expert Panel for Cosmetic Ingredient Safety concluded that the following 24 silicate ingredients are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating, with the exception that the available data are insufficient to make a determination of safety for the use of naturally-sourced (i.e., mined) silicate ingredients in products that may be incidentally inhaled: Sodium Metasilicate.Safe for use in cosmetics, with qualificationsThe Expert Panel for Cosmetic Ingredient Safety concluded that the following 24 silicate ingredients are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating, with the exception that the available data are insufficient to make a determination of safety for the use of naturally-sourced (i.e., mined) silicate ingredients in products that may be incidentally inhaled: Sodium Silicate.
A 57 yr old man had had recurrent ulcerative lesions on his left hand for 2 yr. The ulcers were associated with chronic eczematous changes resulting from primary irritant contact dermatitis to sodium silicate, as indicated by positive patch tests. He used sodium silicate in a dyeing process in his work. He also had contact urticaria. An immediate wheal and flare reaction was found 15 min after application of sodium silicate to a scratch test site. This response was not seen in healthy control subjects.MORE...CAUSTIC THAN SODIUM SILICATE. ... /IT IS/ THE MOST ALKALINE & CORROSIVE SUBSTANCE IN.../PHOSPHATE-FREE & LOW-PHOSPHATE LAUNDRY DETERGENTS & DISHWASHER PRODUCTS/.IRRITATING & CAUSTIC TO SKIN, MUCOUS MEMBRANES. IF SWALLOWED CAUSES VOMITING & DIARRHEA.Upper airway irritation, fever/hyperthermia (metal fume fever), leukocytosis (metal fume fever).ACCIDENTAL SPLASHES IN EYE FOLLOWED PROMPTLY BY WASHING WITH WATER HAVE BEEN OBSERVED TO DAMAGE THE CORNEAL EPITHELIUM.
Non-Human Toxicity Excerpts
ORAL PREPN OF SODIUM METASILICATE WERE FED TO YOUNG ADULT BEAGLE DOGS AND YOUNG RATS OF BOTH SEXES FOR 4 WK. POLYDIPSIA, POLYURIA & SOFT STOOLS RESULTED IN SOME ANIMALS. GROSS & MICROSCOPIC RENAL LESIONS OBSERVED IN DOGS BUT NOT IN RATS.... /In/ studies of detergent emesis in 11 dogs by gastric intubation ... 8 mg/kg as a 10.5% aqueous solution of a sodium silicate (SiO2:Na2O= 3.2:1) produced emesis in 6 minutes which continued for up to 33 minutes.Sodium metasilicate is used with sodium carbonate in heavy duty alkaline laundry detergents. In rabbits this type of detergent causes damage to the cornea, with opacification, proportional to the alkalinity of the preparation. Irrigation of the eye with water must be done within 60 seconds to reduce the severity of injury.The ip injection in rats of the nonahydrate as a neutral solution in amounts of 300 mg on day 1 and 200 mg on days 2 and 3 produced lesions in the spleen and lymph nodes and caused mitotic changes in the nuclie of cells resembling those from ionizing radiation or hypoxia. /Nonahydrate/For more Non-Human Toxicity Excerpts (Complete) data for SODIUM METASILICATE (6 total), please visit the HSDB record page.Mussels are controlled on water inlets, underwater substructures, ditches, etc by asphyxiation subsequent to coating with a hydrogel made of sodium silicate. Furthermore, algae and aquatic plants can be eliminated by addition of herbicides to the hydrogel. ... Water glass, diluted 1:2, with pH adjusted to 7.4, controlled mussels in a water inlet.
Non-Human Toxicity Values
LD50 Rat oral 1280 mg/kgLD50 Mouse oral 2400 mg/kgLD50 Rat oral 1.1 - 1.6 g/kgLD50 Mouse oral 1,100 mg/kg
