Sodium metasilicate (Na2SiO3)

122.06300

121.94100

215-687-4

052612U92L

0359

1759|3253

DTXSID7029669

COLORLESS MONOCLINIC CRYSTALS|USUALLY OBTAINED AS A GLASS; ALSO ORTHORHOMBIC CRYSTALS|DUSTLESS WHITE GRANULES

2839110000

63.19000

-0.73720

Sodium silicate appears as a powdered or flaked solid substance. Strong irritant to skin, eyes, and mucous membranes. May be toxic by ingestion. Concentrated aqueous solutions used as a glue.

2.614 g/cm³

1089 °C

BOILING POINT: 100 °C -6H20 /NONAHYDRATE/

INDEX OF REFRACTION: 1.520 (GLASS)|INDEX OF REFRACTION: 1.518 (ALPHA), 1.527 (GAMMA)

Solubility in water at 20°C: miscible

Noncombustible

PH: ABOUT 12.5; HAS RELATIVELY HIGH BUFFER CAPACITY /0.5% SOLUTION/

HEAT OF SOLUTION: -7.45 KCAL/MOLE (CRYSTALS); HEAT OF FUSION: 10.3 KCAL/MOLE; SPECIFIC HEAT: 0.217 AT 20 °C; HEAT OF FORMATION: 371.2 KCAL/MOLE|PPT BY ACIDS & BY ALKALINE EARTH & HEAVY METAL IONS|MELTING POINT 72.2 °C; DENSITY 1.75 OR 55 LB/CU FT /PENTAHYDRATE/|Heat of solution: (est) -20 Btu/lb= -10 cal/g= -0.4x10+5 J/kg

Deliquescent. Water soluble [Handbook of Chemistry and Physics].

Salts, Basic

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.]

Not flammable (USCG, 1999)

Sodium metasilicate is considered to be too corrosive to be widely used in consumer product laundering formulations.

III

8

UN 3253

1

R34; R37

S13-S36/37/39-S45

VV9275000

C

Separated from strong acids, aluminium and zinc.

hygroscopic

P261-P280-P305 + P351 + P338-P310

H290-H314-H335

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.

Sodium metasilicate ignites in fluorine.

Substance added directly to human food affirmed as generally recognized as safe (GRAS).

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. For electric vehicles or equipment, ERG Guide 147 (lithium ion batteries) or ERG Guide 138 (sodium batteries) should also be consulted. (ERG, 2016)|Not combustible.

|Danger|H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]|P260, P261, P264, P271, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P363, P403+P233, P405, and P501|H290 (12.22%): May be corrosive to metals [Warning Corrosive to Metals]|P234, P260, P261, P264, P271, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P363, P390, P403+P233, P404, P405, and P501|Aggregated GHS information provided by 2914 companies from 52 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P260, P264, P270, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P309+P311, P310, P321, P330, P363, P405, and P501

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: SMALL FIRE: Dry chemical, CO2 or water spray. LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. Move containers from fire area if you can do it without risk. Dike fire-control water for later disposal; do not scatter the material. FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)|In case of fire in the surroundings, use appropriate extinguishing media.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2016)

Goggles or face shield. (USCG, 1999)

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered plastic containers. If appropriate, moisten first to prevent dusting. Cautiously neutralize remainder with dilute acid (preferably acetic acid). Then wash away with plenty of water.

Separated from strong acids, food and feedstuffs, metals and halogens. Store in an area having corrosion resistant concrete floor.

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed.

The substance is corrosive to the eyes, skin and respiratory tract. Corrosive on ingestion.

PREVENT DISPERSION OF DUST! AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR!

Use local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear face shield or eye protection in combination with breathing protection if powder.

LD50 Rat oral 1280 mg/kg|LD50 Mouse oral 2400 mg/kg

Radiolabeled (31)Si-sodium metasilicate, partially neutralized, was given orally to male guinea pigs... Most of the silica was rapidly absorbed and excreted in the urine but a significant amount was retained in the tissues. These findings are consistent with the recognition that silicon is an essential trace element for bone formation in animals.

If large doses are ingested, some irritation of mucous membranes may occur, similar to that caused by caustic soda solution. (USCG, 1999)

INGESTION (large doses): give water or milk; do NOT induce vomiting. (USCG, 1999)

Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

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/.

monosodium metasilicate

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.

Sore throat. Burning sensation. Cough. Shortness of breath.

Redness. Pain. Skin burns.

Redness. Pain. Severe burns.

(ALL SODIUM SILICATES): 35% TO MAKE SILICA GEL AND CATALYSTS; 18% AS ADDITIVES TO DETERGENTS & SOAPS; 15% AS CORROSION-INHIBITING BINDERS FOR PIGMENTS; 10% AS COMPONENT OF BOXBOARD ADHESIVES; 6% AS WATER CLARIFYING AGENT, A BLEACH STABILIZER FOR PAPER & A DISPERSANT & SURFACE CONDITIONER FOR ORE TREATMENT; & 16% FOR MISC USES (1975)

Grades or purity: A wide variety of grades, which differ in concentration of sodium silicate in water, in specific gravity, and in viscosity.

Aerospace/Land Turbines|Silicic acid (H2SiO3), sodium salt (1:2): ACTIVE|Cmpd containing sodium metasilicate, an alkali metal carbonate, and a preservative, have been used in field experiments as desiccants for forage crops.

Sodium metasilicate in soaps and detergents is determined by ashing to remove organic matter, dissolving the residue in HCl, igniting and redissolving twice, and measuring SiO2 ...|For microgram quantities in air, as from escaping steam of treated boiler water, a colorimetric method using an ammonium molybdate-sulfuric acid reagent has been described.

EPA Safer Chemical Functional Use Classes -> Processing Aids and Additives|Safer Chemical Classes -> Green circle - The chemical has been verified to be of low concern|Cosmetics -> Buffering; Chelating