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Sodium Silicate Powder Toxicology

Identification

Cas Number : 1344-09-8

French Names :

Silicate de sodium

Silicate de sodium (ratio SiO₂:Na₂O greater than 2,4:1)

English Names :

Sodium silicate

Silicic acid, sodium salt

Sodium sesquisilicate

Uses and Sources of Emission :

Manufacture of soaps and detergents.

Fluxing of casting slips in ceramics.

Physical and Chemical Properties :

I-Appearance :

Powder.

II-Color :

White.

III-Odor :

Odorless or musty odor.

IV-pH :

Approximately 12.7

V-Bulk density :

Approximately 90 pounds/ft³

VI-Solubility in water :

Soluble in all proportions.

Stability and Reactivity :

I-Stability :

This material is stable under all conditions of use and storage.

II-Conditions to avoid :

None.

III-Materials to avoid :

Generates heat when mixed with acid. May react with ammonium salt solutions resulting in evolution of ammonia gas. Flammable hydrogen gas may be produced on contact with aluminum, tin, lead, and zinc.

IV-Hazardous decomposition products :

Sodium oxide.

Inflammability and Explosiveness :

I-Inflammability :

This product is non flammable.

II- Fire-fighting equipment :

The following protective equipment for fire fighters is recommended when this material is present in the area of a fire:

- chemical goggles,

- body-covering protective clothing,

- chemical resistant gloves,

- rubber boots.

III-Combustion Product :

Sodium Oxide.

IV-Materials to Avoid :

This product is incompatible with these substances:

- acids,

- carbon dioxide.

When mixed with an acid it generates heat. Can react with ammonium salt solutions and release gaseous ammonia.

Flammable hydrogen gas can be produced on contact with :

- aluminium,

- tin,

- lead,

- Zinc

Toxicology

I-Experimental Toxicology :

DL50 :

Rat (Oral): 1 280 mg/kg.

Mouse (Oral): 2 400 mg/kg.

Rat (Oral): 1 600 mg/kg.

II-Absorption :

This product is absorbed by the respiratory and the digestive tracts.

III-Acute Effects :

A-Ocular Contact :

Severe irritation or corrosion.

B-Skin Contact :

Severe irritation or corrosion.

C-Inhalation :

Severe irritation or corrosion.

D-Ingestion :

Severe irritation or corrosion.

Nausea, vomiting, diarrhoea, burns of the mouth, oesophagus and stomach.

Death is possible.

Note : Sodium silicate is considered corrosive when its ratio SiO₂:Na₂O is lower than

2.4 for the powdered product or lower than 1.8 for solutions, otherwise it is considered irritating.

IV-Chronic Effects :

Contact dermatitis.

Effects on Development :

No data concerning an effect on development was found in the consulted documentary sources.

Effects on Reproduction :

No data concerning the effects on reproduction was found in the consulted documentary sources.

Data on Mother's milk :

There is no data concerning its excretion or detection in milk.

Cancerogenic Effects :

No data concerning a cancerogenic effect was found in the consulted documentary sources.

Mutagenic Effects :

No data concerning a mutagenic in vivo or in vitro effect on cells of mammals was found in the consulted documentary sources.

First Aid Measures

I-Eye :

In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. If easy to do, remove contact lenses, if worn.

Get medical attention.

II-Skin :

In case of contact, immediately flush skin with plenty of water. Remove contaminated clothing and shoes.

Get medical attention.

III-Inhalation :

Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen.

Get medical attention.

IV-Ingestion :

Do not induce vomiting. Seek medical attention immediately. If the victim is conscious, give a cup of water.

Never give anything by mouth to somebody who is unconscious.

Accidental Release Measures

I-Personal protection :

Wear chemical goggles, body-covering protective clothing, chemical resistant gloves, and rubber boots, an approved dust respirator where dust occurs.

II-Environmental Hazards :

Sinks and mixes with water. High pH of this material is harmful to aquatic life

III-Small spill cleanup :

Carefully shovel or sweep up spilled material and place in suitable container. Avoid generating dust. Use appropriate Personal Protective Equipment

IV-Large spill cleanup :

Keep unnecessary people away; isolate hazard area and deny entry. Do not touch or walk through spilled material. Carefully shovel or sweep up spilled material and place in suitable container. Avoid generating dust.

Use appropriate Personal Protective Equipment. In case of contact with water, prevent runoff from entering into storm sewers and ditches which lead to natural waterways. Neutralize contaminated area and flush with large quantities of water.

Comply with applicable environmental regulations.

Handling and Storage

I-Handling :

Do not get in eyes. Avoid contact with skin and clothing. Avoid breathing dust. Keep container closed. Promptly clean up spills.

II-Storage :

Keep containers closed. Store in clean steel or plastic containers. Separate from acids, reactive metals, and ammonium salts. Do not store in aluminum, fiberglass, copper, brass, zinc or galvanized containers. This product can absorb water from the air. In case of high humidity or storage for extended periods of time, use plastic bags to enclose product containers to avoid caking.

Exposure Controls/Personal Protection

I-Engineering controls :

Use only with adequate ventilation. Keep containers closed. Safety shower and eyewash fountain should be within direct access.

II-Respiratory protection :

Use an approved dust respirator where dust occurs.

III-Skin protection :

Wear body-covering protective clothing and gloves.

IV-Eye protection :

Wear chemical goggles.

Environmental Fate

This material is not persistent in aquatic systems, but its high pH when undiluted or unneutralized is acutely harmful to aquatic life. Diluted material rapidly depolymerizes to yield dissolved silica in a form that is indistinguishable from natural dissolved silica.

This material does not bioaccumulate except in species that use silica as a structural material such as diatoms and siliceous sponges.

Where abnormally low natural silica concentrations exist (less than 0.1 ppm), dissolved silica may be a limiting nutrient for diatoms and a few other aquatic algal species.

However, the addition of excess dissolved silica over the limiting concentration will not stimulate the growth of diatom populations; their growth rate is independent of silica concentration once the limiting concentration is exceeded. Neither silica nor sodium will appreciably bioconcentrate up the food chain.

Références :

1-Occupational Medicine,Carl Zenz, dernière édition.

2-Clinical Environmental Health and Toxic Exposures, Sullivan & Krieger; dernière édition.

3-Sax's Dangerous Properties of Industrial Materials, Lewis C., dernière édition.

4-Toxicologie Industrielle et Intoxications Professionnelles, Lauwerys R. dernière édition.

5-Chemical Hazards of the Workplace, Proctor & Hughes, 4e édition.

6-CSST-Québec, Service du Répertoire Toxicologique, 2005

7- PQ Corporation, Sodium Silicate Powder, MSDS, John G. Blumberg, 05/29/02

By Edouard Bastarache

Related Information

Links

Materials	Sodium Silicate A sticky, viscous liquid. The most common deflocculant used in ceramics. Also used as a bonding agent.
Typecodes	Article by Edouard Bastarache Edouard Bastarache is a well known doctor that has written many articles on the subject of toxicity of ceramic materials and books on technical aspects of ceramics. He writes in both English and French.

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