Sodium metasilicate

  • Silicic acid, sodium salt
  • Disodium metasilicate
Formula
Na2O3Si
Structure
Description
Colorless monoclinic crystals.
Uses
In fireproofing mixtures, boiler compound.

Registry Numbers and Inventories.
CAS
6834-92-0
EC (EINECS/ELINCS)
229-912-9
EC Index Number
014-010-00-8
EC Class
Corrosive; Irritant
RTECS
VV9275000
RTECS class
Reproductive Effector; Human Data; Primary Irritant
UN (DOT)
1759
Merck
12,8788
Beilstein/Gmelin
19151 (G)
EPA OPP
72604
Swiss Giftliste 1
G-7481
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
Na2O3Si
Formula mass
122.06
Melting point, °C
72.2
Odor Threshold Odor threshold Odorless
Density
1.749 g/cm3 (20 C)
Solubility in water
Soluble
Viscosity
1000 cp (1088 C)
Refractive index
1.52 (20 C)
Thermal expansion
0.000022/K
Heat of fusion
0.12 kJ/mol

Hazards and Protection.
Storage
Keep tightly closed in a cool place in a tightly closed container.
Handling
Containers of this material may be hazardous when emptied. Since emptied containers retain product residues (vapor, liquid, and/or solid), all hazard precautions given in the data sheet must be observed.
Protection
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
ELIMINATE all ignition sources. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS.
Stability
Stable.
Incompatibilities
Reacts violently with acid and is corrosive in moist air to metals like zinc, aluminum, tin and lead forming a flammable/explosive gas (H2).

Fire.
Fire fighting
Extinguish using agent most appropriate for surrounding fire.
Fire potential
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Hazards
Contact with metals may evolve flammable hydrogen gas.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
3
 
Flammability
0
 
 
Reactivity
0
 

Health.
Poison_Class
3
Exposure effects
   Ingestion
Burns of the esophagus and less commonly the stomach may occur after caustic ingestion; the absence of oral mucosal injury does not reliably exclude esophageal burns. Patients with stridor, drooling or vomiting are more likely to have esophageal burns.
   Inhalation
Stridor, dyspnea, upper airway injury, and pulmonary edema, especially following inhalation of vaporized caustics, may occur.
   Skin
Severe skin irritation and/or burns may occur.
   Eyes
See Inhalation.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult.
   Skin
Remove and isolate contaminated clothing and shoes. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
1759
Response guide
Hazard class
8
Packing Group
I; II; III
 
USCG CHRIS Code
SSN
 
43 Misc. water solutions
IMO Chemical Code
17
IMO Pollution Category
C