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Chemical Datasheet

FLUOROSILICIC ACID

Chemical Identifiers

UN/NA Number CAS Number CHRIS Code DOT Hazard Label
  • 1778
  • 16961-83-4
  • FSL
  • CORROSIVE
NFPA 704: data unavailable
General Description
A colorless fuming liquid with a penetrating pungent odor. Corrosive to metals and tissue. Both the fumes and very short contact with the liquid can cause severe and painful burns. Used in water fluoridation, in hardening cement and ceramics, as a wood preservative.

Hazards

Reactivity Alerts
Air & Water Reactions
Fumes in air. Soluble in water with release of heat and corrosive fumes.
Fire Hazard
Special Hazards of Combustion Products: Irritating fumes of hydrogen fluoride may form in fire. (USCG, 1999)
Health Hazard
Inhalation of vapor produces severe corrosive effect on mucous membrane. Ingestion causes severe burns of mouth and stomach. Contact with liquid or vapor causes severe burns of eyes and skin. (USCG, 1999)
Reactivity Profile
FLUOROSILICIC ACID can react with strong acids (such as sulfuric acid) to release fumes of toxic hydrogen fluoride. Attacks glass and materials containing silica. Reacts exothermically with chemical bases (examples: amines, amides, inorganic hydroxides). Reacts with active metals, including iron and aluminum to dissolve the metal and liberate hydrogen and/or toxic gases. Can initiate polymerization in certain alkenes. Reacts with cyanide salts and compounds to release gaseous hydrogen cyanide. Flammable and/or toxic gases are also often generated by reactions with dithiocarbamates, isocyanates, mercaptans, nitrides, nitriles, sulfides, and weak or strong reducing agents. Additional gas-generating reactions may occur with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), and carbonates. Can catalyze (increase the rate of) chemical reactions. Decomposes when heated to the boiling point to produce very toxic and corrosive hydrogen fluoride gas.
Belongs to the Following Reactive Group(s)

Response Recommendations

Firefighting
Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. (AAR, 2003)
Non-Fire Response
Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Use water spray to knock-down vapors. Do not use water on material itself. Neutralize spilled material with crushed limestone, soda ash, or lime. (AAR, 2003)
Protective Clothing
Rubber gloves; safety glasses; protective clothing (USCG, 1999) 
_____Dupont Average Standardized Breakthrough Times_____
(for FLUOSILICIC ACID)

Tychem® BR
     greater than 480 min.  (concentration:  95+%)
Tychem® LV
     greater than 480 min.  (concentration:  95+%)
Tychem® Reflector®
     greater than 480 min.  (concentration:  95+%)
Tychem® Responder®
     greater than 480 min.  (concentration:  95+%)
     greater than 480 min.  (concentration:  30%)
Tychem® Responder® CSM
     greater than 480 min.  (concentration:  95+%)
     greater than 480 min.  (concentration:  30%)
Tychem® ThermoPro
     greater than 480 min.  (concentration:  100%)
Tychem® TK
     greater than 480 min.  (concentration:  95+%)  (DuPont, 2008)
Copyrighted information of E.I. du Pont de Nemours and Company. Tychem® is a registered trademark of E.I. du Pont de Nemours and Company.
First Aid
INHALATION: remove victim to fresh air; get medical attention.

INGESTION: give large amounts of water; do NOT induce vomiting.

EYES: immediately wash with water for 15 min.; call a physician.

SKIN: wash affected parts with water; treat as for hydrogen fluoride burn with iced benzalkonium chloride soaks. (USCG, 1999)

Physical Properties

Molecular Formula:
  • H2SiF6
Flash Point: data unavailable
Lower Explosive Limit: data unavailable
Upper Explosive Limit: data unavailable
Autoignition Temperature: data unavailable
Melting Point: -4.0 ° F (USCG, 1999)
Vapor Pressure: data unavailable
Vapor Density: data unavailable
Specific Gravity: 1.3 at 77.0 ° F (approx.) (USCG, 1999)
Boiling Point: 212.0 ° F at 760.0 mm Hg (water) approx. (USCG, 1999)
Molecular Weight: 144.09 (solute only) (USCG, 1999)
Water Solubility: data unavailable
AEGL: data unavailable
ERPG: data unavailable
TEEL-1 TEEL-2 TEEL-3
9.48 mg/m3 15.8 mg/m3 50.0 mg/m3
(SCAPA, 2008)
IDLH: data unavailable

Regulatory Information

Regulatory Names: none
CAA RMP: Not a regulated chemical.
CERCLA: Not a regulated chemical.
EHS (EPCRA 302): Not a regulated chemical.
TRI (EPCRA 313): Not a regulated chemical.
RCRA Chemical Code: none

Alternate Chemical Names