ICSC 1233 - FLUOROSILICIC ACID

[List of Chemicals] [Risk Notes] [Risk Phrases] [Safety Phrases] [Danger Symbols]

FLUOROSILICIC ACID

ICSC: 1233
_{October 2004}

Hexafluorosilicic acid
Dihydrogen hexafluorosilicate
Fluosilicic acid
Hydrosilicofluoric acid

CAS No: 16961-83-4
RTECS No: VV8225000
UN No: 1778
EC No: 009-011-00-5

F₆H₂Si / H₂SiF₆
Molecular mass: 144.1

TYPES OF HAZARD / EXPOSURE	ACUTE HAZARDS / SYMPTOMS	PREVENTION	FIRST AID / FIRE FIGHTING
FIRE	Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.		In case of fire in the surroundings: use appropriate extinguishing media.
EXPLOSION

EXPOSURE		AVOID ALL CONTACT!	IN ALL CASES CONSULT A DOCTOR!
Inhalation	Burning sensation. Cough. Laboured breathing. Shortness of breath. Symptoms may be delayed (see Notes).	Ventilation, local exhaust, or breathing protection.	Fresh air, rest. Half-upright position. Refer for medical attention.
Skin	Redness. Pain. Skin burns.	Protective gloves. Protective clothing.	Remove contaminated clothes. Rinse skin with plenty of water or shower. Immediately refer for medical attention.
Eyes	Redness. Pain. Severe deep burns.	Face shield or eye protection in combination with breathing protection.	First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.
Ingestion	Burning sensation. Abdominal cramps. Vomiting. Shock or collapse.	Do not eat, drink, or smoke during work.	Rinse mouth. Do NOT induce vomiting. Give plenty of water to drink. Refer for medical attention.

SPILLAGE DISPOSAL	PACKAGING & LABELLING
Personal protection: complete protective clothing including self-contained breathing apparatus. Collect leaking and spilled liquid in sealable iron containers as far as possible. Absorb remaining liquid in sand or inert absorbent and remove to safe place Do NOT let this chemical enter the environment.	C Symbol R: 34 S: (1/2-)26-27-45 Note: B UN Hazard Class: 8 UN Pack Group: II	Unbreakable packaging; put breakable packaging into closed unbreakable container. Do not transport with food and feedstuffs.

EMERGENCY RESPONSE	SAFE STORAGE
Transport Emergency Card: TEC (R)-80S1778 and 80GC1-II+III	Separated from strong bases, food and feedstuffs. Well closed.

IMPORTANT DATA

Physical State; Appearance
FUMING COLOURLESS LIQUID, WITH PUNGENT ODOUR.

Chemical dangers
The substance decomposes on heating producing toxic fumes including hydrogen fluoride. The solution in water is a strong acid, it reacts violently with bases and is corrosive. Reacts with water or steam to produce toxic and corrosive fumes. Attacks glass and stoneware. Attacks many metals forming flammable/explosive gas (hydrogen - see ICSC 0001). This substance (anhydrous form) dissociates almost instantly into silicon tetrafluoride and corrosive and toxic hydrogen fluoride.

Occupational exposure limits
TLV: (as F) 2.5 mg/m³ as TWA; A4 (not classifiable as a human carcinogen); BEI issued; (ACGIH 2004).
MAK not established.

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

Inhalation risk
No indication can be given about the rate in which a harmful concentration in the air is reached on evaporation of this substance at 20°C.

Effects of short-term exposure
The substance is corrosive to the eyes, the skin and the respiratory tract. Corrosive on ingestion. Inhalation of the vapour of this substance may cause lung oedema (see Notes). The effects may be delayed. Medical observation is indicated. See Notes.

Effects of long-term or repeated exposure
The substance may have effects on the bones and teeth, resulting in fluorosis.

PHYSICAL PROPERTIES	ENVIRONMENTAL DATA
Decomposes below boiling point Melting point: see Notes Relative density (water = 1): see Notes Solubility in water: miscible Vapour pressure, kPa at 20°C: see Notes	This substance may be hazardous in the environment; special attention should be given to aquatic organisms.

NOTES

Marketed only as aqueous solution. Solidification point for 60-70% solution: solidifies at about 19°C, forming a crystalline dihydrate. Melting point for 35% solution: <-30°C.
Relative density for a 61% solution is 1.46 and for 35% solution is 1.38. Vapour pressure for a 35% solution is about 3 kPa.
The symptoms of lung oedema often do not become manifest until a few hours have passed and they are aggravated by physical effort. Rest and medical observation are therefore essential.
Temperature of decomposition unknown in literature.
Immediate administration of an appropriate inhalation therapy by a doctor or a person authorized by him/her, should be considered.
Card has been partly updated in April 2005. See sections Occupational Exposure Limits, EU classification,.

IPCS
International
Programme on
Chemical Safety

Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004

LEGAL NOTICE

Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.

Updated by {ModOper}. Approved by {ModAppr}. Last update: {ModDate}