Ammonium hexafluorosilicate

  • Ammonium silicofluoride
  • Cryptophthalite
  • Ammonium fluorosilicate
Formula
(NH4)2SiF6
Structure
Description
A white crystalline solid. Corrodes aluminum.
Uses
Former use: insecticide dri-die.

Registry Numbers and Inventories.
CAS
16919-19-0
EC (EINECS/ELINCS)
240-968-3
EC Index Number
009-012-00-0
EC Class
Toxic
R 23/24/25
RTECS
VV7800000
RTECS class
Agricultural Chemical and Pesticide
UN (DOT)
2854
Merck
13,529
Beilstein/Gmelin
18191 (G)
EPA OPP
75301
Swiss Giftliste 1
G-1119
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
F6H8N2Si
Formula mass
178.15
Decomposition point, °C
120
Density
1.9469 g/cm3 (14 C)
Thermal expansion
0.000099/K

Hazards and Protection.
Storage
Store in a tightly closed container. Do not store in glass. Store in a cool, dry area away from incompatible substances.
Handling
Wash thoroughly after handling. Use only in a well ventilated area. Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Clean up spills immediately, using the appropriate protective equipment. Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents, strong acids.
Decomposition
Nitrogen oxides, hydrogen fluoride, fluoride fumes, ammonia.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Extinguishing media: Use agent most appropriate to extinguish fire.
Fire potential
Nonflammable.
Combustion products
Toxic and irritating hydrogen fluoride, silicon tetrafluoride, and oxides of nitrogen may form in fires.

Health.
Poison_Class
3
Exposure effects
Hyperactive reflexes, painful muscle spasms, weakness and tetanic contractures may be noted due to fluoride induced hypocalcemia. Prenatal fluoride supplementation (2.2 mg NaF or 1 mg fluoride daily) during the last two trimesters of pregnancy has been reported to be safe.
   Ingestion
Ingestion of large amounts of fluoride may include salivation, nausea, vomiting, abdominal pain, fever, labored breathing. Exposure to fluoride compounds can result in systemic toxic effects on the heart, liver, and kidneys. It may also deplete calcium levels in the body leading to hypocalcemia and death. Fluoride can reduce calcium levels leading to fatal hypocalcemia.
   Inhalation
May cause respiratory tract irritation.
   Skin
Causes severe skin irritation.
   Eyes
Causes severe eye irritation.

First aid
 
   Ingestion
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen.
   Skin
Get medical aid immediately. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
UN number
2854
Response guide
USCG CHRIS Code
ASL
 
Std. Transport #
4925198