Chemical Properties
Amorphous silica, the noncrystalline form of SiO2, is a transparent to gray, odorless, amorphous powder
Chemical Properties
white to off-white powder
Uses
Production of filters, polishes,
absorbents, insulators.
Uses
Diatomaceous earth may be used as an adsorbent for column chromatography.
Uses
Celite (R) 545 AW was used as stationary phase in purification of fagopyritols using preparative chromatography. Celite (R) 545 AW was used as packing material for fractionating procedure and the fractions were analysed using GC-ECD, GC/ECNI-MS 2 and IC-MS/MS.
Definition
ChEBI: Silicon dioxide is a silicon oxide made up of linear triatomic molecules in which a silicon atom is covalently bonded to two oxygens.
General Description
Chromosorb
? W is a diatomite which provides solid support for the packed GC columns. It is suitable for use with polar compounds, due to its low surface area and high inertness.
Health Hazard
Amorphous silica, natural
diatomaceous earth, is usually considered to be
of low toxicity; however, pure amorphous silica
is rarely found.
Flammability and Explosibility
Non flammable
Potential Exposure
Amorphous fumed silica is used as a mineral, natural or synthetic fiber. A potential danger to those involved in the production and handling of fumed silica for paint pigments or catalysts. Diatomaceous earth is used in clarifying liquids, in manufacture of fire brick and heat insulators; used as a filtering agent; as a filler in construction materials; pesticides, paints, and varnishes. A potential danger to those involved in mining of diatomaceous earth or fabrication of products there from.
Carcinogenicity
Amorphous silica has been tested for carcinogenicity
in a variety of animal studies by a
number of routes. Most of the tests were negative
or were inadequate primarily because of
poorly defined physiochemical characteristics
of the silica. The IARC concluded that evidence
is inadequate to describe amorphous
silica as carcinogenic in either experimental
animals or humans. Crystalline silica, however,
has been designated by IARC as a probable
human carcinogen (category 2A), based on
“sufficient evidence” in experimental animals
and “limited evidence” in humans.Therefore,
although evidence for the carcinogenicity
of crystalline silica in humans is unconvincing,
certainly from exposures insufficient to cause
silicosis, appropriate hazard warnings are
obligatory in the United States. These apply
to all materials containing 0.1% or more of
crystalline silica (quartz, cristobalite, and/or
tridymite).
Incompatibilities
Silica, amorphous is a noncombustible solid. Generally unreactive chemically. Incompatible with fluorine, oxygen difluoride, chlorine trifluoride. Soluble in molten alkalis and reacts with most metallic oxides at high temperature.
Waste Disposal
Sanitary landfill.
