| Identification | Back Directory | [Name]
Fumes, silica | [CAS]
69012-64-2 | [Synonyms]
SILICAFUMES
Fumes, silica
Einecs 273-761-1
silica welding fumes
AMORPHOUS-FUMESILICA
AMORPHOUS SILICA FUME
Silica Fume (powder form)
Silica, amorphous - Fume total dust
Silica, amorphous - Fume, respirable | [EINECS(EC#)]
273-761-1 |
| Chemical Properties | Back Directory | [Appearance]
Amorphous silica, the noncrystalline form of SiO2, is a transparent to gray, odorless, amorphous powder | [density ]
0.45-0.67[at 20℃] | [form ]
Fine white powder with particle
sizes generally below 1mm. This is not
the same as the commercial products “fumes
silica,” “silica gel,” “precipitated silica,” or
“fused silica.” It is formed during the electric
arc production of elemental silicon from quartz, which is reduced to silicon monoxide,
escaping from the furnace and oxidized by air
to silicon dioxide. This condenses to form
spherical particles. For the production of ferrosilicon,
iron metal is added to the charge;
during charging there is also exposure to
crystalline silica. | [Water Solubility ]
135mg/L at 37℃ | [EPA Substance Registry System]
Fumes, silica (69012-64-2) |
| Safety Data | Back Directory | [Symbol(GHS) ]
GHS08 | [Signal word ]
Warning | [Hazard statements ]
H373 | [Precautionary statements ]
P260-P314-P501 | [Safety Profile]
An inhalation hazard. Much less toxic than crystalline forms. Does not cause silicosis. See also other silica entries |
| Hazard Information | Back Directory | [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. | [First aid]
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. If this chemical has been inhaled, remove from exposure. Transfer promptly to a medical facility. | [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. | [Chemical Properties]
Amorphous silica, the noncrystalline form of SiO2, is a transparent to gray, odorless, amorphous powder | [Waste Disposal]
Sanitary landfill. | [Uses]
None; produced only as a by-product. | [Application]
Silica-fume forms most of the dust and other
particulates in the off-gases produced during the electrothermal production of ferrosilicon
(Fe-Si) or silicon (Si). The dust is collected in baghouses and bagged without further treatment. Due to its high surface area, microsilica reacts readily with hydrated calcium silicates
forming strong bonds, and for that reason it is sometimes called reactive silica. Therefore the
addition of microsilica to hydraulic cements improves their mechanical strength, reduces
their permeability, and enhances their workability, cohesiveness, and flowing properties and
hence is extensively used as an additive to cements and monolithic refractories. | [Definition]
Produced by the volatilization and vaporization of furnace feed materials during the production of ferrosilicon and silicon metals. Consists primarily of silicon dioxide with carbon and trace elements. | [Health Hazard]
Amorphous silica fume exposure
is associated with recurrent fever, similar
to metal fume fever, and nonprogressive pulmonary
changes.More recently, the importance of silica
fume particle size on toxicity has been noted.8
Specifically, particles of the ultrafine size range
may be expected to have higher toxicity compared
with particles of larger size. |
|
|