General Description
DICHLOROSILANE(4109-96-0) is a flammable and poisonous gas, with a strong repulsive odor. DICHLOROSILANE(4109-96-0) is easily ignited in air, reacts with oxidizing agents, is very toxic by inhalation, and is a strong irritant to skin, eyes and mucous membranes. Under prolonged exposure to fire or intense heat the container may rupture violently or rocket.
Reactivity Profile
Chlorosilanes, such as DICHLOROSILANE, are compounds in which silicon is bonded to from one to four chlorine atoms with other bonds to hydrogen and/or alkyl groups. Chlorosilanes react with water, moist air, or steam to produce heat and toxic, corrosive fumes of hydrogen chloride. They may also produce flammable gaseous H2. They can serve as chlorination agents. Chlorosilanes react vigorously with both organic and inorganic acids and with bases to generate toxic or flammable gases.
Air & Water Reactions
Highly flammable. Based on the properties of similar materials, there is the possibility that the reaction of this compound with water may be vigorous or violent. Products of the reaction include hydrogen chloride. The reaction generates heat and this heat may be sufficient to ignite the product. The chlorosilicon hydrides(ClxSiHy) are spontaneously flammable in air, NFPA 1991.
Health Hazard
TOXIC; may be fatal if inhaled or absorbed through skin. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution.
Fire Hazard
Flammable; may be ignited by heat, sparks or flames. May form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Some of these materials may react violently with water. Cylinders exposed to fire may vent and release toxic and flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. Runoff may create fire or explosion hazard.
Application
Gives improved yields in reduction of imines over that of
trichlorosilane.Easier to handle form of dichlorosilane.
Hazard
Dichlorosilane is toxic by inhalation and skin absorption. Hydrogen chloride causes severe eye and skin burns and is irritating to the skin, eyes, and respiratory system. The four-digit UN identification number is 2189. The NFPA 704 designation is health 4, flammability 4, and reactivity 2. The white area at the bottom of the diamond contains a W with a slash through it, indicating water reactivity.
Flammability and Explosibility
Extremelyflammableliquifiedgas
Materials Uses
Dichlorosilane, in the complete absence of water,
can be safely stored in mild steel equipment.
In the presence of even small traces of water,
dichlorosilane becomes extremely corrosive
since the Si-CI bonds react rapidly with water,
generating hydrogen chloride.br/>
Because of reactivity with water, dichlorosilane
should always be handled in dry equipment with a dry inert gas such as nitrogen.
For transfer service, dry inert gas is preferred to
pumping. Some examples of other common
compatible materials used include: Viton, Teflon,
Kel-F, nickel, Monel, and some types of
stainless steel.
storage
Since dichlorosilane is a highly flammable, corrosive,
and toxic liquefied gas, appropriate precautions
must be taken in its storage and handling.
During the handling of chlorosilanes, the
use of such protective equipment as goggles,
neoprene or natural rubber gloves, and protective
clothing is essential. SCBAs, as well as
both safety showers and eyewash fountains,
should be available for emergency use.
Cylinders should be assigned a definite area
for storage. The area should be dry, cool, well
ventilated, fire resistant, and away from ignition
sources. Keep cylinders protected from excessive
temperature rise by storing them away from
radiators or other heat sources. Storage conditions
should comply with local and state regulations.
Cylinders may be stored in the open, but must
be protected against extremes of weather and
from the dampness of the ground to prevent
rusting. During the summer, cylinders stored in
the open should be shaded against the continuous
direct rays of the sun in those localities
where extreme temperatures prevail.
Waste Disposal
Dichlorosilane should not be discharged directly
into surface waters or sewer systems since an
acidic waste product is formed. The disposal
can be accomplished by controlled introduction
of the product into water. The exothermic reactions
of dichlorosilane with water (hydrolysis)
result in the formation of hydrochloric acid and
an insoluble silicon containing solid or fluid. In
order to prevent air pollution, the quantity of
water must be sufticient to dissolve all of the
hydrogen chloride that will be formed. The ratio
of water to dichlorosilane should be at least 10
to 1. The corrosive and exothermic nature of the
reaction should be t;onsidered in selecting materials
of construction for the equipment used in
this procedure.
The hydrochloric acid formed should then be
neutralized with an alkali agent such as aqueous
ammonia, sodium hydroxide, lime slurry, etc.,
and should be added as an aqueous solution
with agitation to the acidic medium. Consideration must be given to the additional heat that
will be produced by the neutralization.
Silicon-containing solids should be washed to
remove residual acid. Discard any product, residue,
disposable container, or liner in an environmentally
acceptable manner. Disposal of
dichlorosilane by neutralizing, scrubbing, incineration,
or by other means, may be subject to
permitting by federal, state or provincial regulations.
Persons involved with disposal of dichiorosilane
should check with the environmental
authorities having jurisdiction to determine
the applicability of permitting regulations
to disposal activities.
