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9. Read the text CHEMICAL HAZARDS and guess Russian equiva-
lent for the terms:
vapor dust fume
mist fiber
CHEMICAL HAZARDS
These are commonly classified as either particulate or gas and vapor
contaminants. The most common particulate contaminants include dusts,
fumes, mists, aerosols, and fibers. Dusts are solid particles that are formed or
generated from solid organic or inorganic materials by reducing their size
through mechanical processes such as crushing, grinding, drilling, abrading
or blasting.
Fumes are formed when material from a volatilized solid condenses in
cool air. In most cases, the solid particles resulting from the condensation re-
act with air to form an oxide.
Fibers are solid particles whose length is several times greater than their
diameter.
The term mist is applied to a finely divided liquid suspended in the at-
mosphere. Mists are generated by liquids condensing from a vapor back to a
liquid or by breaking up a liquid into a dispersed state such as by splashing,
foaming or atomizing. Aerosols are also a form of a mist characterized by
highly respirable, minute liquid particles.
Gases are formless fluids that expand to occupy the space or enclosure
in which they are confined. Examples are welding gases such as acetylene,
nitrogen, helium, and argon; and carbon monoxide generated from the opera-
tion of internal combustion engines or by its use as a reducing gas in a heat
treating operation. Another example is hydrogen sulfide which is formed
wherever there is decomposition of materials containing sulfur under reduc-
ing conditions.
Liquids change into vapors and mix with the surrounding atmosphere
through evaporation. Vapors are the volatile form of substances that are nor-
mally in a solid or liquid state at room temperature and pressure. They are
formed by evaporation from a liquid or solid and can be found where parts
cleaning and painting takes place and where solvents are used.
Airborne chemical hazards exist as concentrations of mists, vapors, gas-
es, fumes, or solids. Some are toxic through breathing and some of them irri-
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