Английский для сварщиков. Гричин С.В. - 139 стр.

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Text 1. Health Risks of Welding Fume/Gases
What is welding fume/gases?
Welding fume is a mixture of airborne fine particles.
Toxic gases may also be generated during welding and
cutting.
Particulate fume
More than 90% of the particulate fume arises from
vaporisation of the consumable electrode, wire or rod as
material is transferred across the arc or flame. The range of
welding particles size is shown in relation to the more familiar types of dust
and fume. The respirable fraction of particles (especially less than 3µm) are
potentially the more harmful as they can penetrate to the innermost parts of
the lung.
Gases
Gases encountered in welding may be:
- Fuel gases which, on combustion, form carbon dioxide and, if the flame is
reducing, carbon monoxide;
- Shielding gases such as argon, helium and carbon dioxide, either alone or in
mixtures with oxygen or hydrogen;
- Carbon dioxide and monoxide produced by the action of heat on the
welding flux or slag;
- Nitric oxide, nitrogen dioxide and ozone produced by the action of heat or
ultraviolet radiation on the atmosphere surrounding the welding arc;
- Gases from the degradation of solvent vapours or surface contaminants on
the metal.
The degree of risk to the welder's health from fume/gases will depend on
composition, concentration, the length of time the welder is exposed, the
welder's susceptibility.
Health hazards from particulate fume
The potential hazards from breathing in particulate fume are:
1. Irritation of the respiratory tract. Fine
particles can cause dryness of the throat, tickling,
coughing and if the concentration is particularly high,
tightness of the chest and difficulty in breathing.
2. Metal fume fever. Breathing in metal oxides
such as zinc and copper can lead to an acute flu-like
illness called 'metal fume fever'. It most commonly
occurs when welding galvanised steel; symptoms usually begin several hours

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