20. CHEMICALS
Shielding gas
The primary role of the shielding gas is to protect the hot weld and molten metal from
the effects of ambient air. The shielding gas is non-flammable, colourless, odourless
and tasteless, slightly heavier than air. Shielding gas leaks reduces the oxygen content
and may cause risk of suffocation, especially in confined and enclosed spaces where
there is limited ventilation.
Common gases and hazards associated with them are presented on page 75.
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