3. Safety
3.7 Handling of insulating gases and gas mixtures
SF₆ gas is a greenhouse gas which is listed in the Kyoto Protocol. SF₆ gas must not be
released into the atmosphere, but must be collected in suitable containers.
Properties of insulating gases
Colourless and odourless
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Chemically neutral
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Inert
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Not flammable
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Heavier than air
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No toxicity
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No damage to the ozone layer
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Detailed information is given in IEC 60376 and IEC 61634.
Danger of suffocation caused by insulating gases and gas mixtures
High concentrations of gases can lead to asphyxiation, since breathable air is displaced
from the lungs with the inhalation of gas.
Since SF₆ gas is heavier than air, it collects, especially, at ground level or lower-lying
rooms below the reference level (e.g. cellars). This is particularly dangerous since SF
gas is colourless and odourless and thus may be imperceptible to people.
3.8 Danger caused by decomposition products
Insulating gas in electrical systems may contain decomposition products generated by
electric arcs:
Gaseous sulphur fluorides
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Sulphur hexafluorides
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Solid and atomized metal fluorides, metal sulphides, metal oxides
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Hydrogen fluoride
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Sulphur dioxide
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Decomposition products can be harmful to health.
They can cause poisoning by inhalation, ingestion or contact with the skin.
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They may be irritating to the eyes, the respiratory system or the skin and burn them.
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Inhalation of large quantities may damage the lungs.
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Observe the following safety instructions in order to avoid danger from insulating gas:
Wear personal protective equipment.
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Read the material safety data sheet of the gas supplier.
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With large leaks, evacuate the area quickly.
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Ensure good ventilation.
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Ensure the leak tightness of the equipment with a leak detector (e.g. model GIR-10).
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WIKA operating instructions, model GDM-RC-100
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