Sioen Professional Protective Clothing - 2016

Multi-norm
FR + AST
Protection against the risks
caused by static electricity
The risk
Despite all preventive measures the risk of an
explosion can often not be totally excluded in
industries where potentially explosive mixtures of
air and fl ammable gasses or concentrations of dust
and powders can be accumulated. Those potentially
explosive environments (ATEX) can occur for
example in (petro)chemical industry or companies
with activities in gas production, distribution and
maintenance of installations or industries where
concentrations of dust or powders
can be accumulated.
In those environments even a little spark can
be enough to ignite an explosion. One of the
major risks in those environments is the built up
of electrostatic electricity on the surface of the
garment. If the electrostatic charges reach a too
high level this can give rise to uncontrolled electrical
discharges (sparks) that can cause ignition of the
explosive atmosphere.
to the building up of electrical charges, but that
dissipates them.
To dissipate static electricity, electrically conductive
yarns containing carbon are integrated in the
fabric. The yarns that are most commonly used in
professional protective clothing are based on surface
conductivity. The layer that dissipates the static
electricity is placed at the outside on the surface
of the yarn. Our R&D department has come up
with a better solution based on hybrid electrostatic
dissipative technology. This technology offers a lot of
advantages.
If you work in such an environment it is of great
importance to wear garments of which the outer
fabric is made in a fabric that does not give rise
Yarn with surface
conductor
Yarn with hybrid
electrostatic dissipative
technology
dvantages o hbrid conductive fibers
1. increased safety in case of inadequate earthing:
• improved dissipative properties using a double
mechanism to dissipate the electrostatic
charges (by transfer and by point discharge)
• the maximum energy of the stored electrostatic
charge will be lower, so the minimum ignition
energy of a particular gas/air mixture in an
ATEX environment will less likely be exceeded
by a spark.
As per the EN1149-5 requirements, we specify the
wearer must always be properly earthed eg. Through
the use of conductive or static dissipative flooring
and footwear (as defined in EN ISO 20345, but with a
maximum resistance of 10 8 Ω).
2. increased durability of the anti-static protection:
The conductive layer is embedded in the yarn. This
means that it is better protected against abrasion
during normal use: wear, tear, rubbing, washing and
drying, contact with chemicals.
3. increased comfort for the wearer:
Utility workers sometimes work in gas supply
other times in electricity supply. The use of hybrid
conductive fibres avoids nuisance for a wearer –
respecting the safety distances - in high voltage
electro magnetic fields.
Anti-static clothing is not designed to protect against
exposure to mains electricity or other electrical
currents, nor are they giving protection against the
thermal hazards of electrical arcs (unless this is stated
in the garment)
378 NORMS & STANDARDS MULTI-NORM