Other pigments as Stainless steel and Bronze do not create an increased explosion risk
over and above normal powder coatings. However, it is considered that it would be best to
follow the same operational cycle as for Aluminium. Allowing the operator to alter the cycle
to a non-inerting cycle for other pigments may be risky as they may forget to change it
back to the required cycle for Aluminium. The same applies to Mica pigments. Use of
pigments from different suppliers should not alter the process risks as the basis of safety
has been derived for the finest un-coated leafing grades of Aluminium pigment.
Alumnium is considered the highest risk material irrespective of supplier.
Good maintenance is key to ensuring the on-going safe operation of any plant. Typical
maintenance and inspection required is as follows:
· Plant earthing should be regularly checked.
· Rotating parts such as bearings should be regularly inspected.
· Instrumentation and control systems should be regularly tested, in particular hardwired
· Dust extraction ductwork should be internally inspected on a regular basis as should
the interior of the dust filter unit.
· Duct velocity and capture device face velocity should be regular checked.
· The interior of the mixer drive casing should be regularly checked to ensure dust isn’t
accumulating near to belt drives etc.
· The shaft seal purge openings must be regularly checked preferable visually after each
batch to ensure they are clear.
· Safety interlocks on the mixer lid etc. should be regularly tested.
· Stored kegs of aluminium pigment should be periodically inspected for damage.
· The building roof should be periodically inspected to prevent water leakage into any
aluminium handling area.
It is important that operators used for the bonding of Aluminium are trained in the hazards
of the process and in the handling of aluminium powders. It would be preferable to use the
best operators for this process and to dedicate them to this operation if possible.
Operators must also be trained in the hazards of nitrogen gas such as asphyxiation, and in
the safe handling and connection of nitrogen cylinders. It would be preferable to get the
nitrogen cylinder supplier to handle and fit the cylinders if possible. Operators should be
taught permissible methods for isolating Aluminium fires.
Operating Procedures should be written for all steps in the operation.
The plant should be subject to regular on-going operational and housekeeping audits to
ensure that key procedures essential to safety are being followed. The housekeeping audit
should include checks of Aluminium dust accumulation on horizontal surfaces.
Any plant modifications should be subject to hazard study and risk assessment prior to