Static Electricity 2000 Edition

9.1.6 Nonconductive Intermediate Bulk Containers.
9.1.6.1
The term nonconductive applies to any IBC that has a
volume resistivity greater than 10
10
ohm-m or a surface resistiv-
ity greater than 10
11
ohms.
9.1.6.2
When a material is transferred into a nonconductive
IBC, the container material will hinder the relaxation to
ground of any static electric charge that is present on the
material. In this instance, even conductive contents can accu-
mulate charge.
9.1.6.3
Nonconductive IBCs should not be filled or emptied
in areas where easily ignitible atmospheres (i.e., minimum
ignition energy less than 10 mJ) are present (i.e., gases, flam-
mable vapors, sensitive dusts, and hybrid mixtures.) When
powders are to be added to flammable liquids from noncon-
ductive containers, the receiving system should be closed and
inerted.
9.1.6.4
Nonconductive IBCs should not be used with solvent
wet powders in locations where the ambient temperature is
near or above the flash point of the solvent. Powders should be
considered to be solvent-wet powders if they contain more
than 0.2 percent by weight of solvent.
9.1.6.5
If a nonconductive IBC is moved into a location where
flammable gases or vapors are also present, rubbing of the
container should be avoided.
9.1.7 Flexible Intermediate Bulk Containers (FIBCs).
9.1.7.1 Description.
Flexible intermediate bulk containers
(FIBCs) are basically very large fabric bags supported in a
frame. They are more convenient than rigid IBCs because they
can be fully collapsed after use, taking up little storage space.
The fabric is usually polypropylene and the fabric is sewn to
form a three-dimensional cube or rectangle with lifting straps.
A FIBC can be filled with a powder or granular material and
moved about with conventional materials-handling equip-
ment. An advantage of FIBCs is that they can be unloaded very
quickly, typically 300 kg to 500 kg in 30 seconds or less. There-
fore, rates at which static electric charges are generated can
often exceed the rates at which the charges can relax under
common conditions of use and accumulation of a static elec-
tric charge can be expected. In general, the precautions given
in this subsection for IBCs also apply to FIBCs.