Static Electricity 2000 Edition

7.13.4 Plastic-Lined Metal Containers.
The effects of static
electricity from thin, internal coatings such as phenolic or
epoxy paints can be neglected, provided the lining is not
thicker than 2 mm. A container with a thin lining up to 2 mm
in thickness can be treated as a metal container. Where the
drum has a lining of nonconductive plastic thicker than 2 mm,
it should be treated as a nonconductive container, unless it
can be shown that the surface resistivity is not greater than 10
10
ohms per square.
7.13.5 Plastic Containers.
The use of plastic containers for
Class I liquids is limited by NFPA 30, Flammable and Combusti-
ble Liquids Code. Where such containers are used for Class II
and Class III liquids, the precautions for filling depend on
the size of the container, the container design, and the con-
ductivity of the liquid. Since plastic containers cannot be
grounded, they should not be used for Class I liquids or han-
dled in flammable atmospheres without expert review of the
hazards. For Class II liquids, hazards of static electricity
should be addressed as follows:
(1) Where the liquid might exceed its flash point during fill-
ing or emptying
(2) Where the container might be stored or handled in an
ignitible ambient atmosphere
In 7.13.5(1), options include bottom filling and cooling of
the liquid prior to unloading, especially if the container has
been in direct sunlight or in a hot storage area. Continuous
inerting during unloading can also be considered.
In 7.13.5(2), plastic containers should be stored away from
containers of flammable liquids, so that the hazard of static
electric discharge from the external surface of the plastic con-
tainer is avoided.
7.13.6 Hand-Held Containers Not Greater than 20 L Ca-
pacity.
The fire risk from static electricity increases with the vol-
ume of the container and the volatility of liquid handled. Thus,
the smallest volume container capable of effectively fulfilling a