CONFINED HAZARDS
from flowing into the confined space.
4. Control the physical hazards such as
noise, heat or cold, vibration, electrical,
and lighting:
BY: DALE GREENE,
BMB OF FLORIDA
• Proper PPE will help with hearing
concerns. Grinding, cutting,
drilling, or welding would be
examples of noise sources.
• Limiting the time in a confined
space in a hot environment, plus
cool down periods and water every
15 minutes, will help with this
exposure.
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Cold exposure control includes
proper clothing; limiting time in
the confined space will help.
Ergonomic concerns from
vibration exposures can be
controlled. Vibration-dampening
gloves, employee rotation, and
control of pneumatic discharge
ports will go a long way to help
alleviate the vibration concerns. • Electrical energy sources are
best controlled through a well-
designed lock-out, tag-out (LOTO)
program. Access the space, know
the obvious hazards, and take the
appropriate steps to control the
electrical hazards. The baffles in a chlorine chamber
at a waste water treatment plant
offer a restrictive structure when
it comes to rescue. Accidental
water release becomes a drowning
hazard. Plan ahead and enforce
the LOTO.
• alls from or into a pit becomes
F
an issue. Internal inspections of
vertical boilers as high as three
stories are a classic example of
the need for a good fall protection
plan inside a confined space.
Proper lighting will allow workers
to function in a more efficient
manner.
5. Moving or rotating equipment,
structural restrictions, engulfment,
and fall hazards are often overlooked.
will show the Lower Explosion Limit
(LEL) and the Upper Explosion Limit
(UEL). The air quality should be
maintained at 10 percent of the LEL in
the confined space for anyone to enter
the space. Nearly all forms of dust will
present an explosion hazard in the
right concentration in the presence of
oxygen and with an ignition source. •
3. Isolation of process-related hazards.
Lock it out, tag it out, block it out,
isolate and bleed it out is the key to
safer confined space work. Use the
correct lock and tag to isolate process
piping to prevent material or chemicals •
The nature of the
restricted space
makes it much
more important
to plan, direct,
monitor, and
control the
hazards.
A pug mill is used to mix clay and
aggregate for road base material.
The mixing blades must be cleared
of clay at the end of a run. Time
and again, employees have been
injured or worse cleaning these
mills. A good LOTO program
will identify and help control this
hazard.
The floors of grain elevators must
be cleaned on occasions. The
wheel valve needs to be locked out
to prevent material from being
dumped on top of a cleaning
employee. LOTO is the key, but
enforcement of the program must
be assured.
6. Animal and insects are also common
hazards. Rats in attics, bees or wasps in
an enclosed rooftop HVAC structure,
and snakes in a culvert or pit are just a
few examples. The pre-entry meeting
should, at a minimum, include a
discussion of these issues.
There are biological hazards, visibility
hazards, loss of communication, shifting
or moving materials, release of gases,
changing air quality due to operations,
chemical exposures (skin, eyes, and lungs),
and a litany of other potential issues that
could affect employees entering, observing,
supervising, or rescuing confined space
workers. Confined spaces have the same
hazards as other workplaces. The nature
of the restricted space makes it much more
important to plan, direct, monitor, and
control the hazards.
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