|
Confined
space
|
(This the fifth in a series of safety and health bulletins on specific issues developed/adapted for
the
GCIU by Dan Huziak of Toronto 100M.)
"Are you all right brother?" These were the last words of Robert
LaPolice. He called them out to John Hewson, 31, who had climbed down into a Hamilton,
Ontario, steel maker's vacuum degreaser tank to clean it. As Hewson reached the bottom of the
tank he collapsed, his lungs filled with argon gas. LaPolice, 26, entered the tank in an attempt to
rescue him. In the end, both men died. As a result, Gordon Hewson, 7, Bryant Hewson, 4, and
Matthew LaPolice, 8, must face life without their fathers.
A coroner's inquest into the two fatalities made 30 recommendations including ones which
suggested improvements to the steel maker's confined space entry program and minimum
standards regulated by the Ontario government. Unfortunately, any improvements that may result
will not benefit LaPolice, Hewson or their families. Nonetheless, both families and area health and
safety advocates are working for the implementation of the recommendations. They hold dear the
wish that no others suffer as the Hewson and LaPolice families suffer still.
The names may change, but every year workers in many industries work in or around confined
spaces, whether they are tunnels, vats, or tankers. All too often, the same scenario is played out
a worker is in trouble, a co-worker goes in to help, and both are killed in the rescue. It is
estimated that 60 percent of confined space fatalities occur among rescuers. Too often they are ill
equipped and untrained.
What is a confined space?
The first step in controlling any hazard comes with its proper recognition. While confined spaces
come in many different forms from tanks to trenches, they characteristically have limited routes of
entry and exit and they often lack natural ventilation. In addition, their atmospheric conditions can
rapidly change without warning. When you combine these characteristics, dangerous conditions
can arise for anyone who must work inside the space.
Most legislation defines a confined space as a space in which, because of its construction,
location, contents or work activity therein, the accumulation of a hazardous gas, vapor, dust or
fume or the creation of an oxygen-deficient atmosphere occurs. Similar standards exist in most
states and provinces.
How are workers
exposed?
Workers in a variety of work environments may encounter confined spaces. These areas are often
designed to store a product, enclose materials or processes, or transport substances. As such, they
are not usually considered a regular work area. Workers may enter the confined space to perform
a specific task such as construction, maintenance, inspection, emergency repairs, or for routine
servicing or cleaning. Other workers, however, may work in these spaces almost daily. Those who
repair boilers or elevator shafts are two such examples. Some other examples of confined spaces
are ink tanks, sewers, silos, furnaces, and septic tanks.
What are the potential
hazards?
A variety of hazards may exist in the confined space depending on its construction and type of
materials being used. It is critical to recognize, assess and control these hazards, especially since
conditions can change rapidly.
Atmospheric Hazards:
Oxygen Deficiency: Ontario's Industrial Regulations require acceptable breathing air to
contain between 18 percent and 23 percent oxygen. OSHA revised standard, 29 CFR 1910.146
requires acceptable breathing air to contain between 19.5 percent and 23.5 percent oxygen. (See
other legislation.)
Oxygen Excess: Oxygen rich environments can cause flammable materials to ignite.
F1ammable Atmospheres: Gases, vapors and dusts can become trapped in confined
spaces and create flammable or explosive atmospheres.
Toxic Atmospheres: While they might be safer in other workspaces, some toxic
substances even at low concentrations can cause health effects in a confined
space.
Physical hazards:
Entry and Exit: Openings may be small or constricted.
Machinery and Equipment: As in other work settings, unless properly locked out (see
Hazards Watch on lockout) machinery and equipment could be inadvertently started up.
Electrical Hazards: Tools that aren't grounded or properly insulated could cause
electrocution and accidental start-ups.
Lines and Systems: If these systems are not properly disconnected and blanked off, they
may leak, potentially leaving workers trapped, burned, drowned or smothered.
Walking/Working Surfaces and Visibility: Poor lighting may add to hazards caused by
an irregular, sloped, or constricted working surface.
Noise and Vibration: Noise from equipment can be intensified in some confined spaces.
Temperature Extremes and Humidity: Hot and cold temperatures can affect a worker's
ability to perform tasks, while excess humidity can create slippery surfaces.
How to assess a confined
space
Procedures for working, entering, and exiting safely are crucial and must be tailored to the space
itself. A standard program must be developed, but it should be further customized to the hazards
found in each particular space. Additional workplace policies and procedures are communicating
this hazard information. Any entry program should equally apply for all workers, whether they are
regular employees or employed by an outside contractor.
An effective confined space entry program should include the following components.
- Identification: The joint health and safety committee should routinely inspect all
areas considered to be confined spaces.
- Inspection and evaluation: Assess for all exiting and potential hazards, including
those in adjacent work areas.
- Site preparation: Clear all debris from the area; bring in equipment only as needed.
- Isolation-lockout and blanking off procedures: Lock out all energy sources.
Disconnect lines and systems, implement lockout procedure.
- Testing and monitoring: Test for oxygen levels, flammability and toxic materials or
possibly a combination of tests. Be sure to conduct stratification monitoring, which tests levels of
a substance at various points of the tank or pit. For instance, substances that are heavier than air
could pool at the bottom.
- Purging and ventilation: Remove contaminants by using liquids or non- flammable
gases. Introduce gases to make contaminants unreactive. Use proper ventilation sources.
- Personal protective equipment: Use proper protective equipment, ensure it
conforms to standards, and train workers in its use. This equipment should include personal gas
monitors.
- Equipment and tools: Inspect for defects, ensure equipment and tools are insulated
and grounded.
- Attendant and communications: Provide proper training for attendants. Establish a
communications system and emergency response procedure.
- Rescue: Inspect all rescue equipment and provide training in its use.
- Documented work procedures: Establish procedures for all aspects of confined
space work.
- Entry permits: Effective permits will include a list of identified hazards, safe entry
testing, the type of work to be carried out, safe work procedures, necessary protective equipment,
and training requirements. Permits will be signed off by a competent confined space supervisor.
- Training: This must be provided not only to the workers, but also to supervisors,
attendants, standby persons and rescue personnel. Training must include rescue drills as well.
Additional strategies
Once you have developed a confined space entry program, it must be monitored and adapted as
needed to be most effective. Joint health and safety committees in many workplaces have
introduced improvements to make confined spaces safer by substituting toxic materials with less
hazardous materials; designing newer confined spaces that allow routine maintenance and repairs
to be done from outside the space; stationing a fully equipped rescue person outside the confined
space, in addition to the attendant; advocating for personal gas monitors; and carrying on
continuous monitoring of the environment while workers are inside the confined space.
[back to top]