from Construction Safety Association of Ontario Magazine, Autumn 2000)
Safety Association of Ontario
Over the last decade,
one category of fatalities has steadily increased in Ontario construction.
Among the top four
killers, "crushed or hit by object or material" now ranks third, after
falls and traffic. This type of fatal accident has affected a broad range
of trades and activities, as summarized in Table 1. The cases do not include
victims struck by vehicles or heavy equipment; those deaths are classified
1: Construction personnel fatally crushed or hit by object or material29
(15%) of 200 fatalities in 1990-1999
was struck by part of shaft of overhead crane being demolished.
manager was crushed under staircase being demolished.
owner died of blood clot in hospital after his leg was struck and
broken by tree during demolition.
4. Worker was
struck in head by concrete manhole section being lowered to him.
5. Worker was
struck in head by debris when barn being lifted collapsed.
6. Worker was
crushed when penthouse collapsed during demolition.
was crushed when beam shifted on forklift and fell.
major artery was severed by electric circular saw.
9. Worker demolishing
a barn was struck by large wooden beam when barn collapsed.
10. Truck driver
was crushed by material while unloading flatbed.
11. Truck driver
was crushed between dump truck and 1000-lb frozen slab of fill.
was crushed while demolishing precast concrete structure.
was crushed when ventilation stack collapsed.
was crushed when walls of barn under construction collapsed.
15. Supervisor on demolition project was crushed between beam he
was removing and another beam.
engineer was struck by pressure plug during sewer testing.
was struck by unsupported section of hull being cut from ship.
was struck by unsupported metal structure being cut.
19. Boom truck
operator was crushed while attempting to move a load.
was crushed when 4000-lb steel liner plate being installed at mine
was struck by flying rock during blasting operation.
was crushed when powered elevating work platform struck pipe rack.
was crushed during demolition of structure.
was crushed by falling roof trusses.
was crushed when foundation wall toppled over.
mechanic was crushed by elevator car while working in pit.
installer was crushed when precast beam fell off column.
was crushed when safe being removed fell off dolly.
was crushed when water-weakened concrete wall collapsed.
Effective hazard analysis
involves recognition, assessment, and control.
include construction people killed by
- collapsing buildings
- falling walls
- heavy objects
- falling material
- demolishing part
of a building
- erecting a wall
or structure that collapsed
- moving heavy objects
- installing building
material that fell.
helps us to recognize potential hazards in the workplace. We can then
pay special attention to operations such as demolition, erection, and
- health and safety
training and experience
- knowledge of the
Occupational Health and Safety Act and Regulations for Construction
- familiarity with
the site and the work being done
- familiarity with
equipment and materials being used
- regular inspection.
hazards are recognized, they need to be assessed. Assessment determines
the seriousness of the hazard by identifying
- which workers are exposed
- how long exposure may last
- how serious the effects of exposure would be
- whether existing rules and controls apply or alternate measures are
Controls can be implemented
- at the worker
- along the hazard
- at the hazard
the worker This is the last resort in protection when hazards
can't be controlled at the source or along the path. Control at the worker
consists of enclosure, isolation, or personal protective clothing and
equipment. Enclosure and isolation would be impractical in most of the
situations described in Table 1. Nor would personal protective equipment
afford any protection against hazards such as falling beams, collapsing
walls, inadequately secured overhead loads, or rock fragments from blasting.
the path Barriers and screens are examples of controls along
the hazard path. But they could prevent very few of the fatal accidents
listed in Table 1.
the source Ideally the best control for any hazard is elimination
at its source. With most crushed/hit hazards, this is the only
controls depend on
- compliance with
- adherence to
the company's health and safety policy and program
- accident prevention
training for workers and supervision
- site orientation
and safety talks
- regular site
controls against crushed/hit hazards entail some clearly defined and engineered
involve different trades, circumstances, and causes. But it's possible
to identify some basic prevention measures. Several of these are required
by the construction regulation (O. Reg. 213/91).
- Before starting
a particular job such as removing steel beams or dismantling a staircase,
consider what may happen at each stage of the work. Devise and follow
a plan until some new development makes it necessary to reassess your
- On demolition
or dismantling projects, determine how frames, beams, and other components
are tied into the structure and connected to each other.
- O. Reg. 213/91
prohibits any truss, girder, or other structural member from being
disconnected until it is relieved of all loads other than its own
weight and is provided with temporary support: Section 220.
- Work above a
tier or floor of a structure being demolished or dismantled must be
completed before the work affects the support of the tier or floor:
- Whether being
demolished, moved, or erected, structures must be temporarily supported
or stabilized where necessary to prevent collapse in whole or in part.
- Under the construction
regulation (O. Reg. 213/91), damaged structures that may endanger
people must be braced and shored progressively from a safe area towards
the hazardous area so that workers installing safeguards are protected:
- Sections cut
or unfastened from a structure should not be allowed to drop freely
unless there's no danger of hitting anyone below.
- O. Reg. 213/91
requires that blocking be installed to prevent the collapse or movement
of part or all of any equipment being dismantled, altered, or repaired:
- Loads must be
arranged and secured so that when banding or other fasteners are removed
the load does not come apart uncontrollably.
- Before hoisting
any load, inspect all rigging equipment to ensure that it's in good
condition and that each component has a stated load rating capable
of safely supporting the intended load.
- Loads should
not be hoisted or allowed to pass over people below. Specifically
O. Reg. 213/91 prohibits the operation of a power shovel, backhoe,
or similar excavating device in such a way that it or any part of
its load passes over a worker: Section 103(1).
- Avoid pinch
points between moving equipment and stationary objects or between
stationary objects and equipment or material that may move once you
- When using boom
trucks and forklifts, operate wherever possible on firm, level ground.
Handle controls smoothly, without suddenly starting, stopping, raising,
or lowering. These actions may dislodge the load or tip the machine.
- Forklifts and
other lifting devices should be equipped with overhead protection
to prevent loads from striking the operator.
- Try to determine
the center of gravity of loads to be lifted or materials to be erected
or demolished. Fatalities have occurred when steel beams, precast
panels, and other components have twisted, tipped, or pivoted unexpectedly,
crushing workers underneath or pinning them against objects. In several
cases this happened because material wasn't supported, suspended,
or anchored near its center of gravity.
When referring to
the Occupational Health and Safety Act and Regulations for Construction
Projects, make sure you have the latest, revised version, issued
in June 2000.
This is the final
article in a series dealing with the four major causes of construction
fatalities. Falls were covered in Volume 10, Number 3 (Autumn
1999); traffic in Volume 10, Number 4 (Winter 1999/2000);
and electrocution in Volume 11, Number 1 (Spring 2000).
This paper appears in the eLCOSH website with the permission of the author
and/or copyright holder and may not be reproduced without their consent.
eLCOSH is an information clearinghouse. eLCOSH and its sponsors are not
responsible for the accuracy of information provided on this web site,
nor for its use or misuse.
| CDC | NIOSH
| Site Map | Search
| Links | Help