01/03/2006

Catch Me If I Fall: Preventing Falls From Heights And Suspension Trauma

Working at heights is by nature a risky business. Nonetheless, construction
workers, painters, window washers, firefighters, scaffolders and live
performance workers are among those whose jobs require them to work at
elevations. The question of safety is paramount in their performance.
Prevention is the goal, but if falls do occur, a method of arresting or
stopping and cushioning the impact is necessary.

Much research has focused on the best methods of fall prevention. The obvious
one is simply to eliminate the risk of a fall by eliminating the need to work
at heights. In the construction and other trades, however, this is impractical.
Several studies have looked at the effectiveness of various safety devices for
workers who are at risk of falling more than 2.4 meters (8 feet). These devices
include:

  • guardrails
  • safety decking
  • fall arrest mats
  • safety netting
  • various types of fall arrest systems, including full-body safety harnesses
    and lanyards.

All of these have their benefits and disadvantages and appropriate uses.

Guardrails are structures, often made of wood, positioned at the edges of
construction sites, roofs, and scaffoldings. Standards for the dimensions of
guardrails may vary from province to province.

Safety netting can be used effectively in construction of industrial framed
buildings. Trained personnel are required to install, dismantle and inspect the
netting, and no worker should work above nets without proper training.

Safety harnesses, also called fall protection harnesses, are widely used, and
are effective if fitted properly. The one-size-fits-all harness is obviously
wishful thinking. A 70 kg worker will not get the same protection from the same
harness as a 110 kg worker. An ill fitting harness will certainly still stop a
fall, but can injure the worker who is dangling in mid-air if the straps and
metal supports are not contoured to the individual's shape.

Just as important as the harness are the lanyard or line that stops the fall,
and the anchor point for the lanyard. Even a short-distance fall by a worker
will generate substantial forces - sometimes compared to suspending an
automobile in mid-air. Anchor points must be carefully planned, usually in
consultation with an engineer. And the length of the lanyard must allow for the
stretch in the material resulting from the fall. Manufacturers provide data so
you can choose the correct length and avoid contact with the ground or other
objects.

A word on suspension trauma

When fall arrest systems are used, the possibility of suspension trauma is a
serious concern. This condition, which is potentially fatal, occurs when a
person is suspended motionless in a vertical position in the harness while
awaiting rescue.

Normally, muscle contractions during walking and other movement help push
circulating blood back up to the heart. However, if a person is vertical,
motionless and perhaps in shock, blood tends to pool around the legs, putting
extra pressure on the heart while it attempts to pump blood to the brain. The
situation can be made worse by the constrictions of the harness. Suspended
workers with head injuries or who are unconscious are particularly at risk. The
person must be rescued quickly (under ten minutes) and gradually brought to a
horizontal position. Otherwise, cardiac arrest may occur.

For these reasons, it is important that managers develop and implement an
on-site rescue plan. Co-workers must be trained and practiced in rescue
procedures, so they can act quickly and knowledgeably in an emergency. Smaller
companies may contract for assistance from rescue organizations such as the
local fire department. Coordination with local medical personnel is essential
to support on-site efforts.

People working at heights must be trained in practical fall prevention and fall
arrest techniques. Whenever personal protective equipment is used, the worker
needs to know how to properly use and maintain the gear. The manager is
responsible to provide appropriate training, and safety equipment that complies
with safety standards. Managers should be aware of new developments to keep up
with the ongoing research in fall prevention and arrest. Creating a culture of
safety that includes all workers, whether on short or long-term projects, is
the underlining net you really need.

Further Information


AplusA-online.de - Source: Canadian Centre for Occupational Health and Safety