Theories of Accident Causation

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Theories of Accident Causation
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CII OSHA Recordable Performance - 1993-2000
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Lost Time
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Recordables
10.4
297
First Aid
Near Misses??
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A DISPROPORTIONATE NUMBER OF ACCIDENTS OCCUR IN
CONSTRUCTION

• Nearly 6.6 of the industrial workforce is in
  construction.
• But, over 18 of the fatalities occur in
  construction (1,200 fatalities per year)
• And, over 12 of the disabling injuries occur in
  construction (over 500,000 injuries per year)
• Do these statistics have anything to do with
  firms serious about safety?

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What Is An Accident?

• Unplanned event
• Generally associated with negative consequences
• Fatalities
• Injuries
• Near misses
• Damaged materials
• Shattered nerves

Do accidents just happen or are they caused?
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Theories of Accident Causation

• Understanding the causes of accidents may lead to
  an effective means of their prevention.
• No worker wants to be injured, but it still
  happens thousands of times every working day.
• Why??

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1 Accident Proneness Theory
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Accident-Proneness Theory
Old View

• Injuries happen to people who have a genetic
  predisposition to being injured
• The theory states that there are inherent
  characteristics of some individuals that
  predispose them to a greater probability of being
  involved in accidents.

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Accident-Proneness Theory

• A very controversial theory
• Many research studies have been conducted which
  lend support for the theory (Studies show
  injuries are not randomly distributed, but do
  studies recognize differences in hazard
  exposure?)
• Other studies have shown that there is no basis
  for the theory

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Accident-Proneness Theory
New View

• Recent researchers view accident proneness as
  being associated with the propensity of
  individuals to take risks or to take chances.
• This presents a more positive view for safety, as
  behavior can be altered even if the propensity to
  take risks cannot.

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2 GOALS-FREEDOM-ALERTNESS THEORY
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Goals-Freedom-Alertness Theory

• This is a fundamental concept that accidents are
  the result of low quality (unsafe) behavior
  resulting from an unrewarding psychological
  climate that does not contribute to mental
  alertness.

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Goals-Freedom-Alertness Theory

• Workers should have the ability to set attainable
  goals.
• Workers should have the freedom to pursue their
  goals.
• This will result in a rich work climate with
  alertness and fewer accidents (Workers stay
  focused)

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Goals-Freedom-Alertness Theory

• A positive work environment is good for safety.

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3 ADJUSTMENT STRESS THEORY
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Adjustment Stress Theory

• A negative work environment contributes to
  accident causation.
• A negative work environment is often caused by
  stress.
• Excessive stress prevents the individual from
  focusing on the work.

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Adjustment Stress Theory

• Stress comes from many sources.
• On the Job
• Poor relationship with the supervisor
• Poor relationship with crew members
• Harsh deadlines
• Poor coordination
• Excessive rework
• Cost overruns
• Long overtime commitments
• Crowded work areas
• Jobsite hazards

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Adjustment Stress Theory

• Stress comes from many Sources.
• Off the Job
• Poor relationship with the spouse
• sick child
• mortgage due date

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4 Chain of Events
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Chain of Events

• This is not truly a theory of accident causation,
  but is often referred to as one.
• It is really a conceptual portrayal of how
  accidents occur.
• The chain of events states that there is not a
  single cause of an accident but there are many
  causes an accident.

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Chain of Events

• In general, every accident is preceded by a
  series of events or activities.
• If any one event or activity had been done
  differently, the accident would not have occurred
  (break the chain to avoid the accident).
  Different people may be associated with the
  different links in the chain.

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Chain of Events

• This has implications for many parties on the
  construction site (the worker who was injured,
  the workers crew, the foreman, the
  superintendent, other crews, the project manager,
  the subcontractors, the safety rep., etc.).
• There are many links in the chain and only one
  link needs to be broken.
• Also called the Domino Theory

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If I had done this, that would not have happened
Contributing Factors
Only one party is required to break the chain!!
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5 Distractions Theory
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Distractions Theory

• This theory states that accidents are caused when
  workers are distracted when they are performing
  their work tasks.
• There are two types of distractions.

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Distractions Theory

• Jobsite Hazards can be a source of distraction
• Workers will try to avoid being injured so they
  naturally focus on the hazard, but this occurs as
  they are trying to do work. Trying to get the
  task done may cause the worker to be distracted
  and to ignore the hazard, resulting in an injury.

Focus on the Hazards
The Dilemma
or
Focus on Getting Tasks Done
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high
low focus on distraction
Distraction Working near a powerline
Probability of Injury Occurrence
high focus on distraction
Safe Zone
Safe Zone
low
low
high
Work Task Achievement
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high
Probability of Injury Occurrence
Distraction Minor Hazard
low focus on distraction
high focus on distraction
low
high
low
Work Task Achievement
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Injury Occurrence
Low Focus on Hazard
High Focus on Hazard
Low
High
Task Achievement
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Injury Occurrence
Dont work in this zone!!!
Low Focus on Hazard
High Focus on Hazard
Low
High
Task Achievement
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Distractions Theory

• Mental worries can be a source of distraction.
• Workers will try to focus on the work to be done,
  but may be distracted by worries caused by
  personal or job-related concerns. Failure to be
  able to focus on the work increases the
  likelihood of being injured.
• Remember the Holmes and Rahe Scale

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high
high focus on distraction
Major Mental Distraction
Probability of Injury Occurrence
low focus on distraction
low
high
low
Work Task Achievement
Can distracted workers be identified?
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Each of the Accident Theories Help Our
Understanding of Accident Causation

• Remember, no worker wants to be injured.
• Worker tasks should be structured so they are
  least likely to be injured.

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How to Achieve Safety

• Dont permit unsafe behavior
• Provide a rewarding work environment
• Make everyone responsible for safety
• Provide a safe work environment

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