3. Domino Theory
The Domino Theory is widely
attributed to Heinrich(1959,
Ridely and Channing,1999)
and is based on the
chronological order of the
causes of an accident.
4. Single Cause Domino Theory
Heinrich’s Theory
Each factor is the fault of the factor that immediately
precedes it.
A preventable injury is the natural culmination of a
series of events or circumstances, which occur in a
fixed logical order.
5. The five stage are: Fig 1
Ancestry and social environment,
leading to
Fault of the person, constituting the
proximate reason for
An unsafe act or condition, which
results in
The injury, damage loss or
combination of these
outcomes.
The accident ,which
leads to
7. Single Cause Domino Theory
If one of the dominoes is removed then he chain of
events will be halted, and the accident will not happen
Element 3 (unsafe act or mechanical or physical
hazard) is probably the easiest factor to remove.
8. Accidents Causes
Immediate or primary causes of accidents
are often grouped into unsafe acts and
unsafe conditions.
9. Working without authority
Failure to warn others of danger
leaving equipment in dangerous condition
Using equipment in wrong speed
Disconnected safety devices e.g. guards ,
10. Unsafe Acts Cont…...
• Using defective equipment
• Using equipment in the wrong way
• Failure to use or wear PPE
• Bad loading of vehicles
• Failure to lift loads correctly
11. Unsafe conditions can include:-
inadequate or missing guards / moving
machines parts
defective tool or equipment
inadequate fire warning systems
12. Unsafe Conditions
• fire hazards
• hazardous atmospheric conditions
• excessive noise
• exposure to radiation
• inadequate illumination or ventilation
13. Multi- Causality Theory
The multi- causality approach is based on
the principle that accidents are the result of
many causes.
This is best illustrated by figure 2 (blinder
et al,1999) which shows the causal tree
analysis of an accident in a timber factory.
15. Multiple Causation
May be more than one cause, not only in sequence,
but occurring at the same time
In accident investigation all causes must be identified
Usually simple accidents have a single cause
Major disasters normally have multiple causes.
16. Multiple Causation
This approach allows for the analysis and identification
of active failures i.e. direct causes and latent or hidden
causes which can relate to management, designers
etc., that is the underlying causes.
Awareness of such issues is crucial in the process of
risk assessment, because in a proactive approach it is
necessary to identify potential risk, not just the
obvious ones.
17. Unsafe Acts
Unsafe acts can be active or passive:
Active Unsafe Acts: - Worker deliberately removes
machine guard
Passive Unsafe Acts: - More difficult to deal with
- By pursuing an active safety policy, it is possible to
achieve a reduction in bad habits and hence accidents.
18. The categories of causes that need to
be considered are:
People
Equipment
Materials
Environment
19. Unsafe Acts/Conditions
The diagram shows how unsafe acts & conditions may
interact to produce an accident.
Accident potential is increased when unsafe acts &
conditions occur simultaneously.
This is not to say that an act or condition alone could
not result in an accident.
21. Calculating accident
incidence rate
Incident rate;-( helpful where the number of work
hours is either low or not available)
Number of injuries x 1,000
Average number employed during the period
OR
Number of fatal or major injuries x
100,000
Number at the risk of an industry sector
22. Fatal Accidents/100,000 Employees in the
UK
The Health and Safety Executive publishes data on the fatal accident rate per 100 000
employed. The fatal accident rate for the period 1996/97 – 2004/05 is shown in figure 5.3.
23. Frequency rate;- Number of injuries x
100,000
Total number of hours
work
Severity rate;- Total number of days lost x
1000
Total number of hours
worked
24. Accident Reporting
Information should be kept for all injuries, and
preferably for near misses
The safety practitioner needs to design a suitable form
to ensure that he gets the information that he needs
for investigations.
25. Internal reporting
Internal reporting is a vital component of a
well-run buversioning overlap and manual
processes. These roadblocks often result in
inaccuracy, inefficiency and a lot of
frustration.
What makes this process more challenging is
the frequency with which internal reporting
occurs; its continuous nature makes it difficult
for organizations to streamline internal
reporting methodssiness, but in most
organizations, it’s fraught with challenges.
26. Recording & Reporting
Accidents
Recording and reporting accidents and ill health at
work is a legal requirement under .The reporting
of injuries, diseases and dangerous occurrences
regulation 2013 (RIDDOR)
RIDDOR places a legal duty on:
employers
self – employed people
people in control of premises
27. Accident Investigation
Records
Format:
Name and personal details of victim
Date, day and time of accident
Location of accident
Job being done at the time
Nature of injure or damage
What inflicted the injury or damage
Who had control of the cause of the injury or damage
What actually happened
Immediate remedial action taken
Recommendations to prevent recurrence
28. Use of Investigation Records
Accident records should not only be used to count
accidents.
Detailed and thorough study of the records as part of
the normal ongoing accident prevention programme.
29. Use of Investigation Records
Useful information from reports:
Relative importance of the various injury&
damage sources
Conditions, processes, machines and activities
which cause the injuries/damages
The extent of repetition of each type of injury or
accident in each operation
Accident repeaters, i.e. those workers who tend to
be repeatedly injured or are involved in more
accidents
How to prevent similar accidents in future
30. Accident Investigation
Could be carried out by
Safety Practitioner
Management or Supervisor
Safety Representative
Inspector
31. Accident Investigation
Initial Actions –
Promptness – as soon as possible after the event
Question the victim
Witnesses & Conditions
34. Reporting of Accidents &
Investigation
Inform the Chief Inspector fort with
Must fill out the prescribe form “3”
Written report submitted within 48 hours. (OSH)
Prepare a general Resister keep for 5 years on site.
A joint investigation by company /safety rep is often a good idea.
An investigation which does not discover what when wrong, and produce some useful information and recommendations for corrective action, is just a waste of time.
