E-LEARNING

Environment Health & Safety

Accident / Incident Theories

D. Annadurai

OVERVIEW/DESCRIPTION

This course helps to know the way of happening of accident/ incident and find out the different causes involved through various available theories.

Gives an idea to interpret these causes while doing accident / incident investigation to reach preventive actions with respect to them.

Target Audience This training course is intended for Foreman, Engineers & Managers.

Expected Duration 3.0 hour

LESSON OBJECTIVES

To know various theories on accident / incident.

To know interrelation of causes in accident / incident occurrences.

To develop knowledge to interpret those causes in accident / incident Investigation.

To develop knowledge about potential causes for use in accident / incident prevention.

COURSE OVERVIEW

Theories on Accident / Incident

Domino Theories Heinrich’s Domino Theory Bird’s Domino Updated Theory

Human Factors Theory Peterson Accident / Incident Theory Epidemiological Theory System Theory Model Swiss Cheese Theory Model Energy Release Theory Combination Model

Interpretation of Causes in Accident / Incident Investigation & Prevention

HEINRICH DOMINO THEORY

BIRD’S UPDATED DOMINO THEORY

FERREL’S HUMAN FACTOR

Ferrell identifies three general causes of accidents:

overload

incompatibility

and improper activities

PETERSON’S MODEL

EPIDEMIOLOGICAL THEORY

Suchman stated epidemiological definition of accident  as  "An  unexpected;  unavoidable, unintentional act resulting from the interaction of host (accident victim), agent (injury deliverer) and environmental factors within situations which involve risk taking and perception of danger". 

SYSTEM MODEL THEORY

SWISS CHEESE MODEL

The holes in the cheese slices represent individual weaknesses in individual parts of the system, and are continually varying in size and position in all slices. The system as a whole produces failures when all of the holes in each of the slices momentarily align, permitting (in Reason's words) "a trajectory of accident opportunity", so that a hazard passes through all of the holes in all of the defences, leading to a failure.

ENERGY RELEASE THEORY Dr. Leslie Ball, former Director of Safety for NASA,

introduced a causation theory. His thesis is that all accidents are caused by hazard, and all hazards involve energy, either due to involvement with destructive energy sources or due to a lack of critical energy needs. This model is most useful to identify hazards and to understand system safety.

 Gibson noted that injury to a living organism can be only by some energy interchange. Hence it was suggested that the energy exchange should be considered as the injury agent. The energy exchange resulting in an injury could be mechanical, chemical, thermal, electrical etc.  This concept is useful in understanding the way injury caused and examining the solutions.

William Hadden, 1970, explained 'energy transfer or release' as the main factor for accident causation and said that accidents and injuries are caused because of transfer or release of energy between objects, events or environment interacting with people.

COMBINATION MODEL

Under Preparation

INTERPRETATION OF CAUSES IN ACCIDENT / INCIDENT INVESTIGATION & PREVENTION

Recommends to have the Combination Model approach in Accident / Incident Investigation & Preventive Actions.