ACCIDENT PREVENTION THEORY & RISK MANAGEMENT

Dr yinka ADENIRAN

LEARNING OBJECTIVES

• DISCUSS ACCIDENTS CAUSATION THEORIES

• DISCUSS ACCIDENT PREVENTION

• DESCRIBE/DISCUSS RISK ASSESSMENT &

MANAGEMENT

INTRODUCTION

Industrial work place accidents

• 3/100 persons per year

• One accidental death every 51 minutes

• One injury every 19 seconds

OCCUPATIONAL ACCIDENT

A sudden and unexpected event or series

of events occur or occurs when work is

performed that results in something

injurious causing injury or damage to

people, materials, processes, etc.

RELATED CONCEPTS

The near miss

”A sudden and unexpected event or series of events that contains or contain something that can cause injury or damage, but due to fortuitous circumstances does not have injurious consequences”.

Dangerous situations and dangerous actions

” Situations or actions that have the potential for the occurrence of sudden and unexpected events, which contain a source of danger that can cause injury or damage”.

WHY DO ACCIDENTS HAPPEN?

WHY DO ACCIDENTS HAPPEN?

• Is there a theory that explains the causes of

accidents?

• To prevent accidents we need to know the causes.

• Six widely used theories for accident causation

Factory managers reasoned that

workers were hurt because —

ACCIDENT

PEOPLE PROBLEM

Industrial Revolution

Number is Up

People ErrorCarelessness

Act of GodCost of doing

Business

THEORIES OF ACCIDENTS CAUSATION

• Domino Theory

• Human Factors Theory

• Accident / Incident Theory

• Epidemiological Theory

• Systems Theory

• Combination Theory

“Industrial Accident Prevention”

1932 First Scientific Approach to

Accident/Prevention - H.W. Heinrich.

Domino Theory

Social Environmentand Ancestry

Fault of thePerson

(Carelessness)

Unsafe Act or

Physical hazardAccident Injury

MISTAKES OF PEOPLE

HEINRICH’S THEOREMS

• INJURY - caused by accidents.

• ACCIDENTS - caused by an unsafe act –injured person or an unsafe condition –work place.

• UNSAFE ACTS/PHYSICAL HAZARD - caused by careless persons or poorly designed or improperly maintained equipment ETC

• FAULT OF PERSONS - created by social environment or acquired by ancestry.

• SOCIAL ENVIRONMENT/ANCESTRY - where and how a person was raised and educated.

HEINRICH’S AXIOMS OF INDUSTRIAL SAFETY

1. Injuries result from a series of preceding factors.

2. Accidents occur as the result of physical hazard or an unsafe act.

3. Most accidents are the result of unsafe behavior.

4. Unsafe acts and hazards do not always result in immediate accidents and injuries.

5. Understanding why people commit unsafe acts helps to establish guidelines for corrective actions.

HEINRICH’S AXIOMS OF INDUSTRIAL SAFETY

6. The severity of the injury is largely fortuitous

and the accident that caused it is preventable.

7. Best accident prevention techniques are analogous to best quality /

productivity techniques.

8. Management should assume safety responsibilities.

9. The supervisor is the key person in the prevention of industrial

accidents.

10. Cost of accidents include both direct costs and indirect costs.

HUMAN FACTORS THEORY

Chain of events ultimately caused

by human error

Three factors

• Overload

• Inappropriate response

• Inappropriate activities

HUMAN FACTORS THEORY

Overload

• Capacity - abilities

• Load

• Environmental factors (e.g noise)

• Internal factors (e.g. personal problems)

• Situational factors (e.g. risk)

HUMAN FACTORS THEORY

Inappropriate response

• Ignores a suspected hazard

• Disregards established safety procedures

• Circumvents safety devices

• Includes incompatibility with person’s workstationSize, Required Force, Reach, Feel, etc

HUMAN FACTORS THEORY

Inappropriate activities

• Doing a task without training

• Misjudging the degree of risk

ACCIDENT/INCIDENT THEORY

Human factors theory plus

• Ergonomic traps

• Decision to err

• System’s failure

• Overload + Ergonomic traps + Decision to err lead

to human error

19

PETERSEN’S

Overload

System Failure

Injury / Damage

Accident

Human Error

Ergonomic Traps Decsion to Err

Accident / Incident Theory

OVERLOAD

• Pressures

• Deadlines, Budget Factors, Peer Pressure

• Fatigue

• Motivation

• Drugs

• Alcohol

• Worry

ERGONOMIC TRAPS

• Incompatible Workstation

• Incompatible Expectations

DECISION TO ERR

• Misjudgment of Risks

• Unconscious Desire to Err

• Logical Decision Based on Situation / Circumstances

• Superman Syndrome (It won’t happen to me!)

• - Bulletproof, Invincible, Immortal, Lucky

SYSTEM FAILURES

• Potential for causal relationship between

managerial decisions/behaviors regarding safety

• Policies

• Responsibilities

• Training

• Inspections

• Corrective Actions

• Standards

EPIDEMIOLOGICAL THEORY

• Causal relationship between environmental factors

and disease

• Extended to accidents

• Study causal relationships between environmental

factors and the accident

25

EPIDEMIOLOGICAL THEORY

Can cause or prevent accident conditions

Predispositional

Characteristics

Situational

Characteristics

Epidemiological Theory

SYSTEMS THEORY

• System - interacting components intended to meet a

common goal. A change in any component affects the

entire system

• Components

• Person

• Machine

• Environment

• Collect information, weigh risks, make

decisions

FIRENZIE’S SYSTEMS THEORY

Person/Machine/Environment

• Information Gathering

• Risks Assessment

• Decision Making

• Task Performance

• Stressors can cloud the judgment during information gathering, risk weighing, decision making processes.

Stressors

FIRENZIE’S RECOMMENDATIONS

Consider Five Factors -

before beginning the process of information

gathering, risk weighing, decision making.

• Job Requirements

• Worker’s Abilities and Limitations

• Gain from Successful Task Completion

• Loss if Task Attempted but Results in Failure

• Loss if Task is Not Attempted

COMBINATION THEORY

• In many cases, one theory is not sufficient

• Need to use several models to explore the causes of accidents

• Don’t rely on one theory

ACCIDENTS PREVENTION

It is impossible to remove and minimise all risks. Accident

risks will always be present where people travel, act, work,

develop and live.

Accident prevention is not about achieving ZERO risk, but

rather about achieving ZERO accidents

ACCIDENT PREVENTION

•DISCUSS

RISK ASSESSMENT

QUIZ

HerbertW. Heinrich's study of the causes of industrial accidents in

the 1920s concluded that most accidents are caused by:

Unsafe acts committed by fellow workers

Poor management

Lack of health and safety programs

Faulty machines and equipment

QUIZ

Carelessness, training, and management

Carelessness, overload, and training

Pressure, motivation, and fatigue

Overload, inappropriate response, and inappropriate activities

Which three factors lead to human error in the human factors theory?

The systems theory views a situation in which an accident might occur as a system comprised of:

Person, machine, and motivation

Motivation, peer pressure, and overload

Person, machine, and environment

Attitude, risk, and motivation

T/F

• Why accidents happen is a concern for health and safety decision-makers

• Theories of accident causation are used to predict and prevent accidents.

• The domino theory of accident causation was one of the earliest theories developed.

• According to Heinrich's Axioms on Industrial Safety, the plant manager is the key person concerning industrial accidents

• The human factors theory of accident causation attributes accidents to a chain of events caused by human error

• An accident program does not have to take all ten axioms into account to be effective

• The accident/incident theory is an extension of the human factors theory.

ANSWER THE QUIZ

https://www.onlinequizcreator.com/accident-theories/quiz-261169

ESSAY QUESTIONS

• Discuss the domino theory of accident causation.• Compare the human factors theory of accident

causation and the accident/incident theory of accident causation.

• Discuss your opinion on how accidents are caused.• Explain the concept of the epidemiological theory

of accident causation.

QUESTIONS