Theory of Accident Causation and Investigation, Slides of Public Health Engineering

Download Theory of Accident Causation and Investigation and more Slides Public Health Engineering in PDF only on Docsity!

INTRODUCTION TO

MDM SITI FARHANA BINTI ZAINAL BAKRI

LECTURER

FACULTY OF ENGINEERING & TECHNOLOGY

1

CHAPTER 4:

4.2 THEORY OF ACCIDENT CAUSATION & INVESTIGATION

2

SINGLE FACTORS THEORY OF

ACCIDENT CAUSATION

4

Domino Theories

• There are several domino theories of accident causation. While each domino theory presents a different explanation for the cause of accidents, they all have one thing in common. All **_domino theories are divided into three phases:

1. Pre-contact phase:_** refers to those events or conditions that lead up to the accident. 2. Contact phase: refers to the phase during which the individual, machinery, or facility comes into contact with the energy forms or forces beyond their physical capability to manage. 3. Post-contact phase: refers to the results of the accident or energy exposure. Physical injury, illness, production downtime, damage to equipment and/or facility, and loss of reputation are just some of the possible results that can occur during the post-contact phase of the domino theory.

5

UNSAFE ACT / UNSAFE CONDITION

INCIDENT / ACCIDENT

INJURY / DEATH / DAMAGE / HARM EFFECT

H. W. Heinrich developed the original domino theory of

accident causation in the late 1920s. Although written

decades ago, his work in accident causation is still the basis

for several contemporary theories. According to Heinrich’s

early theory, the following five factors influence all

accidents and are represented by individual dominos:

i. Negative character traits leading a person to behave in an unsafe manner can be inherited or acquired as a result of the social environment. ii. Negative character traits are why individuals behave in an unsafe manner and why hazardous conditions exist. iii. Unsafe acts committed by individuals and mechanical or physical hazards are the direct causes of accidents. iv. Falls and the impact of moving objects typically cause accidents resulting in injury. v. Typical injuries resulting from accidents include lacerations and fractures.

Heinrich’s Domino Theory

7

1 2 3 4 5

8

Bird and Loftus (1976) updated the domino sequence to reflect the management’s relationship with the causes and effects of all incidents. Bird and Loftus’ theory uses five dominos that represent the following events involved in all incidents:

1. Lack of Control—Management: Control in this instance refers to the functions of a manager: planning, organizing, leading, and controlling. Purchasing substandard equipment or tools, not providing adequate training, or failing to install adequate engineering controls are just a few examples represented by this domino. 2. Basic Cause(s)—Origin(s): The basic causes are frequently classified into two groups: i. Personal factors such as lack of knowledge or skill, improper motivation, and/or physical or mental problems, and ii. Job factors including inadequate work standards, inadequate design or maintenance, normal tool or equipment wear and tear, and/or abnormal tool usage such as lifting more weight than the rated capacity of an overhead crane. These basic causes explain why people engage in substandard practices.

Bird and Loftus’ Domino Theory

10

3. Immediate Causes(s)—Symptoms: The primary symptoms of all incidents are unsafe acts and unsafe conditions. ‘‘When the basic causes of incidents that could downgrade a business operation exist, they provide the opportunity for the occurrence of substandard practices and conditions (sometimes called errors) that could cause this domino to fall and lead directly to loss’’ (Bird and Loftus, 1976 , p. 44 ). 4. Incident—Contact: ‘‘An undesired event that could or does make contact with a source of energy above the threshold limit of body or structure’’ (Bird and Loftus, 1976). The categories of contact incident events are often represented by the 11 accident types. The 11 accident types include struck-by, struck-against, contact-by, contact-with, caught-in, caught-on, caught-between, foot-level fall, fall-to-below, overexertion, and exposure (ANSI Z 16.2). 5. People-Property-Loss: Loss refers to the adverse results of the accident. It is often evaluated in terms of property damage, as well as the effects upon humans, such as injuries and the working environment. The central point in this theory is that management is responsible for the safety and health of the employees. Like Heinrich’s theory, the Bird and Loftus domino theory emphasizes that contact incidents can be avoided if unsafe acts and conditions are prevented. Using the first three dominos to identify conditions permitting incidents to occur, and then ensuring the appropriate management activities are performed, can eliminate accidents and related losses according to this theory.

11

• According to C. E. Marcum’s (1978) Seven Domino Sequence of Misactsidents, a misactsident is an identifiable sequence of misacts associated with inadequate task preparation leading to substandard performance and miscompensated risks. The misactsident permits individuals and facilities to come in contact with harmful agents, energy forms, forces, or substances in ways that initiate adverse reactions sufficiently extensive so that unwarranted losses are sustained and resultant costs incurred.
• Marcum’s theory focuses on management responsibility for protecting employee safety as well as preventing the downgrading of an organization.

Marcum’s Domino Theory

13

• Downgrading of an organization includes incurring losses to equipment and facilities and to intangible assets of the organization such as reputation or corporate goodwill.
• This theory attempts to examine management accident response protocols to ensure that sustained losses and the subsequent incurred costs were minimized.
• Throughout this theory, Marcum focuses on the human element of misacts. This includes misacts of employees who fail to recognize or appreciate risks in the workplace, as well as misacts of organization managemen t who permit risks to go unrecognized, unappreciated, and/or uncorrected.
• Marcum uses the term misactsidents to emphasize the

deterministic aspects of his accident causation theory.

14

16

MULTIPLE FACTORS THEORY

OF ACCIDENT CAUSATION

• Manuele (1997a) believes the domino theories are too simplistic.
• He proposes the term unsafe act also be eliminated. He suggests the chief culprits in accident causation are less- than-adequate safety policies, standards, and procedures; and inadequate implementation accountability systems. Manuele attempts to pull different causation theories together into one working theory.
• Grose’s multiple factors theory uses four M s to represent factors causing an accident: Machine, Media, Man, and Management (Brauer, 1990).

17

A. Multiple Factors Theory

3. Man:  deals with the people and human factors contributing to the incident.  Characteristics of man are psychological state; gender; age; physiological variables (including height, weight, or condition); and cognitive attributes (such as memory, recall, or knowledge level). 4. Management:  also incorporates the other three Ms, looking at the methods used to select equipment, train personnel, or ensure a relatively hazard-free environment.  Characteristics of management could include safety rules, organizational structure, or policy and procedures. 19

4 Ms:

Multiple factors theories attempt to identify specific workplace characteristics that reveal underlying, and often hidden, causes of an accident by pointing to existing hazardous conditions.

20