Theories of Accident Causation

Theories of Accident Causation

I. Introduction: Framing Accident Causation

When investigating occupational injuries, efforts to prevent accidents are heavily shaped by the assumptions we make about how they occur. Historically, there have been two broad paradigms in understanding accident causation:

  1. Blaming the Victim: Early theories (such as the concept of "accident-proneness" from the 1920s) assumed that certain workers were inherently susceptible to accidents, leading to the conclusion that safety could be managed by screening out "unsuitable" workers. Other views within this paradigm blamed worker apathy, ignorance, or "macho" risk-taking behaviors (Occupational Health and Safety in Construction Project Management, pp. 120-122).
  2. Blaming the System: Modern alternative explanations view accidents as complex system failures. This paradigm recognizes the impact of the social relations of production (e.g., pressure to meet deadlines), the physical/technological environment, and organizational breaches of safety codes (Occupational Health and Safety in Construction Project Management, pp. 122-123).

II. Early Linear Models

A. Heinrich’s Domino Theory (1930s) Developed by H.W. Heinrich after analyzing 75,000 insurance claims, this early linear model posited that 88% of accidents are caused by unsafe acts and 10% by unsafe conditions (Occupational Health and Safety in Construction Project Management, p. 125). He proposed a chronological sequence likened to falling dominoes:

  1. Ancestry and social environment leads to...
  2. Personal factors (e.g., recklessness, lack of knowledge), which lead to...
  3. Unsafe acts or conditions (the proximate causes), which lead to...
  4. Accidents (e.g., falls, collisions), which result in...
  5. Injuries (Occupational Health and Safety in Construction Project Management, pp. 123-124). While influential, this model is heavily criticized today for being overly simplified and focusing too much on immediate circumstances rather than systemic root causes (Occupational Health and Safety in Construction Project Management, p. 125).

B. The Updated Domino Sequence (Bird and Loftus, 1976) Bird and Loftus revised Heinrich's theory to incorporate the role of management. They argued that long-term safety solutions must focus on the first domino: Lack of control by management. This lack of control leads to basic causes (e.g., unrealistic schedules), which create immediate causes (substandard practices/conditions), resulting in an accident and subsequent loss (Occupational Health and Safety in Construction Project Management, pp. 126-127).

III. Complex and Multiple Causation Models

A. Multiple Causation Theory (Peterson) Peterson challenged the single-cause domino theory by asking how many other underlying factors are overlooked when we only identify one unsafe act. For example, if a worker falls from a defective ladder, multiple causality asks: Why wasn't the ladder inspected? Why did the supervisor allow its use? Was the worker trained? This approach recognizes that contributing causes combine randomly, and an accident occurs only when all factors align (Construction Safety Management Systems, pp. 675-676; Occupational Health and Safety in Construction Project Management, p. 128).

B. The Epidemiological Approach (Gordon, 1949; Suchman, 1961) This approach treats accidents similarly to infectious diseases, arguing that accidents result from a combination of forces from three sources:

  1. The Host: The person suffering the injury (influenced by age, competence, fatigue).
  2. The Agent: The injury deliverer (e.g., tools, machinery, chemicals).
  3. The Environment: The physical (noise, lighting), biological, and socio-political (subcontracting pressures, piece-rate payments) conditions of the workplace (Occupational Health and Safety in Construction Project Management, pp. 130-133). This model moves away from simply blaming the "agent" directly involved (e.g., a sheet of glass) and demands a broader etiological inquiry (Construction Safety Management Systems, p. 679).

C. Energy-Damage Model (Haddon, 1980) This model conceptualizes hazards as potentially damaging energies (kinetic, electrical, chemical, etc.). According to this theory, damage or injury arises when a source of energy contacts a recipient and exceeds their damage threshold. For instance, an object left on a scaffold is not the hazard itself; the gravitational potential energy of the person walking and dislodging it is the true hazard (Occupational Health and Safety in Construction Project Management, p. 137).

IV. Psychological and Behavioral Models










A. Surry’s Decision Model (1974) Surry proposed a cognitive model based on the brain's activity, divided into two stages:

  • Danger Build-up: When the possibility of injury is present (e.g., a trench showing signs of collapse). The worker must perceive the warning, cognitively recognize the avoidance needed, and physiologically be able to avoid it.
  • Danger Release: The accident process has begun. The victim must perceive the imminent danger and act. If the answer to any cognitive or physiological question in this sequence is "no," an injury or damage is inevitable. This model is highly useful for differentiating between errors arising from lapses in concentration versus errors of judgment (Occupational Health and Safety in Construction Project Management, pp. 134-137; Construction Safety Management Systems, pp. 652-653).

B. Hinze’s Distractions Theory (1996) Hinze theorized that workers distracted by hazards have a higher probability of accidents. As workers shift their focus from their task to the hazard, productivity declines. Conversely, safety and productivity are compatible when hazards are removed, reducing distractions and stress for the worker (Construction Safety Management Systems, p. 566).

V. Socio-Technical Systems and Organizational Models

A. The "Swiss Cheese" Model (Reason, 1997) James Reason developed a systems-based model illustrating that organizations have multiple defensive layers (barriers, safeguards), but each layer has "holes" or flaws. An accident occurs when these holes momentarily align, creating a trajectory for an accident. The holes are created by:

  • Active Failures: Unsafe acts, slips, or mistakes committed by people at the human-system interface.
  • Latent Conditions: "Accidents waiting to happen" that arise from upstream organizational decisions (e.g., understaffing, unworkable procedures, poor design). These lay dormant until triggered by an active failure (Occupational Health and Safety in Construction Project Management, pp. 138-140; Integrating work health and safety into construction project management, pp. 359-361).

B. The ConAC (Construction Accident Causality) Model (Haslam et al., 2003) Based on a study of 100 construction incidents in the UK, this model applies systems thinking specifically to the construction industry. It outlines a chain of causality:

  1. Originating Influences: Distal factors like client requirements, design of the permanent works, economic climate, and project management issues.
  2. Shaping Factors: Issues like site constraints, work scheduling, supervision levels, and worker fatigue/communication.
  3. Immediate Circumstances: The condition/usability of materials and equipment, site layout, and individual worker actions (Integrating work health and safety into construction project management, pp. 363-366; Occupational Health and Safety in Construction Project Management, pp. 140-144).

C. Constraint-Response Model (Suraji, Duff, and Peckitt, 2001) This model emphasizes that accidents result from constraints originating in the wider business environment. For instance, a client's budget constraint may lead a quantity surveyor to under-price safety equipment. Adversarial relationships can block hazard communication, ultimately creating proximal hazards on site that cause injury (Construction Safety Management Systems, p. 569).



Bibliography

  • Construction Safety Management Systems. (2004). S. Rowlinson. Spon Press.
  • Integrating work health and safety into construction project management. (2019). Helen Lingard & Ron Wakefield. Wiley.
  • Occupational Health and Safety in Construction Project Management. (2005). Helen Lingard. Spon Press.

Comments

Post a Comment

Popular posts from this blog

P1 Construction Quality Implementation Plan for a Multi-storeyed Building

Construction Quality Implementation Plan for a Multi-storeyed Building A Construction Quality Implementation Plan, frequently referred to as a Contractor’s Quality Control Plan (CQCP) or Project Quality Plan, is a fundamental, tailor-made document that sets out the specific quality activities, resources, and procedures pertaining to a particular project. It translates company-wide quality management systems into a specific plan to demonstrate to the client exactly how the project's quality requirements will be fulfilled. Below is a comprehensive implementation plan tailored for a multi-storeyed building project: 1. Purpose and Project Description Purpose: The plan provides the mechanism to achieve the specified quality by identifying the procedures, controls, instructions, and tests required during construction to meet the owner’s objectives and ensure compliance with contract specifications. Project Description: The facility comprises a multi-storeyed building featuring multi...
Read more

Quality management systems and methods

Image
Construction Quality Management Systems and Methods Construction is Not Manufacturing Unlike factory goods, construction projects are  custom-made, non-repetitive, and immovable. Quality is defined by the total management approach to the facility, not just the product itself. I. Introduction to Quality in Construction A. Definition and Nature Unique Context: Unlike manufacturing, construction projects are custom-made, non-repetitive, and immovable. Quality must be defined not just by the product, but by the total management approach to completing the facility,. Core Definitions: Juran: "Fitness for use". Crosby: "Conformance to requirements". ISO Definition: The totality of characteristics of an entity that bear on its ability to satisfy stated or implied needs. The Construction Project Trilogy: Quality is inextricably linked to the balance of three components: Defined Scope Schedule (Time) Budget (Cost). B. Quality Assurance (QA) vs. Q...
Read more

Cause-and-effect (Fishbone) diagram

Image
1. The Layman’s Intro: The "Car Won't Start" Analogy Understand the core logic of this tool using a simple, everyday analogy: troubleshooting a car that won't start. Imagine you wake up, get into your car, turn the key, and hear nothing but a click. The car not starting is the "Effect" (the problem). If you were to draw this, "Car Won't Start" goes in a box at the far right, like the head of a fish. Instead of randomly guessing what is wrong, you brainstorm major categories of potential issues to form the "bones" of the fish: Electrical: Is the battery dead? (If yes, why? Left the headlights on). Fuel: Is the gas tank empty? Is there a leak? Mechanical: Is the starter motor broken? Human Error: Is the car not actually in "Park"? The Fishbone diagram visually organizes your troubleshooting process. It forces you to look at every possible category of failure rather than jumping to the most obvious conclusion. By repeated...
Read more