Human Factors Theory of Accident Causation

Attributes accidents to a chain of events that were ultimately the result of human error.

Three broad factors leading to human error:

1. Overload
2. Inappropriate Responses
3. Inappropriate Activities

1. Overload

Worker’s Capacity -
Natural Ability, Training, State of Mind,
Fatigue, Stress, Physical Condition

Environmental Factors -
Noise, Climatic, Lighting, Distractions, etc

Internal Factors -
Personal Problems, Emotional Stress, Worry

Situational Factors -
Level of Risk, Unclear Instructions, Novelty, etc

2. Inappropriate Responses

Ignores a suspected hazard

Disregards established safety procedures

Circumvents safety devices

Includes incompatibility with person’s workstation
(Size, Required Force, Reach, Feel, etc)


3. Inappropriate Activities

Performing tasks without requisite training

Misjudging the degree of risk