Click here to order reprint of this paper.


By Ludwig Benner, .Jr.

University of Southern California, USA


In our efforts to discover and correct workplace safety and health problems, we often wait too long and then fix the wrong problems. The reasons: inadequate intellectual concepts of the phenomenon of accidental harm lead to use of inappropriate investigation and analysis tools, which misdirect the search for data that define our safety and health problems and their solutions. Borrowed technology from other disciplines is inadequate for future safety improvement tasks. This paper explores underlying accident concepts and investigative practices) how they affect workplace safety, and what is happening to overcome some intellectual shortcomings.

To illustrate this issue, differing conceptual models of the accident phenomenon currently driving safety problem identification in 17 U. S. government agencies were examined. From this examination, criteria for judging the merit of alternative accident models in occupational safety and health programs were defined. The criteria were then used to rate each model. The models’ impact on the investigative methodologies resulting were examined next, and criteria for judging the methodologies were defined. Applications of the highest—rated models and methodology were then compared with existing practice to determine what improvements might be expected. Based on the findings, further development and applications efforts are suggested.


In 1982 an estimated 11,100 fatal and 1,900,000 disabling injuries in workplaces were experienced in the United States(1). In 1970, amid much fanfare, national legislation was adopted in the U.S. to stop this carnage in workplaces, and much action has been taken. Yet since then, almost 2% of our working population suffers serious workplace injury each year. For each of these workers, the safety control system failed. Why did it fail?


Compelling evidence that points to the reason is accumulating from my inquiries into a wide range of safety matters. This evidence indicates that these failings flow from intellectual shortcomings in the safety problem discovery and definition processes, rather than from other origins. Each new examination of that process I undertake seems to add greater weight to that conclusion. With each new inquiry, specific intellectual inadequacies seem to become clearer. Apparently my concern is shared by others.(2,31,32) My work indicates that this matter deserves urgent attention. It is gratifying to be able to discuss the issue at this seminar, and I thank the sponsors for this opportunity.

The information in this paper reflects observations in many inquiries into this safety problem definition and response issue. The inquiries were conducted both as an employee of the National Transportation Safety Board in accident investigations, and during personal research in support of my teaching activities. The issue was examined from many individuals’ perspectives. For example, it was examined from the workers viewpoint. An early inquiry related to defining tasks facing emergency response workers dealing with hazardous materials.(3) In emergency situations, what techniques should they use to identify and define the danger?(4) How are these workers expected to interpret emergency response instructions(5) How does one define and measure their effectiveness in accident emergencies(6)?

. . .
(Example of intellectual confusion from paper)


QUESTION l. What do you mean by the word “cause” as you use it in accident investigations?


l. that which leads to an outcome or result.

2. the primary underlying reason for an act or event.

3. something that takes the actions of an object or being and is the reason for the second action.

4. a word used to show the relationship of an action to an individual or thing; means made or associated with a happening; it is responsible for the happening .

5. an effort by individuals or groups to achieve a desired end.

6. an event which leads to the resultant occurrence of another event.

7. an influence that determine a particular outcome.

8. some event or combination of events that determine the outcome of a

subsequent event.
9. a condition that leads to an occurrence.

10. something that results in an effect or another phenomenon.

11. a state, situation, occurrence, event which leads to, is primarily conducive to a second state, situation, etc.(etc) which is partially responsible for a second occurrence, event (etc).

12. a reason for a studied occurrence.

13. a determination of what happened.

14. an event, state, action or reason that leads to a fact.

15. a root source by which a resultant event can be explained.

16. The cause is-the event or set of events producing the accident. l believe cause is the same as factors.

17. the reason that an event occurred; the driving force or motivation.

18 something that brings about an effort or result.

19 any event, circumstance or condition or any combination of these that brings about or helps bring about a result. (Webster and l agree)

20. the sum effect of various factors which, in combination, precipitate the occurrence of an event.

21. every accident, except for 2% that are classified as acts of nature, is caused by the unsafe behavior of an individual, or an unsafe mechanical or environmental condition, or both. The investigator must identify and describe the causes, as failure to do so negates the entire investigation effort.

22. a reason for the state of things.

23. anything producing an effect or result; a person or thing acting voluntarily or involuntarily as the agent that brings about an effect or result.

24. the reason for an event to occur.

25. factors, as those singularly or in combination, that bring about a result (usually a known result); an entity that is the agent of bringing something about .

26. can be an action of a person; can be a failure on the part of a mechanism.

27. the item that allows or drives the event to occur.

28. a factor must be logically related — traceable to the result. Must be a factor without which the result, the, accident, would not have occurred, or would not have the same way with the same outcome.

29. an event(s) which deviated from the usual or accepted operating procedures.

30. an event which if changed would have interrupted the chain of events and prevented the mishap.

31. what starts an imbalance in a balanced system.

32. something/someone that if not present or active would have stopped or

possibly stopped (or altered) the outcome of a sequence.
33. a summary of what happened; let management pick out what they believe to be the cause.

34. acts or conditions most closely associated with the injurious event which make the injurious event irreversible.

35. the events, situations or circumstances which lead to an accident or permit the accident to occur.

36. an off—normal action or event without which the accident would or could not have happened.
37. something/situation/happening/event which directly contributes to an event called an accident.

38. an energy input that produces or contributes to the energy of the accident.

39. something that helps tell me “why” and accident occurred.

40. that which triggers an action or that which is a motivating force in the

accident sequence.
41. a factor which, when it is present alone or in the proper combination with other such factors, results in the occurrence of the accident.

42. one of the verifiable circumstances contributing to the accident; the source of such being human, environmental, mechanical or whatever.

43. an event that produces a 2nd event.

44. a factor which led to or formed the conditions necessary for the accident to happen .

46. those events and factors which together brought on the accident.

47. the factors which contributed to or the deficiency in the system to control the flow of energy or prevention of accidents.

48. all events and factors that combined to result in an accident; these may range from general systemic oversights to specific events immediately preceding the accident event.

49. the failure or failures that led to or created the accident.

50. those chain—of-events or things that occurred that permitted an incident to occur .

51. event or condition sufficient to produce an unwanted result.

52. the cause in a cause-effect relationship.

53. a condition which effects an event with either wanted or unwanted results.

54. individual, group or system actions, conditions, deficiencies, failures, changes, errors and responses which contribute to the initiation of potential or accident losses.

Source: Ludwig Benner, Jr. Univ. of Southern California 05-19-83
5 groups: Replies/populations:5/5: l5/l6: 15/15: 19/25: total=54/61
Total nouns counted = 88 in 53 replies