The Heinrich Accident Triangle—Too Simplistic A Model For HSE Management in the 21st Century?

Abstract

The accident triangle, developed by H.W. Heinrich in the 1930s, is a fundamental cornerstone of safety philosophy which postulates that there is a numerical relationship between unsafe acts, minor injuries, and major (fatal) injuries. This principle has driven the approach and techniques used by all companies actively engaged in reducing injuries in the workforce for over 70 years.All companies in the oil and gas industry have the ultimate goal of zero injuries and, in particular, zero fatal injuries within their workforce. Current injury trends show that the total recordable injury rate (TRIR) for a given company can still be systematically reduced year on year if the right commitment and focus is given to safety. This does not hold true in many cases for the fatal accident rate (FAR) which often no longer mirrors the TRIR trend as one would intuitively expect. This begs an answer to the question of whether the tools and methods used to reduce fatalities are still working. This paper demonstrates that Heinrich's principle works only when applied to a large number of combined hazards and activities. The paper shows that ratios postulated by Heinrich do not work when applied to specific activities. The result is that companies tend to over focus on the easily identifiable risks which follow the Heinrich triangle but are often nonfatal, at the cost of losing sight of activities that have the potential of a fatal outcome.By drawing on the 2.3 million risk reports recorded in the health, safety, and environment (HSE) database of an oilfield services company, the paper also demonstrates the value of focusing on risk potential-rather than only on actual event outcomeas a key tool for minimizing catastrophic loss. It discusses strategies of how to specifically target and actively work on improving the FAR as opposed to the more general TRIR.

Cultural Drift and the Occlusion of Electrical Safety

“…8. [15] and Cawley and Brenner [9]. This figure shows the ratio of lost time injuries to fatalities by type of incident.…”

20 Years later: Creating a continuous improvement environment for electrical safety

“…Manuel and Krause have also noted that focusing on reducing frequency of injuries may show successful results without a corresponding reduction in severe injuries. Anderson and Denkl conducted analysis of 2007 US Bureau of Labor Statistics data on 5,657 fatalities and 1,158,870 losttime injuries and concluded Heinrich's model does not correlate to injuries and fatalities from hazards that have high potential for fatality [21]. To illustrate the limitation of applying the accident triangle to electrical safety, consider the question: How many minor incidents involving 12V automotive batteries must be eliminated to prevent an electrocution fatality at the top of the triangle?…”