Incident ratio triangle

Additionally, these losses would fit a traditional loss incident ratio triangle with ever increasing number of losses as the magnitudes of the losses decreases (i.e., as the steps in the triangle widen) (see Figure 6.12). 

Accident investigation indicates that there are often many individual causes to an accident, and that a series of incidents occur simultaneously to cause the accident. The following figure is called the safety triangle", and shows the approximate ratios of occurrence of accidents with different severities. This is based on industrial statistics. 

A statistical ratio of incidents, which highlights the frequency and severity. The relationship is depicted in a graphical form of a triangle (see Figure A.l). Sometimes depicted as a loss pyramid, with frequencies on one side and severities on the adjacent side. See also Accident Ratios. 

To test the validity of published accident ratios and triangles, I did the research resulting in the publication of a paper titled Injury Ratios. The most important conclusion drawn from that research is that variations on the inherent risk levels in industries and businesses—as indicated by the substantial differences in OSHA incidence recordable rates and the percent of incidents that result in lost workday cases—are so great that it is impossible to develop meaningful injury ratios which are universally applicable. 

The results vary in practice but look something like those in Table 6.3 (note, for example, the variation in the major injury to minor injury ratio). Some people s that the triangle tells us that if we want to control major injirries arrd fatalities, we mrrst record and investigate all non-injtrry incidents. However, the eorrrmon eairses of minor injuries may not necessarily be very similar to the eorrrmon eairses of major irgnries. Secondly, investigating every minor injury or near miss thoroughly conld take up time better spent on other approaches to prevention. 

The following discussion and statistics establish that the ratios upon which the foregoing citation is based are questionable and that reducing incident frequency does not necessarily achieve an equivalent reduction in injury severity. Heinrich s 300-29-1 ratios have been depicted as a triangle or a pyramid (Figure 10.1). 

Most people involved with workplace safety are aware of the iceberg theory, the safety triangle, or its correct terminology, the accident ratio. For every recorded injury or loss sitting above the surface, there are many unrecorded near miss incidents submerged below the surface. This was first proposed by H. W. Heinrich in 1931 when he published his 1 29 300 ratios. 

The accident ratio depicted in Model 1.1 shows that for every serious injury as a result of an accident there are some minor injuries, more property damage events, and plenty of near miss incidents. The only way to reduce the injuries that make up the peak of the triangle is to identify, investigate, and rectify the near miss events before they result in injuries or other losses. 

The Heinrich Triangle. Most safety professionals are familiar with "Heinrich s Law." As illustrated in Figure 18.4, Heinrich proposed over 60 years ago a 300 29 1 ratio between "near-miss" incidents, minor injuries, and major injuries (Heinrich, 1931 Heinrich et al., 1980). Ever since, safety professionals have been encouraged to investigate near hits in order to reduce minor and major injuries. Heinrich also estimated that 88 percent of all near hits and workplace injuries resulted from imsafe acts. As a result, some presentations of "Heinrich s Law" add a wider base to the triangle with the label "unsafe acts."... 

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