Causes of FSIs
It is important to realize that the causes of FSIs often differ from those causing less serious injuries. As author Dan Petersen observed in 1989, “Different sets of circumstances surround their severity.” Dan found that, unlike less serious incidents, FSIs tend to occur:
In unusual and non-routine work;
Where upsets occur;
In non-production activities;
Where sources of high energy are present; and
During at-plant construction operations.
Also, reducing injury frequency does not necessarily produce equivalent severity reduction. As Fred Manuele notes in “On the Practice of Safety,” “The data require that we adopt a different mindset, and a particularly different focus on preventing events that have serious injury potential.”
This theory is bolstered by a 2007 Rand study that found no apparent relationship between OSHA reported injury rates and workplace fatalities. The absence of minor injuries is not predictive of the absence of future fatalities, and the presence of minor injuries is not predictive of the occurrence of fatalities in the future.
Current measurement systems create a “blind spot” for serious injury prevention. The traditional safety triangle is not predictive of FSIs, as author Tom Krause states. A study group led by Tom found that workplace situations with high proportions of FSI precursors are those with process instability, significant process upsets, unexpected maintenance, unexpected changes, high potential energy jobs, and emergency shutdown procedures.
Current measurement systems create a “blind spot” for serious injury prevention.
Similarly, work activities that may have a high proportion of FSI precursors include operation of mobile equipment (and interaction with pedestrians); confined space entry; jobs that require lockout/tagout; lifting operations; working at height; and manual handling.
In working with member companies ORCHSE has found that these factors vary among different operations. For example, one of our members in the electric power business found that during emergency situations its workers maintained a high state of vigilance and were less prone to serious incidents. They experienced serious incidents in routine maintenance and service operations where workers let their guard down and failed to wear necessary protective equipment.
At ORCHSE we define an FSI precursor differently than others: it is a situation involving a combination of hazard(s) and underlying human and organizational factors that, left unaddressed, could result in a fatal or serious injury.
This is an important difference because context is critically important to identify causation. The relationship between human and organizational factors and risk is presented in part III.