ABSTRACT
Maintaining the integrity of machine safeguarding systems has long been problematic for safety professionals and supervisors. Workers occasionally compromise safeguarding by defeating interlocks, cutting holes to gain access, or simply leaving guards off. These deliberate “unsafe acts” result from decisions by workers based on their individual “cost/ benefit” evaluation. Human factors and behavioral psychology can be used to explain this decision phenomenon in terms of a decision criterion and man’s limited ability to assess risk. Using this information, the ergonomist can increase the perceived “cost” and reduce the “benefit” of compromising the safeguarding system by applying a variety of design techniques. Among the techniques discussed are: making guards easy to replace, reducing visual obstruction, preventing inadvertent trips of emergency stops, and encouraging machine lockout.
