What percentage range is typical for incidents caused by unsafe acts?

• A. 60-70 percent
• B. 80-90 percent
• C. 30-40 percent
• D. 10-20 percent

Answer: (B)

Incidents are understood to be driven mainly by human action—unsafe acts or errors people make in the course of work. In safety data and classic models, the majority of incidents are linked to these unsafe acts, with figures commonly cited around 80-90 percent. This reflects the emphasis on training, supervision, and behavior-based safety as key prevention levers, since changing how people act has the biggest potential impact on reducing incidents.

So the typical range to remember is 80-90 percent. The other ranges would understate or misrepresent where human factors sit in incident causation: 60-70 percent is lower than the common figure, while 30-40 percent or 10-20 percent would imply that unsafe acts contribute only a minority of incidents, which isn’t aligned with the usual distribution seen in investigations.