What are accurate definitions of risk and safety? ISO/IEC Guide 51, which is an international standard, gives the following definitions.
What does it mean for risk to be present? Examine the following figure.
In the picture on the left, there is a lion, which is a hazard, but this alone is not enough to cause harm to occur. In the picture on the right, a person is present. This introduces the possibility of harm occurring should the lion attack the person. The picture on the right indicates a situation in which “risk” exists. It is necessary to understand that this situation is distinct from the situation in which a “hazard” exists.
The definition of “safety” is “freedom from risk which is not tolerable” according to ISO/IEC Guide 51. In other words, safety can be achieved by risk reduction to a tolerable level.
