A 
robot safety 
system configured to protect humans in the vicinity of a working 
robot (1, 11, 21, 31) against harmful impacts by said 
robot (1, 11, 21, 31), said safety 
system comprising a 
sensor system (3, 13, 23) and a safety controller (4, 14, 24) configured to establish an 
impact risk profile of the robot (1, 11, 21, 31) and deliver an operating 
signal to a 
robot controller (2, 12, 22) based on said 
impact risk profile, wherein the safety controller (4, 14, 24) is configured to establish the 
impact risk profile based on stored data and input signals, and that the stored data and input signals comprise stored impact data, stored data related to the path of the robot (1, 11, 21, 31), and signals from the 
sensor system of events in the vicinity of the robot (1, 11, 21, 31), such as a detected human (P1, P11, P21, P22, P31, P32) in the vicinity of the robot (1, 11, 21, 31).