In risk assessment, what distinguishes a 'hazard' from a 'risk'?

In risk assessment, a 'hazard' is a potential source of harm or adverse health effect to a person or persons, while 'risk' is the probability that the hazard will cause harm and the severity of that harm. A hazard is the inherent danger, while risk is a measure of the likelihood and potential consequences of that hazard causing injury or damage. For example, a moving robot arm is a hazard because it has the potential to collide with a person. The risk associated with that hazard depends on factors such as the robot's speed, the size of its work envelope, the frequency of human access to the work cell, and the effectiveness of safety measures like guarding and light curtains. If the robot is slow-moving, well-guarded, and rarely accessed by humans, the risk associated with the moving arm is low, even though the hazard remains. Conversely, if the robot is fast, unguarded, and frequently accessed, the risk is high. Risk assessment involves identifying hazards, estimating the probability and severity of harm, and then determining whether the risk is acceptable or if additional safety measures are needed to reduce the risk to an acceptable level. Therefore, identifying the hazard is only the first step, the risk takes into account how likely and severe the potential harm could be.