Hazard is any undesirable condition that may cause damage to people, property, or the environment.
Risk is the probability that an undesirable event will occur. It is often defined as the likelihood of a negative outcome and its consequences. Risk means the possibility that an event might occur. It does not mean that the event has already occurred.
A hazard has the potential to cause harm. A hazard becomes a risk when there is exposure to it. For example, when it is snowing heavily, then slippery roads, because of snow are a hazard. The risk of an accident increases when driving in such conditions.
Without hazard, there is no risk.