The definition of Hazard can be confusing...yup...it is...
in order to find a very simple and straight forward clear definition to justify my research, i found some of 'em :

A hazard is any source of potential damage, harm or adverse health effects on something or someone under certain conditions at work.

Basically, a hazard can cause harm or adverse effects (to individuals as health effects or to organizations as property or equipment losses).

Sometimes a hazard is referred to as being the actual harm or the health effect it caused rather than the hazard. For example, the disease tuberculosis (TB) might be called a hazard by some but in general the TB-causing bacteria would be considered the "hazard" or "hazardous biological agent".
(adapt from CCOSH)

for engineer risk can be refer to hazard....so the relation between hazard and risk can not be separated...

so, what is risk?

Risk is the chance or probability that a person will be harmed or experience an adverse healtheffect if exposed to a hazard. It may also apply to situations with property or equipment loss.

Hazard>possible consequences
Risk>probability or likelihood

BUT....
Not necessarily exposure to hazards in the workplace always cause injury,illness and adverse health effects...

It depend on.....(to be continued)

ngee ngee ngee...~(*v*)~