According to the European Community guidelines (European Commission. Guidance on risk assessment at work. Office for Official Publication of the European Communities. Luxembourg 1996), hazard is defined as the intrinsic property or ability of a specific factor (e.g. working materials or equipment, working methods or practices) to potentially cause harm.
On the other hand, risk is defined as the probability of attaining the potential harm threshold under the conditions of employment of a certain factor and/or exposure to this factor.
Finally, an occupational risk factor is any physical, chemical or biological agent present in the workplace that is able to harm the worker.