Occupational hygiene (IH) is the anticipation, recognition, assessment, control and avoidance of hazards from work that will result in injury, illness, or affect the health of workers. These hazards or stressors can be divided into the categories biological, compound, physical, ergonomic and psychosocial. The risk of the health effect from a given stressor is often a function of the hazard multiplied with the exposure to the person or group.