Consistent risk assessment

The principle behind assessing risk levels is to first evaluate the severity of consequences and then the likelihood of an event or the probability of exposure. Absolute accuracy is not of paramount importance, what matters more is acting consistently.
 
First, the assessment describes as accurately as possible a danger or sickness due to exposure or other health hazard whilst bearing in mind the expected consequences.

Occupational health professionals are familiar with the sicknesses typically encountered by a workforce as well as the health impacts of chemical and biological hazards. They are also able to make valuable contributions when assessing ergonometric loading factors.