Hazard identification serves to establish whether the hazard is probable or actual in the food product and to document important known information about the relationships and interactions between the hazard, the food and the host, and also their relationship to human disease. Given that a wide range of microbiological hazards can cause foodborne illness, hazard identification should determine whether a potential hazard is realistic for the food product concerned. Hazard identification is the first stage in risk assessment. Food contamination surveillance data, along with product and process assessments, can help identify combinations of hazards and foods. Evidence from these sources is usually quantitative (i.e. it includes information on the concentration or number of units of the hazard in the food) and may also provide information that feeds into other stages of microbiological risk assessment, such as exposure assessment and/or establishment of a dose–response relationship.