The Opinion considers and discusses efficacy of food irradiation as the ability of irradiation to reduce food-borne pathogens in foods and microbiological safety of food irradiation as the contribution of irradiation to reduce the risks to human health from food-borne pathogens. The chemical safety and nutritional aspects of irradiation are addressed in a separate Opinion by the EFSA Panel on Food contact materials, enzymes, flavourings and processing aids. Potential microbiological risks linked to food irradiation are reviewed and the Opinion confirms that there are no microbiological risks for the consumer linked to the use of food irradiation and its consequences on the food microflora. The Opinion recommends that food irradiation should be based on risk assessment and on the desired risk reduction rather than on predefined food classes/commodities and doses as proposed in the past. In addition, with respect to efficacy and microbiological safety, it is recommended that upper dose limits for pathogen reduction should not be specified, since other constraints, such as undesirable chemical changes, will limit the doses applied. Irradiation should be considered as one of several approaches to reducing pathogens in food and thus helping to ensure protection of consumers' health. It is also recommended that food irradiation should only be used in conjunction with an integrated food safety management program and the Opinion concludes that when this includes GAP, GHP, GMP and HACCP, and depending on the dose applied, food irradiation can contribute to improved consumer safety by reducing food-borne pathogens. for the preparatory work on this scientific opinion.Efficacy and microbiological safety of irradiation of food 2 EFSA Journal 2011;9(4):2103 SUMMARY Following a request from the European Commission, the Panel on Biological Hazards (BIOHAZ Panel) was asked to deliver a scientific Opinion on the irradiation of food (efficacy and microbiological safety). Using the previous Opinions of the Scientific Committee on Food (SCF) on irradiation of food, EFSA was asked to establish whether the food classes/commodities and doses specified in those Opinions are still up-to-date to ensure consumer safety.Within this Opinion the BIOHAZ Panel considers and discusses efficacy of food irradiation as the ability of irradiation to reduce food-borne pathogens in foods and microbiological safety of food irradiation as the contribution of irradiation to reduce the risks to human health from food-borne pathogens. The chemical safety and nutritional aspects of irradiation are not considered in this Opinion as they are addressed in a separate Opinion by the EFSA Panel on Food contact materials, enzymes, flavourings and processing aids (CEF Panel).This Opinion also evaluates, for each food class/commodity requested, any recent change in biological hazards and food processing, preparation or consumption patterns which could have modified the risks for consumers and whether irradiation can be used in combination with other treatments and ho...