The agency is amending the food additive regulations to allow the technique following a food additive petition by the National Fisheries Institute.
The group requested a maximum absorbed dose of 6.0 kiloGray to achieve a 6-log reduction of Listeria monocytogenes.
Under the relevant regulation a source of radiation used to treat food is defined as a food additive.
Irradiation is not a substitute for proper food-handling practices, so treated crustaceans must be stored, handled, and cooked in the same way as non-irradiated foods, the agency said.
FDA said its decision was based on a safety assessment that considered potential toxicity, the effect of irradiation on nutrients, and potential microbiological risk that may result from treating crustaceans with ionizing radiation.
The rule covers raw, frozen, cooked, partially cooked, shelled, or dried crustaceans, or cooked, or ready-to-cook, crustaceans processed with spices or small amounts of other food ingredients.
At the maximum permitted dose of 6 kGy, this use of ionizing radiation will reduce, but not entirely eliminate, the number of pathogenic microorganisms in or on crustaceans.
The maximum dosage of irradiation approved is capable of reducing pathogens, including Listeria, Vibrio, and E. coli.
The agency looked at whether furan, believed to cause tumors in lab animals, was formed as a radiolysis product.
“Testing of irradiated raw shrimp and cooked crab meat show that if furan is formed when these foods are irradiated, it is formed at levels that are below the limit of detection of the available analytical methods, or below the background levels of natural furan formation during storage.”
The evaluation considered safety tests of irradiation of foods including poultry, meat, molluscan shellfish, iceberg lettuce and fresh spinach.
“Under 21 CFR 179.26(c), we require that irradiated foods bear the international symbol for irradiation (radura) and carry the statement "Treated with radiation" or "Treated by irradiation" on the food label,” said the agency.
Identifying irradiated products
Consumers will be able to identify irradiated foods, including crustaceans, by the irradiation statement and symbol on the label.
For foods not in package form, the logo and phrase must be displayed with the labeling of the bulk container in view or a counter sign, car, or other appropriate device bearing the information that the product has been treated with radiation.
FDA said it does not require that multi-ingredient foods that contain ingredients that have been irradiated (e.g., spices) be labeled if the food itself has not been irradiated, or labeling of irradiated food served in restaurants.
Objections and requests for a hearing must be submitted by May 14 2014 .