A number of foods derived from genetically engineered plants are entering the marketplace. These products have been subjected to extensive food safety evaluations including addressing any allergy concerns. The allergy assessment should focus on the source of the introduced gene. If the gene is derived from an allergenic soure, the developer should verify that the gene product is not an allergen, For genes derived from non-allergenic sources, amino acid similarity analysis to known allergens provides an initial assessment of allergenic potential. In addition, common food allergens share important physiochemical properties such as resistance to digestive degradation, stability to food processing and prevalence in the diet that can be used as a basis for a scientific evaluation of allergenic potential.An allergenicity assessment of the protein expressed in soybean to confer selectivity to glyphosate, the active ingredient in the herbicide Roundup@, was conducted using these criteria. The protein expressed was shown to be derived from a non-allergenic source, to have no significant amino acid homology to known allergens, to be rapidly degraded in a digestion model and to be present in relative low levels relative to commonly allergenic proteins. Most importantly, the introduced protein is closely related, both structurally and functionally, to the corresponding soybean protein. Based on this information, it was concluded that this introduced protein posed no significant allergenic concern. This approach should be generally applicable to assess allergenic concerns of foods derived from any genetically engineered plant variety.