An interlaboratory trial was conducted for the validation of an enzyme-linked immunosorbent assay (ELISA) method for determination of appropriate heat treatment of animal meal. A commercially available ELISA test kit developed for the identification of beef in cooked food was used in the study. Twelve laboratories from 7 European countries examined 2 different analytical protocols to establish the most appropriate analytical method. Three different samples were used, 2 animal waste materials sterilized at 129 and 134 degrees C (wet conditions), respectively, and a meat and bone meal material processed at dry conditions (maximum temperature, 140 degrees C). Statistical evaluation applying t-statistics showed that the animal meal treated according to European legislation (>133 degrees C) was clearly distinguishable from the 2 other test materials at a 99% confidence level using both analytical protocols. This method can be considered as a complementary test to the immunoassay developed for the detection of pork in cooked food that is already applied in routine analysis for the surveillance of rendering plants.