AbstractThe European Commission requested EFSA to provide an assessment of the processing conditions which makeAmbrosiaseeds non‐viable in feed materials and compound feed. This assessment also includes information on a reliable procedure to verify the non‐viability of the seeds.Ambrosiaseeds are known contaminants in feed with maximum levels set in the Directive 2002/32/EC. The manufacturing processes and processing conditions applied to the feed may affect the viability of theAmbrosiaseeds. Therefore, the CONTAM Panel compared these conditions with conditions that have been shown to be sufficient to renderAmbrosiaseeds non‐viable. The Panel concluded with a certainty of 99–100% that solvent extraction and toasting of oilseed meals at temperatures of 120°C with steam injection for 10 min or more will makeAmbrosiaseeds non‐viable. Since milling/grinding feed materials for compound feed of piglets, aquatic species and non‐food producing animals would not allow particles of sizes ≥1 mm (the minimum size of viableAmbrosiaseeds) passing the grinding process it was considered very likely (with ≥ 90% certainty) that these feeds will not contain viableAmbrosiaseeds. In poultry, pig, and possibly cattle feed, particle sizes are ≥ 1 mm and thereforeAmbrosiaseeds could likely (66–90% certainty) survive the grinding process. Starch and gluten either from corn or wheat wet milling would not containAmbrosiaseeds with 99–100% certainty. Finally, ensiling fresh forages contaminated withA. artemisiifoliaseeds for more than 3 months is very likely to render all seeds non‐viable. The Panel concluded that a combination of the germination test and a subsequent triphenyl‐tetrazolium‐chloride (TTC) test will very likely (with ≥ 90% certainty) verify the non‐viability ofAmbrosiaseeds. The Panel recommends that data on the presence of viableAmbrosiaseeds before and after the different feed production processes should be generated.