9. Cross-contamination You can expect certain foods to contain pathogens, especially raw meat, raw poultry, and raw seafood. Use extreme caution when you bring these foods intoyourkitchen.Cross-contaminationhappenswhensomethingthatcancause illness (pathogens or chemicals) is accidentally put into a food where not previously found. This can include, for example, pathogens from raw meats getting into ready-to-eat foods like deli meats. It can also include nuts (which somepeopleareveryallergicto)gettingintoafoodthatdoesnotnormallyhave nuts (e.g., tomato sauce).