Why must scalding and defeathering be separated from evisceration in U.S. poultry plants?

In the United States, federal law mandates that the scalding and defeathering stages of poultry processing must be physically separated from the evisceration process by a wall.1

This requirement is a critical sanitary measure designed to minimize cross-contamination. Because poultry carcasses naturally carry a high microbial load on their exterior—including feathers and feet—keeping these initial slaughtering steps isolated prevents the spread of bacteria to the eviscerated carcasses. Maintaining this separation is essential for food safety, as it helps prevent the transfer of pathogens like Salmonella and other spoilage microorganisms from the "dirty" areas of the plant to the exposed internal tissues of the birds during the evisceration and inspection phases.123