A new study has revealed that the US Department of Agriculture’s system for safeguarding against salmonella in chicken might be seriously flawed. Led by the department’s own scientists, the study identified a possibility of false-negatives in salmonella screenings carried out on carcasses. Current protocols call for carcasses to be sprayed with antimicrobial chemicals to ward off pathogens and dunked into another antimicrobial chemical solution before randomly selected carcasses are placed into a bag of liquid that leaches lingering pathogens. The liquid is lab-analyzed and, pending the absence of a certain amount of pathogens, serves to signify that a slaughterhouse’s chicken supply is safe for human consumption. The new study by the USDA’s Agricultural Research Service, however, suggests that the myriad antimicrobial solutions carcasses are showered and bathed with aren’t adequately rinsed away, and trace amounts end up in testing bags where they continue to kill bacteria while testing awaits, leading to much lower final numbers than would exist on the production line. According to Mother Jones, while incidences of positive test results for salmonella on chicken carcasses are decreasing (3.9 percent in 2013 versus 7.2 percent in 2009), actual cases of salmonella infections in the past 15 years remain strong, exemplified by another USDA study that tested chicken samples from the end of the production line (butchered into pieces as opposed to the entire carcass) that found a positive rate for salmonella of 26 percent—six times more than the testing of carcasses. “[This] means consumers could be being exposed to salmonella-contaminated chicken at much higher rates than the [USDA’s] carcass numbers suggest,” author Tom Philpott said.