The presence of E. coli, although an indicator organism for fecal matter, does not mean the product is, in fact, contaminated by feces. E. coli that is present in feathers or environmental contaminants, like dust, can also contaminate a poultry carcass. As part of poultry inspection procedures, FSIS enforces a "zero tolerance" standard for visible fecal material on poultry carcasses. It also requires slaughter establishments to perform microbiological testing for generic E. coli on carcasses to verify that slaughter processes are under control for the prevention and removal of fecal contamination.