In　this　study,　black　peppercorns　and　cumin　seeds　were　inoculated　with　a　five-serotype　cocktail　of　Salmonella　or　its　surrogate　Enterococcus　faecium　NRRL　B-2354.　The　inoculated　samples　(ca.　107　CFU/g)　were　treated　by　ClO2　gas　at　different　gas　concentrations　(5,　10,　and　15　mg/L)　and　relative　humidities　(60,　70,　and　80%)　at　room　temperature　(25　degrees　C)　at　five　gas　exposure　times　(60,　120,　180,　240,　300　min).　More　than　5-log　reduction　of　Salmonella　was　achieved　in　both　spices　with　300　min　of　ClO2　gas　treatment　at　15　mg/L　and　80%　RH.　The　corresponding　values　for　E.　faecium　were　4.36　and　4.17　log　CFU/g　in　black　peppercorns　and　cumin　seeds,　respectively,　which　were　significant　lower　than　Salmonella　(p　＜　0.05).　Gas　concentration,　RH,　and　exposure　time　showed　significantly　positive　linear　associations　with　Salmonella　inactivation.　E.　faecium　appears　a　suitable　surrogate　for　Salmonella　and　can　be　used　for　future　process　validations　using　comparable　conditions.