Salmonella　outbreaks　linked　to　spices　and　herbs　call　for　an　effective　inactivation　process.　Non-thermal　technologies　such　as　gaseous　chlorine　dioxide　(ClO2)　has　been　explored　for　the　decontamination　of　spices　and　herbs　while　minimizing　quality　deterioration.　However,　microbial　inactivation　post-ClO2　treatment　and　post-treatment　quality　analysis　has　not　been　explored.　This　study　monitored　microbial　survival　in　black　peppercorns,　cumin　seeds,　and　basil　leaves　post-ClO2　treatment　for　one　week,　and　the　color　parameter,　gas　residuals,　and　byproducts　were　determined.　One-week　post　ClO2　treatment　(10　mg/L)　resulted　in　an　additional　increase　in　Salmonella　reductions　by　1.1,　1.0,　and　1.4　log　CFU/g　in　black　peppercorns,　cumin　seeds,　and　basil　leaves,　and　contributed　to　a　total　of　5.3,　5.0,　and　4.7　log　CFU/g　reductions,　respectively　at　80%　RH.　The　surrogate,　Enterococcus　faecium　NRRL　B-2354　populations　were　also　determined　at　all　treatment　conditions;　E.　faecium　showed　lower　microbial　reductions　than　Salmonella　in　all　samples,　indicating　its　suitability　as　a　surrogate　for　Salmonella　during　ClO2　treatment.　The　color　changes　in　black　peppercorns　and　cumin　seeds　were　negligible,　while　the　color　change　in　basil　leaves　after　ClO2　treatment　was　noticeable.　The　concentrations　of　gaseous　ClO2　in　all　three　products　were　under　the　detection　limit　after　being　stored　for　one　week.　The　byproducts　such　as　chlorate,　chloride,　and　chlorite　at　gas　concentration　of　10　mg/L　were　determined　to　be　0.48,　1.88,　and　0.23　mg/g,　0.56,　8.32,　and　0.25　mg/g,　and　0.69,　10.41,　and　0.02　mg/g　in　black　peppercorns,　cumin　seeds,　and　dried　basil　leaves,　respectively.　In　summary,　extended　storage　time　post　ClO2　treatment　resulted　in　additional　microbial　inactivation,　which　can　be　considered　while　designing　the　decontamination　of　spices　and　herbs.　ClO2　gas　concentration　of　10　mg/L　for　300　min　was　suitable　for　the　decontamination　of　black　peppercorn　and　cumin　seeds.　©　2023　Elsevier　Ltd