diff --git a/Modules/CTP/include/CTP/RawDataReaderCheck.h b/Modules/CTP/include/CTP/RawDataReaderCheck.h
index ae1d17fd45..0b2a98b876 100644
--- a/Modules/CTP/include/CTP/RawDataReaderCheck.h
+++ b/Modules/CTP/include/CTP/RawDataReaderCheck.h
@@ -58,6 +58,7 @@ class RawDataReaderCheck : public o2::quality_control::checker::CheckInterface
   float mThresholdRateMedium = -1;         // threshold for the relative change in ctp input and class rates
   float mThresholdRateRatioBad = -1;       // threshold for the relative change in ctp input and class ratios
   float mThresholdRateRatioMedium = -1;    // threshold for the relative change in ctp input and class ratios
+  float mNSigBC = -1;                      // n sigma for BC threshold
   bool mFlagRatio = false;                 // flag that a ratio plot is checked
   bool mFlagInput = false;                 // flag that an input plot is checked
   TH1D* mHistInputPrevious = nullptr;      // histogram storing ctp input rates from previous cycle
@@ -73,7 +74,7 @@ class RawDataReaderCheck : public o2::quality_control::checker::CheckInterface
   std::bitset<o2::constants::lhc::LHCMaxBunches> mLHCBCs;                                                                                                                                                                                                                                                                                                                                // LHC filling scheme
   const char* ctpinputs[49] = { " T0A", " T0C", " TVX", " TSC", " TCE", " VBA", " VOR", " VIR", " VNC", " VCH", "11", "12", " UCE", "DMC", " USC", " UVX", " U0C", " U0A", "COS", "LAS", "EMC", " PH0", "23", "24", "ZED", "ZNC", "PHL", "PHH", "PHM", "30", "31", "32", "33", "34", "35", "36", "EJ1", "EJ2", "EG1", "EG2", "DJ1", "DG1", "DJ2", "DG2", "45", "46", "47", "48", "49" }; // ctp input names
 
-  ClassDefOverride(RawDataReaderCheck, 7);
+  ClassDefOverride(RawDataReaderCheck, 8);
 };
 
 } // namespace o2::quality_control_modules::ctp
diff --git a/Modules/CTP/src/RawDataReaderCheck.cxx b/Modules/CTP/src/RawDataReaderCheck.cxx
index 404cef071e..60a67696b3 100644
--- a/Modules/CTP/src/RawDataReaderCheck.cxx
+++ b/Modules/CTP/src/RawDataReaderCheck.cxx
@@ -62,6 +62,12 @@ void RawDataReaderCheck::configure()
   if (mThresholdRateRatioMedium > 4 || mThresholdRateRatioMedium < 0) {
     mThresholdRateRatioMedium = 2;
   }
+
+  param = mCustomParameters.atOrDefaultValue("nSigmaBC", "2");
+  mNSigBC = std::stof(param);
+  if (mNSigBC < 0) {
+    mNSigBC = 2;
+  }
 }
 
 Quality RawDataReaderCheck::check(std::map<std::string, std::shared_ptr<MonitorObject>>* moMap)
@@ -89,7 +95,7 @@ Quality RawDataReaderCheck::check(std::map<std::string, std::shared_ptr<MonitorO
         continue;
       }
       mThreshold = h->GetEntries() / mLHCBCs.count();
-      mThreshold = sqrt(mThreshold);
+      mThreshold = mThreshold - mNSigBC * sqrt(mThreshold);
       for (int i = 0; i < o2::constants::lhc::LHCMaxBunches; i++) {
         if (mLHCBCs[i] && h->GetBinContent(i + 1) <= mThreshold) {
           mVecMediumBC.push_back(i); // medium BC occures when BC is expected on this possition but there is less inputs than threshold
diff --git a/Modules/CTP/src/qc-ctp.json b/Modules/CTP/src/qc-ctp.json
index f42c66a68c..80058381eb 100644
--- a/Modules/CTP/src/qc-ctp.json
+++ b/Modules/CTP/src/qc-ctp.json
@@ -65,7 +65,8 @@
           "thresholdRateBad": "3",
           "thresholdRateMedium": "2",
           "thresholdRateRatioBad": "3",
-          "thresholdRateRatioMedium": "2"
+          "thresholdRateRatioMedium": "2",
+          "mNSigBC": "2"
         }
       }
     }