diff --git a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.C b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.C
index 5520b8f1..ece81a57 100644
--- a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.C
+++ b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.C
@@ -150,7 +150,8 @@ heatTransferGunn::heatTransferGunn
     partRe_(NULL),
     partNu_(NULL),
     scaleDia_(1.),
-    typeCG_(propsDict_.lookupOrDefault<scalarList>("coarseGrainingFactors",scalarList(1,1.0)))
+    typeCG_(propsDict_.lookupOrDefault<scalarList>("coarseGrainingFactors",scalarList(1,1.0))),
+    maxTypeCG_(typeCG_.size())
 {
     allocateMyArrays();
 
@@ -209,7 +210,10 @@ heatTransferGunn::heatTransferGunn
         scaleDia_=scalar(readScalar(propsDict_.lookup("scale")));
         typeCG_[0] = scaleDia_;
     }
-    else if (typeCG_.size()>1) multiTypes_ = true;
+    else if (typeCG_.size()>1)
+    {
+        multiTypes_ = true;
+    }
 
     if (initPartTemp_ && !partTempField_.headerOk())
     {
@@ -340,6 +344,10 @@ void heatTransferGunn::calcEnergyContribution()
                 if (multiTypes_)
                 {
                     partType = particleCloud_.particleType(index);
+                    if (partType > maxTypeCG_)
+                    {
+                        FatalError<< "Too few coarse-graining factors provided." << abort(FatalError);
+                    }
                     cg = typeCG_[partType - 1];
                     scaleDia3 = cg*cg*cg;
                 }
diff --git a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.H b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.H
index bc808c4c..06b9a5ac 100644
--- a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.H
+++ b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferGunn/heatTransferGunn.H
@@ -126,6 +126,8 @@ protected:
 
     scalarList typeCG_;
 
+    const label maxTypeCG_;
+
     void allocateMyArrays() const;
 
     void partTempField();
diff --git a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.C b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.C
index c3dcdf5c..fdfabc13 100644
--- a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.C
+++ b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.C
@@ -149,7 +149,8 @@ heatTransferRanzMarshall::heatTransferRanzMarshall
     partRe_(NULL),
     partNu_(NULL),
     scaleDia_(1.),
-    typeCG_(propsDict_.lookupOrDefault<scalarList>("coarseGrainingFactors",scalarList(1,1.0)))
+    typeCG_(propsDict_.lookupOrDefault<scalarList>("coarseGrainingFactors",scalarList(1,1.0))),
+    maxTypeCG_(typeCG_.size())
 {
     allocateMyArrays();
 
@@ -208,7 +209,10 @@ heatTransferRanzMarshall::heatTransferRanzMarshall
         scaleDia_=scalar(readScalar(propsDict_.lookup("scale")));
         typeCG_[0] = scaleDia_;
     }
-    else if (typeCG_.size()>1) multiTypes_ = true;
+    else if (typeCG_.size()>1)
+    {
+        multiTypes_ = true;
+    }
 
     if (initPartTemp_ && !partTempField_.headerOk())
     {
@@ -340,6 +344,10 @@ void heatTransferRanzMarshall::calcEnergyContribution()
                 if (multiTypes_)
                 {
                     partType = particleCloud_.particleType(index);
+                    if (partType > maxTypeCG_)
+                    {
+                        FatalError<< "Too few coarse-graining factors provided." << abort(FatalError);
+                    }
                     cg = typeCG_[partType - 1];
                     scaleDia3 = cg*cg*cg;
                 }
diff --git a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.H b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.H
index db30ffb6..17baedb8 100644
--- a/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.H
+++ b/src/lagrangian/cfdemParticle/subModels/energyModel/heatTransferRanzMarshall/heatTransferRanzMarshall.H
@@ -125,6 +125,8 @@ protected:
 
     scalarList typeCG_;
 
+    const label maxTypeCG_;
+
     void allocateMyArrays() const;
 
     void partTempField();
diff --git a/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.C b/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.C
index 18381aa3..3e5e2ac3 100644
--- a/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.C
+++ b/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.C
@@ -58,8 +58,9 @@ BeetstraDrag::BeetstraDrag
     minVoidfraction_(propsDict_.lookupOrDefault<scalar>("minVoidfraction",0.1)),
     UsFieldName_(propsDict_.lookup("granVelFieldName")),
     UsField_(sm.mesh().lookupObject<volVectorField> (UsFieldName_)),
-    scaleDia_(1.),
+    maxTypeCG_(1),
     typeCG_(propsDict_.lookupOrDefault<scalarList>("coarseGrainingFactors",scalarList(1,1.0))),
+    scaleDia_(1.),
     scaleDrag_(1.),
     rhoP_(0.),
     rho_(0.),
@@ -102,7 +103,11 @@ BeetstraDrag::BeetstraDrag
         scaleDrag_=scalar(readScalar(propsDict_.lookup("scaleDrag")));
     }
 
-    if (typeCG_.size()>1) multiTypes_ = true;
+    if (typeCG_.size()>1)
+    {
+        multiTypes_ = true;
+        maxTypeCG_ = typeCG_.size();
+    }
 
     if (propsDict_.found("useFilteredDragModel"))
     {
@@ -219,6 +224,10 @@ void BeetstraDrag::setForce() const
                 if (multiTypes_)
                 {
                     partType = particleCloud_.particleType(index);
+                    if (partType > maxTypeCG_)
+                    {
+                        FatalError<< "Too few coarse-graining factors provided." << abort(FatalError);
+                    }
                     cg = typeCG_[partType - 1];
                     scaleDia3 = cg*cg*cg;
                 }
diff --git a/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.H b/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.H
index cfeeea39..eb466cc2 100644
--- a/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.H
+++ b/src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.H
@@ -64,9 +64,11 @@ protected:
 
     const volVectorField& UsField_;
 
-    mutable scalar scaleDia_;
+    mutable label maxTypeCG_;
 
-    mutable scalarList typeCG_;
+    scalarList typeCG_;
+
+    mutable scalar scaleDia_;
 
     mutable scalar scaleDrag_;
 
diff --git a/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.C b/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.C
index 9f1a555b..88fed5d4 100644
--- a/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.C
+++ b/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.C
@@ -56,6 +56,7 @@ dSauter::dSauter
     multiTypes_(false),
     d2_(NULL),
     d3_(NULL),
+    maxTypeCG_(1),
     typeCG_(propsDict_.lookupOrDefault<scalarList>("coarseGrainingFactors",scalarList(1,1.0))),
     d2Field_
     (   IOobject
@@ -95,7 +96,11 @@ dSauter::dSauter
         "zeroGradient"
     )
 {
-    if (typeCG_.size()>1) multiTypes_ = true;
+    if (typeCG_.size()>1)
+    {
+        multiTypes_ = true;
+        maxTypeCG_ = typeCG_.size();
+    }
     allocateMyArrays();
     dSauter_.write();
 
@@ -153,6 +158,10 @@ void dSauter::setForce() const
             if (multiTypes_) 
             {
                 partType = particleCloud_.particleType(index);
+                if (partType > maxTypeCG_)
+                {
+                    FatalError<< "Too few coarse-graining factors provided." << abort(FatalError);
+                }
                 cg = typeCG_[partType - 1];
             }
             ds = particleCloud_.d(index);
diff --git a/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.H b/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.H
index f1e1ca6e..eb875ca5 100644
--- a/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.H
+++ b/src/lagrangian/cfdemParticle/subModels/forceModel/dSauter/dSauter.H
@@ -49,6 +49,8 @@ private:
     
     mutable double **d3_;
 
+    label maxTypeCG_;
+
     scalarList typeCG_;
     
     mutable volScalarField d2Field_;
diff --git a/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.C b/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.C
index ff0de5d0..d79f03d2 100644
--- a/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.C
+++ b/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.C
@@ -122,14 +122,6 @@ pdCorrelation::pdCorrelation
         sm.mesh(),
         dimensionedScalar("zero", dimless, 0)
     ),
-    typeCG_
-    (
-        propsDict_.lookupOrDefault
-        (
-            "coarseGrainingFactors",
-            scalarList(1, sm.cg())
-        )
-    ),
     particleDensities_
     (
         propsDict_.lookupOrDefault
@@ -138,6 +130,15 @@ pdCorrelation::pdCorrelation
             scalarList(1, -1.)
         )
     ),
+    typeCG_
+    (
+        propsDict_.lookupOrDefault
+        (
+            "coarseGrainingFactors",
+            scalarList(1, sm.cg())
+        )
+    ),
+    maxTypeCG_(typeCG_.size()),
     constantCG_(typeCG_.size() < 2),
     CG_(!constantCG_ || typeCG_[0] > 1. + SMALL),
     runOnWriteOnly_(propsDict_.lookupOrDefault("runOnWriteOnly", false))
@@ -222,6 +223,10 @@ void pdCorrelation::setForce() const
             typei = particleCloud_.particleTypes()[pi][0] - 1;
             rhop  = densityFromList ? particleDensities_[typei]
                                     : particleCloud_.particleDensity(pi);
+            if (!constantCG_ && typei >= maxTypeCG_)
+            {
+                FatalError<< "Too few coarse-graining factors provided." << abort(FatalError);
+            }
             cg    = constantCG_     ? typeCG_[0] : typeCG_[typei];
         }
 
diff --git a/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.H b/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.H
index 7ea99050..04fb2bf0 100644
--- a/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.H
+++ b/src/lagrangian/cfdemParticle/subModels/forceModel/pdCorrelation/pdCorrelation.H
@@ -58,8 +58,9 @@ private:
 
     mutable volScalarField cg3Field_;
 
-    const scalarList typeCG_;
     const scalarList particleDensities_;
+    const scalarList typeCG_;
+    const label maxTypeCG_;
     const Switch     constantCG_;
     const Switch     CG_;
     const Switch     runOnWriteOnly_;