diff --git a/include/cantera/thermo/PDSS_IdealGas.h b/include/cantera/thermo/PDSS_IdealGas.h
index 771216575..efadbc45d 100644
--- a/include/cantera/thermo/PDSS_IdealGas.h
+++ b/include/cantera/thermo/PDSS_IdealGas.h
@@ -419,21 +419,7 @@ public:
     virtual void initThermo();
 
     //@}
-
-
-
-protected:
-
-    //! Maximum temperature the standard states are good for
-    doublereal m_tmin;
-
-    //! Minimum temperature the standard states are good for
-    doublereal m_tmax;
-
 };
 }
 
 #endif
-
-
-
diff --git a/include/cantera/thermo/PDSS_IonsFromNeutral.h b/include/cantera/thermo/PDSS_IonsFromNeutral.h
index e52b304bd..01c23da39 100644
--- a/include/cantera/thermo/PDSS_IonsFromNeutral.h
+++ b/include/cantera/thermo/PDSS_IonsFromNeutral.h
@@ -455,14 +455,6 @@ public:
 
 
 protected:
-
-    //! Maximum temperature the standard states are good for
-    doublereal m_tmin;
-
-    //! Minimum temperature the standard states are good for
-    doublereal m_tmax;
-
-
     //! Pointer to the Neutral Molecule ThermoPhase object
     /*!
      *  This is a shallow pointer.
diff --git a/src/thermo/PDSS_IdealGas.cpp b/src/thermo/PDSS_IdealGas.cpp
index 299cc2609..4b5e6c5fc 100644
--- a/src/thermo/PDSS_IdealGas.cpp
+++ b/src/thermo/PDSS_IdealGas.cpp
@@ -76,10 +76,6 @@ PDSS_IdealGas& PDSS_IdealGas::operator=(const PDSS_IdealGas& b)
         return *this;
     }
     PDSS::operator=(b);
-
-    m_tmin       =   b.m_tmin;
-    m_tmax       =   b.m_tmax;
-
     return *this;
 }
 
diff --git a/src/thermo/PDSS_IonsFromNeutral.cpp b/src/thermo/PDSS_IonsFromNeutral.cpp
index fc0bd21b9..7f6844e51 100644
--- a/src/thermo/PDSS_IonsFromNeutral.cpp
+++ b/src/thermo/PDSS_IonsFromNeutral.cpp
@@ -87,9 +87,6 @@ PDSS_IonsFromNeutral& PDSS_IonsFromNeutral::operator=(const PDSS_IonsFromNeutral
 
     PDSS::operator=(b);
 
-    m_tmin                  = b.m_tmin;
-    m_tmax                  = b.m_tmax;
-
     /*
      *  The shallow pointer copy in the next step will be insufficient in most cases. However, its
      *  functionally the best we can do for this assignment operator. We fix up the pointer in the