diff --git a/bld/build-namelist b/bld/build-namelist
index ddd9acd699..0974972ddf 100755
--- a/bld/build-namelist
+++ b/bld/build-namelist
@@ -3660,7 +3660,6 @@ if ($clubb_sgs  =~ /$TRUE/io) {
 # Tuning for wet scavenging of modal aerosols
 if ($chem =~ /_mam/) {
     add_default($nl, 'sol_facti_cloud_borne');
-    add_default($nl, 'sol_factb_interstitial');
     add_default($nl, 'sol_factic_interstitial');
 }
 if ($carma =~ /trop_strat/) {
diff --git a/src/chemistry/aerosol/aerosol_state_mod.F90 b/src/chemistry/aerosol/aerosol_state_mod.F90
index c835219df0..d56bade22d 100644
--- a/src/chemistry/aerosol/aerosol_state_mod.F90
+++ b/src/chemistry/aerosol/aerosol_state_mod.F90
@@ -927,7 +927,7 @@ function sol_factb_interstitial(self, bin_ndx, ncol, nlev, aero_props) result(so
     real(r8) :: totmmr(ncol,nlev)
     real(r8) :: solmmr(ncol,nlev)
     integer :: ispc
-    character(len=aero_name_len) :: spectype
+    real(r8) :: spechygro
 
     sol_factb(:,:) = 0.0_r8
 
@@ -936,26 +936,11 @@ function sol_factb_interstitial(self, bin_ndx, ncol, nlev, aero_props) result(so
 
     do ispc = 1, aero_props%nspecies(bin_ndx)
 
-       call aero_props%species_type(bin_ndx, ispc, spectype)
+       call aero_props%get(bin_ndx, ispc, hygro=spechygro)
        call self%get_ambient_mmr(ispc, bin_ndx, aer_mmr)
 
        totmmr(:ncol,:) = totmmr(:ncol,:) + aer_mmr(:ncol,:)
-
-       if (trim(spectype) == 'sulfate') then
-          solmmr(:ncol,:) = solmmr(:ncol,:) + aer_mmr(:ncol,:)*0.5_r8
-       end if
-       if (trim(spectype) == 'p-organic') then
-          solmmr(:ncol,:) = solmmr(:ncol,:) + aer_mmr(:ncol,:)*0.2_r8
-       end if
-       if (trim(spectype) == 's-organic') then
-          solmmr(:ncol,:) = solmmr(:ncol,:) + aer_mmr(:ncol,:)*0.2_r8
-       end if
-       if (trim(spectype) == 'dust') then
-          solmmr(:ncol,:) = solmmr(:ncol,:) + aer_mmr(:ncol,:)*0.1_r8
-       end if
-       if (trim(spectype) == 'seasalt') then
-          solmmr(:ncol,:) = solmmr(:ncol,:) + aer_mmr(:ncol,:)*0.8_r8
-       end if
+       solmmr(:ncol,:) = solmmr(:ncol,:) + aer_mmr(:ncol,:)*spechygro
 
     end do   !nspec
 
@@ -963,13 +948,6 @@ function sol_factb_interstitial(self, bin_ndx, ncol, nlev, aero_props) result(so
        sol_factb = solmmr/totmmr
     end where
 
-    where ( sol_factb > 0.8_r8 )
-       sol_factb = 0.8_r8
-    end where
-    where ( sol_factb < 0.1_r8 )
-       sol_factb = 0.1_r8
-    end where
-
   end function sol_factb_interstitial