diff --git a/src/main/java/gov/nih/ncats/molwitch/cdk/CdkChemicalImpl.java b/src/main/java/gov/nih/ncats/molwitch/cdk/CdkChemicalImpl.java
index e6d0660..4fea33b 100644
--- a/src/main/java/gov/nih/ncats/molwitch/cdk/CdkChemicalImpl.java
+++ b/src/main/java/gov/nih/ncats/molwitch/cdk/CdkChemicalImpl.java
@@ -256,6 +256,8 @@ public static void setMaxUndefinedStereoCenters(int maxUndefinedStereoCenters) {
 				} else {
 					Logger.getLogger(this.getClass().getName()).fine("This molecule is considered NOT complex");
 					try {
+						//The call to label generates an Exception down in the bowels of CDK.
+						// trapping it in a try/catch allows the process to continue
 						CIPToolMod.label(cimp.getContainer());
 					} catch (NoSuchAtomException ex) {
 						Logger.getLogger(this.getClass().getName()).warning("Error in call to CIPToolMod.label. Processing will continue");