Cans for food have had an epoxy lining for while as an attempt to ensure the contents do not react to the metal - but his lining has been linked in several studies to various health problems, inc. the formation of contaminants that imitate female hormones, to some cancers - same health links as also found in some dental fillings . . .
If you are asking about storing part used contents in an opened can - don't. Transfer to a sealed container and use within 2 days