Why should NEKTON-Desi-Natural not be in contact with untreated metal surfaces?

These metal surfaces have no protection.

When NEKTON-Desi-Natural comes into contact with it, the surface will begin to oxidize and is getting rusty.

If NEKTON-Desi-Natural should be in contact with a untreated metal surface, please wipe off the liquid immediately and make sure that there are no residues on it.