I don't know for sure - I will not touch any product that has such high PPM. I drank about 1o ounces or so of Utopia Silver's Advanced Colloidal Silver. It is a true colloidal silver product and the particles are neither large nor artificially suspended, which is not the case in either instance for your 500 PPM product.
IMO, there are only two true colloidal silver ultra small particle products out there. The one I use and Mesosilver. Not saying that others do not work, or home generated ionic/colloidal silver does not work - as most of them do work for most things (depending on how much you take). Just saying those two are the best. Ask Trapper, he'll tell you that Utopia Silver's ACS is the bomb!