The human body can be allergic to almost anything, so it's impossible for anyone to claim anything won't give you an allergic reaction. However, we are confident in saying that our rings are very hypoallergenic - the reason is that we use a cobalt binder in our rings, rather than cobalt.Cobalt can oxidize (rust) when mixed with your body's naturally occurring oils and cause an allergic reaction - none of our rings have any cobalt in them. In addition,