Yes, the black coated locks and collars are Hypoallergenic as well as 24/7 and can withstand normal daily activities like sweating, bathing, and swimming.  Just remember any item that has a 'coating' or 'plating' will eventually wear off.  It doesn't matter where it comes from, plating is temporary.  It can last years or only months.  How fast depends on how you care for it as well as things like environment and body chemistry. We only carry a few black items and this is due to customer requests.  As you can see 99% of our products are solid pure metals that will last a lifetime.  Other than our black coated items we don't make anything 'plated' or 'coated' for this reason.