The Wella Demi is the only brand I've found that doesn't contain PPD in the dark colors. Professional Feria contains quite a bit and pushed me over the edge so I'm allergic to it now (and I did hair for years!). I use it when I want black hair, and it stays nicely. It also has the added bonus of not being as stubbornly permanent as permanent black dye when you decide you don't want it anymore. ;)